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Sample records for granites

  1. Speciation in granitic melts

    SciTech Connect

    Burnham, C.W.; Nekvasil, H.

    1985-01-01

    Refinement of the cryoscopic equations for the major granitic melt components, NaAlSi/sub 3/O/sub 8/(ab), CaAl/sub 2/O/sub 8/(an), KAlSi/sub 3/O/sub 8/(or), and Si/sub 4/O/sub 8/(qz), has led to the recognition of several major speciation reactions in anhydrous and hydrous melts of the system Ab-An-Or-Qz-H/sub 2/O. These reactions involve either dissociation of the feldspar-like components, as in incongruent melting, or interaction between them and qz. In all cases of interaction, one of the speciation products has the stoichiometry of dpy or py (pyrophyllite) (Al/sub 1.455/Si/sub 2.91/O/sub 8/ +/- 0.73H/sub 2/O), in which Al is presumed to be in either fivefold (dpy) or sixfold (py) coordination. The py component also is a major product of speciation by interaction between sil (Al/sub 3.2/Si/sub 1.6/O/sub 8/) and qz in peraluminous melts of the system Ab-Or-Qz-Sil-H/sub 2/O; as a consequence, the quartz liquidus field boundary is shifted to lower temperatures and toward qz. There is no evidence in peraluminous haplogranite melts for the existence of a muscovite-like species. Application of the refined thermodynamic model to the system Ab-Qz-Eu - H/sub 2/O at 2.0 kbar predicts the occurrence of a eu and qz-consuming reaction that produces a petalite-like species and a consequent dramatic shift in liquidus field boundaries. Higher pressures favor conversion of pe to qz + sp. In the spodumene-like species, sp, Al presumably is six-coordinated.

  2. Vermont granite workers' mortality study.

    PubMed

    Costello, J; Graham, W G

    1988-01-01

    A cohort mortality study was carried out in Vermont granite workers who had been employed between the years 1950 and 1982. The cohort included men who had been exposed to high levels of granite dust prior to 1938-1940 (average cutters to 40 million parts/cubic foot), and those employed at dust levels after 1940, which on average were less than 10 million parts/cubic foot. Deaths were coded by a qualified nosologist and standardized mortality ratios were calculated. The results confirm previous studies that show that death rates from silicosis and tuberculosis, the major health threats in the years before 1940, were essentially eliminated after dust controls. However, we found excessive mortality rates from lung cancer in stone shed workers who had been employed prior to 1930, and hence had been exposed to high levels of granite dust. When information was available, 100% of those dying from lung cancer had been smokers.

  3. Status of LLNL granite projects

    SciTech Connect

    Ramspott, L.D.

    1980-12-31

    The status of LLNL Projects dealing with nuclear waste disposal in granitic rocks is reviewed. This review covers work done subsequent to the June 1979 Workshop on Thermomechanical Modeling for a Hardrock Waste Repository and is prepared for the July 1980 Workshop on Thermomechanical-Hydrochemical Modeling for a Hardrock Waste Repository. Topics reviewed include laboratory determination of thermal, mechanical, and transport properties of rocks at conditions simulating a deep geologic repository, and field testing at the Climax granitic stock at the USDOE Nevada Test Site.

  4. Emanation of radon from household granite.

    PubMed

    Kitto, Michael E; Haines, Douglas K; Arauzo, Hernando Diaz

    2009-04-01

    Emanation of radon (222Rn) from granite used for countertops and mantels was measured with continuous and integrating radon monitors. Each of the 24 granite samples emitted a measurable amount of radon. Of the two analytical methods that utilized electret-based detectors, one measured the flux of radon from the granite surfaces, and the other one measured radon levels in a glass jar containing granite cores. Additional methods that were applied utilized alpha-scintillation cells and a continuous radon monitor. Measured radon flux from the granites ranged from 2 to 310 mBq m-2 s-1, with most granites emitting <20 mBq m-2 s-1. Emanation of radon from granites encapsulated in airtight containers produced equilibrium concentrations ranging from <0.01 to 11 Bq kg-1 when alpha-scintillation cells were used, and from <0.01 to 4.0 Bq kg-1 when the continuous radon monitor was used.

  5. Progressive silicosis in granite workers

    PubMed Central

    Gründorfer, W.; Raber, A.

    1970-01-01

    Gründorfer, W., and Raber, A.(1970).Brit. J. industr. Med.,27, 110-120. Progressive silicosis in granite workers. The first case of silicosis was discovered in a granite quarry and crushing plant in Lower Austria in 1958 after 30 years of freedom. A routine ϰ-ray survey then revealed no further cases but three more cases were discovered in the next two years. Detailed investigation revealed that these and further cases came from the area where the granite was crushed and loaded. In 10 years 18 cases were found out of a labour force of 170 falling to 120. Average exposure was 15 years and the disease tended to progress. Fifteen of the 18 cases came from the crushing plant where only 20 men were at risk, indicating a very high incidence within 15 years of first exposure. The risk is attributed to increased size and working capacity of the machines without improved dust suppression. This had led to dust levels over 10 times the accepted maximum in places. As well as more effective dust suppression, a reduction in staff, the wearing of masks and effective medical supervision of those particularly at risk are recommended. Images PMID:5428630

  6. Cancer mortality of granite workers.

    PubMed

    Koskela, R S; Klockars, M; Järvinen, E; Kolari, P J; Rossi, A

    1987-02-01

    A retrospective cohort study was undertaken to investigate the cancer mortality of granite workers. The study comprised 1,026 workers hired between 1940 and 1971. The number of person-years was 20,165, and the number of deaths 235. During the total follow-up 46 tumors were observed and 44.9 were expected. An excess mortality from tumors was observed for the workers followed for 20 years or more, the greatest excess occurring during the follow-up period of 25-29 years (observed 11, expected 5.2). Of the 46 tumors, 22 were lung cancers (expected 17.1) and 15 were gastrointestinal cancers (expected 9.7), nine of which were cancers of the stomach (expected 6.0). Mortality from lung cancer was excessive for workers with at least 15 years since entry into granite work (latency) (21 observed and 9.5 expected), being highest during the follow-up period of 25-29 years (observed 8, expected 2.1). The results indicate that granite exposure per se may be an etiologic factor in the initiation or promotion of malignant neoplasms.

  7. Mortality experience of Vermont granite workers.

    PubMed

    Davis, L K; Wegman, D H; Monson, R R; Froines, J

    1983-01-01

    The proportional mortality experience (1952-1978) of 969 deceased white male granite workers was compared with that of United States white males. Industrial hygiene information was combined with work histories to develop an estimate of lifetime granite dust exposure for each individual. Subjects were grouped into four cumulative exposure categories, and exposure-response relationships were examined. Trends of increasing silicosis and tuberculosis with increasing lifetime exposure were observed. These are consistent with earlier findings. With the exception of excess suicide among granite workers dying before 1970, there was little evidence of association between other causes of death and employment in the granite industry.

  8. GRANITE PEAK ROADLESS AREA, CALIFORNIA.

    USGS Publications Warehouse

    Huber, Donald F.; Thurber, Horace K.

    1984-01-01

    The Granite Peak Roadless Area occupies an area of about 5 sq mi in the southern part of the Trinity Alps of the Klamath Mountains, about 12 mi north-northeast of Weaverville, California. Rock and stream-sediment samples were analyzed. All streams draining the roadless area were sampled and representative samples of the rock types in the area were collected. Background values were established for each element and anomalous values were examined within their geologic settings and evaluated for their significance. On the basis of mineral surveys there seems little likelihood for the occurrence of mineral or energy resources.

  9. 6. Photocopied August 1971 from Photo 13731, Granite Folder #1, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Photocopied August 1971 from Photo 13731, Granite Folder #1, Engineering Department, Utah Power and Light Co., Salt Lake City, Utah. GRANITE STATION, MAY 24, 1915. - Utah Power Company, Granite Hydroelectric Plant, Holladay, Salt Lake County, UT

  10. Fracture process zone in granite

    USGS Publications Warehouse

    Zang, A.; Wagner, F.C.; Stanchits, S.; Janssen, C.; Dresen, G.

    2000-01-01

    In uniaxial compression tests performed on Aue granite cores (diameter 50 mm, length 100 mm), a steel loading plate was used to induce the formation of a discrete shear fracture. A zone of distributed microcracks surrounds the tip of the propagating fracture. This process zone is imaged by locating acoustic emission events using 12 piezoceramic sensors attached to the samples. Propagation velocity of the process zone is varied by using the rate of acoustic emissions to control the applied axial force. The resulting velocities range from 2 mm/s in displacement-controlled tests to 2 ??m/s in tests controlled by acoustic emission rate. Wave velocities and amplitudes are monitored during fault formation. P waves transmitted through the approaching process zone show a drop in amplitude of 26 dB, and ultrasonic velocities are reduced by 10%. The width of the process zone is ???9 times the grain diameter inferred from acoustic data but is only 2 times the grain size from optical crack inspection. The process zone of fast propagating fractures is wider than for slow ones. The density of microcracks and acoustic emissions increases approaching the main fracture. Shear displacement scales linearly with fracture length. Fault plane solutions from acoustic events show similar orientation of nodal planes on both sides of the shear fracture. The ratio of the process zone width to the fault length in Aue granite ranges from 0.01 to 0.1 inferred from crack data and acoustic emissions, respectively. The fracture surface energy is estimated from microstructure analysis to be ???2 J. A lower bound estimate for the energy dissipated by acoustic events is 0.1 J. Copyright 2000 by the American Geophysical Union.

  11. Lunar granites with unique ternary feldspars

    NASA Technical Reports Server (NTRS)

    Ryder, G.; Stoeser, D. B.; Marvin, U. B.; Bower, J. F.

    1975-01-01

    An unusually high concentration of granitic fragments, with textures ranging from holocrystalline to glassy, occurs throughout Boulder 1, a complex breccia of highland rocks from Apollo 17, Station 2. Among the minerals included in the granites are enigmatic K-Ca-rich feldspars that fall in the forbidden region of the ternary diagram. The great variability in chemistry and texture is probably the result of impact degradation and melting of a granitic source-rock. Studies of the breccia matrix suggest that this original granitic source-rock may have contained more pyroxenes and phosphates than most of the present clasts contain. Petrographic observations on Apollo 15 KREEP basalts indicate that granitic liquids may be produced by differentiation without immiscibility, and the association of the granites with KREEP-rich fragments in the boulder suggests that the granites represent a residual liquid from the plutonic fractional crystallization of a KREEP-rich magma. Boulder 1 is unique among Apollo 17 samples in its silica-KREEP-rich composition. We conclude that the boulder represents a source-rock unlike the bedrock of South Massif.

  12. CO2 laser cutting of natural granite

    NASA Astrophysics Data System (ADS)

    Riveiro, A.; Mejías, A.; Soto, R.; Quintero, F.; del Val, J.; Boutinguiza, M.; Lusquiños, F.; Pardo, J.; Pou, J.

    2016-01-01

    Commercial black granite boards (trade name: "Zimbabwe black granite") 10 mm thick, were successfully cut by a 3.5 kW CO2 laser source. Cutting quality, in terms of kerf width and roughness of the cut wall, was assessed by means of statistically planned experiments. No chemical modification of the material in the cutting walls was detected by the laser beam action. Costs associated to the process were calculated, and the main factors affecting them were identified. Results reported here demonstrate that cutting granite boards could be a new application of CO2 laser cutting machines provided a supersonic nozzle is used.

  13. Potassium-argon dating of the cape granite and a granitized xenolith at sea point.

    PubMed

    Schreiner, G D; Basson, H H; Verbeek, A A

    1968-11-01

    Ages obtained by potassium-argon dating are reported for the total rock, light mineral fraction and heavy mineral fractions of the Cape Granite, and of a granitized xenolith derived from the Malmesbury sediments. These ages lie between 430 and 554 million years. The heavy mineral fractions from each rock type show the oldest age, 540 (granite) and 554 (xenolith) million years. These ages are interpreted as lower limits, and the granite age confirms the age of 553 million years found by rubidium-strontium dating. The coincidence of the ages of the different fractions of the granite and xenolith samples is discussed in the light of the different suggestions about the age of the Malmesbury sediments. The conclusion is reached that all pre-granitization history has been eliminated. The possibility of the use of argon retention as a measure of metamorphic activity is suggested. PMID:18960415

  14. Potassium-argon dating of the cape granite and a granitized xenolith at sea point.

    PubMed

    Schreiner, G D; Basson, H H; Verbeek, A A

    1968-11-01

    Ages obtained by potassium-argon dating are reported for the total rock, light mineral fraction and heavy mineral fractions of the Cape Granite, and of a granitized xenolith derived from the Malmesbury sediments. These ages lie between 430 and 554 million years. The heavy mineral fractions from each rock type show the oldest age, 540 (granite) and 554 (xenolith) million years. These ages are interpreted as lower limits, and the granite age confirms the age of 553 million years found by rubidium-strontium dating. The coincidence of the ages of the different fractions of the granite and xenolith samples is discussed in the light of the different suggestions about the age of the Malmesbury sediments. The conclusion is reached that all pre-granitization history has been eliminated. The possibility of the use of argon retention as a measure of metamorphic activity is suggested.

  15. AMS studies in Portuguese variscan granites

    NASA Astrophysics Data System (ADS)

    Sant'Ovaia, Helena; Martins, Helena; Noronha, Fernando

    2014-05-01

    A large volume of Variscan granitic rocks outcrop in Central Iberian Zone which are well documented concerning geological mapping, petrography and geochemistry but whose magnetic characteristics and fabric remain unknown. In this study we summarize the available AMS data from approximately 644 sampling stations (5152 samples) on different massifs of Variscan Portuguese granites. Despite their different geological, petrographic and geochemical characteristics, magnetic susceptibility (K) values obtained for the majority of the studied granites range from 15 to 300 × 10-6 SI. The dominant paramagnetic behaviour of the granite bodies reflects the presence of ilmenite as the main iron oxide. This feature indicates the reduced conditions involved in the granite melt formation during the Variscan orogeny. The two-mica granites show K values ranging between 15 to 70 × 10-6 SI which are lower than values displayed by the biotite-rich facies scattered within the interval of 70 and 300 × 10-6 SI. The magnetite-bearing granites are scarce but represented in Lavadores, Gerês and Manteigas. Even so, only the Lavadores body could be considered as a true magnetite-type granite (K >3.0 × 10-3 SI) in face of its K, comprised between 1550 and 19303 × 10-6 SI. Magnetic anisotropy can be used as a "marker" for the deformation experienced by granite mushes during their crustal emplacement and further cooling. Magnetic anisotropy can thus be correlated with the finite deformation of a rock, as record by mineral fabrics. Post-tectonic granites, such as those from Vila Pouca de Aguiar, Pedras Salgadas, Caria, Vila da Ponte, Chaves and Lamas de Olo, have a magnetic anisotropy <2.5% which corresponds to a deformation hardly visible to the naked eye. Nevertheless, at microscopic scale, these granites display almost ubiquitous magmatic to submagmatic microstructures (rare wavy extinction in quartz, erratic subgrain boundaries in quartz and, eventually, folded or kinked biotites). For

  16. Grusification of granite (scheme based on the study of granites from Sudety Mts., SW Poland)

    NASA Astrophysics Data System (ADS)

    Kajdas, Bartlomiej; Michalik, Marek

    2014-05-01

    Gruses that are developed on the Karkonosze granite (three outcrops) and the Izera granite (one outcrop) were investigated using optical microscope, scanning electron microscope equipped with EDS and electron microprobe, X-ray diffraction, IR spectrometry, chemical analysis (ICP-AES and ICP-MS), hydrogen and oxygen isotopic ratio determination and K-Ar dating. Three groups of samples were distinguished according to the degree of grusification (group I - compact granite; group II - friable granite; group III - granitic grus). The results of the examination allowed to present the simplified scheme of the grusification: 1. Development of microcracks (caused by tectonic stress, mechanical upload or magma cooling processes) promote circulation of hydrothermal fluids in granites; 2. The presence of the microcracks in granite facilitate the circulation of low-temperature fluids (low-temperature hydrothermal or weathering fluids). Fluids cause hydration and expansion of primary biotite (vermiculitization), what leads to development of secondary cracks in a rock. Fluids can also induce advanced alteration of plagioclases into clay minerals (mainly smectite or vermiculite). Expansion of biotite during vermiculitization is the most important factor in grusification. Other processes of alteration also contribute to grusification. Hydrothermal fluids in granite contribute the increase of alteration degree of primary minerals (e.g. sericitization and albitization of feldspar, chloritization or muscovitization of biotite, decomposition of monazite-(Ce) and formation of secondary REE phosphates). If primary biotite is subjected to muscovitization or chloritization, complete grusification of granite does not occur because of lack of vermiculitation.

  17. Neutrons and Granite: Transport and Activation

    SciTech Connect

    Bedrossian, P J

    2004-04-13

    In typical ground materials, both energy deposition and radionuclide production by energetic neutrons vary with the incident particle energy in a non-monotonic way. We describe the overall balance of nuclear reactions involving neutrons impinging on granite to demonstrate these energy-dependencies. While granite is a useful surrogate for a broad range of soil and rock types, the incorporation of small amounts of water (hydrogen) does alter the balance of nuclear reactions.

  18. Granite Exfoliation, Cosumnes River Watershed, Somerset, California

    NASA Astrophysics Data System (ADS)

    Crockett, I. Q.; Neiss-Cortez, M.

    2015-12-01

    In the Sierra Nevada foothills of California there are many exposed granite plutons within the greater Sierra Nevada batholith. As with most exposed parts of the batholith, these granite slabs exfoliate. It is important to understand exfoliation for issues of public safety as it can cause rock slides near homes, roads, and recreation areas. Through observation, measuring, and mapping we characterize exfoliation in our Cosumnes River watershed community.

  19. Radiological implications of granite of northern Pakistan.

    PubMed

    Asghar, M; Tufail, M; Sabiha-Javied; Abid, A; Waqas, M

    2008-09-01

    Granite is an igneous rock that contains natural radioactivity of primordial radionuclides. In Pakistan, granite is distributed in a vast area called the Ambela Granitic Complex (AGC) in North West Frontier Province (NWFP). Granite is a hard rock that exists in different colours and is used to decorate floors, kitchen counter tops, etc. The use of granite in a building as a decor material is a potential source of radiation dose; therefore, natural radioactivity has been measured in 20 granite samples of the AGC with an HPGe (high purity germanium) based gamma ray spectrometer. The average specific activities and their range (given in parentheses) for primordial radionuclides (40)K, (226)Ra and (232)Th were 1218 (899-1927), 659 (46-6120) and 598 (92-3214) Bq kg(-1), respectively. The measured activity concentrations were used for the assessment of hazard indices and radiation dose which were evaluated based on the permissible limits defined for these parameters. The measured specific activities and the derived quantities, hazard indices and radiation dose, have been compared with those given in the literature for these parameters.

  20. Origin of late Archean granite: geochemical evidence from the Vermilion Granitic Complex of northern Minnesota

    NASA Astrophysics Data System (ADS)

    Day, Warren C.; Weiblen, P. W.

    1986-07-01

    The 2,700-Ma Vermilion Granitic Complex of northern Minnesota is a granite-migmatite terrane composed of supracrustal metasedimentary rocks, mafic rocks, tonalitic and granodioritic plutonic rocks, and granite. The metasedimentary rocks are predominantly graywacke, which has been regionally metamorphosed to garnet-sillimanite-muscovite-bearing biotite schist, and has locally undergone anatexis. The mafic rocks form early phases within the complex and are of two types: (1) basaltic amphibolite, and (2) monzodiorite and essexite rich in large ion lithophile elements (LILE). The members of the early plutonic suite form small bodies that intrude the metasedimentary rocks and mafic rocks, producing an early migmatite. The granite is of two distinct varieties: (1) white garnet-muscovite-biotite leucogranite ( S-type; Chappell and White 1974) and (2) grayish-pink biotite-magnetite Lac La Croix Granite ( I-type). The leucogranite occurs in the early migmatite and in paragneissic portions of the complex, whereas the Lac La Croix Granite is a late-stage intrusive phase that invades the early migmatite and metasediment (producing a late migmatite) and forms a batholith. This study focuses specifically on the origin of granite in the Vermilion Granitic Complex. Chemical mass-balance calculations suggest that the S-type two-mica leucogranite had a metagraywacke source, and that the I-type Lac La Croix Granite formed via partial fusion of calc-alkaline tonalitic material, which may have been similar to rocks of the early plutonic suite. This model is satisfactory for petrogenesis of similar Late Archean post-kinematic granites throughout the Canadian Shield.

  1. Origin of late Archean granite: geochemical evidence from the Vermilion Granitic Complex of northern Minnesota

    USGS Publications Warehouse

    Day, W.C.; Weiblen, P.W.

    1986-01-01

    The 2,700-Ma Vermilion Granitic Complex of northern Minnesota is a granite-migmatite terrane composed of supracrustal metasedimentary rocks, mafic rocks, tonalitic and granodioritic plutonic rocks, and granite. The metasedimentary rocks are predominantly graywacke, which has been regionally metamorphosed to garnet-sillimanite-muscovite-bearing biotite schist, and has locally undergone anatexis. The mafic rocks form early phases within the complex and are of two types: (1) basaltic amphibolite, and (2) monzodiorite and essexite rich in large ion lithophile elements (LILE). The members of the early plutonic suite form small bodies that intrude the metasedimentary rocks and mafic rocks, producing an early migmatite. The granite is of two distinct varieties: (1) white garnet-muscovite-biotite leucogranite (S-type; Chappell and White 1974) and (2) grayish-pink biotite-magnetite Lac La Croix Granite (I-type). The leucogranite occurs in the early migmatite and in paragneissic portions of the complex, whereas the Lac La Croix Granite is a late-stage intrusive phase that invades the early migmatite and metasediment (producing a late migmatite) and forms a batholith. This study focuses specifically on the origin of granite in the Vermilion Granitic Complex. Chemical mass-balance calculations suggest that the S-type two-mica leucogranite had a metagraywacke source, and that the I-type Lac La Croix Granite formed via partial fusion of calc-alkaline tonalitic material, which may have been similar to rocks of the early plutonic suite. This model is satisfactory for petrogenesis of similar Late Archean post-kinematic granites throughout the Canadian Shield. ?? 1986 Springer-Verlag.

  2. Frictional slip of granite at hydrothermal conditions

    USGS Publications Warehouse

    Blanpied, M.L.; Lockner, D.A.; Byerlee, J.D.

    1995-01-01

    To measure the strength, sliding behavior, and friction constitutive properties of faults at hydrothermal conditions, laboratory granite faults containing a layer of granite powder (simulated gouge) were slid. The mechanical results define two regimes. The first regime includes dry granite up to at least 845?? and wet granite below 250??C. In this regime the coefficient of friction is high (?? = 0.7 to 0.8) and depends only modestly on temperature, slip rate, and PH2O. The second regime includes wet granite above ~350??C. In this regime friction decreases considerably with increasing temperature (temperature weakening) and with decreasing slip rate (velocity strengthening). These regimes correspond well to those identified in sliding tests on ultrafine quartz. The results highlight the importance of fluid-assisted deformation processes active in faults at depth and the need for laboratory studies on the roles of additional factors such as fluid chemistry, large displacements, higher concentrations of phyllosilicates, and time-dependent fault healing. -from Authors

  3. Geochemical evolution of the metaluminous and peraluminous granites of Ganawuri Younger Granite Complex, northern Nigeria

    NASA Astrophysics Data System (ADS)

    Imeokparia, Ebo. Gab.

    The Ganawuri Complex is one of the numerous high level composite granitoid bodies occurring in the central plateau sector of the Nigerian Younger Granite province. Lithologically the Complex is composed of a hastingsite-fayalite granite, hastingsite-biotite granite and biotite granite. Although the major element chemistry of the constituent rock types shows only subtle variation typical of granites with minimum melt composition, the trace elements data and variation indicate that the granites in the Complex formed essentially by fractional crystallization. Geochemically the late-stage rock types are characterized by anomalously high contents of F, Li, Y, Th, Ga, Rb, Sn and Nb and by unusually low contents of Ba, Sr and Zr. These geochemical peculiarities are interpreted to be due to extreme fractionation. The ultimate product of fractional crystallization was a water-saturated melt, enriched in incompatible elements whose crystallization resulted in tin mineralization. The chemistry of the rocks can be compared with A-type granites which are considered typical of anorogenic extensional environments and/or Continental rifts.

  4. Thermometers and thermobarometers in granitic systems

    USGS Publications Warehouse

    Anderson, J.L.; Barth, A.P.; Wooden, J.L.; Mazdab, F.; ,

    2008-01-01

    The ability to determine the thermal and barometric history during crystallization and emplacement of granitic plutons has been enhanced by several new calibrations applicable to granitic mineral assemblages. Other existing calibrations for granitic plutons have continued to be popular and fairly robust. Recent advances include the trace element thermometers Ti-in-quartz, Ti-in-zircon, and Zr-in-sphene (titanite), which need to be further evaluated on the roles of reduced activities due to lack of a saturating phase, the effect of pressure dependence (particularly for the Ti-in-zircon thermometer), and how resistive these thermometers are to subsolidus reequilibration. As zircon and sphene are also hosts to radiogenic isotopes, these minerals potentially also provide new insights into the temperature - time history of magmas. When used in conjunction with pressure-sensitive mineral equilibria in the same rocks, a complete assessment of the P-T-t (pressure-temperature-time) path is possible given that the mineralogy of plutons can reflect crystallization over a range of pressure and temperature during ascent and emplacement and that many intrusions are now seen as forming over several millions of years during the protracted history of batholith construction. Accessory mineral saturation thermometers, such as those for zircon, apatite, and allanite, provide a different and powerful perspective, specifically that of the temperature of the onset of crystallization of these minerals, which can allow an estimate of the range of temperature between the liquidus and solidus of a given pluton. In assessment of the depth of crystallization and emplacement of granitic plutons, the Al-in-hornblende remains popular for metaluminous granites when appropriately corrected for temperature. For peraluminous granites, potential new calibrations exist for the assemblages bearing garnet, biotite, plagioclase, muscovite, and quartz. Other thermometers, based on oxygen abundance, and

  5. OVERALL VIEW OF QUARRY, FACING NORTH, WITH UNQUARRIED GRANITE OUTCROP ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    OVERALL VIEW OF QUARRY, FACING NORTH, WITH UN-QUARRIED GRANITE OUTCROP IN BACKGROUND - Granite Hill Plantation, Quarry No. 3, South side of State Route 16, 1.3 miles northeast east of Sparta, Sparta, Hancock County, GA

  6. 7. Photocopied August 1971 from Photo 13729, Granite Station Special ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Photocopied August 1971 from Photo 13729, Granite Station Special Folder, Engineering Department, Utah Power and Light Co., Salt Lake City, Utah. GRANITE HYDRO-ELECTRIC PLANT (1500KW) STATION. PENSTOCK AND SPILWAY, NOVEMBER 1914. - Utah Power Company, Granite Hydroelectric Plant, Holladay, Salt Lake County, UT

  7. 8. Photocopied August 1971 from Photo 11479, Granite Station Special ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Photocopied August 1971 from Photo 11479, Granite Station Special Folder, Engineering Department, Utah Power and Light Co., Salt Lake City, Utah. GRANITE HYDRO-ELECTRIC PLANT (1500 KW) STATION. PENSTOCK AND SPILWAY, NOVEMBER 1914. - Utah Power Company, Granite Hydroelectric Plant, Holladay, Salt Lake County, UT

  8. 9. Photocopied August 1971 from Photo 13730, Granite Folder #1, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Photocopied August 1971 from Photo 13730, Granite Folder #1, Engineering Department, Utah Power and Light Co., Salt Lake City, Utah. GRANITE STATION: WESTINGHOUSE 750 K.V.A., 2- PHASE GENERATORS AND SWITCHBOARD, MAY 24, 1915. - Utah Power Company, Granite Hydroelectric Plant, Holladay, Salt Lake County, UT

  9. The global age distribution of granitic pegmatites

    USGS Publications Warehouse

    McCauley, Andrew; Bradley, Dwight C.

    2014-01-01

    An updated global compilation of 377 new and previously published ages indicates that granitic pegmatites range in age from Mesoarchean to Neogene and have a semi-periodic age distribution. Undivided granitic pegmatites show twelve age maxima: 2913, 2687, 2501, 1853, 1379, 1174, 988, 525, 483, 391, 319, and 72 Ma. These peaks correspond broadly with various proxy records of supercontinent assembly, including the age distributions of granites, detrital zircon grains, and passive margins. Lithium-cesium-tantalum (LCT) pegmatites have a similar age distribution to the undivided granitic pegmatites, with maxima at 2638, 1800, 962, 529, 485, 371, 309, and 274 Ma. Lithium and Ta resources in LCT pegmatites are concentrated in the Archean and Phanerozoic. While there are some Li resources from the Proterozoic, the dominantly bimodal distribution of resources is particularly evident for Ta. This distribution is similar to that of orogenic gold deposits, and has been interpreted to reflect the preservation potential of the orogenic belts where these deposits are formed. Niobium-yttrium-fluorine (NYF) pegmatites show similar age distributions to LCT pegmatites, but with a strong maximum at ca. 1000 Ma.

  10. Granite School District First Grade Reading Study.

    ERIC Educational Resources Information Center

    Castner, Myra H.; And Others

    A comparative study of first-grade reading instructional methods was undertaken with the support of the Granite School District Exemplary Center for Reading Instruction. This study was conducted in 19 schools of the district and involved approximately 1,295 students. Nine hypotheses concerning the various approaches used in reading instruction…

  11. Voluminous granitic magmas from common basaltic sources

    USGS Publications Warehouse

    Sisson, T.W.; Ratajeski, K.; Hankins, W.B.; Glazner, A.F.

    2005-01-01

    Granitic-rhyolitic liquids were produced experimentally from moderately hydrous (1.7-2.3 wt% H2O) medium-to-high K basaltic compositions at 700 MPa and f O2 controlled from Ni-NiO -1.3 to +4. Amount and composition of evolved liquids and coexisting mineral assemblages vary with fO2 and temperature, with melt being more evolved at higher fO2s, where coexisting mineral assemblages are more plagioclase- and Fe-Ti oxide-rich and amphibole-poor. At fO2 of Ni-NiO +1, typical for many silicic magmas, the samples produce 12-25 wt% granitic-rhyolitic liquid, amounts varying with bulk composition. Medium-to-high K basalts are common in subduction-related magmatic arcs, and near-solidus true granite or rhyolite liquids can form widely, and in geologically significant quantities, by advanced crystallization-differentiation or by low-degree partial remelting of mantle-derived basaltic sources. Previously differentiated or weathered materials may be involved in generating specific felsic magmas, but are not required for such magmas to be voluminous or to have the K-rich granitic compositions typical of the upper continental crust. ?? Springer-Verlag 2005.

  12. The origin of granites and related rocks

    USGS Publications Warehouse

    Brown, Michael; Piccoli, Philip M.

    1995-01-01

    This Circular is a compilation of abstracts for posters and oral presentations given at the third Hutton symposium on the Origin of granites and related rocks. The symposium was co-sponsored by the Department of Geology, University of Maryland at College Park; the U.S. Geological Survey, Reston, Virginia; and the Department of Terrestrial Magnetism and Geophysical Laboratory, Carnegie Institution of Washington.

  13. Fractal patterns of fractures in granites

    USGS Publications Warehouse

    Velde, B.; Dubois, J.; Moore, D.; Touchard, G.

    1991-01-01

    Fractal measurements using the Cantor's dust method in a linear one-dimensional analysis mode were made on the fracture patterns revealed on two-dimensional, planar surfaces in four granites. This method allows one to conclude that: 1. (1)|The fracture systems seen on two-dimensional surfaces in granites are consistent with the part of fractal theory that predicts a repetition of patterns on different scales of observation, self similarity. Fractal analysis gives essentially the same values of D on the scale of kilometres, metres and centimetres (five orders of magnitude) using mapped, surface fracture patterns in a Sierra Nevada granite batholith (Mt. Abbot quadrangle, Calif.). 2. (2)|Fractures show the same fractal values at different depths in a given batholith. Mapped fractures (main stage ore veins) at three mining levels (over a 700 m depth interval) of the Boulder batholith, Butte, Mont. show the same fractal values although the fracture disposition appears to be different at different levels. 3. (3)|Different sets of fracture planes in a granite batholith, Central France, and in experimental deformation can have different fractal values. In these examples shear and tension modes have the same fractal values while compressional fractures follow a different fractal mode of failure. The composite fracture patterns are also fractal but with a different, median, fractal value compared to the individual values for the fracture plane sets. These observations indicate that the fractal method can possibly be used to distinguish fractures of different origins in a complex system. It is concluded that granites fracture in a fractal manner which can be followed at many scales. It appears that fracture planes of different origins can be characterized using linear fractal analysis. ?? 1991.

  14. The geology and petrogenesis of the southern closepet granite

    NASA Technical Reports Server (NTRS)

    Jayananda, M.; Mahabaleswar, B.; Oak, K. A.; Friend, C. R. L.

    1988-01-01

    The Archaean Closepet Granite is a polyphase body intruding the Peninsular Gneiss Complex and the associated supracrustal rocks. The granite out-crop runs for nearly 500 km with an approximate width of 20 to 25 km and cut across the regional metamorphic structure passing from granulite facies in the South and green schist facies in the north. In the amphibolite-granulite facies transition zone the granite is intimately mixed with migmatites and charnockite. Field observations suggests that anatexis of Peninsular gneisses led to the formation of granite melt, and there is a space relationship between migmatite formation, charnockite development and production and emplacement of granite magma. Based on texture and cross cutting relationships four major granite phases are recognized: (1) Pyroxene bearing dark grey granite; (2) Porphyritec granite; (3) Equigranular grey granite; and (4) Equigranular pink granite. The granite is medium to coarse grained and exhibit hypidiomorphic granular to porphyritic texture. The modal composition varies from granite granodiorite to quartz monzonite. Geochemical variation of the granite suite is consistent with either fractional crystallization or partial melting, but in both the cases biotite plus feldspar must be involved as fractionating or residual phases during melting to account trace element chemistry. The trace element data has been plotted on discriminant diagrams, where majority of samples plot in volcanic arc and within plate, tectonic environments. The granite show distinct REE patterns with variable total REE content. The REE patterns and overall abundances suggests that the granite suite represents a product of partial melting of crustal source in which fractional crystallization operated in a limited number of cases.

  15. Identification of granite varieties from colour spectrum data.

    PubMed

    Araújo, María; Martínez, Javier; Ordóñez, Celestino; Vilán, José Antonio

    2010-01-01

    The granite processing sector of the northwest of Spain handles many varieties of granite with specific technical and aesthetic properties that command different prices in the natural stone market. Hence, correct granite identification and classification from the outset of processing to the end-product stage optimizes the management and control of stocks of granite slabs and tiles and facilitates the operation of traceability systems. We describe a methodology for automatically identifying granite varieties by processing spectral information captured by a spectrophotometer at various stages of processing using functional machine learning techniques.

  16. Assessment of radiological hazard of commercial granites from Extremadura (Spain).

    PubMed

    Guillén, J; Tejado, J J; Baeza, A; Corbacho, J A; Muñoz, J G

    2014-06-01

    The term "commercial granite" comprises different natural stones with different mineralogical components. In Extremadura, western Spain, "commercial granites" can be classified in three types: granite s.s. (sensus stricti), granodiorite, and diorite. The content of naturally occurring radionuclides depended of the mineralogy. Thus, the (40)K content increased as the relative content of alkaline feldspar increased but decreased as the plagioclase content increased. The radioactive content decreased in the following order: granite s.s. > granodiorite > diorite. In this work, the radiological hazard of these granites as building material was analyzed in terms of external irradiation and radon exposure. External irradiation was estimated based on the "I" index, ranged between 0.073 and 1.36. Therefore, these granites can be use as superficial building materials with no restriction. Radon exposure was estimated using the surface exhalation rates in polished granites. The exhalation rate in granites depends of their superficial finishes (different roughness). For distinct mechanical finishes of granite (polish, diamond sawed, bush-hammered and flamed), the surface exhalation rate increased with the roughness of the finishes. Thermal finish presented the highest exhalation rate, because the high temperatures applied to the granite may increase the number of fissures within it. The exhalation rates in polished granites varied from 0.013 to 10.4 Bq m(-2) h(-1). PMID:24583635

  17. Assessment of radiological hazard of commercial granites from Extremadura (Spain).

    PubMed

    Guillén, J; Tejado, J J; Baeza, A; Corbacho, J A; Muñoz, J G

    2014-06-01

    The term "commercial granite" comprises different natural stones with different mineralogical components. In Extremadura, western Spain, "commercial granites" can be classified in three types: granite s.s. (sensus stricti), granodiorite, and diorite. The content of naturally occurring radionuclides depended of the mineralogy. Thus, the (40)K content increased as the relative content of alkaline feldspar increased but decreased as the plagioclase content increased. The radioactive content decreased in the following order: granite s.s. > granodiorite > diorite. In this work, the radiological hazard of these granites as building material was analyzed in terms of external irradiation and radon exposure. External irradiation was estimated based on the "I" index, ranged between 0.073 and 1.36. Therefore, these granites can be use as superficial building materials with no restriction. Radon exposure was estimated using the surface exhalation rates in polished granites. The exhalation rate in granites depends of their superficial finishes (different roughness). For distinct mechanical finishes of granite (polish, diamond sawed, bush-hammered and flamed), the surface exhalation rate increased with the roughness of the finishes. Thermal finish presented the highest exhalation rate, because the high temperatures applied to the granite may increase the number of fissures within it. The exhalation rates in polished granites varied from 0.013 to 10.4 Bq m(-2) h(-1).

  18. Physics of the granite sphere fountain

    NASA Astrophysics Data System (ADS)

    Snoeijer, Jacco H.; der Weele, Ko van

    2014-11-01

    A striking example of levitation is encountered in the "kugel fountain" where a granite sphere, sometimes weighing over a ton, is kept aloft by a thin film of flowing water. In this paper, we explain the working principle behind this levitation. We show that the fountain can be viewed as a giant ball bearing and thus forms a prime example of lubrication theory. It is demonstrated how the viscosity and flow rate of the fluid determine (i) the remarkably small thickness of the film supporting the sphere and (ii) the surprisingly long time it takes for rotations to damp out. The theoretical results compare well with measurements on a fountain holding a granite sphere of one meter in diameter. We close by discussing several related cases of levitation by lubrication.

  19. GRANITE FIORDS WILDERNESS STUDY AREA, ALASKA.

    USGS Publications Warehouse

    Berg, Henry C.; Pittman, Tom L.

    1984-01-01

    Mineral surveys of the Granite Fiords Wilderness study area revealed areas with probable and substantiated mineral-resource potential. In the northeastern sector, areas of probable and substantiated resource potential for gold, sivler, and base metals in small, locally high grade vein and disseminated deposits occur in recrystallized Mesozoic volcanic, sedimentary, and intrusive rocks. In the central part, areas of probable resource potential for gold, silver, copper, and zinc in disseminated and locally massive sulfide deposits occur in undated pelitic paragneiss roof pendants. A molybdenite-bearing quartz vein has been prospected in western Granite Fiords, and molybdenum also occurs along with other metals in veins in the northeastern sector and in geochemical samples collected from areas where there is probable resource potential for low-grade porphyry molybdenum deposits in several Cenozoic plutons. No energy resource potential was identified in the course of this study.

  20. Heater test 1, Climax Stock granite, Nevada

    SciTech Connect

    Montan, D.N.; Bradkin, W.E.

    1984-10-01

    We conducted a series of in-situ tests in the Climax Stock, an intrusive granite formation at the Nevada Test Site, to validate the concept of housing a nuclear waste repository in granitic crystalline rock. The thermal properties of the granite were measured with resistance heaters and thermocouple frames that had been emplaced in drilled holes in the floor of a drift 420 m below the surface. Data analysis was performed primarily by comparing the measured and calculated temperature histories, varying conductivity and diffusivity in the calculations until reasonable agreement was achieved. The best-fit value for in-situ conductivity was approximately 3.1 W/m x K, and the deduced value for in-situ diffusivity was approximately 1.2 mm{sup 2}/s. Anisotropic effects in the thermal field were less than 10%. Permeability was determined by sealing off portions of the drilled holes, using inflatable rubber packers and an air-pressurization system. We then compared the resulting decay in pressure with analytic solutions of the pressure loss from a cylindrical source in an infinite isotropic medium, obtaining a permeability of approximately 1 nanodarcy (nD) at about 30{sup 0}C. As the temperature increased, the permeability decreased to about 0.2 nD at about 50{sup 0}C and became too small to measure (<0.02 nD) at higher temperatures. These tests provided new data on the in-situ properties of a granite typical of the Basin and Range province and significantly advanced our understanding of and ability to perform in-situ thermal and permeability measurements. This knowledge will be of considerable value for future spent-fuel tests.

  1. Retention of Anionic Species on Granite: Influence of Granite Composition - 12129

    SciTech Connect

    Videnska, Katerina; Havlova, Vaclava

    2012-07-01

    Technetium (Tc-99, T{sub 1/2} = 2.1.10{sup 5} yrs) and selenium (Se-79, T{sub 1/2} = 6.5.10{sup 4} yrs) belong among fission products, being produced by fission of nuclear fuel. Both elements can significantly contribute to risk due to their complicated chemistry, long life times, high mobility and prevailing anionic character. Therefore, knowledge of migration behaviour under different conditions can significantly improve input into performance and safety assessment models. Granite is considered as a potential host rock for deep geological disposal of radioactive waste in many countries. Granitic rocks consist usually of quartz, feldspar, plagioclase (main components), mica, chlorite, kaolinite (minor components). The main feature of the rock is advection governed transport in fractures, complemented with diffusion process from fracture towards undisturbed rock matrix. The presented work is focused on interaction of anionic species (TcO{sub 4}{sup -}, SeO{sub 4}{sup 2-}, SeO{sub 3}{sup 2-}) with granitic rock. Furthermore, the importance of mineral composition on sorption of anionic species was also studied. The batch sorption experiments were conducted on the crushed granite from Bohemian Massive. Five fractions with defined grain size were used for static batch method. Mineral composition of each granitic fraction was evaluated using X-ray diffraction. The results showed differences in composition of granitic fractions, even though originating from one homogenized material. Sorption experiments showed influence of granite composition on adsorption of both TcO4{sup -} and SeO3{sup 2-} on granitic rock. Generally, Se(IV) showed higher retention than Tc(VII). Se(VI) was not almost sorbed at all. Fe containing minerals are pronounced as a selective Se and Tc sorbent, being reduced on their surface. As micas in granite are usually enriched in Fe, increased sorption of anionic species onto mica enriched fractions can be explained by this reason. On the other hand

  2. Silicosis in West Country Granite Workers

    PubMed Central

    Hale, L. W.; Sheers, G.

    1963-01-01

    The granite industry in Cornwall and Devon is briefly described, especially the production of dust in dressing the stone. In 1951, 210 granite masons were examined (about 84% of the total at that time) and 37 (17·6%) showed silicosis. These men were followed up for 10 years. No silicosis was seen in men with less than 15 years' exposure, but after this time the risk increased to 11 out of 14 in those with over 35 years' exposure. Nine deaths occurred, two of which were due to silicosis. Radiological progression was observed in 13 of the 28 survivors. It was not necessarily associated with additional exposure but was related to age. More young men progressed. In 1961, 132 of the granite masons (about 93% of the total at that time) were re-examined and nine new cases of silicosis were found to have developed during the 10-year interval. The exposure in the 1961 cases was comparable with that of similar cases in 1951. Thus the risk has not been much reduced over this period. Pulmonary tuberculosis occurred in eight of the 37 cases of silicosis in 1951, and between 1951 and 1961 a further five cases were diagnosed, four being from one locality. This was by far the most frequent and disabling complication. Only one case of progressive massive fibrosis was seen. More extensive use of protective antituberculous chemotherapy is advocated, and also better dust control. Images PMID:14046159

  3. Natural radioactivity of granites used as building materials.

    PubMed

    Pavlidou, S; Koroneos, A; Papastefanou, C; Christofides, G; Stoulos, S; Vavelides, M

    2006-01-01

    Sixteen kinds of different granites, used as building materials, imported to Greece mainly from Spain and Brazil, were sampled and their natural radioactivity was measured by gamma-ray spectrometry. The activity concentrations of (238)U, (226)Ra, (232)Th and (40)K of granites are presented and compared to those of other building materials as well as other granite types used all over the world. In order to assess the radiological impact from the granites investigated, the absorbed and the effective doses were determined. Although the annual effective dose is higher than the limit of 1mSvy(-1) for some studied granites, they could be used safely as building materials, considering that their contribution in most of the house constructions is very low. An attempt to correlate the relatively high level of natural radioactivity, shown by some of the granites, with their constituent radioactive minerals and their chemical composition, was also made.

  4. Preface to special issue: Granite magmatism in Brazil

    NASA Astrophysics Data System (ADS)

    Janasi, Valdecir de Assis; de Pinho Guimarães, Ignez; Nardi, Lauro Valentim Stoll

    2016-07-01

    Granites are important both to the geologic evolution and to the economy of Brazil. Deposits of precious and rare metals, such as Au, Sn and many others, are directly or indirectly associated with granites, especially in the geologically under-explored Amazon region. On the opposite eastern side of the country, expanding exploitation of natural granite as dimension stone makes Brazil currently the world's second largest exporter of granite blocks. Granites are a major constituent of the Brazilian Archean-Proterozoic cratonic domains (the Amazon and São Francisco cratons) and their surrounding Neoproterozoic fold belts. The granites are thus fundamental markers of the major events of crustal generation and recycling that shaped the South American Platform. As a result, Brazilian granites have received great attention from the national and international community, and a number of influential meetings focused on the study of granites were held in the country in the last three decades. These meetings include the two International Symposia on Granites and Associated Mineralization (Salvador, January 21-31, 1987, and August 24-29, 1997), the Symposium on Rapakivi Granites and Related Rocks (Belém, August 2-5, 1995) and the Symposium on Magmatism, Crustal Evolution, and Metallogenesis of the Amazonian Craton (Belém, August 2006). Special issues dedicated to contributions presented at these meetings in the Journal of South American Earth Sciences (Sial et al., 1998), Lithos (Stephens et al., 1999), Canadian Mineralogist (Dall'Agnol and Ramo, 2006), Precambrian Research (Ramo et al., 2002) and Anais da Academia Brasileira de Ciências (Dall'Agnol and Bettencourt, 1997; Sial et al., 1999a) are still important references on the knowledge of Brazilian granites and granite petrology in general.

  5. Imaging of water distribution in thermally fractured granites by SPRITE.

    PubMed

    Yamaguchi, Makoto; Kobori, Kazuo; Suzuki, Kazunori; Ikeda, Yasuhisa; Altobelli, Stephen

    2005-02-01

    Water distribution in thermally fractured granite samples was visualized by using SPRITE sequences. Networks of intergranular fractures were observed in the coarse-grained Inada granite after heating at 873 K or above. On the other hand, bright spots were observed in the fine-grained Okazaki granite, which may be due to pore water in feldspar grains. D2O diffusion into samples saturated with H2O was also observed by 2D-projected SPRITE imaging.

  6. Characterization of Climax granite ground water

    SciTech Connect

    Isherwood, D.; Harrar, J.; Raber, E.

    1982-08-01

    The Climax ground water fails to match the commonly held views regarding the nature of deep granitic ground waters. It is neither dilute nor in equilibrium with the granite. Ground-water samples were taken for chemical analysis from five sites in the fractured Climax granite at the Nevada Test Site. The waters are high in total dissolved solids (1200 to 2160 mg/L) and rich in sodium (56 to 250 mg/L), calcium (114 to 283 mg/L) and sulfate (325 to 1060 mg/L). Two of the samples contained relatively high amounts of uranium (1.8 and 18.5 mg/L), whereas the other three contained uranium below the level of detection (< 0.1 mg/L). The pH is in the neutral range (7.3 to 8.2). The differences in composition between samples (as seen in the wide range of values for the major constituents and total dissolved solids) suggest the samples came from different, independent fracture systems. However, the apparent trend of increasing sodium with depth at the expense of calcium and magnesium suggests a common evolutionary chemical process, if not an interconnected system. The waters appear to be less oxidizing with depth (+ 410 mV at 420 m below the surface vs + 86 mV at 565 m). However, with Eh measurements on only two samples, this correlation is questionable. Isotopic analyses show that the waters are of meteoric origin and that the source of the sulfate is probably the pyrite in the fracture-fill material. Analysis of the measured water characteristics using the chemical equilibrium computer program EQ3 indicates that the waters are not in equilibrium with the local mineral assemblage. The solutions appear to be supersaturated with respect to the mineral calcite, quartz, kaolinite, muscovite, k-feldspar, and many others.

  7. Thermoluminescence of the mineral components in granite

    SciTech Connect

    Schwartzman, R.G.; Kierstead, J.A.; Levy, P.W.

    1982-01-01

    The thermoluminescence (TL) of the minerals in Climax Stock (Nevada, USA) granite has been studied. The principal mineral constituents are plagioclase, quartz, potassium feldspar and biotite. Pyrite, sphene apatite and zircon occur at one percent or less. All exhibit TL except biotite. The TL kinetics were determined for plagioclase, quartz, potassium feldspar and pyrite. Plagioclase and potassium feldspar exhibit second order and pyrite first orker kinetics. Natural TL of quartz follows second order and artificial TL first order kinetics. However, in these four minerals unrealistic kinetic parameters are often obtained; thus more general kinetics, e.g. interactive kinetics, may apply. 8 figures.

  8. GRANITE CHIEF WILDERNESS STUDY AREA, CALIFORNIA.

    USGS Publications Warehouse

    Harwood, David S.; Federspiel, Francis E.

    1984-01-01

    The Granite Chief Wilderness study area encompasses 57 sq mi near the crest of the Sierra Nevada 6 mi west of Tahoe City, California. Geologic, geochemical, and mines and prospect studies were carried out to assess the mineral-resource potential of the area. On the basis of the mineral-resource survey, it is concluded that the area has little promise for the occurrence of precious or base metals, oil, gas, coal, or geothermal resources. Sand, gravel, and glacial till suitable for construction materials occur in the area, but inaccessability and remoteness from available markets preclude their being shown on the map as a potential resource.

  9. Strain localization during deformation of Westerly granite

    NASA Technical Reports Server (NTRS)

    Brodsky, N. S.; Spetzler, H. A.

    1984-01-01

    A specimen of Westerly granite was cyclically loaded to near failure at 50 MPa confining pressure. Holographic interferometry provided detailed measurements of localized surface deformations during loading and unloading. The data are consistent with deformation occurring primarily elastically at low differential stress; in conjunction with one incipient fault zone between approximately 350 and 520 MPa differential stress; and in conjunction with a second incipient fault zone above 580 MPa and/or during creep. During unloading only one fault zone, that which is active at the intermediate stress levels during loading, is seen to recede.

  10. Rare accessory uraninite in a Sierran granite

    NASA Technical Reports Server (NTRS)

    Snetsinger, K. G.; Polkowski, G.

    1977-01-01

    One grain of uraninite was found in a single thin-section of Sierran granite. Electron and ion microprobe analysis were used to determine the composition. Since the U-Pb age calculated for the uraninite does not differ greatly from the K-Ar age of the unit in which it occurs, it is suggested that the mineral is primary and not reworked from a preexisting rock. No uraninite has been detected in heavy mineral concentrates from other rocks of the local area.

  11. Multivariate analyses of Erzgebirge granite and rhyolite composition: Implications for classification of granites and their genetic relations

    USGS Publications Warehouse

    Forster, H.-J.; Davis, J.C.; Tischendorf, G.; Seltmann, R.

    1999-01-01

    High-precision major, minor and trace element analyses for 44 elements have been made of 329 Late Variscan granitic and rhyolitic rocks from the Erzgebirge metallogenic province of Germany. The intrusive histories of some of these granites are not completely understood and exposures of rock are not adequate to resolve relationships between what apparently are different plutons. Therefore, it is necessary to turn to chemical analyses to decipher the evolution of the plutons and their relationships. A new classification of Erzgebirge plutons into five major groups of granites, based on petrologic interpretations of geochemical and mineralogical relationships (low-F biotite granites; low-F two-mica granites; high-F, high-P2O5 Li-mica granites; high-F, low-P2O5 Li-mica granites; high-F, low-P2O5 biotite granites) was tested by multivariate techniques. Canonical analyses of major elements, minor elements, trace elements and ratio variables all distinguish the groups with differing amounts of success. Univariate ANOVA's, in combination with forward-stepwise and backward-elimination canonical analyses, were used to select ten variables which were most effective in distinguishing groups. In a biplot, groups form distinct clusters roughly arranged along a quadratic path. Within groups, individual plutons tend to be arranged in patterns possibly reflecting granitic evolution. Canonical functions were used to classify samples of rhyolites of unknown association into the five groups. Another canonical analysis was based on ten elements traditionally used in petrology and which were important in the new classification of granites. Their biplot pattern is similar to that from statistically chosen variables but less effective at distinguishing the five groups of granites. This study shows that multivariate statistical techniques can provide significant insight into problems of granitic petrogenesis and may be superior to conventional procedures for petrological interpretation.

  12. Mortality and disability among granite workers.

    PubMed

    Koskela, R S; Klockars, M; Järvinen, E; Kolari, P J; Rossi, A

    1987-02-01

    The objective of the present study was to investigate the mortality, disability, and long-term morbidity of granite workers. The study included 1,026 workers hired between 1940 and 1971 and followed until the end of 1981. The total number of deaths was 235, and the expected number was 229.7. Excess mortality rates were observed for respiratory diseases (observed/expected = 28/13.9). The number of tumor deaths was 46 (expected 44.9). Excess lung cancer mortality was evident at 15 to 35 years of latency; the observed number of lung cancer deaths for the follow-up period of 25 to 29 years was 8, while 2.1 were expected. Mortality from cardiovascular diseases and violent deaths was slightly less than expected. The results for disability and long-term morbidity showed elevated incidence and prevalence rates for respiratory diseases and rheumatoid arthritis. The observed number of disability pensions due to rheumatoid arthritis in 1981 was 10 observed versus 1.8 expected, and the observed number of patients granted free medication was 19 versus 8.1 expected. The results indicate that granite dust exposure per se may be an etiologic and pathogenetic factor for lung cancer, cancer of the gastrointestinal tract, and some extrapulmonary nonmalignant chronic diseases.

  13. Effectiveness of granite cleaning procedures in cultural heritage: A review.

    PubMed

    Pozo-Antonio, J S; Rivas, T; López, A J; Fiorucci, M P; Ramil, A

    2016-11-15

    Most of the Cultural Heritage built in NW Iberian Peninsula is made of granite which exposition to the environment leads to the formation of deposits and coatings, mainly two types: biological colonization and sulphated black crusts. Nowadays, another form of alteration derives from graffiti paints when these are applied as an act of vandalism. A deep revision needs to be addressed considering the severity of these deterioration forms on granite and the different cleaning effectiveness achieved by cleaning procedures used to remove them. The scientific literature about these topics on granite is scarcer than on sedimentary carbonate stones and marbles, but the importance of the granite in NW Iberian Peninsula Cultural Heritage claims this review centred on biological colonization, sulphated black crusts and graffiti on granite and their effectiveness of the common cleaning procedures. Furthermore, this paper carried out a review of the knowledge about those three alteration forms on granite, as well as bringing together all the major studies in the field of the granite cleaning with traditional procedures (chemical and mechanical) and with the recent developed technique based on the laser ablation. Findings concerning the effectiveness evaluation of these cleaning procedures, considering the coating extraction ability and the damage induced on the granite surface, are described. Finally, some futures research lines are pointed out. PMID:27443454

  14. Experimental methods of determining thermal properties of granite

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Determination of thermal properties of granite using the block method is discussed and compared with other methods. Problems that limit the accuracy of contact method in determining thermal properties of porous media are evaluated. Thermal properties of granite is determined in the laboratory with a...

  15. Detail of south granite pier revealing riveted truss ends and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of south granite pier revealing riveted truss ends and iron footing plates on top of granite cap stones. View north - New York, New Haven & Hartford Railroad, Fort Point Channel Rolling Lift Bridge, Spanning Fort Point Channel, Boston, Suffolk County, MA

  16. Effectiveness of granite cleaning procedures in cultural heritage: A review.

    PubMed

    Pozo-Antonio, J S; Rivas, T; López, A J; Fiorucci, M P; Ramil, A

    2016-11-15

    Most of the Cultural Heritage built in NW Iberian Peninsula is made of granite which exposition to the environment leads to the formation of deposits and coatings, mainly two types: biological colonization and sulphated black crusts. Nowadays, another form of alteration derives from graffiti paints when these are applied as an act of vandalism. A deep revision needs to be addressed considering the severity of these deterioration forms on granite and the different cleaning effectiveness achieved by cleaning procedures used to remove them. The scientific literature about these topics on granite is scarcer than on sedimentary carbonate stones and marbles, but the importance of the granite in NW Iberian Peninsula Cultural Heritage claims this review centred on biological colonization, sulphated black crusts and graffiti on granite and their effectiveness of the common cleaning procedures. Furthermore, this paper carried out a review of the knowledge about those three alteration forms on granite, as well as bringing together all the major studies in the field of the granite cleaning with traditional procedures (chemical and mechanical) and with the recent developed technique based on the laser ablation. Findings concerning the effectiveness evaluation of these cleaning procedures, considering the coating extraction ability and the damage induced on the granite surface, are described. Finally, some futures research lines are pointed out.

  17. Geophysical Studies of Irish Granites Using Magnetotelluric and Gravity Data

    NASA Astrophysics Data System (ADS)

    Farrell, T. F.; Muller, M. R.; Rath, V.; Feely, M.; Hogg, C.

    2014-12-01

    We present results of on-going geophysical studies of Caledonian radiothermal granite bodies in Ireland, which are being undertaken to investigate the volumetric depth extent and structural features of these granites. During three field seasons, magnetotelluric (MT) and audio-magnetotelluric (AMT) data were acquired at 156 sites targeting three separate granite bodies. These studies will contribute to a crustal-scale investigation of the geothermal energy potential of the granites and their contribution to the thermal field of the Irish crust. Across the calc-alkaline Galway granite, located on the Irish west coast, MT and AMT data were acquired at 75 sites distributed in a grid. Preliminary 3D inversion reveals the presence of a resistor, thickest beneath the central block of the granite where it extends to depths of 11 - 12 km. The greater depth of the resistor beneath the central block is in contrast to previous thinking that proposed the central block granites to have shallower depth extent than those of the western block, based on Bouguer anomaly maps of the area in which the western block exhibited a more pronounced negative Bouguer anomaly than the central block. At the S-type Leinster granite, in eastern Ireland and to the south of Dublin, MT and AMT data were acquired along two profiles (LGN - 27 sites and LGS - 32 sites). Preliminary 1D inversions of AMT data along profile LGN show the Northern Units of the Leinster granite to extend to a depth of 4.5 km and the Lugnaquilla pluton extending to 2.5 km depth. MT and AMT data were acquired at 22 sites along a profile across the buried Kentstown granite, 35 km to the NW of Dublin. The Kentstown granite was intersected by two mineral exploration boreholes at depths of 492 m and 663 m. Preliminary 2D inversions do not yet satisfactorily resolve the top of the buried granite. Inversion of MT and AMT data is continuing, with the electrical conductivity structures revealed by these inversions being used to

  18. IRETHERM: The geothermal energy potential of Irish radiothermal granites

    NASA Astrophysics Data System (ADS)

    Farrell, Thomas; Jones, Alan; Muller, Mark; Feely, Martin; Brock, Andrew; Long, Mike; Waters, Tim

    2014-05-01

    The IRETHERM project is developing a strategic understanding of Ireland's deep geothermal energy potential through integrated modelling of new and existing geophysical and geological data. One aspect of IRETHERM's research focuses on Ireland's radiothermal granites, where increased concentrations of radioelements provide elevated heat-production (HP), surface heat-flow (SHF) and subsurface temperatures. An understanding of the contribution of granites to the thermal field of Ireland is important to assessing the geothermal energy potential of this low-enthalpy setting. This study focuses on the Galway granite in western Ireland, and the Leinster and the buried Kentstown granites in eastern Ireland. Shallow (<250 m) boreholes were drilled into the exposed Caledonian Leinster and Galway granites as part of a 1980's geothermal project. These studies yielded HP = 2-3 μWm-3 and HF = 80 mWm-2 at the Sally Gap borehole in the Northern Units of the Leinster granite, to the SW of Dublin. In the Galway granite batholith, on the west coast of Ireland, the Costelloe-Murvey granite returned HP = 7 μWm-3 and HF = 77 mWm-2, measured at the Rossaveal borehole. The buried Kentstown granite, 35 km NW of Dublin, has an associated negative Bouguer anomaly and was intersected by two mineral exploration boreholes at depths of 660 m and 490 m. Heat production is measured at 2.4 μWm-3 in core samples taken from the weathered top 30 m of the granite. The core of this study consists of a program of magnetotelluric (MT) and audio-magnetotelluric (AMT) data acquisition across the three granite bodies, over three fieldwork seasons. MT and AMT data were collected at 59 locations along two profiles over the Leinster granite. Preliminary results show that the northern units of the Leinster granite (40 km SW of Dublin) extend to depths of 2-5 km. Preliminary results from the southern profile suggest a greater thickness of granite to a depth of 6-9 km beneath the Tullow pluton, 75 km SW of

  19. Lower Granite Pool and Turbine Survival Study, 1987.

    SciTech Connect

    Giorgi, Albert E.; Stuehrenberg, Lowell

    1988-06-01

    Survival of yearling spring chinook salmon was estimated as they traversed Lower Granite Reservoir and passed through a turbine at Lower Granite Dam. Fish were PIT tagged at Rapid River Hatchery and transported to release sites near Asotin, Washington, and at Lower Granite Dam. Recovery ratios of treatment and control groups were used to estimate survival. Estimates were based on tags intercepted at both Lower Granite and Little Goose dams. Turbine survival was estimated to be 83.1% (95% CI = 74.1 to 92.2%). A qualified estimate of survival from Asotin to Lower Granite Dam for a single release group was calculated as 71.9%. Uncertainties associated with satisfying certain key mark and recapture statistical assumptions are examined. As a result of these uncertainties, an alternate study design and analytical procedure are recommended for future investigations. 14 refs., 7 figs., 5 tabs.

  20. Plane shock wave studies of Westerly granite and Nugget sandstone

    SciTech Connect

    Larson, D.B.; Anderson, G.D.

    1980-12-01

    Plane shock wave experiments were performed by using a light-gas gun on dry and water-saturated Westerly granite and dry Nugget sandstone. Changes in the slopes of the shock velocity versus particle velocity curves at 2 to 3 GPa and 1 to 2 GPa for dry granite and for dry sandstone, respectively, are attributed to the onset of pore collapse. However, there is little apparent loss of shear strength in either dry rock over the stress range of the experiments (i.e., 9.3 GPa in Westerly granite and 9.2 GPa in Nugget sandstone). Agreement between the shock wave data and quasistatic, uniaxial strain data for the dry rock implies the absence of rate-dependence in uniaxial strain. The shock data on saturated granite agree well with those for dry granite, thus suggesting there was no loss in shear strength as a result of pore pressure buildup.

  1. Petrogenesis of magmatic albite granites associated to cogenetic A-type granites: Na-rich residual melt extraction from a partially crystallized A-type granite mush

    NASA Astrophysics Data System (ADS)

    Barboni, Mélanie; Bussy, François

    2013-09-01

    The uncommon association of cogenetic and nearly contemporaneous potassic K-feldspar A-type granites and sodic albite granites is observed within the 347 Ma-old bimodal Saint-Jean-du-Doigt (SJDD) intrusion, Brittany, France. A-type granites outcrop as small bodies (< 1 km2) of fine-grained, pinkish to yellowish rock or as meter-thick sills in-between mafic layers. They emplaced early within the thermally “cool” part of the SJDD pluton directly beneath the Precambrian host rock, forming the pluton roof. Albite granites are fine-grained hololeucocratic yellowish rocks emplaced slightly after the A-type granites in the thermally mature part of the pluton. They form meter-thick sills that mingle with adjacent mafic layers and represent ca. 1 vol.% of the outcropping part of the pluton. The two granite types are similar in many respects with comparable Sr-Nd-Hf isotope compositions (87Sr/86Sr347 = 0.7071 for A-type granites vs. 0.7073 for albite granites; εNd347 = + 0.2 vs. + 0.3; εHf347zircon = + 2.47 vs. + 2.71, respectively) and SiO2 contents (74.8 vs. 74.4 wt.%). On the other hand, they have contrasting concentrations in K2O (5.30 vs. 1.97 wt.%), Na2O (2.95 vs. 4.73 wt.%) and CaO (0.48 vs. 2.04, respectively) as well as in some trace elements like Sr (59 vs. 158 ppm in average), Rb (87 vs. 35 ppm), Cr (170 vs. 35 ppm) and Ga (30 vs. 20 ppm). The isotopic composition of the A-type and albite granites is very distinct from that of the associated and volumetrically dominant mafic rocks (i.e. 87Sr/86Sr347 = 0.7042; εNd347 = + 5.07; εHf347zircon = + 8.11), excluding a direct derivation of the felsic rocks through fractional crystallization from the basaltic magma. On the other hand, small volumes of hybrid, enclave-bearing granodiorite within the SJDD lopolith suggest mixing processes within a reservoir located at deeper crustal levels. A-type granites may therefore form by magma mixing between the mafic magma and crustal melts. Alternatively, they might derive

  2. Chemical characteristics of zircon from A-type granites and comparison to zircon of S-type granites

    NASA Astrophysics Data System (ADS)

    Breiter, Karel; Lamarão, Claudio Nery; Borges, Régis Munhoz Krás; Dall'Agnol, Roberto

    2014-04-01

    The trace element content in zircons from A-type granites and rhyolites was investigated by using back-scattered electron images and electron microprobe analyses. The studied Proterozoic (Wiborg batholith, Finland and Pará, Amazonas and Goiás states, Brazil) and Variscan (Krušné Hory/Erzgebirge, Czech Republic and Germany) plutons cover a wide range of rocks, from large rapakivi-textured geochemically primitive plutons to small intrusions of F-, Li-, Sn-, Nb-, Ta-, and U-enriched rare-metal granites. While zircon is one of the first crystallized minerals in less fractionated metaluminous and peraluminous granites, it is a late-crystallized phase in peralkaline granites and in evolved granites that may crystallize during the whole process of magma solidification. The early crystals are included in mica, quartz, and feldspar; the late grains are included in fluorite or cryolite or are interstitial. The zircon in hornblende-biotite and biotite granites from the non-mineralized plutons is poor in minor and trace elements; the zircon in moderately fractionated granite varieties is slightly enriched in Hf, Th, U, Y, and HREEs; whereas the zircon in highly fractionated ore-bearing granites may be strongly enriched in Hf (up to 10 wt.% HfO2), Th (up to 10 wt.% ThO2), U (up to 10 wt.% UO2), Y (up to 12 wt.% Y2O3), Sc (up to 3 wt.% Sc2O3), Nb (up to 5 wt.% Nb2O5), Ta (up to 1 wt.% Ta2O5), W (up to 3 wt.% WO3), F (up to 2.5 wt.% F), P (up to 11 wt.% P2O5), and As (up to 1 wt.% As2O5). Metamictized zircons may also be enriched in Bi, Ca, Fe, and Al. The increase in the Hf content coupled with the decrease in the Zr/Hf value in zircon is one of the most reliable indicators of granitic magma evolution. In the zircon of A-type granites, the Zr/Hf value decreases from 41-67 (porphyritic granite) to 16-19 (equigranular granite) in the Kymi stock, Finland, and from 49-52 (biotite granite) to 18-36 (leucogranite) in the Pedra Branca pluton, Brazil. In the in situ strongly

  3. Enigmatic reticulated filaments in subsurface granite.

    PubMed

    Miller, A Z; Hernández-Mariné, M; Jurado, V; Dionísio, A; Barquinha, P; Fortunato, E; Afonso, M J; Chaminé, H I; Saiz-Jimenez, C

    2012-12-01

    In the last few years, geomicrobiologists have focused their researches on the nature and origin of enigmatic reticulated filaments reported in modern and fossil samples from limestone caves and basalt lava tubes. Researchers have posed questions on these filaments concerning their nature, origin, chemistry, morphology, mode of formation and growth. A tentative microbial origin has been elusive since these filaments are found as hollow tubular sheaths and could not be affiliated to any known microorganism. We describe the presence of similar structures in a 16th century granite tunnel in Porto, Northwest Portugal. The reticulated filaments we identify exhibit fine geometry surface ornamentation formed by cross-linked Mn-rich nanofibres, surrounded by a large amount of extracellular polymeric substances. Within these Mn-rich filaments we report for the first time the occurrence of microbial cells. PMID:23760930

  4. Example of fracture characterization in granitic rock

    SciTech Connect

    Thorpe, R.K.

    1981-03-01

    A detailed study of geologic discontinuities for an underground heater test in highly fractured granitic rock is reported. Several prominent shear fractures were delineated within a 6 x 30 x 15 m rock mass by correlating surface mapping and borehole fracture logs. Oblique-reverse faulting is suspected on at least one of the surfaces, and its inferred borehole intercepts appear to be collinear in the direction of slickensiding observed in the field. Four distinct joint sets were identified, one of which coincides with the shear fractures. Another lies nearly horizontal, and two others are steeply inclined and orthogonal. Fracture lengths and spacings for the four joint sets are represented by lognormal probability distributions.

  5. Enigmatic reticulated filaments in subsurface granite.

    PubMed

    Miller, A Z; Hernández-Mariné, M; Jurado, V; Dionísio, A; Barquinha, P; Fortunato, E; Afonso, M J; Chaminé, H I; Saiz-Jimenez, C

    2012-12-01

    In the last few years, geomicrobiologists have focused their researches on the nature and origin of enigmatic reticulated filaments reported in modern and fossil samples from limestone caves and basalt lava tubes. Researchers have posed questions on these filaments concerning their nature, origin, chemistry, morphology, mode of formation and growth. A tentative microbial origin has been elusive since these filaments are found as hollow tubular sheaths and could not be affiliated to any known microorganism. We describe the presence of similar structures in a 16th century granite tunnel in Porto, Northwest Portugal. The reticulated filaments we identify exhibit fine geometry surface ornamentation formed by cross-linked Mn-rich nanofibres, surrounded by a large amount of extracellular polymeric substances. Within these Mn-rich filaments we report for the first time the occurrence of microbial cells.

  6. Radiographic abnormalities in Vermont granite workers exposed to low levels of granite dust.

    PubMed

    Graham, W G; Ashikaga, T; Hemenway, D; Weaver, S; O'Grady, R V

    1991-12-01

    The issue of whether low levels of granite dust exposure lead to radiographic abnormalities after a lifetime of exposure has not been settled. In 1983, we carried out a radiographic survey of the Vermont granite industry, consisting of quarry and stone shed workers who had been exposed to the low dust levels prevailing in the industry since 1938 to 1940. Films were read by three "B" readers, using the ILO classification system, which requires the identification of both rounded and irregular opacities, as well as combinations of both. X-ray films were taken of 972 workers, out of a total work force of approximately 1,400. Of these films, 28 (3 percent) were interpreted by either two or three of the three readers as showing abnormalities consistent with pneumoconiosis. Only seven films (or 0.7 percent of the entire cohort) showed nodular or rounded opacities of the type typically seen in uncomplicated silicosis. The remainder of the abnormal x-ray films showed irregular opacities, largely in the lower lung zones, which are of uncertain significance, but may be related to heavy cigarette smoking and aging, and possibly dust inhalation. In addition, total gravimetric dust concentrations in the workplace were measured; 417 respirable-size mass samples showed concentrations of 601 micrograms/cu m +/- 368 micrograms/cu m. Using previously published estimates of 10 percent quartz in granite dust, the average quartz concentration was 60 micrograms/cu m. Twelve percent of the samples exceeded 100 micrograms/cu m, the current OSHA standard for quartz. We conclude that control of quartz exposure in the Vermont granite industry to levels which are on average less than the current OSHA standard has essentially eliminated definite radiographic changes of silicosis. The significance of the irregular opacities in the lower lung zones seen on a majority of the 28 x-ray films judged to be abnormal is not clear.

  7. Permeability reduction in granite under hydrothermal conditions

    USGS Publications Warehouse

    Morrow, C.A.; Moore, Diane E.; Lockner, D.A.

    2001-01-01

    The formation of impermeable fault seals between earthquake events is a feature of many models of earthquake generation, suggesting that earthquake recurrence may depend in part on the rate of permeability reduction of fault zone materials under hydrothermal conditions. In this study, permeability measurements were conducted on intact, fractured, and gouge-bearing Westerly granite at an effective pressure of 50 MPa and at temperatures from 150?? to 500??C, simulating conditions in the earthquake-generating portions of fault zones. Pore fluids were cycled back and forth under a 2 MPa pressure differential for periods of up to 40 days. Permeability of the granite decreased with time t, following the exponential relation k = c(10-rt). For intact samples run between 250?? and 500??C the time constant for permeability decrease r was proportional to temperature and ranged between 0.001 and 0.1 days-1 (i.e., between 0.4 and 40 decades year-1 loss of permeability). Values of r for the lower-temperature experiments differed little from the 250??C runs. In contrast, prefractured samples showed higher rates of permeability decrease at a given temperature. The surfaces of the fractured samples showed evidence of dissolution and mineral growth that increased in abundance with both temperature and time. The experimentally grown mineral assemblages varied with temperature and were consistent with a rock-dominated hydrothermal system. As such mineral deposits progressively seal the fractured samples, their rates of permeability decrease approach the rates for intact rocks at the same temperature. These results place constraints on models of precipitation sealing and suggest that fault rocks may seal at a rate consistent with earthquake recurrence intervals of typical fault zones.

  8. Uranium-lead isotope systematics and apparent ages of zircons and other minerals in precambrian granitic rocks, Granite Mountains, Wyoming

    USGS Publications Warehouse

    Ludwig, K. R.; Stuckless, J.S.

    1978-01-01

    Zircon suites from the two main types of granite in the Granite Mountains, Wyoming, yielded concordia-intercept ages of 2,640??20 m.y. for a red, foliated granite (granite of Long Creek Mountain) and 2,595??40 m.y. for the much larger mass of the granite of Lankin Dome. These ages are statistically distinct (40??20 m.y. difference) and are consistent with observed chemical and textural differences. The lower intercepts of the zircon chords of 50??40 and 100+ 75 m.y. for the granite of Long Creek Mountain and granite of Lankin Dome, respectively, are not consistent with reasonable continuous diffusion lead-loss curves but do correspond well with the known (Laramide) time of uplift of the rocks. Epidote, zircon, and apatite from silicified and epidotized zones in the granites all record at least one postcrystallization disturbance in addition to the Laramide event and do not define a unique age of silicification and epidotization. The lower limit of ???2,500 m.y. provided by the least disturbed epidote, however, suggests that these rocks were probably formed by deuteric processes shortly after emplacement of the granite of the Lankin Dome. The earlier of the two disturbances that affected the minerals of the silicified-epidotized rock can be bracketed between 1,350 and 2,240 m.y. ago and is probably the same event that lowered mineral K-Ar and ages in the region. Zircon suites from both types of granite show well-defined linear correlations among U content, common-Pb content, and degree of discordance. One of the zircon suites has an extremely high common-Pb content (up to 180 ppm) and exhibits a component of radiogenic-Pb loss that is apparently unrelated to radiation damage. ?? 1978 Springer-Verlag.

  9. Radon exhalation from granites used in Saudi Arabia.

    PubMed

    al-Jarallah, M

    2001-01-01

    Measurements of radon exhalation for a total of 50 selected samples of construction materials used in Saudi Arabia were taken using a radon gas analyzer. These materials included sand, aggregate, cement, gypsum, hydrated lime, ceramics and granite. It was found that the granite samples were the main source of radon emanations. A total of 32 local and imported granite samples were tested. It was found that the radon exhalation rates per unit area from these granite samples varied from not detectable to 10.6 Bq m-2 h-1 with an average of 1.3 Bq m-2 h-1. The linear correlation coefficient between emanated radon and radium content was 0.92. The normalized radon exhalation rates from 2.0 cm thick granite samples varied from not detectable to 0.068 (Bq m-2 h-1)/(Bq kg-1) with an average of 0.030 (Bq m-2 h-1)/(Bq kg-1). The average radon emanation of the granite samples was found to be 21% of the total radium concentration. Therefore, granite can be a source of indoor radon as well as external gamma-radiation from the uranium decay series.

  10. Radon exhalation from granites used in Saudi Arabia.

    PubMed

    al-Jarallah, M

    2001-01-01

    Measurements of radon exhalation for a total of 50 selected samples of construction materials used in Saudi Arabia were taken using a radon gas analyzer. These materials included sand, aggregate, cement, gypsum, hydrated lime, ceramics and granite. It was found that the granite samples were the main source of radon emanations. A total of 32 local and imported granite samples were tested. It was found that the radon exhalation rates per unit area from these granite samples varied from not detectable to 10.6 Bq m-2 h-1 with an average of 1.3 Bq m-2 h-1. The linear correlation coefficient between emanated radon and radium content was 0.92. The normalized radon exhalation rates from 2.0 cm thick granite samples varied from not detectable to 0.068 (Bq m-2 h-1)/(Bq kg-1) with an average of 0.030 (Bq m-2 h-1)/(Bq kg-1). The average radon emanation of the granite samples was found to be 21% of the total radium concentration. Therefore, granite can be a source of indoor radon as well as external gamma-radiation from the uranium decay series. PMID:11378931

  11. Petrogenesis of pegmatites and granites in southwestern Maine

    SciTech Connect

    Tomascak, P.B.; Walker, R.J.; Krogstad, E.J. . Dept. of Geology)

    1993-03-01

    Granitic pegmatites occurring near the town of Topsham in southwestern Maine are mineralogically diverse, featuring abundant dikes and contain rare earth element minerals as well as one pegmatite that contains Li minerals. The pegmatite series crops out near the Brunswick granite, a texturally diverse granitic pluton, and lies 13 km southeast of the Mississippian age Sebago batholith. Areas intruded by pegmatites that possess such different mineral assemblages are globally rare. The origins of these mixed'' pegmatite series have not been comprehensively investigated. There is no known pattern of regional zonation (mineral/chemical) among Topsham series pegmatites, hence simple fractionation processes are probably not responsible for the compositional variations. The authors are attempting to clarify pegmatite petrogenesis using common Pb isotopic ratios of feldspars and Sm-Nd isotopic data from whole rocks and minerals. Pb isotopic ratios from leached feldspars reflect the Pb ratios of the source from which they were derived. The range of Pb isotopic compositions of alkali feldspars from 7 granitic pegmatites is as follows: [sup 206]Pb/[sup 204]Pb = 18.5-19.1; [sup 207]Pb/[sup 204]Pb = 15.53-15.69; [sup 208]Pb/[sup 204]Pb = 38.3-38.6. The Brunswick granite has K-feldspars with [sup 206]Pb/[sup 204]Pb = 18.40-18.47, [sup 207]/[sup 204]Pb = 15.64-15.66 and [sup 208]Pb/[sup 204]Pb = 38.29-38.39. The Pb isotopic compositions of both pegmatites and granites are significantly more radiogenic than existing data for the Sebago granite and argue against the consanguinity of Topsham pegmatites and the Sebago batholith. These data instead support a genetic link between the pegmatites and the Brunswick granite, which ranges from a fine-grained two-mica granite to a garnet-bearing pegmatitic leucogranite.

  12. Alteration, evaluation and use of extremaduran granite residues

    NASA Astrophysics Data System (ADS)

    Albarrán-Liso, C.; Jordán-Vidal, M. M.; Sanfeliu-Montolio, T.; Liso-Rubio, M. J.

    2006-04-01

    The necessity of eliminating debris from a granite quarry has awakened an interest in applications of by-products, called “marginal arids”, in different fields, like construction and foundations for roadways, restoration, material for the manufacture of artificial rocks, and artesian products etc. Conclusions obtained from the results of tests carried out by X-ray diffraction of granite quarry by-products in Extremadura, Spain, submitted to different treatments, are established. Test pieces from two quarries are analyzed and compared generally and specifically, for commercial use. Finally, conclusions relating to essays in test pieces and mineral dynamics of marginal arid granite are exposed.

  13. Petrogenesis and Tectonic Evolution of Granitic Rocks in The Northern Margin of North China Plate

    NASA Astrophysics Data System (ADS)

    Xu, X.; Zhao, Q.; Zheng, C.; Liu, W.; Xu, B.

    2010-12-01

    The late Paleozoic-early Mesozoic granites in Daqingshan district of the northern margin of north China plate is classified into six types as follows.Aguigou intrusion is consists of gabbro, diorite, quartz diorite, and granodiorite.Its feature is rich in mafic compositions.The formation age is 284.5±2.9Ma or 283.7±3.7Ma for the quartz diorite, and 281.1±3.4Ma for granodiorite. The genesis of the intrusion belongs to I-type granite. Laoyinhada intrusion comprises fine biotite monzonitic granite and porphyritic biotite monzonitic granite. The age is 272±4Ma for the fine biotite monzonitic granite. The genesis of the body is I-type granite.Halaheshao intrusion is a group of medium-coarse biotite-bearing monzonitic granites and large porphyritic-bearing monzonitic granite. The age is 260±0.5Ma for the biotite-bearing monzonitic granite.The tectonic environment belongs to post-orogenic granites.Taolegai intrusion consists of medium-fine granite, medium-coarse granite, porphyritic-bearing granite, and fine granite. The age is 224±3Ma for medium-coarse granite.Its genesis is light color granite co-occurred with muscovite peraluminous granites. The tectonic environment belongs to post-orogenic granites.Gechoushan intrusion is medium-fine monzonitic granite, a kind of typical muscovite granites. Its formation era is late Triassic. The tectonic environment belongs to post-orogenic granite.Shadegai intrusion is mainly composed of biotite granites. The age is 211.2±0.7Ma for medium-coarse biotite granite. The tectonic setting belongs to post-orogenic granites. The different types granites in the area basically reveal all the magmatic events from late Palaeozoic orogeny, to post-orogeny, and to intracontinental orogeny in the north edge of the north China plate. Early Permian Aguigou intrusion is a magmatic arc granite, formed in the continental edge in the early period of the middle Asia ocean plate subduction. Mid-Permian Laoyinhada intrusion is a magmatic arc granite

  14. Granite Monument Plaza Oklahoma City Civic Center, Bounded by ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Granite Monument Plaza - Oklahoma City Civic Center, Bounded by N. Shartel Avenue to the West, N. Hudson Avenue to the East, Couch Drive to the North, and Colcord Drive to the South, Oklahoma City, Oklahoma County, OK

  15. 6. HISTORIC AMERICAN BUILDINGS SURVEY, INTERIOR SHOWING ORIGINAL GRANITE COLUMNS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. HISTORIC AMERICAN BUILDINGS SURVEY, INTERIOR SHOWING ORIGINAL GRANITE COLUMNS AND COLUMN BRICKFACED AFTER THE GREAT FIRE 1904 - Old U.S. Appraisers Stores, Gay & Lombard Streets, Baltimore, Independent City, MD

  16. Detail of track girder, south portal and granite piers at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of track girder, south portal and granite piers at low tide. View Northwest - New York, New Haven & Hartford Railroad, Fort Point Channel Rolling Lift Bridge, Spanning Fort Point Channel, Boston, Suffolk County, MA

  17. 5. VIEW SHOWING DREDGING OF ARIZONA CANAL NEAR THE GRANITE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. VIEW SHOWING DREDGING OF ARIZONA CANAL NEAR THE GRANITE REEF DAM. SOUTH INTAKE OF THE DAM IS IN THE BACKGROUND Photographer: Walter J. Lubken. March 1908 - Arizona Canal, North of Salt River, Phoenix, Maricopa County, AZ

  18. 10. Lighthouse boathouse and granite wharf, view north northeast, southwest ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Lighthouse boathouse and granite wharf, view north northeast, southwest and southeast sides of boathouse, west and south sides of dock - Whitehead Light Station, Whitehead Island, East northeast of Tenants Harbor, Spruce Head, Knox County, ME

  19. Lift Off (Granite City C. U. School District 9)

    ERIC Educational Resources Information Center

    Goodall, Robert C.; And Others

    1970-01-01

    Describes and evaluates the ESEA Title I program in Granite City (Illinois) target area schools which provide preschool classes, remedial reading, and supportive health and counseling services. The programs are considered to be efficient. (DM)

  20. 8. VIEW OF THE LIGHT GREY GRANITE BASE WITH WHITE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. VIEW OF THE LIGHT GREY GRANITE BASE WITH WHITE GLAZED TERRA COTTA FINISH ABOVE. THIS IS THE NORTHEAST CORNER OF THE BUILDING. - Pacific Telephone & Telegraph Company Building, 1519 Franklin Street, Oakland, Alameda County, CA

  1. 8. July, 1970 DETAIL OF BRICK SIDEWALK AND GRANITE CURB, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. July, 1970 DETAIL OF BRICK SIDEWALK AND GRANITE CURB, LOOKING EAST ON NORTH SIDE OF INDIA STREET FROM DRIVEWAY OF 31 INDIA STREET - India Street Neighborhood Study, 15-45 India Street, Nantucket, Nantucket County, MA

  2. 7. July, 1970 DETAIL OF BRICK SIDEWALK AND GRANITE CURB, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. July, 1970 DETAIL OF BRICK SIDEWALK AND GRANITE CURB, LOOKING EAST ON NORTH SIDE OF INDIA STREET FROM DRIVEWAY OF 31 INDIA STREET - India Street Neighborhood Study, 15-45 India Street, Nantucket, Nantucket County, MA

  3. 9. VIEW NORTH, ACROSS DECK AT EAST SIDE SHOWING GRANITE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. VIEW NORTH, ACROSS DECK AT EAST SIDE SHOWING GRANITE BLOCK PAVING, EXPANSION JOINT AND NORTH SIDE PIPE RAILING - Route 1 Extension, South Street Viaduct, Spanning Conrail & Wheeler Point Road at South Street, Newark, Essex County, NJ

  4. 17. SPRINGHOUSE, SOUTHWEST SIDE; NOTE BROKEN GRANITE FOUNDATION FROM SURROUNDING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. SPRINGHOUSE, SOUTHWEST SIDE; NOTE BROKEN GRANITE FOUNDATION FROM SURROUNDING HILLSIDES. - Hondius Water Line, 1.6 miles Northwest of Park headquarters building & 1 mile Northwest of Beaver Meadows entrance station, Estes Park, Larimer County, CO

  5. Lithium Isotopes; a Potential aid to Understanding Granite Petrogenesis

    NASA Astrophysics Data System (ADS)

    Bryant, C.; Chappell, B.; Bennett, V.

    2002-12-01

    Significant enrichment in 6Li occurs during the weathering of continental crustal materials to clays, contributing to depleted δ7Li in the resultant sedimentary rocks. As such Li isotopes potentially provide a unique perspective on the nature of crustal components involved granite genesis. Carboniferous-Permian granites of the New England Batholith (NEB), Australia, emplaced in a Devonian-Triassic arc setting, are subdivided into 5 major supersuites1. Bundarra and Hillgrove are both S-types, interpreted to be derived from strongly weathered arc rocks1, and immature greywackes2, respectively. Moonbi, Uralla and Clarence River represent three distinct I-type supersuites. Moonbi granites are high-K and strongly oxidised. Uralla granites are medium-high-K, and more reduced. Clarence River are low-K, isotopically primitive granites, equivalent to arc magmas. Li isotopes were evaluated using MC-ICP-MS analysis under conditions of reduced RF power. This 'cool' plasma technique yields precision equivalent to TIMS (2\\sigma SD; 0.5‰ , 680W; 0.7‰ , 800W)3. Overall variations of ~10‰ δ 7Li are observed, greater than the differences observed in arc lavas worldwide (δ 7Li = ~2 to 7‰ ). Clarence River granites typically have δ7Li > 4‰ , similar to lavas from sediment poor island arcs (e.g. Izu-Bonin and Kuriles). Bundarra granites have low δ7Li, consistent with involvement of more strongly weathered source components. The higher δ7Li (< 4.9‰ ) observed for Hillgrove supports the inferred derivation from immature arc sediments2. Moonbi and Uralla overlap with the lighter values observed for arc lavas. The slightly heavier values for Uralla granites are consistent with the greater involvement of sedimentary components in the latter. Although no simple delineation exists between NEB S- and I-type granites, Li isotopes provide important insights into the nature of the crustal components involved in granite magma-genesis. 1Shaw, S.E. and Flood, R.H. 1981. JGR, 86

  6. Radionuclide Transport in Fracture-Granite Interface Zones

    SciTech Connect

    Hu, Q; Mori, A

    2007-09-12

    In situ radionuclide migration experiments, followed by excavation and sample characterization, were conducted in a water-conducting shear zone at the Grimsel Test Site (GTS) in Switzerland to study diffusion paths of radionuclides in fractured granite. In this work, we employed a micro-scale mapping technique that interfaces laser ablation sampling with inductively coupled plasma-mass spectrometry (LA/ICP-MS) to measure the fine-scale (micron-range) distribution of actinides ({sup 234}U, {sup 235}U, and {sup 237}Np) in the fracture-granite interface zones. Long-lived {sup 234}U, {sup 235}U, and {sup 237}Np were detected in flow channels, as well as in the adjacent rock matrix, using the sensitive, feature-based mapping of the LA/ICP-MS technique. The injected sorbing actinides are mainly located within the advective flowing fractures and the immediately adjacent regions. The water-conducting fracture studied in this work is bounded on one side by mylonite and the other by granitic matrix regions. These actinides did not penetrate into the mylonite side as much as the relatively higher-porosity granite matrix, most likely due to the low porosity, hydraulic conductivity, and diffusivity of the fracture wall (a thickness of about 0.4 mm separates the mylonite region from the fracture) and the mylonite region itself. Overall, the maximum penetration depth detected with this technique for the more diffusive {sup 237}Np over the field experimental time scale of about 60 days was about 10 mm in the granitic matrix, illustrating the importance of matrix diffusion in retarding radionuclide transport from the advective fractures. Laboratory tests and numerical modeling of radionuclide diffusion into granitic matrix was conducted to complement and help interpret the field results. Measured apparent diffusivity of multiple tracers in granite provided consistent predictions for radionuclide transport in the fractured granitic rock.

  7. Natural radioactivity content of granite tiles used in Greece.

    PubMed

    Papaefthymiou, H

    2008-01-01

    Measurements of (226)Ra, (232)Th and (40)K activity concentrations in commercial granite tiles imported in Greece were performed using gamma-ray spectrometry. The activity concentration of (226)Ra, (232)Th and (40)K ranged from 1 to 434, 2 to 239 and 71 to 1576 Bq kg(-1), respectively. The calculated activity concentration index (I) values for all granite samples examined were found to be within the EC limit values for superficial and other materials with restricted use.

  8. Activity concentrations and dose rates from decorative granite countertops.

    PubMed

    Llope, W J

    2011-06-01

    The gamma radiation emitted from a variety of commercial decorative granites available for use in U.S. homes has been measured with portable survey meters as well as an NaI(Th) gamma spectrometer. The (40)K, U-nat, and (232)Th activity concentrations were determined using a full-spectrum analysis. The dose rates that would result from two different arrangements of decorative granite slabs as countertops were explored in simulations involving an adult anthropomorphic phantom.

  9. Mortality experience of Vermont granite workers

    SciTech Connect

    Davis, L.K.; Wegman, D.H.; Monson, R.R.; Froines, J.

    1982-01-01

    A comparison was made between the chief cause of death among 969 deceased white male granite workers in Vermont and the causes of death among other individuals not in that occupation. Tuberculosis deaths were ten times the number predicted, based on the U.S. white male experience. Of the 65 tuberculosis deaths, 48 were silicotuberculosis and 16 were pulmonary tuberculosis. A notable increase was found for deaths due to all respiratory diseases, with 28 deaths due to silicosis. Excluding deaths due to silicosis and tuberculosis left a small excess of emphysema-related deaths. For 25 men in the respiratory disease category whose cause of death was not listed as silicosis, ten had evidence of silicosis in their x-ray records suggesting some misdiagnoses may have occurred. An excess of lung cancer deaths was noted among sawyers and polishers, suggesting possible effects of abrasive exposures. No tuberculosis deaths were noted in men who started work in the post dust control period, after 1950. There was an excess of suicide deaths before 1970.

  10. A proportionate mortality study of granite cutters.

    PubMed

    Steenland, K; Beaumont, J

    1986-01-01

    Several recent studies (animal and human) have suggested an association between lung cancer and silica exposure. To test the hypothesis, we have studied death benefit records of 1,905 members of the Granite Cutters Union. A proportionate mortality analysis (PMR) was conducted, using U.S. deaths as a comparison population. Statistically (PMR) was conducted, using U.S. deaths as a comparison population. Statistically significant excesses were observed for death from nonmalignant respiratory significant excesses were observed for death from nonmalignant respiratory disease (largely silicosis) (183 obs, 43.7 exp) and for tuberculosis (largely silicotuberculosis) (262 obs, 19.3 exp). Other significant excesses were observed for bone cancer (6 obs, 1.9 exp) and arthritis (5 obs, 1.5 exp). A significant decrease was observed for leukemia (5 obs, 13.0 exp). For lung cancer a slight but nonsignificant excess was observed (97 obs, 81.1 exp, PMR = 1.19, 95% CI 0.97-1.46). A proportionate cancer mortality analysis (PCMR) showed similar results for lung cancer (PCMR = 1.09, 95% CI 0.89-1.33). Lung cancer mortality also failed to show any trend with either calendar time or duration of exposure. Although no significant excess of lung cancer was observed for the entire silica-exposed cohort, there was an indication that those who were silicotic had an excess risk of lung cancer, based on a review of contributing causes on the death certificate.

  11. Neural tuning in the granite spiny lizard.

    PubMed

    Turner, R G

    1987-01-01

    Scanning electron microscopy was used to examine the basilar papilla of the granite spiny lizard. The papilla contains three distinct hair cell populations: an apical and a basal population with free-standing cilia, and a central population with a tectorial membrane. In the free-standing populations, stereocilium length decreases towards the ends of the papilla. Ciliary tuft morphology differs in the free-standing and the tectorial membrane populations, except that several of the free-standing hair cells with the shortest stereocilia have a tuft morphology like the hair cells in the tectorial membrane population. On the basis of single-fiber physiology, auditory nerve fibers can be divided into a low characteristic frequency (CF) and a high CF population. Mappings of the tonotopic organization of the nerve demonstrated two groups of high CF fibers that correspond to the two free-standing hair cell populations. The low CF fibers are associated with the tectorial membrane hair cell population. Fiber CF correlated with hair cell cilium length, not position on basilar membrane, for hair cells with free-standing cilia. Tonotopic organization of high CF fibers could be predicted reasonably well from the histogram of fiber CFs.

  12. Hydraulic fracturing in granite under geothermal conditions

    USGS Publications Warehouse

    Solberg, P.; Lockner, D.; Byerlee, J.D.

    1980-01-01

    The experimental hydraulic fracturing of granite under geothermal conditions produces tensile fracture at rapid fluid injection rates and shear fracture at slow injection rates and elevated differential stress levels. A sudden burst of acoustic emission activity accompanies tensile fracture formation whereas the acoustic emission rate increases exponentially prior to shear fracture. Temperature does not significantly affect the failure mechanism, and the experimental results have not demonstrated the occurrence of thermal fracturing. A critical result of these experiments is that fluid injection at intermediate rates and elevated differential stress levels increases permeability by more than an order of magnitude without producing macroscopic fractures, and low-level acoustic emission activity occurs simultaneously near the borehole and propagates outward into the specimen with time. Permeability measurements conducted at atmospheric pressure both before and after these experiments show that increased permeability is produced by permanent structural changes in the rock. Although results of this study have not demonstrated the occurrence of thermal fracturing, they suggest that fluid injection at certain rates in situ may markedly increase local permeability. This could prove critical to increasing the efficiency of heat exchange for geothermal energy extraction from hot dry rock. ?? 1980.

  13. Radioactivity and radon emanation fraction of the granites sampled at Misasa and Badgastein.

    PubMed

    Sakoda, Akihiro; Hanamoto, Katsumi; Ishimori, Yuu; Nagamatsu, Tomohiro; Yamaoka, Kiyonori

    2008-05-01

    The chemical composition was analyzed and the radioactivity, radon exhalation rate and emanation fraction were measured to investigate the characteristics of the granites sampled at Misasa and Badgastein, world famous for radon therapy. The Misasa granite was probably composed of quartz, albite and microcline. The Badgastein granite was probably composed of quartz and muscovite. The radon exhalation rates and emanation fractions of the Misasa granite were much higher than those of the Badgastein granite, regardless of the (226)Ra activity concentrations.

  14. Smolt Monitoring at the Head of Granite Reservoir and Lower Granite Dam, 1989 Annual Report.

    SciTech Connect

    Buettner, Edwin W.; Nelson, V. Lance

    1990-04-01

    This project monitored the daily passage of chinook salmon Oncorhynchus tshawytscha and steelhead trout O. mykiss smolts during the 1989 spring outmigration at a migrant trap on the Snake River and the Clearwater River. Chinook salmon catch at the Snake River trap was much higher in 1989 than in either of the 1987 or 1988 drought years. The 1989 Snake River trap catch was similar to 1986. Effort was the same during the four years. Steelhead trout catch was greater than in any previous year. Chinook salmon and steelhead trout catch at the Clearwater River trap was similar to 1986, even though effort was greatly reduced in 1989 due to high runoff during most of the season. The 1989 Clearwater River trap catch was lower than in the two drought years (1987 and 1988) and was due to the minimal number of days the trap was operated. Fish tagged with Passive Interrogated Transponder (PIT) tags at the Snake River trap were recovered at the three dams (Lower Granite, Little Goose, and McNary) with PIT tag detection systems. Travel time (days) and migration rate (km/d) through Lower Granite Reservoir for PIT-tagged chinook salmon and steelhead trout, marked at the head of the reservoir, was affected by discharge. Statistical analysis showed that as discharge increased from 40 kcfs to 80 kcfs, chinook salmon travel time decreased three-fold and steelhead trout travel time decreased two-fold. 11 refs., 8 figs., 17 tabs.

  15. Silicified Granites (Bleeding Stone and Ochre Granite) as Global Heritage Stones Resources from Avila (Central of Spain)

    NASA Astrophysics Data System (ADS)

    Garcia-Talegon, Jacinta; Iñigo, Adolfo C.; Vicente-Tavera, Santiago; Molina-Ballesteros, Eloy

    2015-04-01

    Silicified Granites have been widely used to build the main Romanesque monuments in the 12 th century of Avila city that was designated a World Heritage Site by the UNESCO in 1985. The stone was used in the Cathedral (12 th century); churches located interior and exterior of the Walls (e.g. Saint Vincent; Saint Peter). During the Renaissance and Gothic period, 15 th century Silicified Granites have been used mainly to buid ribbed vaults in Avila city (e.g. Royal Palace of the Catholic Monarchs, and Chapel of Mosén Rubí). Silicified Granites are related to an intermediate and upper parts of a complex palaeoweathering mantle developed on the Iberian Hercynian Basement (the greatest part of the western Iberian Peninsula and its oldest geological entity). In the Mesozoic the basement underwent tropical weathering processes. The weathered mantle were truncated by the Alpine tectonic movements during the Tertiary, and Its remnants were unconformably covered by more recent sediments and are located in the west and south part of the Duero Basin and in the north edge of the Ambles Valley graben. For the weathering profiles developed on the Hercynian Basement is possible to define three levels from bottom to top: 1) Lower level (biotitic granodiorite/porphyry and aplite dykes); 2) Intermediate level (ochre granite); 3) Upper level (red/white granite). The lower level has been much used as a source of ornamental stone, Avila Grey granite. The porphyry and applite dykes are mainly used to built the Walls of the City. The intermediate level is called Ochre granite or Caleño and was formed from the previous level through a tropical weathering process that, apart from variations in the petrophysical characteristics of the stone, has been accompanied by important mineralogical changes (2:1 and 1:1 phyllosilicates) and decreases in the contents of the most mobile cations. The upper level has received several names, Bleeding stone, Red and White granite or Silcrete and was formed

  16. Smolt Monitoring at the Head of Lower Granite Reservoir and Lower Granite Dam, 2005 Annual Report.

    SciTech Connect

    Buettner, Edwin W.; Putnam, Scott A.

    2009-02-18

    This project monitored the daily passage of Chinook salmon Oncorhynchus tshawytscha, steelhead trout O. mykiss, and sockeye salmon O. nerka smolts during the 2005 spring out-migration at migrant traps on the Snake River and Salmon River. In 2005 fish management agencies released significant numbers of hatchery Chinook salmon and steelhead trout above Lower Granite Dam that were not marked with a fin clip or coded-wire tag. Generally, the age-1 and older fish were distinguishable from wild fish by the occurrence of fin erosion. Age-0 Chinook salmon are more difficult to distinguish between wild and non-adclipped hatchery fish and therefore classified as unknown rearing. The total annual hatchery spring/summer Chinook salmon catch at the Snake River trap was 0.34 times greater in 2005 than in 2004. The wild spring/summer Chinook catch was 0.34 times less than the previous year. Hatchery steelhead trout catch was 0.67 times less than in 2004. Wild steelhead trout catch was 0.72 times less than the previous year. The Snake River trap collected 1,152 age-0 Chinook salmon of unknown rearing. During 2005, the Snake River trap captured 219 hatchery and 44 wild/natural sockeye salmon and 110 coho salmon O. kisutch of unknown rearing. Differences in trap catch between years are due to fluctuations not only in smolt production, but also differences in trap efficiency and duration of trap operation associated with flow. Trap operations began on March 6 and were terminated on June 3. The trap was out of operation for a total of one day due to heavy debris. FPC requested that the trap be restarted on June 15 through June 22 to collect and PIT tag age-0 Chinook salmon. Hatchery Chinook salmon catch at the Salmon River trap was 1.06 times greater and wild Chinook salmon catch was 1.26 times greater than in 2004. The hatchery steelhead trout collection in 2005 was 1.41 times greater and wild steelhead trout collection was 1.27 times greater than the previous year. Trap operations

  17. Smolt Monitoring at the Head of Lower Granite Reservoir and Lower Granite Dam, 2003 Annual Report.

    SciTech Connect

    Buettner, Edwin W.; Putnam, Scott A.

    2009-02-18

    This project monitored the daily passage of Chinook salmon Oncorhynchus tshawytscha, steelhead trout O. mykiss, and sockeye salmon O. nerka smolts during the 2003 spring out-migration at migrant traps on the Snake River and Salmon River. In 2003 fish management agencies released significant numbers of hatchery Chinook salmon and steelhead trout above Lower Granite Dam that were not marked with a fin clip or coded-wire tag. Generally, these fish were distinguishable from wild fish by the occurrence of fin erosion. Total annual hatchery Chinook salmon catch at the Snake River trap was 2.1 times less in 2003 than in 2002. The wild Chinook catch was 1.1 times less than the previous year. Hatchery steelhead trout catch was 1.7 times less than in 2002. Wild steelhead trout catch was 2.1 times less than the previous year. The Snake River trap collected 579 age-0 Chinook salmon of unknown rearing. During 2003, the Snake River trap captured five hatchery and 13 wild/natural sockeye salmon and 36 coho salmon O. kisutch of unknown rearing. Differences in trap catch between years are due to fluctuations not only in smolt production, but also differences in trap efficiency and duration of trap operation associated with flow. The significant differences in catch between 2003 and the previous year were due mainly to low flows during much of the trapping season and then very high flows at the end of the season, which terminated the trapping season 12 days earlier than in 2002. Trap operations began on March 9 and were terminated on May 27. The trap was out of operation for a total of zero days due to mechanical failure or debris. Hatchery Chinook salmon catch at the Salmon River trap was 16.8% less and wild Chinook salmon catch was 1.7 times greater than in 2002. The hatchery steelhead trout collection in 2003 was 5.6% less than in 2002. Wild steelhead trout collection was 19.2% less than the previous year. Trap operations began on March 9 and were terminated on May 24 due to high

  18. Smolt Monitoring at the Head of Lower Granite Reservoir and Lower Granite Dam, 2004 Annual Report.

    SciTech Connect

    Buettner, Edwin W.; Putnam, Scott A.

    2009-02-18

    This project monitored the daily passage of Chinook salmon Oncorhynchus tshawytscha, steelhead trout O. mykiss, and sockeye salmon O. nerka smolts during the 2004 spring out-migration at migrant traps on the Snake River and Salmon River. In 2004 fish management agencies released significant numbers of hatchery Chinook salmon and steelhead trout above Lower Granite Dam that were not marked with a fin clip or coded-wire tag. Generally, these fish were distinguishable from wild fish by the occurrence of fin erosion. Total annual hatchery Chinook salmon catch at the Snake River trap was 1.1 times greater in 2004 than in 2003. The wild Chinook catch was 1.1 times greater than the previous year. Hatchery steelhead trout catch was 1.2 times greater than in 2003. Wild steelhead trout catch was 1.6 times greater than the previous year. The Snake River trap collected 978 age-0 Chinook salmon of unknown rearing. During 2004, the Snake River trap captured 23 hatchery and 18 wild/natural sockeye salmon and 60 coho salmon O. kisutch of unknown rearing. Differences in trap catch between years are due to fluctuations not only in smolt production, but also differences in trap efficiency and duration of trap operation associated with flow. Trap operations began on March 7 and were terminated on June 4. The trap was out of operation for a total of zero days due to mechanical failure or debris. Hatchery Chinook salmon catch at the Salmon River trap was 10.8% less and wild Chinook salmon catch was 19.0% less than in 2003. The hatchery steelhead trout collection in 2004 was 20.0% less and wild steelhead trout collection was 22.3% less than the previous year. Trap operations began on March 7 and were terminated on May 28 due to high flows. There were two days when the trap was taken out of service because wild Chinook catch was very low, hatchery Chinook catch was very high, and the weekly quota of PIT tagged hatchery Chinook had been met. Travel time (d) and migration rate (km

  19. Smolt Monitoring at the Head of Lower Granite Reservoir and Lower Granite Dam, 2002 Annual Report.

    SciTech Connect

    Buettner, Edwin W.; Putnam, Scott A.

    2009-02-18

    This project monitored the daily passage of Chinook salmon Oncorhynchus tshawytscha, steelhead trout O. mykiss, and sockeye salmon smolts O. nerka during the 2002 spring out-migration at migrant traps on the Snake River and Salmon River. In 2002 fish management agencies released significant numbers of hatchery Chinook salmon and steelhead trout above Lower Granite Dam that were not marked with a fin clip or coded-wire tag. Generally, these fish were distinguishable from wild fish by the occurrence of fin erosion. Total annual hatchery Chinook salmon catch at the Snake River trap was 11.4 times greater in 2002 than in 2001. The wild Chinook catch was 15.5 times greater than the previous year. Hatchery steelhead trout catch was 2.9 times greater than in 2001. Wild steelhead trout catch was 2.8 times greater than the previous year. The Snake River trap collected 3,996 age-0 Chinook salmon of unknown rearing. During 2002, the Snake River trap captured 69 hatchery and 235 wild/natural sockeye salmon and 114 hatchery coho salmon O. kisutch. Differences in trap catch between years are due to fluctuations not only in smolt production, but also differences in trap efficiency and duration of trap operation associated with flow. The significant increase in catch in 2002 was due to a 3.1 fold increase in hatchery Chinook production and a more normal spring runoff. Trap operations began on March 10 and were terminated on June 7. The trap was out of operation for a total of four days due to mechanical failure or debris. Hatchery Chinook salmon catch at the Salmon River trap was 4.2 times greater and wild Chinook salmon catch was 2.4 times greater than in 2001. The hatchery steelhead trout collection in 2002 was 81% of the 2001 numbers. Wild steelhead trout collection in 2002 was 81% of the previous year's catch. Trap operations began on March 10 and were terminated on May 29 due to high flows. The trap was out of operation for four days due to high flow or debris. The increase

  20. Geology of the Andover Granite and surrounding rocks, Massachusetts

    USGS Publications Warehouse

    Castle, Robert O.

    1964-01-01

    Field and petrographic studies of the Andover Granite and surrounding rocks have afforded an opportunity for an explanation of its emplacement and crystallization. The investigation has contributed secondarily to an understanding of the geologic history of southeastern New England, particularly as it is revealed in the Lawrence, Wilmington, South Groveland, and Reading quadrangles of Massachusetts. The Andover Granite and Sharpners Pond Tonalite together comprise up to 90 percent of the Acadian(?) subalkaline intrusive series cropping out within the area of study. The subalkaline series locally invades a sequence of early to middle Paleozoic and possibly Precambrian metasedimentary and metavolcanic rocks. Much of the subalkaline series and most of the Andover Granite is confined between two prominent east-northeast trending faults or fault systems. The northern fault separates the mildly metamorphosed Middle Silurian(?) Merrimack Group on the north from a highly metamorphosed and thoroughly intruded Ordovician(?) sequence on the south. The southern 'boundary '' fault is a major structural discontinuity characterized by penetrative, diffuse shearing over a zone one-half mile or more in width. The magmatic nature of the Andover Granite is demonstrated by: (1) sharply crosscutting relationships with surrounding rocks; (2) the occurrence of tabular-shaped xenoliths whose long directions parallel the foliation within the granite and whose internal foliation trends at a high angle to that of the granite; (3) continuity with the clearly intrusive Sharpners Pond Tonalite; (4) the compositional uniformity of the granite as contrasted with the compositional diversity of the rocks it invades; (5) its modal and normative correspondence with (a) calculated norms of salic extrusives and (b) that of the ternary (granite) minimum for the system NaAlSi3O8-KAlSi3O8-SiO2. Orogenic granites, as represented by the Andover, contrast with post-orogenic granites, represented locally by

  1. Prevalence of dry methods in granite countertop fabrication in Oklahoma.

    PubMed

    Phillips, Margaret L; Johnson, Andrew C

    2012-01-01

    Granite countertop fabricators are at risk of exposure to respirable crystalline silica, which may cause silicosis and other lung conditions. The purpose of this study was to estimate the prevalence of exposure control methods, especially wet methods, in granite countertop fabrication in Oklahoma to assess how many workers might be at risk of overexposure to crystalline silica in this industry. Granite fabrication shops in the three largest metropolitan areas in Oklahoma were enumerated, and 47 of the 52 shops participated in a survey on fabrication methods. Countertop shops were small businesses with average work forces of fewer than 10 employees. Ten shops (21%) reported using exclusively wet methods during all fabrication steps. Thirty-five shops (74%) employing a total of about 200 workers reported using dry methods all or most of the time in at least one fabrication step. The tasks most often performed dry were edge profiling (17% of shops), cutting of grooves for reinforcing rods (62% of shops), and cutting of sink openings (45% of shops). All shops reported providing either half-face or full-face respirators for use during fabrication, but none reported doing respirator fit testing. Few shops reported using any kind of dust collection system. These findings suggest that current consumer demand for granite countertops is giving rise to a new wave of workers at risk of silicosis due to potential overexposure to granite dust.

  2. Modelling granite migration by mesoscale pervasive flow

    NASA Astrophysics Data System (ADS)

    Leitch, A. M.; Weinberg, R. F.

    2002-06-01

    Mesoscale pervasive magma migration leads to granite injection complexes, common in hot crustal terranes. Pervasive migration is limited by magma freezing when intruding cold country rock. Here, we explore numerically the feedback mechanism between magma intrusion and heating of the country rock, which allows younger intrusive batches to reach increasingly shallower/cooler levels. This process relies on the higher solidus temperature of a rock compared to that of its melt, once melt is segregated. We define the 'free-ride layer' as the region above the melt source, where magma may freely migrate because rock temperature is above melt solidus. The top of the free-ride layer, which corresponds to the melt solidus ( TS) isotherm, is at the 'limiting depth', zS. After magma passes through the free-ride layer, the magma 'front' is always at the limiting depth. We modeled the thickening and heating of the crust above the source as melt at its liquidus ( TL) intrudes it pervasively from below. We found that: (a) magma quickly warms crust below zS to about TL, forming a step in temperature at zS; (b) the front ( zS) moves up through the crust as more magma is intruded; (c) as magma is emplaced at the front, a mingled layer of about half magma half crust forms below it, so that the total rise of the front corresponds approximately to half of the thickness of magma added to the free-ride layer; (d) the rate of rise of the front depends on the temperature difference between crust and TL, and slows down as the magma front rises; (e) for most reasonable intrusion rates and volumes, the crust above zS feels little influence of the intrusion, because the diffusion time scale is much smaller than the rise rate of the front. In summary, pervasive migration is an efficient way of heating the lower to middle crust, and can result in an injection complex several kilometers thick, consisting of about half magma and half original crust.

  3. Earth's youngest exposed granite and its tectonic implications: the 10-0.8 Ma Kurobegawa Granite.

    PubMed

    Ito, Hisatoshi; Yamada, Ryuji; Tamura, Akihiro; Arai, Shoji; Horie, Kenji; Hokada, Tomokazu

    2013-01-01

    Although the quest for Earth's oldest rock is of great importance, identifying the youngest exposed pluton on Earth is also of interest. A pluton is a body of intrusive igneous rock that crystallized from slowly cooling magma at depths of several kilometers beneath the surface of the Earth. Therefore, the youngest exposed pluton represents the most recent tectonic uplift and highest exhumation. The youngest exposed pluton reported to date is the Takidani Granodiorite (~ 1.4 Ma) in the Hida Mountain Range of central Japan. Using LA-ICP-MS and SHRIMP U-Pb zircon dating methods, this study demonstrates that the Kurobegawa Granite, also situated in the Hida Mountain Range, is as young as ~ 0.8 Ma. In addition, data indicate multiple intrusion episodes in this pluton since 10 Ma with a ~ 2-million-year period of quiescence; hence, a future intrusion event is likely within 1 million years. PMID:23419636

  4. Earth's youngest exposed granite and its tectonic implications: the 10-0.8 Ma Kurobegawa Granite.

    PubMed

    Ito, Hisatoshi; Yamada, Ryuji; Tamura, Akihiro; Arai, Shoji; Horie, Kenji; Hokada, Tomokazu

    2013-01-01

    Although the quest for Earth's oldest rock is of great importance, identifying the youngest exposed pluton on Earth is also of interest. A pluton is a body of intrusive igneous rock that crystallized from slowly cooling magma at depths of several kilometers beneath the surface of the Earth. Therefore, the youngest exposed pluton represents the most recent tectonic uplift and highest exhumation. The youngest exposed pluton reported to date is the Takidani Granodiorite (~ 1.4 Ma) in the Hida Mountain Range of central Japan. Using LA-ICP-MS and SHRIMP U-Pb zircon dating methods, this study demonstrates that the Kurobegawa Granite, also situated in the Hida Mountain Range, is as young as ~ 0.8 Ma. In addition, data indicate multiple intrusion episodes in this pluton since 10 Ma with a ~ 2-million-year period of quiescence; hence, a future intrusion event is likely within 1 million years.

  5. Smolt Monitoring at the Head of Lower Granite Reservoir and Lower Granite Dam, 1994 Annual Report.

    SciTech Connect

    Buettner, Edwin W.; Brimmer, Arnold F.

    1994-10-01

    This project monitored the daily passage of chinook salmon Oncorhynchus tshawytscha and steelhead trout O. mykiss smolts during the 1994 spring outmigration at migrant traps on the Snake River, Clearwater River, and Salmon River. The 1994 snowpack was among the lowest since the beginning of the present drought, and the subsequent runoff was very poor. All hatchery chinook salmon released above Lower Granite Dam were marked with a fin clip in 1994. Total annual (hatchery + wild) chinook salmon catch at the Snake River trap was 1.5 times greater than in 1993. Hatchery and wild steelhead trout catches were similar to 1993. The Snake River trap collected 30 age 0 chinook salmon. Hatchery chinook salmon catch at the Clearwater River trap was 3.5 times higher than in 1993, and wild chinook salmon catch was 4.2 times higher. Hatchery steelhead trout trap catch was less than half of 1993 numbers because the trap was fishing near the north shore during the majority of the hatchery steelhead movement due to flow augmentations from Dworshak. Wild steelhead trout trap catch was 2 times higher than in 1993. The Salmon River trap was operated for about a month longer in 1994 than in 1993 due to extremely low flows. Hatchery chinook salmon catch was 1.4 times greater in 1994 than the previous year. Wild chinook salmon catch was slightly less in 1994. The 1994 hatchery steelhead trout collection did not change significantly from 1993 numbers. Wild steelhead trout collection in 1994 was 59% of the 1993 catch. Fish tagged with Passive Integrated Transponder (PIT) tags at the Snake River trap were interrogated at four dams with PIT tag detection systems (Lower Granite, Little Goose, Lower Monumental, and McNary dams). Because of the addition of the fourth interrogation site (Lower Monumental) in 1993, cumulative interrogation data is not comparable with the prior five years (1988-1992).

  6. Geochemistry of A-type granites in the Huangshaping polymetallic deposit (South Hunan, China): Implications for granite evolution and associated mineralization

    NASA Astrophysics Data System (ADS)

    Li, Huan; Watanabe, Koichiro; Yonezu, Kotaro

    2014-07-01

    The Huangshaping granites in Hunan Province, South China were investigated for their geochemical characteristics. Three types of granites have been petrographically identified: quartz porphyry, granophyre, and granite porphyry. Whole rock geochemistry suggests that the Huangshaping granites, especially the granite porphyry, exhibit typical A-type granite characteristics with their enrichment in Si, Rb, U, Th, and Nb and significant depletion in Ba, Sr, Ti, Eu, and P. Based on the Al, Y and Zr contents as well as the REE patterns of the rocks investigated, the quartz porphyry and the granophyre are classified as A1 type alkaline granites whereas the granite porphyry is considered as A2 type aluminous granite. Whole rock and quartz/feldspar O isotope data yields a wide range of δ18OSMOW values (11.09-26.32‰). The granites are characterized by high radiogenic Pb isotopic composition. The present-day whole rock Pb isotopic ratios are 206Pb/204Pb = 18.706-19.155, 207Pb/204Pb = 15.616-15.711 and 208Pb/204Pb = 38.734-39.296. Combining the O-Pb isotope compositions with major, trace and REE geochemistry and regional geology characteristics, the Huangshaping granites were determined to resemble within-plate granites that were mainly derived from a felsic infracrustal source related to continental extension. The magma source of the quartz porphyry and the granophyre may have been generated from deeper depths, and then ascended rapidly with limited water content and low oxygen fugacity, which contributed to Cu, Pb and Zn mineralization. On the other hand, the magma that generated the granite porphyry may have ascended relatively slower and experienced pronounced crystal fractionation, upper-crustal basement rock contamination (assimilation) and wall-rock interaction, producing the Sn- and W-rich granite porphyry. This study reveals the crustal extension process and associated magmatic-metallogenic activities during 180-150 Ma in South Hunan.

  7. Granite emplacement during tectonic exhumation: The Adirondack example

    NASA Astrophysics Data System (ADS)

    Selleck, Bruce W.; McLelland, James M.; Bickford, M. E.

    2005-10-01

    Sensitive high-resolution ion microprobe U-Pb zircon ages for late to posttectonic leucogranites fix the timing of extensional collapse of a portion of the Mesoproterozoic Grenville orogen of eastern North America. Plutons of Lyon Mountain Granite (LMG) were emplaced within the Carthage Colton shear zone synchronously with formation of extensional mylonite at 1045 1037 Ma. Leucogranite melts were generated in the hot granulite facies core of the Adirondack Highlands Central Granulite terrane that served as the lower plate for down-to-the-northwest extension. The LMG suite is associated with high-temperature hydrothermal magnetite deposits in the Adirondack Highlands, and widespread Cl + CO2 hydrothermal alteration of upper-plate rocks is localized along the Carthage Colton shear zone where LMG granites are present. The relationships between melt generation, granite intrusion, high strain rates, extensional collapse, and high- temperature hydrothermal activity provide a framework for understanding midcrustal processes in modern and ancient orogenic belts.

  8. Radioactivity concentrations in soils of the Xiazhuang granite area, China.

    PubMed

    Yang, Ya-Xin; Wu, Xin-Min; Jiang, Zhong-Ying; Wang, Wei-Xing; Lu, Ji-Gen; Lin, Jun; Wang, Lei-Ming; Hsia, Yuan-Fu

    2005-08-01

    The natural radioactivity of soils at the Xiazhuang granite massif of Southern China has been studied. The radioactivities of 55 samples have been measured with a low-background HPGe detector. The radioactivity concentrations of (238)U and (40)K ranged from 40.2 to 442 and from 442 to 913 Bq/kg, respectively, while the radioactivity concentration of (232)Th varied only slightly. In order to evaluate the radiological hazard of the natural radioactivity, the radium equivalent activity (Ra(eq)), the absorbed dose rate (D ), the annual effective dose rate and the external hazard index (H(ex)) have been calculated and compared with the internationally approved values. The study provides background radioactivity concentrations in a granite area, specifically, the area in the vicinity of a uranium mine in Southern China. The data can be used in exploring granite-type uranium deposits.

  9. Association of lung cancer mortality with precambrian granite.

    PubMed

    Archer, V E

    1987-01-01

    Sixteen counties in New York, Pennsylvania, and New Jersey that are associated with the Reading Prong granite deposits have significantly higher age-adjusted lung cancer rates among whites of both sexes (1950-1979) than do 17 nearby control counties. Elevated radon daughter concentrations have been found in homes near the Reading Prong granites. Fraction of populations living in cities with over 5,000 persons, industrial centers, cities with populations above 20,000, and median incomes did not differ significantly for three county groups (those which include the granite, fringe area, and control areas). Weaknesses were inadequate home measurements of radon and lack of smoking information. Findings are consistent with several other studies relating radon in homes to lung cancer.

  10. Transpressional granite-emplacement model: Structural and magnetic study of the Pan-African Bandja granitic pluton (West Cameroon)

    NASA Astrophysics Data System (ADS)

    Sandjo, A. F. Yakeu; Njanko, T.; Njonfang, E.; Errami, E.; Rochette, P.; Fozing, E.

    2016-02-01

    The Pan-African NE-SW elongated Bandja granitic pluton, located at the western part of the Pan-African belt in Cameroon, is a K-feldspar megacryst granite. It is emplaced in banded gneiss and its NW border underwent mylonitization. The magmatic foliation shows NE-SW and NNE-SSW strike directions with moderate to strong dip respectively in its northern and central parts. This mostly, ferromagnetic granite displays magnetic fabrics carried by magnetite and characterized by (i) magnetic foliation with best poles at 295/34, 283/33 and 35/59 respectively in its northern, central and southern parts and (ii) a subhorizontal magnetic lineation with best line at 37/8, 191/9 and 267/22 respectively in the northern, central and southern parts. Magnetic lineation shows an `S' shape trend that allows to (1) consider the complete emplacement and deformation of the pluton during the Pan-African D 2 and D 3 events which occurred in the Pan-African belt in Cameroon and (2) reorganize Pan-African ages from Nguiessi Tchakam et al. (1997) compared with those of the other granitic plutons in the belt as: 686 ±17 Ma (Rb/Sr) for D 1 age of metamorphism recorded in gneiss; and the period between 604-557 Ma for D 2-D 3 emplacement and deformation age of the granitic pluton in a dextral ENE-WSW shear movement.

  11. Assessing exposure to granite countertops--Part 1: Radiation.

    PubMed

    Myatt, Theodore A; Allen, Joseph G; Minegishi, Taeko; McCarthy, William B; Stewart, James H; Macintosh, David L; McCarthy, John F

    2010-05-01

    Humans are continuously exposed to low levels of ionizing radiation. Known sources include radon, soil, cosmic rays, medical treatment, food, and building products such as gypsum board and concrete. Little information exists about radiation emissions and associated doses from natural stone finish materials such as granite countertops in homes. To address this knowledge gap, gross radioactivity, gamma ray activity, and dose rate were determined for slabs of granite marketed for use as countertops. Annual effective radiation doses were estimated from measured dose rates and human activity patterns while accounting for the geometry of granite countertops in a model kitchen. Gross radioactivity, gamma activity, and dose rate varied significantly among and within slabs of granite with ranges for median levels at the slab surface of ND to 3000 cpm, ND to 98,000 cpm, and ND to 1.5E-4 mSv/h, respectively. The maximum activity concentrations of the (40)K, (232)Th, and (226)Ra series were 2715, 231, and 450 Bq/kg, respectively. The estimated annual radiation dose from spending 4 h/day in a hypothetical kitchen ranged from 0.005 to 0.18 mSv/a depending on the type of granite. In summary, our results show that the types of granite characterized in this study contain varying levels of radioactive isotopes and that their observed emissions are consistent with those reported in the scientific literature. We also conclude from our analyses that these emissions are likely to be a minor source of external radiation dose when used as countertop material within the home and present a negligible risk to human health. PMID:19707248

  12. Granite microcracks: Structure and connectivity at different depths

    NASA Astrophysics Data System (ADS)

    Song, Fan; Dong, Yan-Hui; Xu, Zhi-Fang; Zhou, Peng-Peng; Wang, Li-Heng; Tong, Shao-Qing; Duan, Rui-Qi

    2016-07-01

    Granite is one rock type used to host high-level radioactive waste repositories, and the structure of microcracks in the rock can influence its hydraulic characteristics. Thus, a quantitative analysis of granite microcracks is relevant for understanding the hydrogeological characteristics of the rocks surrounding geological repositories. The analysis can also contribute scientific data to a seepage model for low permeability rocks and materials with microscopic pores. In this study, seven granite core samples were drilled from different depths up to 600 m in Alxa, Inner Mongolia, China. Using a grid survey method and image processing technology, micrographs were converted into binary images of microcracks. The geometric parameters of the microcracks, including their quantity, width, cranny ratio, crack intersections and dimensional parameters of the fracture network, were analyzed in order to fully describe their spatial distribution. In addition, the morphological characteristics and elemental compositions of the microcracks were analyzed by scanning electron microscopy energy dispersive X-ray analysis (SEM-EDS), and the natural moisture content was also determined through heated. Finally, two-dimensional microcrack network seepage models of the granite samples were simulated using the Lattice Boltzmann method (LBM), which revealed the influence of the microcrack structure on their connectivity. The results show that the growth and development of microcracks in the granite samples generally decreases as sampling depth increases in this study area. Connectivity is positively correlated with a number of the geometric parameters: the quantity of microcracks, the cranny ratio, the number of crack intersections and dimensional parameters of the fracture network, which is revealed in the two-dimensional microcrack network seepage models for these granite samples.

  13. Assessing exposure to granite countertops--Part 1: Radiation.

    PubMed

    Myatt, Theodore A; Allen, Joseph G; Minegishi, Taeko; McCarthy, William B; Stewart, James H; Macintosh, David L; McCarthy, John F

    2010-05-01

    Humans are continuously exposed to low levels of ionizing radiation. Known sources include radon, soil, cosmic rays, medical treatment, food, and building products such as gypsum board and concrete. Little information exists about radiation emissions and associated doses from natural stone finish materials such as granite countertops in homes. To address this knowledge gap, gross radioactivity, gamma ray activity, and dose rate were determined for slabs of granite marketed for use as countertops. Annual effective radiation doses were estimated from measured dose rates and human activity patterns while accounting for the geometry of granite countertops in a model kitchen. Gross radioactivity, gamma activity, and dose rate varied significantly among and within slabs of granite with ranges for median levels at the slab surface of ND to 3000 cpm, ND to 98,000 cpm, and ND to 1.5E-4 mSv/h, respectively. The maximum activity concentrations of the (40)K, (232)Th, and (226)Ra series were 2715, 231, and 450 Bq/kg, respectively. The estimated annual radiation dose from spending 4 h/day in a hypothetical kitchen ranged from 0.005 to 0.18 mSv/a depending on the type of granite. In summary, our results show that the types of granite characterized in this study contain varying levels of radioactive isotopes and that their observed emissions are consistent with those reported in the scientific literature. We also conclude from our analyses that these emissions are likely to be a minor source of external radiation dose when used as countertop material within the home and present a negligible risk to human health.

  14. Granites: Relation of Properties in situ to Laboratory Measurements.

    PubMed

    Simmons, G; Nur, A

    1968-11-15

    The velocity of compressional waves and electrical resistivity in granite in situ measured in two 3-kilometer boreholes exhibits very little variation with depth, in contrast with the variation predicted from laboratory measurements on dry samples. These observations can be explained either by the absence of small open cracks in the rocks in situ or by the effects of complete saturation with water. The seismic velocities of many granites at shallow depths in the earth's crust may be significantly larger than was previously believed. Other properties are also affected; correction for the effect of cracks on thermal conductivity raises the average heat flow in shield areas by as much as 20 percent.

  15. Microcracking and healing in granites: new evidence from cathodoluminescence.

    PubMed

    Sprunt, E S; Nur, A

    1979-08-01

    Quartz grains in granitic rocks usually have blue cathodoluminescence (CL). Within the blue-luminescing grains, there are often red-luminescing domains which are frequently impossible to detect without CL contrast. This finding suggests that the red-luminescing quartz is sealing preexisting mnicrocracks. The presence of these now-healed microcracks has important implications with respect to the role of pore fluid pressure and fluid transfer in metamorphism, the origih of granites, longperiod crustal deformation, earthquake mechanics, physical properties of rocks, and deep-seated geothermal energy.

  16. Granite magma formation, transport and emplacement in the Earth's crust.

    PubMed

    Petford, N; Cruden, A R; McCaffrey, K J; Vigneresse, J L

    2000-12-01

    The origin of granites was once a question solely for petrologists and geochemists. But in recent years a consensus has emerged that recognizes the essential role of deformation in the segregation, transport and emplacement of silica-rich melts in the continental crust. Accepted petrological models are being questioned, either because they require unrealistic rheological behaviours of rocks and magmas, or because they do not satisfactorily explain the available structural or geophysical data. Provided flow is continuous, mechanical considerations suggest that--far from being geologically sluggish--granite magmatism is a rapid, dynamic process operating at timescales of < or = 100,000 years, irrespective of tectonic setting.

  17. The Swedish Bohus granite - a stone with a fascinating history

    NASA Astrophysics Data System (ADS)

    Schouenborg, Björn; Eliasson, Thomas

    2015-04-01

    One of the most well-known and well spread Swedish stone types used as building stones is the Bonus granite. It outcrops in an area north of Gothenburgh (SW Sweden), along the coastline, approximately 35 km wide and 85 km long. The granite continues into Norway as the Iddefjord granite. The Bohus granite is one of Sweden's youngest granites. Isotopic dating shows that the magma cooled at about 920 M years ago and thus marking the end of the Sveconorwegian orogoney. It is a composite granite massif area with several granitic intrusions but with rather homogeneous mineralogy. However, colour and texture varies quite a lot and the colour ranges from red to reddish grey although some pure grey varieties occur sparsely. The grain size ranges from medium grained to coarse grained and even with some porphyric parts. Quarrying in an industrial scale started 1842. The merchant A C Kullgren opened the first quarry and produced stones for the construction of the 86 km long Trollhättan channel connecting lake Vänern and the Atlantic ocean in the SW Sweden The stone was used for constructing harbors and wharves along the channel. Several quarries opened in the late 1800 around 1870 - 1890 and the export increased steadily with deliveries to Germany, Denmark, Holland, England and even to South America. The stone industries in Bohuslän (Bohus county), at its peak in 1929, engaged around 7 000 employees. During the depression in 1930 almost all of them became unemployed. However, as a curiosity, production and export continued to Germany for construction of Germania, the future World capital city ("Welthauptstadt Germania"), planned by Adolf Hitler and Albert Speer. About 500 stone workers were kept employed for this project during the late thirties. Today several varieties are still produced: Evja/Ävja, Tossene, Brastad, Näsinge, Broberg, Nolby, Allemarken and Skarstad. However, the number of stone workers is far from that of the early 1900. The Swedish production is mainly

  18. Genesis of a zoned granite stock, Seward Peninsula, Alaska

    USGS Publications Warehouse

    Hudson, Travis

    1977-01-01

    A composite epizonal stock of biotite granite has intruded a diverse assemblage of metamorphic rocks in the Serpentine Hot Springs area of north-central Seward Peninsula, Alaska. The metamorphic rocks include amphibolite-facies orthogneiss and paragneiss, greenschist-facies fine-grained siliceous and graphitic metasediments, and a variety of carbonate rocks. Lithologic units within the metamorphic terrane trend generally north-northeast and dip moderately toward the southeast. Thrust faults locally juxtapose lithologic units in the metamorphic assemblage, and normal faults displace both the metamorphic rocks and some parts of the granite stock. The gneisses and graphitic metasediments are believed to be late Precambrian in age, but the carbonate rocks are in part Paleozoic. Dating by the potassium-argon method indicates that the granite stock is Late Cretaceous. The stock has sharp discordant contacts, beyond which is a well-developed thermal aureole with rocks of hornblende hornfels facies. The average mode of the granite is 29 percent plagioclase, 31 percent quartz, 36 percent K-feldspar, and 4 percent biotite. Accessory minerals include apatite, magnetite, sphene, allanite, and zircon. Late-stage or deuteric minerals include muscovite, fluorite, tourmaline, quartz, and albite. The stock is a zoned complex containing rocks with several textural facies that are present in four partly concentric zones. Zone 1 is a discontinuous border unit, containing fine- to coarse-grained biotite granite, that grades inward into zone 2. Zone 2 consists of porphyritic biotite granite with oriented phenocrysts of pinkish-gray microcline in a coarse-grained equigranular groundmass of plagioclase, quartz, and biotite. It is in sharp, concordant to discordant contact with rocks of zone 3. Zone 3 consists of seriate-textured biotite granite that has been intruded by bodies of porphyritic biotite granite containing phenocrysts of plagioclase, K-feldspar, quartz, and biotite in an

  19. Emplacement and magnetic fabrics of rapakivi granite intrusions within Wiborg and Åland rapakivi granite batholiths in Finland

    NASA Astrophysics Data System (ADS)

    Karell, Fredrik; Ehlers, Carl; Airo, Meri-Liisa

    2014-02-01

    Anisotropy of magnetic susceptibility (AMS) studies were carried out in two areas in Finland: the Ruotsinpyhtää intrusion within the Wiborg rapakivi granite batholith and the Saltvik intrusions within the Åland rapakivi granite batholith. The main aim of this study was to understand the emplacement history of these mid-Proterozoic rapakivi granites. Aeromagnetic images reveal structures of ca. 5-10 km intrusions that build up the large rapakivi granite batholiths of Åland and Wiborg. Magnetic susceptibility data from the database of the Geological Survey of Finland, including more than 1700 samples from the Wiborg rapakivi batholith and almost 900 samples from the Åland rapakivi batholith, were compared with measurements from the present study. The mean susceptibility is ca. 1500 μSI for the Wiborg batholith and ca. 10,000 μSI for the Åland batholith. Samples taken for this study demonstrate that the mean value for the Ruotsinpyhtää intrusion is ca. 1200 μSI and for the Saltvik intrusions ca. 24,000 μSI. Thermomagnetic measurements reveal that the magnetic susceptibility is mainly derived either from paramagnetic minerals or from magnetite. The absence of solid-state deformation features such as breccia or contact deformation indicates a cauldron-type subsidence emplacement. The AMS measurements from Ruotsinpyhtää confirm these proposals, with concentric gently dipping magnetic foliations that support a ring complex structure above a piston-type subsidence system. The Saltvik area consists of a number of smaller elliptical intrusions of different rapakivi granites forming a multiple intrusive complex. The magnetic fabric shows a general westward dipping of the pyterlite and eastward dipping of the contiguous even-grained rapakivi granite, which indicates a central inflow of magma batches towards the east and west resulting from a laccolitic emplacement of magma batches, while the main mechanism for space creation was derived from subsidence.

  20. Smolt Monitoring at the Head of Lower Granite Reservoir and Lower Granite Dam, 1998 Annual Report.

    SciTech Connect

    Buettner, Edwin W.; Brimmer, Arnold F.

    2000-04-01

    This project monitored the daily passage of chinook salmon Oncorhynchus tshawytscha, steelhead trout O. mykiss, and sockeye salmon smolts O. nerka, during the 1998 spring outmigration at migrant traps on the Snake and Salmon rivers. All hatchery chinook salmon released above Lower Granite Dam 19 1998 were marked with a fin-clip. Total annual hatchery chinook salmon catch at the Snake River trap was 226% of the 1997 number and 110% of the 1996 catch. The wild chinook catch was 120% of the 1997 catch but was only 93% of 1996. Hatchery steelhead trout catch was 501% of 1997 numbers but only 90% of the 1996 numbers. Wild steelhead trout catch was 569% of 1997 and 125% of the 1996 numbers. The Snake River trap collected 106 age-0 chinook salmon. During 1998, for the first time, the Snake River trap captured a significant number of hatchery sockeye salmon (1,552) and hatchery coho salmon O. kisutch (166). Differences in trap catch between years are due to fluctuations not only in smolt production, but also differences in trap efficiency and duration of trap operation associated with high flows. Trap operations began on March 8 and were terminated for the season due to high flows on June 12. The trap was out of operation for 34 d during the season due to high flow and debris. Hatchery chinook salmon catch at the Salmon River trap was 476% and wild chinook salmon catch was 137% of 1997 numbers and 175% and 82% of 1996 catch, respectively. The hatchery steelhead trout collection in 1998 was 96% of the 1997 catch and 13% of the 1996 numbers. Wild steelhead trout collection in 1998 was 170% of the 1997 catch and 37% of the 1996 numbers. Travel time (d) and migration rate (km/d) through Lower Granite Reservoir for PIT-tagged chinook salmon and steelhead trout, marked at the head of the reservoir were affected by discharge. For fish tagged at the Snake River trap, statistical analysis of 1998 detected a significant relation between migration rate and discharge. For hatchery and

  1. Smolt Monitoring at the Head of Lower Granite Reservoir and Lower Granite Dam, 1990 Annual Report.

    SciTech Connect

    Buettner, Edwin W.; Nelson, V. Lance

    1991-05-01

    This project monitored the daily passage of chinook salmon Oncorhynchus tshawytscha and steelhead trout Oncorhynchus mvkiss smolts during the 1990 spring outmigration at migrant traps on the Snake River and the Clearwater River. Chinook salmon catch at the Snake River trap was similar to 1987 and 1988, drought years, but considerably less than 1989, a near normal flow year. Trapping effort was the same during the four years. Hatchery steelhead trout catch was similar to 1988 and 1989. Wild steelhead trout catch was greater than in any previous year. Chinook salmon catch at the Clearwater River trap was slightly less than in 1987 or 1988 and considerably higher than in 1989. Hatchery steelhead trout trap catch was 3 to 26 times greater than in previous years. Wild steelhead trout trap catch was 2 to 11 times greater than in previous years. Fish tagged with Passive Integrated Transponder (PIT) tags at the Snake River trap were recovered at the three dams with PIT tag detection systems (Lower Granite, Little Goose, and McNary dams). Cumulative recovery at the three dams for fish marked at the Snake River trap was 64.4% for chinook salmon, 83.1% for hatchery steelhead trout, and 79.0% for wild steelhead trout. Cumulative recovery at the three dams for fish PIT-tagged at the Clearwater River trap was 54.6% for chinook salmon, 77.6% for hatchery steelhead trout, and 70.4% for wild steelhead trout. Travel time (days) and migration rate (km/d) through Lower Granite Reservoir for PIT-tagged chinook salmon and steelhead trout, marked at the head of the reservoir, was affected by discharge. Statistical analysis showed that a two-fold increase in discharge increased migration rate by 2.2 times for PIT-tagged chinook salmon released from the Snake River trap and 1.8 times for chinook salmon released from the Clearwater River trap. A two-fold increase in discharge increased migration rate by 3.1 times for PIT-tagged hatchery steelhead trout released from the Snake River trap

  2. Intestinal helminths of the granite spiny lizard (Sceloporus orcutti).

    PubMed

    Goldberg, S R; Bursey, C R

    1991-04-01

    Examination of the intestinal tracts of 74 granite spiny lizards (Sceloporus orcutti) from Riverside County, California (USA) revealed infection with one cestode species Oochoristica scelopori (Anoplocephalidae) and one nematode species Spauligodon giganticus (Pharyngodonidae). Helminth prevalence was 24%. The presence of Oochoristica scelopori represents a new host record.

  3. Ancient Granite Gneiss in the Black Hills, South Dakota.

    PubMed

    Zartman, R E; Norton, J J; Stern, T W

    1964-07-31

    Granite gneiss, with an age of approximately 2.5 billion years, in the Black Hills, South Dakota, provides a link between ancient rocks in western Wyoming and Montana and in eastern North and South Dakota and Minnesota. The discovery suggests that early Precambrian rocks covered an extensive area in northcentral United States and were not restricted to several small nuclei.

  4. 8. Granite quay wall at foot of Pier 10 (west ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Granite quay wall at foot of Pier 10 (west end), view to north, at low tide. - Charlestown Navy Yard, Pier 10, Between Piers 9 & 11 along Mystic River on Charlestown Waterfront at eastern edge of Charlestown Navy Yard, Boston, Suffolk County, MA

  5. Detail of west span showing connection of superstructure to granite ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of west span showing connection of superstructure to granite pier at low tide. Photograph articulates subdeck support members. View southeast - New York, New Haven & Hartford Railroad, Fort Point Channel Rolling Lift Bridge, Spanning Fort Point Channel, Boston, Suffolk County, MA

  6. Ancient granite gneiss in the Black Hills, South Dakota

    USGS Publications Warehouse

    Zartman, R.E.; Norton, J.J.; Stern, T.W.

    1964-01-01

    Granite gneiss, with an age of approximately 2.5 billion years, in the Black Hills, South Dakota , provides a link betweeen ancient rocks in western Wyoming and Montana and in eastern North and South Dakota and Minnesota. The discovery suggests that early Precambrian rocks covered an extensive area in northcentral United States and were not restricted to several small nuclei.

  7. Flow Chart for Mineral Separation from Granitic Rocks.

    ERIC Educational Resources Information Center

    Mursky, Gregory

    1987-01-01

    Provided is a flow chart for the separation and purification of major, minor, and accessory minerals from granitic rocks. With careful use of heavy liquids, and a Franz Isodynamic Magnetic Separator, it is possible to obtain mineral concentrates with a purity of 95 percent or better. (Author/RH)

  8. Electrical properties of granite with implications for the lower crust.

    USGS Publications Warehouse

    Olhoeft, G.R.

    1981-01-01

    The electrical properties of granite appear to be dominantly controlled by the amount of free water in the granite and by temperature. Minor contributions to the electrical properties are provided by hydrostatic and lithostatic pressure, structurally bound water, oxygen fugacity, and other parameters. The effect of sulphur fugacity may be important but is experimentally unconfirmed. In addition to changing the magnitude of electrical properties, the amount and chemistry of water in granite significantly changes the temperature dependence of the electrical properties. With increasing temperature, changes in water content retain large, but lessened, effects on electrical properties. Near room temperature, a monolayer of water will decrease the electrical resistivity by an order of magnitude. Several weight-percent water may decrease the electrical resistivity by as much as nine orders of magnitude and decrease the thermal activation energy by a factor of five. At elevated temperatures just below granitic melting, a few weight-percent water may still decrease the resistivity by as much as 3 orders of magnitude and the activation energy by a factor of two.-Author

  9. Granite School District's Comprehensive Counseling and Guidance Program in Action.

    ERIC Educational Resources Information Center

    Petersen, Judy

    This paper discusses the development of the Utah Model for Comprehensive Counseling and Guidance, and specifically, its application in the Granite School Districts Guidance Program. This model adopted the National Occupational Information Coordinating Committee (NOICC) competencies as its desired program content, which focuses on student outcomes.…

  10. Monte Carlo simulations for generic granite repository studies

    SciTech Connect

    Chu, Shaoping; Lee, Joon H; Wang, Yifeng

    2010-12-08

    In a collaborative study between Los Alamos National Laboratory (LANL) and Sandia National Laboratories (SNL) for the DOE-NE Office of Fuel Cycle Technologies Used Fuel Disposition (UFD) Campaign project, we have conducted preliminary system-level analyses to support the development of a long-term strategy for geologic disposal of high-level radioactive waste. A general modeling framework consisting of a near- and a far-field submodel for a granite GDSE was developed. A representative far-field transport model for a generic granite repository was merged with an integrated systems (GoldSim) near-field model. Integrated Monte Carlo model runs with the combined near- and farfield transport models were performed, and the parameter sensitivities were evaluated for the combined system. In addition, a sub-set of radionuclides that are potentially important to repository performance were identified and evaluated for a series of model runs. The analyses were conducted with different waste inventory scenarios. Analyses were also conducted for different repository radionuelide release scenarios. While the results to date are for a generic granite repository, the work establishes the method to be used in the future to provide guidance on the development of strategy for long-term disposal of high-level radioactive waste in a granite repository.

  11. Detail of typical subdeck of granite pier showing humanscale arched ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of typical subdeck of granite pier showing human-scale arched openings in pies. Note remnants of fender system. View north - New York, New Haven & Hartford Railroad, Fort Point Channel Rolling Lift Bridge, Spanning Fort Point Channel, Boston, Suffolk County, MA

  12. Chemical composition and origin of black patinas on granite.

    PubMed

    Silva, Benita; Aira, Noelia; Martínez-Cortizas, Antonio; Prieto, Beatriz

    2009-12-15

    Black patinas from the surfaces of granite outcrops (including some with engravings) and granite buildings were analysed. Rock samples were also taken from areas of the same surfaces where there were no black patinas. The constituent elements of the granite rocks, elements of essentially biological origin (C, N, H) and other minor elements, including some typical from pollution, were all determined. The ratios between the concentrations of each element in the patinas and in the corresponding rock samples without patina were calculated in order to determine which elements form the patinas. The data were then examined by hierarchical cluster analysis and principal components analysis to establish the factors that determine the differences between samples. It was found that the elements that differentiate the patinas from the samples of rock without patina are those unrelated to granite, which indicates that, at least from a geochemical point of view, the rocky substrate does not affect patina formation. In all patinas analysed, the concentrations of carbon were higher than in the corresponding samples without patina; there were also relatively higher concentrations of sulphur, phosphorus, chlorine, calcium, etc. in some patinas, depending on the situation of the outcrop or monument.

  13. 16. Detail showing roller nest between granite pier cap and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. Detail showing roller nest between granite pier cap and moveable end of truss at east end of main spans. View to southeast. - Selby Avenue Bridge, Spanning Short Line Railways track at Selby Avenue between Hamline & Snelling Avenues, Saint Paul, Ramsey County, MN

  14. 74. The Butte Water Company Building (124 Weat Granite) was ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    74. The Butte Water Company Building (124 Weat Granite) was built in 1907 for the Montana Independant Telephone Company, which occupied it until 1918. Since then, it has been occupied by the Butte Water Company, and has not been altered substantially. It was designed by George H. Shanley. - Butte Historic District, Bounded by Copper, Arizona, Mercury & Continental Streets, Butte, Silver Bow County, MT

  15. Riftogenic A-type granites of the Polar Urals, Russia

    NASA Astrophysics Data System (ADS)

    Udoratina, Oksana; Kulikova, Ksenia; Shuysky, Alexander

    2016-04-01

    There are granitoids-markers of the riftogenic geodynamic setting in the Polar Urals. Isotope-geochronological and petrographic-petrogeochemical data on granitoids indicate the post-collisional conditions of their formation. Granitoids along with other alkaline massifs North Urals mark rifting in this part of the Urals. These granitoids formed after the collision peak of Timanides formation, after 520 Ma in the absolute chronology, when the intensity of magmatism fell sharply and only small volumes of rhyolite and A-type granites were formed. Granitoid massifs occur within the Northern Urals fragment of the Central Ural uplift composed of preuralide complexes. According to the recent data (U-Pb, SIMS) for single zircon the granitoids of the massifs (hereinafter Ma): Syadatayakhinsky (516±2, 503±6.3), Ochetinsky (500±5), Ingilorsky (487.3±6.9, 503±5), the northern part of Gerdizsky (496.2±7.1), Marunkeu Ridge (495±2.4) and part of massifs of kharbeysky complex of Laptayugansky and Evyugansky domes (497±3 and 487.1±2.1) were formed in the Late Cambrian-Early Ordovician time. Within rare metal ore deposits of Taykeyusky ore unit, except for older granitoids with ages 600-560-540 Ma, the granitoids occur with the following ages: Longotyugansky (512±8, 482±8, 511±11), Taykeusky (513±3.4, 518.6±3.9, 477±12), Ust-Mramorny (516±16). There are the following situation localization of granites in the area of the Central Urals uplift: 1) in Ochetinsky and Syadatayakhinsky blocks without significant tectonic deformations among greenschist metamorphites; 2) in the areas of intense tectonic transformations (Longotyugansky, Taykeusky, Ust-Mramorny), but also among greenschist metamorphites; 3) in highly metamorphized rocks (Marunkeu Ridge, Ingilorsky, Gerdizsky, small bodies of Kharbeysky complex). Granitoids differ by the material and structural-textural features of the rocks. Some are massive with preserved granite fabric (1), the other have clearly expressed

  16. ASTEROIDAL GRANITE-LIKE MAGMATISM 4.53 GYR AGO

    SciTech Connect

    Terada, Kentaro; Bischoff, Addi

    2009-07-10

    Constraining the timescales for the evolution of planetary bodies in our solar system is essential for a complete understanding of planet-forming processes. However, frequent collisions between planetesimals in the early solar system obscured and destroyed much of the primitive features of the old, first-generation planetary bodies. The presence of differentiated, achondritic clasts in brecciated chondrites and of chondritic fragments in achondritic breccias clearly witness multiple processes such as metamorphism, magmatism, fragmentation, mixing, and reaccretion. Here, we report the results of ion microprobe Pb-Pb dating of a granite-like fragment found in a meteorite, the LL3-6 ordinary chondrite regolith breccia Adzhi-Bogdo. Eight spot analyses of two phosphate grains and other co-genetic phases of the granitoid give a Pb-Pb isochron age of 4.48 {+-} 0.12 billion years (95% confidence) and a model age of 4.53 {+-} 0.03 billion years (1{sigma}), respectively. These ages represent the crystallization age of a parental granite-like magma that is significantly older than those of terrestrial (4.00-4.40 Gyr) and lunar granites (3.88-4.32 Gyr) indicating that the clast in Adzhi-Bogdo is the oldest known granitoid in the solar system. This is the first evidence that granite-like formation is not only a common process on Earth, but also occurred on primitive asteroids in the early solar system 4.53 Gyr ago. Thus, the discovery of granite magmatism recorded in a brecciated meteorite provides an innovative idea within the framework of scenarios for the formation and evolution of planetary bodies and possibly exoplanetary bodies.

  17. Index of granitic rock masses in the state of Nevada; A compilation of data on 205 areas of exposed granitic rock masses in Nevada

    SciTech Connect

    1988-12-31

    The compilation of 205 areas of exposed granitic rock in Nevada was undertaken for the US Department of Energy. The purpose was to obtain data for evaluating granitic rock masses as potential underground nuclear waste repositories. Information, compiled by county for areas of granitic rock exposure, includes general location, coordinates, land classification, areal extent, accessibility, composition, age, rocks intruded, aeromagnetic expression, mining activity, and selected references. 49 refs., 18 figs., 3 tabs.

  18. An Occurrence of H2 in Silicate Melt Inclusions in Quartz from Granite of Jiajika Granitic Pegmatite Deposit, China

    NASA Astrophysics Data System (ADS)

    Li, J.; Chou, I.-M.

    2014-06-01

    Laser Raman spectroscopic analyses of silicate melt inclusions in quartz, from granite of Jiajika Li-bearing pegmatite deposit in China, revealed the existence of H_2 in the vapor phase with unknown mechanisms for the formation and retention of H_2.

  19. Petrogenesis of the Neoproterozoic West Highland Granitic Gneiss, Scottish Caledonides: Cryptic mantle input to S-type granites?

    NASA Astrophysics Data System (ADS)

    Fowler, M.; Millar, I. L.; Strachan, R. A.; Fallick, A. E.

    2013-05-01

    The Neoproterozoic (c. 870 Ma) West Highland Granitic Gneiss, exposed in the Northern Highlands Terrane of Scotland, has elemental characteristics that are strikingly similar to those of the host Moine metasediments, which are thus consistent with an origin involving major Moine melting. Most of the constituent bodies have compositions significantly removed from minimum melts of pelites, and trace element constraints suggest variable but significant restite entrainment leading to less silicic bulk compositions with enhanced REE, Zr and Y. However, initial Nd and Hf isotope ratios are not coincident with contemporary Moine and imply a significant juvenile contribution. Close association with a regional suite of metabasites prompts consideration of mafic magma input, for which binary mixing models offer qualitative support. Quantitative difficulties with typical Moine metasediments are eased with radiogenic pelites or by partial melting of the mafic component. A possible alternative is currently unexposed Grenvillian felsic crust. Subsequent interaction of the granitic gneisses with meteoric water has significantly perturbed the oxygen and Sr isotope systems, the timing of which is equivocal but probably occurred during Caledonian events. The elemental characteristics of the West Highland Granitic Gneiss show many similarities with Scandinavian (rift-related?) granites of the same age, but since their geochemistry is largely inherited from the protolith it would be unwise to pursue palaeotectonic attribution on this basis. However, the probable incorporation of significant mantle-derived mafic magma of MORB-like affinity is consistent with an extensional setting.

  20. Petrogenesis of Triassic granites from the Nanling Range in South China: Implications for geochemical diversity in granites

    NASA Astrophysics Data System (ADS)

    Gao, Peng; Zhao, Zi-Fu; Zheng, Yong-Fei

    2014-12-01

    A combined study of whole-rock major-trace elements and Sr-Nd isotopes, zircon U-Pb ages, Hf and O isotopes as well as biotite geochemistry was carried out for Triassic granite intrusions from the Nanling Range in South China. The results provide insights into the effects of source composition and melting conditions on the geochemical diversity of granites. The granites of interest are peraluminous, and contain primary muscovite and tourmaline. They are characterized by high zircon δ18O values of > 9.0‰, high initial 87Sr/86Sr values of ~ 0.7200, and homogeneous εNd(t) values of - 11.3 to - 9.8, as well as variable zircon εHf(t) values of - 12.2 to - 5.8. Biotite geochemistry is similar to that of common peraluminous granites. An integrated interpretation of these petrological, mineralogical and geochemical data indicates that these granites were derived from partial melting of metasedimentary rocks under variable physicochemical conditions. The differences in whole-rock and biotite geochemistry between the intrusions are ascribed to the variable effects of source heterogeneity and melting temperature. The Luxi intrusion exhibits higher contents of MgO, FeOT, TiO2 and CaO than common melts derived from metasedimentary rocks, tight variations in major-trace elements and homogeneous Sr-Nd isotopic compositions, and homogeneous biotite composition with high Mg# [= Mg / (Mg + Fe) in molar] and lower whole-rock A/CNK values [= Al2O3 / (CaO + Na2O + K2O) in molar]. These can be explained by originating from a relatively mafic metasedimentary source. On the other hand, the geochemical diversity of granites can be caused by the difference in melting temperature in addition to the source heterogeneity. This is suggested by the Xiazhuang and Fucheng intrusions which exhibit similar range of SiO2. Nevertheless, the Fucheng intrusion is ferroan, and high in TiO2, (Na2O + K2O)/CaO, TiO2/MgO, Ga/Al and Zr + Nb + Ce + Y, but low in CaO, MgO and Mg#. Most of its major

  1. Zarzalejo granite (Spain). A nomination for 'Global Heritage Stone Resource'

    NASA Astrophysics Data System (ADS)

    Freire Lista, David Martin; Fort, Rafael; José Varas-Muriel, María

    2015-04-01

    Zarzalejo granite is quarried in the Sierra de Guadarrama (Spanish Central System) foothills, in and around Zarzalejo village, in the province of Madrid, Spain. It is an inequigranular monzogranite medium-to-coarse grained, with a slight porphyritic texture (feldspar phenocrysts) and mafic micro-grained enclaves. In this abstract the candidacy of Zarzalejo granite as a "Global Heritage Resource Stone" (GHSR) is presented. This stone ideally fits the newly proposed designation as it has been used in many heritage buildings and its good petrophysical properties and durability have allowed well preserved constructions such as a Roman road, San Pedro Church in Zarzalejo (1492), Descalzas Reales Monastery in Madrid (1559-1564) and the San Lorenzo del Escorial Royal Monastery (1563-1584), to be declared a World Heritage Site by UNESCO. This level of construction has been a landmark in the extraction and proliferation of historic quarries created due to the high demand that such colossal monuments and buildings with granite, have required for their construction. In the mid-20th century, More, Zarzalejo granite has also been used in restoration works including the Royal Palace and the Reina Sofía Museum (2001-2005), both buildings in Madrid, Spain. Extraction of granite ashlars from tors has been a very frequent activity in the Zarzalejo neighbourhood until mid-twentieth century. So there is also a need to preserve these historic quarries. This type of stone has created a landscape that has been preserved as an open-air museum today where you can see the marks left in the granite due to historic quarry operations. The granite industry has been one of the main pillars of the Zarzalejo regional economy. For centuries, the local community have been engaged in quarrying and have created a cultural landscape based on its building stone. A quarryman monument has been erected in Zarzalejo in honor of this traditional craft as well as an architecture museum at San Lorenzo del

  2. A-type granite and the Red Sea opening

    USGS Publications Warehouse

    Coleman, R.G.; DeBari, S.; Peterman, Z.

    1992-01-01

    Miocene-Oligocene A-type granite intrudes the eastern side of the Red Sea margin within the zone of extension from Jiddah, Saudi Arabia south to Yemen. The intrusions developed in the early stages of continental extension as Arabia began to move slowly away from Africa (around 30-20 Ma). Within the narrow zone of extension silicic magmas formed dikes, sills, small plutons and extrusive equivalents. In the Jabal Tirf area of Saudi Arabia these rocks occur in an elongate zone consisting of late Precambrian basement to the east, which is gradually invaded by mafic dikes. The number of dikes increases westward until an igneous complex is produced parallel to the present Red Sea axis. The Jabal Tirf igneous complex consists of diabase and rhyolite-granophyre sills (20-24 Ma). Although these are intrusine intrusive rocks their textures indicate shallow depths of intrusion (< 1 km). To the south, in the Yemen, contemporaneous with alkali basaltic eruptions (26-30 Ma) and later silicic eruptions, small plutons, dikes, and stocks of alkali granite invaded thick (1500 m) volcanic series, at various levels and times. Erosion within the uplifted margin of Yemen suggests that the maximum depth of intrusion was less than 1-2 km. Granophyric intrusions (20-30 Ma) within mafic dike swarms similar to the Jabal Tirf complex are present along the western edge of the Yemen volcanic plateau, marking a north-south zone of continental extension. The alkali granites of Yemen consist primarily of perthitic feldspar and quartz with some minor alkali amphiboles and acmite. These granites represent water-poor, hypersolvus magmas generated from parent alkali basalt magmas. The granophyric, two-feldspar granites associated with the mafic dike swarms and layered gabbros formed by fractional crystallization from tholeiitic basalt parent developed in the early stages of extension. Initial 87Sr/86Sr ratios of these rocks and their bulk chemistry indicate that production of peralkaline and

  3. Scaling minerals from deep-seated granitic geothermal reservoir

    NASA Astrophysics Data System (ADS)

    Yanagisawa, Norio

    2016-04-01

    To promote geothermal energy use and sustainable production, the information of scaling situation from deep-seated geothermal reservoir is important. In Japan, at the Kakkonda geothermal field, Iwate prefecture, north-eastern of Japan, there is 80MW geothermal power plant using about 300 degree C fluid from the reservoir at the boundary between Quaternary Kakkonda granite and Pre-Tertiary formations about 3km depth and more deep-seated reservoir survey was carried out by NEDO. Then, to understand the mechanism of deep-seated reservoir, we survey the metal sulphide minerals deposited at production wellhead and pipeline and compare with the brine And the brine of WD-1a at 3.7km depth, into Quaternary Kakkonda granite rock. In Kakkonda geothermal system, the scales are classified into two types based on sulphide mineralogy, which are Pb-Zn rich type and Cu rich type. Pb-Zn rich scales, for example galena (PbS) and Sphalerite (ZnS), are found in Well-19 located at the marginal part of the Kakkonda granite And Cu-rich scales, for example chalcocite (Cu2S), loellingite (FeAs2) and native antimony (Sb), are found in Well-13, located at the central part of the Kakkonda granite. And the brine of WD-1a at 3.7km depth about 500 degree C, into Quaternary Kakkonda granite rock near Well-19 is rich in Pb and Zn and similar composition as the Well-19 scale. Therefore, deep reservoir of Kakkonda field evolves with mixing the fluid of shallow reservoir and the brine of occurred in the Quaternary Kakkonda granite. Then, the existence of both Pb-Zn rich scale and Cu rich scale is a characteristic feature of Kakkonda geothermal and this fact suggest to have similar zoning as found in Porphyry Copper Zoning. On progress of production the fluids from deep reservoir continue to be suffered by the fluid of shallow reservoir and meteoritic water. With temperature of production well decreasing and chemical composition changed, silica precipitation decreased and the metal sulfide mineral

  4. Smolt Monitoring at the Head of Lower Granite Reservoir and Lower Granite Dam, 1999 Annual Report.

    SciTech Connect

    Buettner, Edwin W.; Brimmer, Arnold F.; Putnam, Scott A.

    2001-06-01

    This project monitored the daily passage of chinook salmon Oncorhynchus tshawytscha, steelhead trout O. mykiss, and sockeye salmon smolts O. nerka during the 1999 spring out-migration at migrant traps on the Snake River and Salmon River. All hatchery chinook salmon released above Lower Granite Dam were marked with a fin clip in 1999. Total annual hatchery chinook salmon catch at the Snake River trap was 440% of the 1998 number. The wild chinook catch was 603% of the previous year's catch. Hatchery steelhead trout catch was 93% of 1998 numbers. Wild steelhead trout catch was 68% of 1998 numbers. The Snake River trap collected 62 age-0 chinook salmon. During 1998 the Snake River trap captured 173 hatchery and 37 wild/natural sockeye salmon and 130 hatchery coho salmon O. kisutch. Differences in trap catch between years are due to fluctuations not only in smolt production, but also differences in trap efficiency and duration of trap operation associated with high flows. Trap operations began on March 14 and were terminated for the season due to high flows on May 25. The trap was out of operation for 18 d during the season due to high flow and debris. Hatchery chinook salmon catch at the Salmon River trap was 214%, and wild chinook salmon catch was 384% of 1998 numbers. The hatchery steelhead trout collection in 1999 was 210% of the 1998 numbers. Wild steelhead trout collection in 1999 was 203% of the 1998 catch. Trap operations began on March 14 and were terminated for the season due to high flows on May 21. The trap was out of operation for 17 d during the season due to high flow and debris.

  5. Smolt Monitoring at the Head of Lower Granite Reservoir and Lower Granite Dam, 1997 Annual Report.

    SciTech Connect

    Buettner, Edwin W.; Nelson, William R.

    1999-04-01

    This project monitored the daily passage of chinook salmon Oncorhynchus tshawytscha and steelhead trout O. mykiss smolts during the 1997 spring out-migration at migrant traps on the Snake River and Salmon River. All hatchery chinook salmon released above Lower Granite Dam were marked with a fin clip in 1997. Total annual hatchery chinook salmon catch at the Snake River trap was 49% of the 1996 number but only 6% of the 1995 catch. The wild chinook catch was 77% of the 1996 but was only 13% of 1995. Hatchery steelhead trout catch was 18% of 1996 numbers but only 7% of the 1995 numbers. Wild steelhead trout catch was 22% of 1996 but only 11% of the 1995 numbers. The Snake River trap collected eight age-0 chinook salmon and one sockeye/kokanee salmon O. nerka. Differences in trap catch between years are due to fluctuations not only in smolt production, but also differences in trap efficiency and duration of trap operation associated with high flows. Trap operations were terminated for the season due to high flows and trap damage on May 8 and were out of operation for 23 d due to high flow and debris. Hatchery chinook salmon catch at the Salmon River trap was 37% and wild chinook salmon catch was 60% of 1996 numbers but only 5% and 11% of 1995 catch, respectively. The 1997 hatchery steelhead trout collection was 13% of the 1996 catch and 32% of the 1995 numbers. Wild steelhead trout collection in 1997 was 21% of the 1996 catch and 13% of the 1995 numbers. Trap operations were terminated for the season due to high flows and trap damage on May 7 and were out of operation for 19 d due to high flow and debris.

  6. Sequence of mineral assemblages in differentiated granitic pegmatites.

    USGS Publications Warehouse

    Norton, J.J.

    1983-01-01

    The sequence of mineral assemblages in internally zoned granitic pegmatites recognized by Cameron et al. (1949) is modified here to account for an observed vertical component, especially in feldspar compositions, in addition to the recognized outer contact-to-inner core differentiation process, and the importance of primary lithium minerals other than spodumene, such as petalite. The zonal patterns of 11 well-known granitic pegmatites are consistent with this revised sequence, with additional explanations for the repeated monomineralic zones of quartz or pollucite, etc. The crystallization history of zoned pegmatites is described in general terms, beginning with the magmatic crystallization which produces the outer zones. Aqueous fluid is exsolved continuously from the magma as relatively anhydrous phases precipitate, and plays an important role in the formation of the inner zones; its evolution is thought to be a major cause of pegmatite differentiation.-J.E.S.

  7. Cancer mortality of granite workers 1940-1985.

    PubMed

    Koskela, R S; Klockars, M; Järvinen, E; Rossi, A; Kolari, P J

    1990-01-01

    A retrospective cohort study was undertaken to investigate the cancer mortality of granite workers. The study comprised 1026 workers who took up such work between 1940 and 1971. The number of person-years was 23,434, and the number of deaths was 296. During the total follow-up period, 59 tumours were observed as compared with 54.4 expected. An excess mortality from tumours was observed in workers followed up for 20 years or more. Of the 59 tumours, 31 were lung cancers (expected 19.9), and 18 gastrointestinal cancers (expected 11.6), nine of which were stomach cancers (expected 7.1). Mortality from lung cancer was excessive for workers followed up for at least 15 years (28 observed, 12.7 expected). The results indicate that granite exposure per se may be an etiological factor in the initiation or promotion of malignant neoplasms.

  8. Reduction of permeability in granite at elevated temperatures.

    PubMed

    Moore, D E; Lockner, D A; Byerlee, J D

    1994-09-01

    The addition of hydrothermal fluids to heated, intact granite leads to permeability reductions in the temperature range of 300 degrees to 500 degrees C, with the rate of change generally increasing with increasing temperature. The addition of gouge enhances the rate of permeability reduction because of the greater reactivity of the fine material. Flow rate is initially high in a throughgoing fracture but eventually drops to the level of intact granite. These results support the fault-valve model for the development of mesothermal ore deposits, in which seals are formed at the base of the seismogenic zone of high-angle thrust faults. The lower temperature results yield varying estimates of mineral-sealing rates at shallower depths in fault zones, although they generally support the hypothesis that such seals develop in less time than the recurrence interval for moderate to large earthquakes on the San Andreas fault.

  9. Natural radioactivity levels of granites used in Turkey.

    PubMed

    Cetin, E; Altinsoy, N; Orgün, Y

    2012-08-01

    Thirty granite samples commonly used in Turkey were surveyed for natural radioactivity. Concentrations of natural radionuclides in all samples were determined by gamma-ray spectroscopy with hyper-pure germanium detector. The activity concentrations measured for (226)Ra and (232)Th ranged from 0.7±0.1 to 186±1 Bq kg(-1), and from 0.5±0.1 to 249±2 Bq kg(-1), respectively. The activity concentrations obtained for (40)K varied from minimum detectable activity (0.4 Bq kg(-1)) to 1935±11 Bq kg(-1). The radium equivalent activity (Ra(eq)), the absorbed dose rate (D), the external hazard index (H(ex)) and the annual effective dose equivalent were also calculated and compared with the international recommended values. Granite samples were also analysed mineralogically. It was observed that the presence of large amount orthoclase and radiogenic accessory minerals are the sources of high activity concentration levels.

  10. Reduction of permeability in granite at elevated temperatures

    USGS Publications Warehouse

    Moore, Diane E.; Lockner, D.A.; Byerlee, J.D.

    1994-01-01

    The addition of hydrothermal fluids to heated, intact granite leads to permeability reductions in the temperature range of 300?? to 500??C, with the rate of change generally increasing with increasing temperature. The addition of gouge enhances the rate of permeability reduction because of the greater reactivity of the fine material. Flow rate is initially high in a throughgoing fracture but eventually drops to the level of intact granite. These results support the fault-valve model for the development of mesothermal ore deposits, in which seals are formed at the base of the seismogenic zone of high-angle thrust faults. The lower temperature results yield varying estimates of mineral-sealing rates at shallower depths in fault zones, although they generally support the hypothesis that such seals develop in less time than the recurrence interval for moderate to large earthquakes on the San Andreas fault.

  11. Preliminary report on a glass burial experiment in granite

    SciTech Connect

    Clark, D.E.; Zhu, B.F.; Robinson, R.S.; Wicks, G.G.

    1983-01-01

    Preliminary results of a two-year burial experiment in granite are discussed. Three compositions of simulated alkali borosilicate waste glasses were placed in boreholes approximately 350 meters deep. The glass sample configurations include mini-cans (stainless steel rings into which glass has been cast) and pineapple slices (thin sections from cylindrical blocks). Assemblies of these glass samples were prepared by stacking them together with granite, compacted bentonite and metal rings to provide several types of interfaces that are expected to occur in the repository. The assemblies were maintained at either ambient mine temperature (8 to 10/sup 0/C) or 90/sup 0/C. The glasses were analyzed before burial and after one month storage at 90/sup 0/C. The most extensive surface degradation occurred on the glasses interfaced with bentonite. In general, very little attack was observed on glass surfaces in contact with the other materials. The limited field and laboratory data are compared.

  12. Lower Granite Dam Smolt Monitoring Program, 1999 Annual Report.

    SciTech Connect

    Verhey, Peter; Morrill, Charles; Mensik, Fred

    1999-01-01

    The 1999 fish collection season at Lower Granite was characterized by high spring flows and spill, low levels of debris, cool water temperatures, increased hatchery chinook numbers, and an overall decrease in numbers of smolts collected and transported. A total of 5,882,872 juvenile salmonids were collected at Lower Granite. Of these, 5,466,057 were transported to release sites below Bonneville Dam, 5,232,105 by barge and 233,952 by truck. An additional 339,398 fish were bypassed back to the river. A total of 117,609 salmonids were examined in daily samples. Nine research projects conducted by four agencies impacted a total of 440,810 smolts (7.5% of the total collected) of which 247,268 were PIT tagged and 572 were recorded as incidental mortalities.

  13. Fault stability inferred from granite sliding experiments at hydrothermal conditions

    USGS Publications Warehouse

    Blanpied, M.L.; Lockner, D.A.; Byerlee, J.D.

    1991-01-01

    Seismicity on crustal faults is concentrated in the depth interval 1-3 to 12-15 km. Tse and Rice (1986) suggested that the lower bound on seismicity is due to a switch with increasing temperature from velocity weakening (destabilizing) to velocity strengthening (stabilizing) friction. New data is presented from sliding experiments on granite at elevated T (23?? to 600??C) plus elevated PH2O(100 MPa). Results show velocity strengthening at room temperature, but velocity weakening from 100?? to 350??C (except at 250??). From 350?? to 600?? there are systematic trends from velocity weakening to strong velocity strengthening, and from high to low friction; neither trend was seen in tests on dry granite. The velocity dependence data imply the potential for unstable slip in the interval 100?? to 350??. Using a geotherm to map temperature to depth, this interval closely matches the observed earthquake distribution. -from Authors

  14. Getting granite dikes out of the source region

    NASA Technical Reports Server (NTRS)

    Rubin, Allan M.

    1995-01-01

    Whether a dike can propagate far from a magma reservoir depends upon the competition between the rate at which propagation widens the dike and the rate at which freezing constricts the aperture available for magma flow. Various formulations are developed for a viscous fluid at temperature T(sub m) intruding a growing crack in an elastic solid. The initial solid temperature equals T(sub m) at the source and decreases linearly with distance from the source. If T(sub m) is the unique freezing temperature of the fluid, dike growth is initially self-similar and an essentially exact solution is obtained; if T(sub m) is above the solidus temperature, the solution is approximate but is designed to overestimate the distance the dike may propagate. The ability of a dike to survive thermally depends primarily upon a single parameter that is a measure of the ratio of the dike frozen margin thickness to elastic thickness. Perhaps more intuitively, one may define a minimum distance from the essentially solid reservoir wall to the point at which the host rock temperature drops below the solidus, necessary for dikes to propagate far into subsolidus rock. It is concluded that for reasonable material properties and source conditions, most basalt dikes will have little difficulty leaving the source region, but most rhyolite dikes will be halted by freezing soon after the magma encounters rock at temperatures below the magma solidus. While these results can explain why granitic dikes are common near granitic plutons but rare elsewhere, the potentially large variation in magmatic systems makes it premature to rule out the possibility that most granites are transported through the crust in dikes. Nonetheless, these results highlight difficulties with such proposals and suggest that it may also be premature to rule out the possibility that most granite plutons ascend as more equidimensional bodies.

  15. Static and kinetic friction of granite at high normal stress

    USGS Publications Warehouse

    Byerlee, J.D.

    1970-01-01

    Frictional sliding on ground surfaces of granite, angle of sliding planes 30?? and 45??, was investigated as a function of confining pressure. Over the normal stress range of 2-12 kb, the static frictional shear stress ??s follows the relationship ??s = 0??5 + 0?? ??n and the kinetic frictional shear stress ??k was calculated to be ??k = 0??25 + 0??47 ??n. ?? 1970.

  16. Lower Granite Dam Smolt Monitoring Program; 1997 Annual Report.

    SciTech Connect

    Verhey, Peter; Witalis, Shirley; Morrill, Charles

    1998-01-01

    The 1997 fish collection season at Lower Granite was characterized by high spring flows, extensive spill, cool spring and early summer water temperatures and comparatively low numbers of fish, particularly yearling chinook. The Fish Passage Center's Smolt Monitoring Program is designed to provide a consistent, real-time database of fish passage and document the migrational characteristics of the many stocks of salmon and steelhead in the Columbia Basin.

  17. In situ geomechanics: Climax granite, Nevada Test Site

    SciTech Connect

    Heuze, F.E.; Patrick, W.C.; De la Cruz, R.V.; Voss, C.F.

    1981-04-01

    The in situ modulus of the Climax granite in the Spent Fuel Test (SFT-C) area of the Nevada Test Site was estimated using six different approaches. Our best estimate of field modulus as E/sub f/ = 26 GPa was obtained from a comparison of the various approaches. A best estimate of laboratory modulus acquired by comparing three different sources was E/sub l/ = 70 GPa. Therefore, the modulus reduction factor for the Climax granite appears to be E/sub f//E/sub l/ = 0.37. In turn, our estimate of in situ rock-mass deformability was used to back-calculate in situ values for the normal stiffness of the granite joints. Our analysis of former stress measurements by the US Geological Survey (USGS) shows that the horizontal stresses in the vicinity of SFT-C vary greatly with azimuth. An unexplained feature of the stresses at SFT-C is the fact that the vertical stress appears to be only 65 to 75% of the calculated lithostatic burden. From the three-dimensional stress ellipsoid at mid-length in the tunnels, assuming a plane strain condition, we were able to estimate an in situ Poisson`s ratio of the rock mass as {nu} = 0.246. Two other techniques were applied in an attempt to measure the stresses around the SFT-C heater and canister drifts: the undercoring method and the borehole jack fracturing approach. The former technique appears to have given reasonable estimates of tangential stresses in the roof of the heater drifts; the latter appears to give low results for stresses in the pillars. Specific recommendations are made for future tests to further characterize the mechanical properties of the Climax granite and the in situ stresses at SFT-C.

  18. Effect of Fe and Mg on crystallization in granitic systems

    SciTech Connect

    Naney, M.T.; Swanson, S.E.

    1980-07-01

    Single-step and multistep undercooling experiments using both Fe, Mg-free and Fe, Mg-bearing model granitic compositions were conducted to investigate the influence of mafic components on the crystallization of granitic melts. Crystallization of granite and granodiorite compositions in the system NaAlSi/sub 3/O/sub 8/-KAlSi/sub 3/O/sub 8/-CaAl/sub 2/Si/sub 2/O/sub 8/-SiO/sub 2/-H/sub 2/O produces assemblages containing one or more of the following phases: plagioclase, alkali feldspar, quartz, silicate liquid, and vapor. The observed phase assemblages are generally in good agreement with equilibrium data reported in the literature on the same bulk compositions. With the addition of Fe and Mg to these bulk compositions six new phases participate in the equilibria (orthopyroxene, clinopyroxene, biotite, hornblende,epidote, and magnetite). However, crystalline assemblages produced in phase equilibrium and crystal growth experiments brought to the same final P-T-X/sub H/sub 2/O/ conditions are in general not equivalent. Perhaps the addition of Fe and Mg has caused a breakdown of the Si-O framework in the melt, thereby promoting the more rapid nucleation of the ino- and phyllosilicates rather than the framework silicates. Border zones of granitic plutons, commonly rich in mafic minerals, may result from the more rapid nucleation of mafic phases from the silicate liquid. These zones are thought to develop by early crystallization along the walls of the pluton. Our results suggest the mafic phases should nucleate more quickly than the feldspars and quartz and thus should enrich the early crystallization products in ferromagnesian minerals.

  19. Archaean greenstone belts and associated granitic rocks - A review

    NASA Astrophysics Data System (ADS)

    Anhaeusser, Carl R.

    2014-12-01

    Archaean greenstone belts and associated granitic rocks comprise some of the most diverse rock types on the Earth's surface and were formed during the early stages of the development of the planet from Eoarchaean to Neoarchaean times - a period extending back from about 4000 to 2500 million years ago. Because of their great age, these rocks have received unprecedented attention from a wide spectrum of Earth scientists striving to learn more about the evolution of the Earth, including its crust, hydrosphere, atmosphere, the commencement of life, and the nature and distribution of mineral deposits. The knowledge gained thus far has accumulated incrementally, beginning with solid field-based studies, the latter being supplemented with increasingly advanced technological developments that have enabled scientists to probe fundamental questions of Earth history. Archaean granite-greenstone terranes display considerable variability of lithologies and geotectonic events, yet there are unifying characteristics that distinguish them from other geological environments. Most greenstone belts consist of a wide variety of volcanic and sedimentary rocks that reflect different evolutionary conditions of formation and all have invariably been influenced by subsequent geotectonic factors, including the intrusion of ultramafic, mafic and granitic complexes, resulting in widespread deformation, metamorphism, metasomatism, as well as mineralization. Geochemical and isotopic age determinations have shown how complex these ancient rocks are and efforts at understanding the nature and evolution of the hydrosphere, atmosphere and primitive life have made Archaean terranes exciting environments in which to study. Conflicting views as to the nature, history and origin of many of the rock types and events in Archaean terranes has been ongoing and stimulating. This review attempts to describe the main lithotypes and other characteristics of granite-greenstone belt geology and points to some

  20. 76. The Silver Bow County Courthouse, 19101912, at West Granite ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    76. The Silver Bow County Courthouse, 1910-1912, at West Granite and Montana Streets, was designed by Link and Haire. The building has a dressed sandstone foundation, brick walls, and sandstone trim, parapet and columns. It was used as a barracks for the State militia when the city was placed under martial law following the dynamiting of the Old Miners' Union Hall in September, 1914. - Butte Historic District, Bounded by Copper, Arizona, Mercury & Continental Streets, Butte, Silver Bow County, MT

  1. Lower Granite Dam Smolt Monitoring Program, 1998 Annual Report.

    SciTech Connect

    Verhey, Peter; Ross, Doug; Morrill, Charles

    1998-12-01

    The 1998 fish collection season at Lower Granite was characterized by relatively moderate spring flows and spill, moderate levels of debris, cool spring, warm summer and fall water temperatures, and increased chinook numbers, particularly wild subyearling chinook collected and transported. The Fish Passage Center's Smolt Monitoring Program is designed to provide a consistent, real-time database on fish passage and document the migrational characteristics of the many stocks of salmon and steelhead in the Columbia Basin.

  2. Lower granite GIS data description and collection guidelines

    SciTech Connect

    Gordon, J.L.; Evans, B.J.; Perry, E.M.

    1995-12-01

    The Lower Granite Geographic Information System (GIS) was developed jointly by the US Army Corps of Engineers (USCOE) Walla Walla District and the Pacific Northwest Laboratory (PNL). The goal of the project is to use GIS technology to analyze impacts of the drawdown mitigation option on the physical and biological environment of the Lower Granite Reservoir. The drawdown mitigation option is based on the hypothesis that faster juvenile salmon travel to the ocean would result in higher juvenile survival and greater smolt-to-adult return ratios; to accomplish this, reservoir elevations would be lowered to increase channel velocities. Altering the elevation of the reservoirs on the Snake River is expected to have a variety of impacts to the Physical environment including changes to water velocity, temperature, dissolved gases, and turbidity. The GIS was developed to evaluate these changes and the resulting impacts on the anadromous and resident fish of the Snake River, as well as other aquatic organisms and terrestrial wildlife residing in the adjacent riparian areas. The Lower Granite GIS was developed using commercial hardware and software and is supported by a commercial relational database. Much of the initial system development involved collecting and incorporating data describing the river channel characteristics, hydrologic properties, and aquatic ecology. Potentially meaningful data for the Lower Granite GIS were identified and an extensive data search was performed. Data were obtained from scientists who are analyzing the habitats, limnology, and hydrology of the Snake River. The next six sections of this document describe the bathymetry, fish abundance, substrate, sediment chemistry, and channel hydrology data.

  3. Laboratory studies of radionuclide transport in fractured Climax granite

    SciTech Connect

    Failor, R.; Isherwood, D.; Raber, E.; Vandergraaf, T.

    1982-06-01

    This report documents our laboratory studies of radionuclide transport in fractured granite cores. To simulate natural conditions, our laboratory studies used naturally fractured cores and natural ground water from the Climax Granite Stock at the Nevada Test Site. For comparison, additional tests used artificially fractured granite cores or distilled water. Relative to the flow of tritiated water, {sup 85}Sr and /sup 95m/Tc showed little or no retardation, whereas {sup 137}Cs was retarded. After the transport runs the cores retained varying amounts of the injected radionuclides along the fracture. Autoradiography revealed some correlation between sorption and the fracture fill material. Strontium and cesium retention increased when the change was made from natural ground water to distilled water. Artificial fractures retained less {sup 137}Cs than most natural fractures. Estimated fracture apertures from 18 to 60 {mu}m and hydraulic conductivities from 1.7 to 26 x 10{sup -3} m/s were calculated from the core measurements.

  4. New contributions to granite characterization by ultrasonic testing.

    PubMed

    Cerrillo, C; Jiménez, A; Rufo, M; Paniagua, J; Pachón, F T

    2014-01-01

    Ultrasound evaluation permits the state of rocks to be determined quickly and cheaply, satisfying the demands faced by today's producers of ornamental stone, such as environmental sustainability, durability and safety of use. The basic objective of the present work is to analyse and develop the usefulness of ultrasound testing in estimating the physico-mechanical properties of granite. Various parameters related to Fast Fourier Transform (FFTs) and attenuation have been extracted from some of the studies conducted (parameters which have not previously been considered in work on this topic, unlike the ultrasonic pulse velocity). The experimental study was carried out on cubic specimens of 30 cm edges using longitudinal and shear wave transducers and equipment which extended the normally used natural resonance frequency range up to 500 kHz. Additionally, a validation study of the laboratory data has been conducted and some methodological improvements have been implemented. The main contribution of the work is the analysis of linear statistical correlations between the aforementioned new ultrasound parameters and physico-mechanical properties of the granites that had not previously been studied, i.e., resistance to salt crystallization and breaking load for anchors. Being properties that directly affect the durability and safety of use of granites, these correlations consolidate ultrasonics as a nondestructive method well suited to this type of material. PMID:23830820

  5. Study of natural radioactivity in Mansehra granite, Pakistan: environmental concerns.

    PubMed

    Qureshi, Aziz Ahmed; Jadoon, Ishtiaq Ahmed Khan; Wajid, Ali Abbas; Attique, Ahsan; Masood, Adil; Anees, Muhammad; Manzoor, Shahid; Waheed, Abdul; Tubassam, Aneela

    2014-03-01

    A part of Mansehra Granite was selected for the assessment of radiological hazards. The average activity concentrations of (226)Ra, (232)Th and (40)K were found to be 27.32, 50.07 and 953.10 Bq kg(-1), respectively. These values are in the median range when compared with the granites around the world. Radiological hazard indices and annual effective doses were estimated. All of these indices were found to be within the criterion limits except outdoor external dose (82.38 nGy h(-1)) and indoor external dose (156.04 nGy h(-1)), which are higher than the world's average background levels of 51 and 55 nGy h(-1), respectively. These values correspond to an average annual effective dose of 0.867 mSv y(-1), which is less than the criterion limit of 1 mSv y(-1) (ICRP-103). Some localities in the Mansehra city have annual effective dose higher than the limit of 1 mSv y(-1). Overall, the Mansehra Granite does not pose any significant radiological health hazard in the outdoor or indoor. PMID:24185916

  6. δ30Si systematics in a granitic saprolite, Puerto Rico

    USGS Publications Warehouse

    Ziegler, Karen; Chadwick, Oliver A.; White, Arthur F.; Brzezinski, Mark A.

    2005-01-01

    Granite weathering and clay mineral formation impart distinct and interpretable stable Si isotope (δ30Si) signatures to their solid and aqueous products. Within a saprolite, clay minerals have δ30Si values ∼2.0‰ more negative than their parent mineral and the δ30Si signature of the bulk solid is determined by the ratio of primary to secondary minerals. Mineral-specific weathering reactions predominate at different depths, driving changes in differing δ30Sipore watervalues. At the bedrock-saprolite interface, dissolution of plagioclase and hornblende creates δ30Sipore water signatures more positive than granite by up to 1.2‰; these reactions are the main contributor of Si to stream water and determine its δ30Si value. Throughout the saprolite, biotite weathering releases Si to pore waters but kaolinite overgrowth formation modulates its contribution to pore-water Si. The influence of biotite on δ30Sipore water is greatest near the bedrock where biotite-derived Si mixes with bulk pore water prior to kaolinite formation. Higher in the saprolite, biotite grains have become more isolated by kaolinite overgrowth, which consumes biotite-derived Si that would otherwise influence δ30Sipore water. Because of this isolation, which shifts the dominant source of pore-water Si from biotite to quartz, δ30Sipore water values are more negative than granite by up to 1.3‰ near the top of the saprolite.

  7. Static and Dynamic Flexural Strength Anisotropy of Barre Granite

    NASA Astrophysics Data System (ADS)

    Dai, F.; Xia, K.; Zuo, J. P.; Zhang, R.; Xu, N. W.

    2013-11-01

    Granite exhibits anisotropy due to pre-existing microcracks under tectonic loadings; and the mechanical property anisotropy such as flexural/tensile strength is vital to many rock engineering applications. In this paper, Barre Granite is studied to understand the flexural strength anisotropy under a wide range of loading rates using newly proposed semi-circular bend tests. Static tests are conducted with a MTS hydraulic servo-control testing machine and dynamic tests with a split Hopkinson pressure bar (SHPB) system. Six samples groups are fabricated with respect to the three principle directions of Barre granite. Pulse shaping technique is used in all dynamic SHPB tests to facilitate dynamic stress equilibrium. Finite element method is utilized to build up equations calculating the flexural tensile strength. For samples in the same orientation group, a loading rate dependence of the flexural tensile strength is observed. The measured flexural tensile strength is higher than the tensile strength measured using Brazilian disc method at given loading rate and this scenario has been rationalized using a non-local failure theory. The flexural tensile strength anisotropy features obvious dependence on the loading rates, the higher the loading rate, the less the anisotropy and this phenomenon may be explained considering the interaction of the preferentially oriented microcracks.

  8. New contributions to granite characterization by ultrasonic testing.

    PubMed

    Cerrillo, C; Jiménez, A; Rufo, M; Paniagua, J; Pachón, F T

    2014-01-01

    Ultrasound evaluation permits the state of rocks to be determined quickly and cheaply, satisfying the demands faced by today's producers of ornamental stone, such as environmental sustainability, durability and safety of use. The basic objective of the present work is to analyse and develop the usefulness of ultrasound testing in estimating the physico-mechanical properties of granite. Various parameters related to Fast Fourier Transform (FFTs) and attenuation have been extracted from some of the studies conducted (parameters which have not previously been considered in work on this topic, unlike the ultrasonic pulse velocity). The experimental study was carried out on cubic specimens of 30 cm edges using longitudinal and shear wave transducers and equipment which extended the normally used natural resonance frequency range up to 500 kHz. Additionally, a validation study of the laboratory data has been conducted and some methodological improvements have been implemented. The main contribution of the work is the analysis of linear statistical correlations between the aforementioned new ultrasound parameters and physico-mechanical properties of the granites that had not previously been studied, i.e., resistance to salt crystallization and breaking load for anchors. Being properties that directly affect the durability and safety of use of granites, these correlations consolidate ultrasonics as a nondestructive method well suited to this type of material.

  9. Study of natural radioactivity in Mansehra granite, Pakistan: environmental concerns.

    PubMed

    Qureshi, Aziz Ahmed; Jadoon, Ishtiaq Ahmed Khan; Wajid, Ali Abbas; Attique, Ahsan; Masood, Adil; Anees, Muhammad; Manzoor, Shahid; Waheed, Abdul; Tubassam, Aneela

    2014-03-01

    A part of Mansehra Granite was selected for the assessment of radiological hazards. The average activity concentrations of (226)Ra, (232)Th and (40)K were found to be 27.32, 50.07 and 953.10 Bq kg(-1), respectively. These values are in the median range when compared with the granites around the world. Radiological hazard indices and annual effective doses were estimated. All of these indices were found to be within the criterion limits except outdoor external dose (82.38 nGy h(-1)) and indoor external dose (156.04 nGy h(-1)), which are higher than the world's average background levels of 51 and 55 nGy h(-1), respectively. These values correspond to an average annual effective dose of 0.867 mSv y(-1), which is less than the criterion limit of 1 mSv y(-1) (ICRP-103). Some localities in the Mansehra city have annual effective dose higher than the limit of 1 mSv y(-1). Overall, the Mansehra Granite does not pose any significant radiological health hazard in the outdoor or indoor.

  10. Assessing exposure to granite countertops--Part 2: Radon.

    PubMed

    Allen, Joseph G; Minegishi, Taeko; Myatt, Theodore A; Stewart, James H; McCarthy, John F; Macintosh, David L

    2010-05-01

    Radon gas ((222)Rn) is a natural constituent of the environment and a risk factor for lung cancer that we are exposed to as a result of radioactive decay of radium ((226)Ra) in stone and soil. Granite countertops, in particular, have received recent media attention regarding their potential to emit radon. Radon flux was measured on 39 full slabs of granite from 27 different varieties to evaluate the potential for exposure and examine determinants of radon flux. Flux was measured at up to six pre-selected locations on each slab and also at areas identified as potentially enriched after a full-slab scan using a Geiger-Muller detector. Predicted indoor radon concentrations were estimated from the measured radon flux using the CONTAM indoor air quality model. Whole-slab average emissions ranged from less than limit of detection to 79.4 Bq/m(2)/h (median 3.9 Bq/m(2)/h), similar to the range reported in the literature for convenience samples of small granite pieces. Modeled indoor radon concentrations were less than the average outdoor radon concentration (14.8 Bq/m(3); 0.4 pCi/l) and average indoor radon concentrations (48 Bq/m(3); 1.3 pCi/l) found in the United States. Significant within-slab variability was observed for stones on the higher end of whole slab radon emissions, underscoring the limitations of drawing conclusions from discrete samples.

  11. Lower Granite Dam Smolt Monitoring Program, 2000 Annual Report.

    SciTech Connect

    Morrill, Charles; Ross, Doug; Mensik, Fred

    2000-01-01

    The 2000 fish collection season at Lower Granite was characterized by lower than average spring flows and spill, low levels of debris, cool water temperatures, increased unclipped yearling and subyearling chinook smolts, and 8,300,546 smolts collected and transported compared to 5,882,872 in 1999. With the continued release of unclipped supplementation chinook and steelhead above Lower Granite Dam, we can no longer accurately distinguish wild chinook, steelhead, and sockeye/kokanee in the sample. Although some table titles in this report still show ''wild'' column headings, the numbers in these columns for 1999 and 2000 include wild and unclipped hatchery origin smolts. The increases over previous years reflect the increased supplementation. A total of 8,300,546 juvenile salmonids were collected at Lower Granite Dam. Of these, 187,862 fish were bypassed back to the river and 7,950,648 were transported to release sites below Bonneville Dam, 7,778,853 by barge and 171,795 by truck. A total of 151,344 salmonids were examined in daily samples. Nine research projects conducted by four agencies impacted a total of 1,361,006 smolts (16.4% of the total collection).

  12. Smolt Monitoring at the Head of Lower Granite Reservoir and Lower Granite Dam, 1992 Annual Report.

    SciTech Connect

    Buettner, Edwin W.; Brimmer, Arnold F.

    1993-11-01

    This project monitored the daily passage of chinook salmon Oncorhynchus tshawytscha and steelhead trout 0. mykiss smolts during the 1992 spring outmigration at migrant traps on the Snake River and the Clearwater River. Annual chinook salmon catch at the Snake River trap was the second lowest since the beginning of this project. The low trap catch wall due to extremely poor trap efficiency associated with severe low flows. Hatchery steelhead trout catch was similar to 1988 through 1991. Wild steelhead trout catch was 35% less than in 1991. Operations at the Snake River trap and a new screw trap were extended through the end of July to collect summer-migrating age-0 chinook. The differentiation of age-0 chinook from spring and Bummer chinook (age-1) using physical characteristics was again employed in 1992. The Snake River trap and the screw trap collected 20 and 18 age-0 chinook salmon, respectively, due to extremely low discharge. Chinook salmon catch at the Clearwater River trap was the highest since trap operation began in 1984. Hatchery steelhead trout trap catch was 23% lower than in 1991. Wild steelhead trout trap catch wall the highest since trap operation began. Fish tagged with Passive Integrated Transponder (PIT) tags at the Snake River trap were interrogated at three dams with PIT-tag detection systems (Lower Granite, Little Goose, and McNary dams). Cumulative interrogation, for fish marked at the Snake River trap, was not calculated for chinook salmon due to a lack of data over the entire migration season. The rates for hatchery steelhead trout and wild steelhead trout were 44.9% and 72.9% respectively. Cumulative interrogation at the three dams for fish PIT-tagged at the Clearwater River trap was 55.1% for chinook salmon, 60.4% for hatchery steelhead trout, and 73.1% for wild steelhead trout. Cumulative interrogations for hatchery steelhead tagged at the Snake River trap and recovered at the downstream dams was about 50% less than in previous years.

  13. Permian ultrafelsic A-type granite from Besar Islands group, Johor, peninsular Malaysia

    NASA Astrophysics Data System (ADS)

    Ghani, Azman A.; Hazad, Fatin Izzani; Jamil, Azmiah; Xiang, Quek Long; Atiqah Wan Ismail, Wan Nur; Chung, Sun-Lin; Lai, Yu-Ming; Roselee, Muhammad Hatta; Islami, Nur; Nyein, Kyaw Kyaw; Amir Hassan, Meor Hakif; Abu Bakar, Mohd Farid; Umor, Mohd Rozi

    2014-12-01

    The granitic rocks of the peninsula have traditionally been divided into two provinces, i.e., Western and Eastern provinces, corresponding to S- and I-type granite respectively. The Western Province granite is characterised by megacrystic and coarse-grained biotite, tin-mineralised, continental collision granite, whereas, the Eastern Province granite is bimodal I-type dominated by granodiorite and associated gabbroic of arc type granite. This paper reports the occurrence of an A-type granite from peninsular Malaysia. The rocks occur in the Besar, Tengah, and Hujung islands located in the southeastern part of the peninsula. The granite is highly felsic with SiO2 ranging from 75.70% to 77.90% (differentiation index = 94.2-97.04). It is weakly peraluminous (average ACNK =1.02), has normative hypersthene (0.09-2.19%) and high alkali content (8.32-8.60%). The granites have many A-type characteristics, among them are shallow level of emplacement, high Ga, FeT/MgO and low P, Sr, Ti, CaO and Nb. Calculated zircon saturation temperatures for the Besar magma ranging from 793 ∘ to 806 ∘C is consistent with high temperature partial melting of a felsic infracrustal source which is taken as one of the mechanisms to produce A-type magma. The occurrence of the A-type granite can be related to the extensional back arc basin in the Indo-China terrane during the earliest Permian.

  14. Magnetic fabric as a vorticity gauge in syntectonically deformed granitic rocks

    NASA Astrophysics Data System (ADS)

    Mamtani, Manish A.

    2014-08-01

    A concept is presented to quantify vorticity using magnetic fabric data determined from anisotropy of magnetic susceptibility (AMS) analysis in syntectonic granites, whose emplacement is synchronous with tectonics of adjacent shear zones. The latter is considered to define the direction of extensional flow apophysis (Ae). It is suggested that the magnetic foliation traces the direction of maximum instantaneous stretching axis during the final stage of ductile deformation. Hence, the angle between mean orientation of magnetic foliation and Ae gives the kinematic vorticity number (Wn). This concept is tested in two granites from India - Godhra Granite (western India) and Chakradharpur Granitoid (eastern India). The analysis explains the kinematics of fabric development within the granites and also the evolution of structural elements in the surrounding rocks. It is also suggested that in cases where granite margins get mylonitized synchronously with tectonic activity along adjacent shear zones, the angle between mean magnetic foliation of the granite margin samples and the shear zone can help calculate Wn. The example of Malanjkhand Granite (central India) is discussed to highlight this. Using magnetic fabric, a value of Wn = 0.98 is recorded for granite margin samples implying their deformation by dominantly simple shear. Oblique quartz foliation recorded on the microscale in the granite margin samples yields Wn = 0.94, which is similar to the value obtained using AMS. It is thus concluded that magnetic fabric provides a possibility to quantify vorticity in syntectonic granites in 2-dimension.

  15. Increase vs. decrease in the strength of granitic rocks subjected to heat

    NASA Astrophysics Data System (ADS)

    Török, Anita; Török, Ákos

    2015-04-01

    Accidental fire generally causes catastrophic loss in granitic structures or tunnels excavated in granitic rocks. It is necessary to measure strength of materials at various degrees to understand the mechanical behaviour of such stone structures or tunnels. Our laboratory experiments were aimed to detect indirect tensile strength and uniaxial compressive strength of granitic rocks that were subjected to temperatures of up to 600°C. For control measurements ultrasonic pulse velocity was also recorded. The studied rocks included three granites: a Hungarian dark pink granite (Mórágy), an Austrian greyish granite (Mauthausen) and a common pinkish Spanish granite (Rosa Beta). Cylindrical tests specimens of the three granites were subjected to 300°C and 600°C, respectively. Compressive strength test and tensile strength test results were compared to strength values obtained at room temperature. Our test results show that two of the studied granites (Hungarian and the Spanish one) have higher strength at 300°C that at room temperature. To the contrary ultrasonic pulse velocity decreased for all the three granites from room temperature to 300°C. The tensile strength of the granites did not show such a clear trend, however Hungarian granite has a slightly increased tensile strength at 300°C than at room temperature. At 600°C the compressive strength, tensile strength and ultrasonic pulse velocity dropped but not at the same rate. Our experiments showed that a given and limited temperature increase can have a positive effect on strength of granites rather than an adverse effect on a short-term.

  16. Bluish granites from Extremadura (Spain): a radiological evaluation.

    NASA Astrophysics Data System (ADS)

    Pereira, Dolores; Neves, Luís.; Peinado, Mercedes; Pereira, Alcides; Rodríguez, Leticia; António Blanco, José

    2010-05-01

    We have found in the area of Trujillo (Extremadura, Spain) a variety of striking bluish granites, outcropping within the Plasenzuela pluton. They are all quarried under different names and are characterized by leucocratic minerals such as quartz, feldspar (both potassium and plagioclase), sometimes giving a fenocrystic texture and muscovite, with some biotite. As accessory phases, idiomorphic tourmaline is found. Recently a bluish phosphate distributed in the whole rock was detected, included within most mineral phases and fillings from stressed structures that are cutting the rock. We attribute the bluish color of the granites to this phosphate. Although biotite is almost always transformed to chlorite, the rock gives an excellent response to be polished. Physico-mechanical properties make this bluish granite a perfect option for most applications. Absorption coefficient is rather low and alteration by thermal changes has not been observed. A secondary facies with yellow colour also occurs, spatially close to the topographic surface, and probably represents an alteration product of the original granite. This facies is also commercialized as ornamental stone. A radiological survey was carried out in the field, using a gamma ray spectrometer. The radiological background is quite homogeneous in the pluton, without significant differences between gamma ray fluxes of both facies (altered and non altered). The average contents of U, Th and K2O determined in situ with the spectrometer are 7.4 ppm, 0.8 ppm and 3.67%, respectively (n=15). Using U as a Ra proxy, the I index of the EU technical document 112 can be determined, and results in a value of 0.64 for the referred composition. This implies that the rock can be used without any restrictions for building purposes. However, a marked difference was observed in radon exhalation tests carried out in laboratorial facilities. The dominant blue variety shows radon exhalation rates comprised between 0.02 and 0.04 Bq.kg-1.h-1

  17. Longitudinal pulmonary function losses in Vermont granite workers. A reevaluation.

    PubMed

    Graham, W G; Weaver, S; Ashikaga, T; O'Grady, R V

    1994-07-01

    Previous studies have suggested that excessive losses of FVC and FEV1 were occurring in Vermont granite workers despite the fact that mean quartz levels existing in the industry were below the current OSHA standard of 100 micrograms/m3. We reexamined these losses in granite workers over an 8-year period, testing the workforce biennially from 1979 to 1987. All workers, including stone shed, quarry, and office, were offered forced spirometry using a 10-L water-sealed spirometer (Collins). In the peak year of participation (1983), 887 workers out of a total of approximately 1,400 were tested. Estimates of longitudinal loss were based on 711 workers who participated in at least three of the surveys. The mean age of this group was 42.9 years, and the mean years employed was 19.3 years; 21.4 percent were non-smokers (NS), 34.2 percent were ex-smokers (ES), and 44.4 percent were current smokers (CS). Average annual losses of FVC were 0.018 (SD = 0.056) L (CS, 0.025 L; NS, 0.006 L: and ES, 0.016 L). Average annual losses of FEV1 were 0.030 (SD = 0.041) L (CS, 0.038 L; NS, 0.020 L; and ES, 0.027 L). Analysis of covariance indicated that losses were related to the initial values for FVC or FEV1, height, age, and smoking status. After adjusting for these variables, the losses of both FVC and FEV1 were not correlated with years employed in the granite industry. No significant differences existed in the loss of FVC or FEV1 in categories of workers exposed to different levels of granite dust, eg, office, quarry, and stone shed workers. The annual losses of pulmonary function were significantly smaller than those estimated previously, which were 0.070 to .080 L in FVC, and 0.050-0.070 L in FEV1. We conclude that dust levels in the Vermont granite industry, which have been in conformance with OSHA permissible exposure limits, do not accelerate pulmonary function loss.

  18. Miocene rapakivi granites in the southern Death Valley region, California, USA

    USGS Publications Warehouse

    Calzia, J.P.; Ramo, O.T.

    2005-01-01

    Rapakivi granites in the southern Death Valley region, California, include the 12.4-Ma granite of Kingston Peak, the ca. 10.6-Ma Little Chief stock, and the 9.8-Ma Shoshone pluton. All of these granitic rocks are texturally zoned from a porphyritic rim facies, characterized by rapakivi textures and miarolitic cavities, to an equigranular aplite core. These granites crystallized from anhydrous and peraluminous to metaluminous magmas that were more oxidized and less alkalic than type rapakivi granites from southern Finland. Chemical and isotope (Nd-Sr-Pb) data suggest that rapakivi granites of the southern Death Valley region were derived by partial melting of lower crustal rocks (possibly including Mesozoic plutonic component) with some mantle input as well; they were emplaced at shallow crustal levels (4 km) in an actively extending orogen.

  19. Potassium-Argon Age from a Granite at Mount Wilbur, Queen Maud Range, Antarctica.

    PubMed

    Minshew, V H

    1965-11-01

    The basement complex of the Robert Scott Glacier area, Queen Maud Range, Antarctica, consists of a complex suite of metasedimentary and metavolcanic rocks intruded by light gray biotite granite. Brown biotite from a granite at Mount Wilbur was dated by the potassium-argon method at 470 +/- 14 million years; this age coincides closely with many other ages from granitic rocks in the Transantarctic Mountains.

  20. Importance of lunar granite and KREEP in very high potassium (VHK) basalt petrogenesis

    NASA Technical Reports Server (NTRS)

    Neal, Clive R.; Taylor, Lawrence A.; Lindstrom, Marilyn M.

    1988-01-01

    Analysis of five very high potassium (VHK) basalts from Apollo 14 breccia 14303 shows the presence of a KREEP component. An assimilation and fractional crystallization model is presented to describe the basalt evolution. The influence of granite assimilation on the basalt evolution is discussed. The presence of VHK basalts containing only a granite signature and those with both granite and KREEP signatures suggests that there are at least two different VHK basalt flows at the Apollo 14 site.

  1. Postcollisional granites in the South Tien Shan Variscan Collisional Belt, Kyrgyzstan

    NASA Astrophysics Data System (ADS)

    Solomovich, L. I.; Trifonov, B. A.

    2002-11-01

    Two major types of the potassium-rich postcollisional granites of Permian age were studied in the South Tien Shan Variscan Collisional Belt. The first type, metaluminous granites of the Jangart complex, are located along the southeastern boundary of this belt with the Precambrian Tarim Block. The plagioclase rims on K-feldspar megacrysts (rapakivi texture), extremely high FeO t/(FeO t+MgO) ratio, indications of the low H 2O and O 2 fugacities, high concentrations of the incompatible elements especially light rare earth elements (LREE), Ba, Nb along with heightened contents of the compatible elements especially Ni, Cr and moderately initial 87Sr/ 86Sr ratio (Sr 0=0.7075) make those granites similar to other rapakivi granites. The second type, peraluminous granites of the Inylchek complex, is located along the northwestern boundary of the belt with the Caledonian Kazakh Microcontinent. Those granites are rich in F, B, Li, Rb, Cs, Sn, Ta and heavy rare earth elements (HREE), but are poor in Ba, Sr, Ni and Cr and are characterized by the relatively high initial 87Sr/ 86Sr ratio (Sr 0=0.7098). Li-mica granites are distributed widely among them. The granites of a transitional type (Uchkoshkon complex) occupy an intermediate geographic position between major granite types. The initial Sr isotopic composition of the transitional granites varies widely (Sr 0 from 0.7080 to 0.7256). The variation in chemical composition of the coeval postcollisional granites across the Collisional belt, together with the variability of initial Sr isotopic ratios of the transitional granites, are thought to indicate basement heterogeneity. This heterogeneity, in turn, is probably related to thrusting of the Tarim Block under South Tien Shan during the collision.

  2. Oxygen isotope studies of early Precambrian granitic rocks from the Giants Range batholith, northeastern Minnesota, U.S.A.

    USGS Publications Warehouse

    Viswanathan, S.

    1974-01-01

    Oxygen isotope studies of granitic rocks from the 2.7 b.y.-old composite Giants Range batholith show that: (1) ??(O18)quartz values of 9 to 10 permil characterize relatively uncontaminated Lower Precambrian, magmatic granodiorites and granites; (2) granitic rocks thought to have formed by static granitization have ??(O18)quartz values that are 1 to 2 permil higher than magmatic granitic rocks; (3) satellite leucogranite bodies have values nearly identical to those of the main intrusive phases even where they transect O18-rich metasedimentary wall rocks; (4) oxygen isotopic interaction between the granitic melts and their O18-rich wall rocks was minimal; and (5) O18/O18 ratios of quartz grains in a metasomatic granite are largely inherited from the precursor rock, but during the progression - sedimentary parent ??? partially granitized parent ??? metasomatic granite ??? there is gradual decrease in ??(O18)quartz by 1 to 2 permil. ?? 1974.

  3. Determination of geochemical affinities of granitic rocks from the Aue-Schwarzenberg zone (Erzgebirge, Germany) by multivariate statistics

    USGS Publications Warehouse

    Forster, H.-J.; Davis, J.C.

    2000-01-01

    Variscan granites of the Erzgebirge region can be effectively classified into five genetically distinct major groups by canonical analysis of geochemical variables. The same classification procedure, when applied to small plutons in the Aue-Schwarzenberg granite zone (ASGZ), shows that all ASGZ granites have compositional affinities to low-F biotite or low-F two-mica granite groups. This suggests that the ASGZ granites were emplaced during the first, late-collisional stage of silicic magmatism in the region, which occurred between about 325 and 318 Ma. The numerous biotite granite bodies in the zone are geochemically distinct from both the neighboring Kirchberg granite pluton and the spatially displaced Niederbobritzsch biotite granite massif. Instead, these bodies seem to constitute a third sub-group within the low-F biotite granite class. The ASGZ biotite granites represent three or more genetically distinct bodies, thus highlighting the enormous compositional variability within this group of granites. Least evolved samples of two-mica granites from the ASGZ apparently reflect the assimilation of low-grade metamorphic country rocks during emplacement, altering the original composition of the melts by enhancing primary Al content. The same genesis is implied for the rare "cordierite granite" facies of the Bergen massif, the type pluton for the low-F two-mica granite group in the Erzgebirge.

  4. Magmatic and crustal differentiation history of granitic rocks from Hf-O isotopes in zircon.

    PubMed

    Kemp, A I S; Hawkesworth, C J; Foster, G L; Paterson, B A; Woodhead, J D; Hergt, J M; Gray, C M; Whitehouse, M J

    2007-02-16

    Granitic plutonism is the principal agent of crustal differentiation, but linking granite emplacement to crust formation requires knowledge of the magmatic evolution, which is notoriously difficult to reconstruct from bulk rock compositions. We unlocked the plutonic archive through hafnium (Hf) and oxygen (O) isotope analysis of zoned zircon crystals from the classic hornblende-bearing (I-type) granites of eastern Australia. This granite type forms by the reworking of sedimentary materials by mantle-like magmas instead of by remelting ancient metamorphosed igneous rocks as widely believed. I-type magmatism thus drives the coupled growth and differentiation of continental crust.

  5. Magmatic and crustal differentiation history of granitic rocks from Hf-O isotopes in zircon.

    PubMed

    Kemp, A I S; Hawkesworth, C J; Foster, G L; Paterson, B A; Woodhead, J D; Hergt, J M; Gray, C M; Whitehouse, M J

    2007-02-16

    Granitic plutonism is the principal agent of crustal differentiation, but linking granite emplacement to crust formation requires knowledge of the magmatic evolution, which is notoriously difficult to reconstruct from bulk rock compositions. We unlocked the plutonic archive through hafnium (Hf) and oxygen (O) isotope analysis of zoned zircon crystals from the classic hornblende-bearing (I-type) granites of eastern Australia. This granite type forms by the reworking of sedimentary materials by mantle-like magmas instead of by remelting ancient metamorphosed igneous rocks as widely believed. I-type magmatism thus drives the coupled growth and differentiation of continental crust. PMID:17303751

  6. Differential rates of feldspar weathering in granitic regoliths

    USGS Publications Warehouse

    White, A.F.; Bullen, T.D.; Schulz, M.S.; Blum, A.E.; Huntington, T.G.; Peters, N.E.

    2001-01-01

    Differential rates of plagioclase and K-feldspar weathering commonly observed in bedrock and soil environments are examined in terms of chemical kinetic and solubility controls and hydrologic permeability. For the Panola regolith, in the Georgia Piedmont Province of southeastern United States, petrographic observations, coupled with elemental balances and 87Sr/86Sr ratios, indicate that plagioclase is being converted to kaolinite at depths > 6 m in the granitic bedrock. K-feldspar remains pristine in the bedrock but subsequently weathers to kaolinite at the overlying saprolite. In contrast, both plagioclase and K-feldspar remain stable in granitic bedrocks elsewhere in Piedmont Province, such as Davis Run, Virginia, where feldspars weather concurrently in an overlying thick saprolite sequence. Kinetic rate constants, mineral surface areas, and secondary hydraulic conductivities are fitted to feldspar losses with depth in the Panola and Davis Run regoliths using a time-depth computer spreadsheet model. The primary hydraulic conductivities, describing the rates of meteoric water penetration into the pristine granites, are assumed to be equal to the propagation rates of weathering fronts, which, based on cosmogenic isotope dating, are 7 m/106 yr for the Panola regolith and 4 m/106 yr for the Davis Run regolith. Best fits in the calculations indicate that the kinetic rate constants for plagioclase in both regoliths are factors of two to three times faster than K-feldspar, which is in agreement with experimental findings. However, the range for plagioclase and K-feldspar rates (kr = 1.5 x 10-17 to 2.8 x 10-16 mol m-2 s-1) is three to four orders of magnitude lower than for that for experimental feldspar dissolution rates and are among the slowest yet recorded for natural feldspar weathering. Such slow rates are attributed to the relatively old geomorphic ages of the Panola and Davis Run regoliths, implying that mineral surface reactivity decreases significantly with

  7. The adsorption behavior of U(VI) on granite.

    PubMed

    Fan, Q H; Hao, L M; Wang, C L; Zheng, Z; Liu, C L; Wu, W S

    2014-03-01

    The effects of pH, counter ions and temperature on the adsorption of U(VI) on Beishan granite (BsG) were investigated in the presence and absence of fulvic acid (FA) and humic acid (HA). The adsorption edge of U(VI) on BsG suggested that U(VI) adsorption was mainly controlled by ion exchange and outer-sphere complexation at low pH, whereas inner-sphere complex was the dominant adsorption species in the pH range of 4.0-9.0. Above pH 9.0, Na2U2O7 might play an important role in the rise of U(VI) adsorption again. Counter ions such as Cl(-), SO4(2-) and PO4(3-) can provoke U(VI) adsorption on BsG to some extent, which was directly correlated to the complexing ability of U(VI)-ligand. More noticeably, the large enhancement of U(VI) adsorption in the presence of phosphate can be attributed to the ternary complex formation (BsG-PO4-UO2), precipitation ((UO2)3(PO4)2(s)) and secondary phase (Na-autunite). Both FA and HA can slightly increase U(VI) adsorption at low pH, whereas they strongly inhibited U(VI) adsorption at high pH range. Artificial synthesized granite (AsG) prepared in the laboratory is impossible to use as an analogue of natural granite because of the large difference in the adsorption and surface properties. PMID:24509808

  8. Ultrasonic evaluation of the physical and mechanical properties of granites.

    PubMed

    Vasconcelos, G; Lourenço, P B; Alves, C A S; Pamplona, J

    2008-09-01

    Masonry is the oldest building material that survived until today, being used all over the world and being present in the most impressive historical structures as an evidence of spirit of enterprise of ancient cultures. Conservation, rehabilitation and strengthening of the built heritage and protection of human lives are clear demands of modern societies. In this process, the use of nondestructive methods has become much common in the diagnosis of structural integrity of masonry elements. With respect to the evaluation of the stone condition, the ultrasonic pulse velocity is a simple and economical tool. Thus, the central issue of the present paper concerns the evaluation of the suitability of the ultrasonic pulse velocity method for describing the mechanical and physical properties of granites (range size between 0.1-4.0 mm and 0.3-16.5 mm) and for the assessment of its weathering state. The mechanical properties encompass the compressive and tensile strength and modulus of elasticity, and the physical properties include the density and porosity. For this purpose, measurements of the longitudinal ultrasonic pulse velocity with distinct natural frequency of the transducers were carried out on specimens with different size and shape. A discussion of the factors that induce variations on the ultrasonic velocity is also provided. Additionally, statistical correlations between ultrasonic pulse velocity and mechanical and physical properties of granites are presented and discussed. The major output of the work is the confirmation that ultrasonic pulse velocity can be effectively used as a simple and economical nondestructive method for a preliminary prediction of mechanical and physical properties, as well as a tool for the assessment of the weathering changes of granites that occur during the serviceable life. This is of much interest due to the usual difficulties in removing specimens for mechanical characterization. PMID:18471849

  9. Ultrasonic evaluation of the physical and mechanical properties of granites.

    PubMed

    Vasconcelos, G; Lourenço, P B; Alves, C A S; Pamplona, J

    2008-09-01

    Masonry is the oldest building material that survived until today, being used all over the world and being present in the most impressive historical structures as an evidence of spirit of enterprise of ancient cultures. Conservation, rehabilitation and strengthening of the built heritage and protection of human lives are clear demands of modern societies. In this process, the use of nondestructive methods has become much common in the diagnosis of structural integrity of masonry elements. With respect to the evaluation of the stone condition, the ultrasonic pulse velocity is a simple and economical tool. Thus, the central issue of the present paper concerns the evaluation of the suitability of the ultrasonic pulse velocity method for describing the mechanical and physical properties of granites (range size between 0.1-4.0 mm and 0.3-16.5 mm) and for the assessment of its weathering state. The mechanical properties encompass the compressive and tensile strength and modulus of elasticity, and the physical properties include the density and porosity. For this purpose, measurements of the longitudinal ultrasonic pulse velocity with distinct natural frequency of the transducers were carried out on specimens with different size and shape. A discussion of the factors that induce variations on the ultrasonic velocity is also provided. Additionally, statistical correlations between ultrasonic pulse velocity and mechanical and physical properties of granites are presented and discussed. The major output of the work is the confirmation that ultrasonic pulse velocity can be effectively used as a simple and economical nondestructive method for a preliminary prediction of mechanical and physical properties, as well as a tool for the assessment of the weathering changes of granites that occur during the serviceable life. This is of much interest due to the usual difficulties in removing specimens for mechanical characterization.

  10. The adsorption behavior of U(VI) on granite.

    PubMed

    Fan, Q H; Hao, L M; Wang, C L; Zheng, Z; Liu, C L; Wu, W S

    2014-03-01

    The effects of pH, counter ions and temperature on the adsorption of U(VI) on Beishan granite (BsG) were investigated in the presence and absence of fulvic acid (FA) and humic acid (HA). The adsorption edge of U(VI) on BsG suggested that U(VI) adsorption was mainly controlled by ion exchange and outer-sphere complexation at low pH, whereas inner-sphere complex was the dominant adsorption species in the pH range of 4.0-9.0. Above pH 9.0, Na2U2O7 might play an important role in the rise of U(VI) adsorption again. Counter ions such as Cl(-), SO4(2-) and PO4(3-) can provoke U(VI) adsorption on BsG to some extent, which was directly correlated to the complexing ability of U(VI)-ligand. More noticeably, the large enhancement of U(VI) adsorption in the presence of phosphate can be attributed to the ternary complex formation (BsG-PO4-UO2), precipitation ((UO2)3(PO4)2(s)) and secondary phase (Na-autunite). Both FA and HA can slightly increase U(VI) adsorption at low pH, whereas they strongly inhibited U(VI) adsorption at high pH range. Artificial synthesized granite (AsG) prepared in the laboratory is impossible to use as an analogue of natural granite because of the large difference in the adsorption and surface properties.

  11. High Resolution Geophysical Characterization of Fractures within a Granitic Pluton

    NASA Astrophysics Data System (ADS)

    Pérez-Estaún, A.; Carbonell, R.

    2007-12-01

    The FEBEX underground gallery was excavated in the Aar Granite (Switzerland), a heterogeneous granite containing from very leucocratic facies to granodiorites. The geology of the gallery shows the existence of various sets of fractures with different attributes: geometry, kinematics, fracture infilling, etc. The study of the structural data, new observations on the FEBEX gallery itself and borehole televiewer data acquired in the newly drilled boreholes, have allowed to identify four sets of fractures. The first group of fractures has a typical distribution and characteristics of en echelon tension fractures and were formed in late magmatic stages, according with the paragenesis of the minerals that filled the craks. The main strike is around 300 (280-300). These fractures are deformed and displaced by the other group of faults. The second group corresponds to the lamprophyre dikes, of mantelic origin, with an orientation oblique to the tunnel, and slightly oblique to the first group of fractures (strike, 310-330). They were formed during an extension event well evidenced by their irregular margins and flame structures into the granite. The margins of these dikes show several reactivations as strike slip faults. Geophysical data has been acquired to characterized the fracture network of the surrounding volume within the FEBEX gallery. The geophysic data include new borehole logging such as Natural Gamma and Borehole Ground Penetrating radar. The processing and integration of these different data sets indicates that the GPR record can provide images of a third set of fractures, which are probably fluid filled. This set of fractures a subparallel to the tunnel axis and appear to intersect older boreholes which are nearly perpendicular to the axis of the FEBEX gallery.

  12. Lead-alpha age determinations of granitic rocks from Alaska

    USGS Publications Warehouse

    Matzko, John J.; Jaffe, H.W.; Waring, C.L.

    1957-01-01

    Lead-alpha activity age determinations were made on zircon from seven granitic rocks of central and southeastern Alaska. The results of the age determinations indicate two periods of igneous intrusion, one about 95 million years ago, during the Cretaceous period, and another about 53 million years ago, during the early part of the Tertiary. The individual ages determined on zircon from 2 rocks from southeastern Alaska and 1 from east-central Alaska gave results of 90, 100, and 96 million years; those determined on 4 rocks from central Alaska gave results of 47, 56, 58, and 51 million years.

  13. Constant strain frequency sweep measurements on granite rock.

    PubMed

    Haller, Kristian C E; Hedberg, Claes M

    2008-02-15

    Like many materials, granite exhibits both nonlinear acoustic distortion and slow nonequilibrium dynamics. Measurements to date have shown a response from both phenomena simultaneously, thus cross-contaminating the results. In this Letter, constant strain frequency sweep measurements eliminate the slow dynamics and, for the first time, permit evaluation of nonlinearity by itself characterized by lower resonance frequencies and a steeper slope. Measurements such as these are necessary for the fundamental understanding of material dynamics, and for the creation and validation of descriptive models.

  14. Spent fuel test project, Climax granitic stock, Nevada Test Site

    SciTech Connect

    Ramspott, L.D.

    1980-10-24

    The Spent Fuel Test-Climax (SFT-C) is a test of dry geologic storage of spent nuclear reactor fuel. The SFT-C is located at a depth of 420 m in the Climax granitic stock at the Nevada Test Site. Eleven canisters of spent commercial PWR fuel assemblies are to be stored for 3 to 5 years. Additional heat is supplied by electrical heaters, and more than 800 channels of technical information are being recorded. The measurements include rock temperature, rock displacement and stress, joint motion, and monitoring of the ventilation air volume, temperature, and dewpoint.

  15. An oxygen buffer for some peraluminous granites and metamorphic rocks.

    USGS Publications Warehouse

    Zen, E.

    1985-01-01

    The mineral assemblage biotite-garnet-muscovite-magnetite-quartz and its sub-sets are common in many peraluminous granites, schists and gneisses. If the biotite and garnet are reasonably iron-rich, then the system is a useful buffer for fO2. Available thermochemical data indicate that, in T-fO2 space, the buffer curve is located between the hematite-magnetite curve and the quartz-magnetite-fayalite curve, in a region that previously had no buffer curve applicable to peraluminous rocks. -J.A.Z.

  16. The effect of dilatancy on velocity anisotropy in Westerly granite

    NASA Technical Reports Server (NTRS)

    Soga, N.; Mizutani, H.; Spetzler, H.; Martin, R. J., III

    1978-01-01

    Jacketed samples of Westerly granite were fractured at confining pressures up to 1 kbar, and compressional and horizontally as well as vertically polarized shear velocities were measured in orthogonal directions perpendicular to the compression axis. Changes occurring with increased strain are described, and the velocity data were analyzed by application of the Anderson et al (1974) approach. Observed and calculated velocities are found to be in good agreement, and the degree of dilatancy was determined from the differences between the strains measured perpendicularly to the compression axis and the estimated elastic strains in those directions.

  17. Origin and tectonic implications of the ∼200 Ma, collision-related Jerai pluton of the Western Granite Belt, Peninsular Malaysia

    NASA Astrophysics Data System (ADS)

    Jamil, Azmiah; Ghani, Azman A.; Zaw, Khin; Osman, Syamir; Quek, Long Xiang

    2016-09-01

    Triassic granitoids (∼200-225 Ma) are widespread in the Western Belt of Peninsular Malaysia. The Main Range granite is the biggest batholith in the Western Belt composed of peraluminous to metaluminous granite and granodiorite and displays typical ilmenite-series characteristics. Jerai granitic pluton occurs at the northwestern part of the Main Range granite batholith. The Jerai granite can be divided into three facies: (i) biotite-muscovite granite; (ii) tourmaline granite; and (iii) pegmatite and aplopegmatite. Biotite-muscovite granite accounts for 90% of the Jerai pluton, and the rest is tourmaline granite. Geochemical data reveal that pegmatite and tourmaline granite are more differentiated than biotite-muscovite granite. Both pegmatite and tourmaline granite have a higher SiO2 content (70.95-83.94% versus 69.45-73.35%) and a more pronounced peraluminous character. The U-Pb zircon geochronology of the Jerai granite gave an age ranging from 204 ± 4.3 Ma, 205 ± 4 Ma and 205 ± 2 Ma for pegmatite biotite-muscovite granite and tourmaline granite, respectively. The biotite-muscovite Jerai granites are similar to S-type Main Range granite, but the tourmaline granite has a signature of late-stage hydrothermal fluid interaction such as tourmaline quartz pods, the accumulation of large pegmatitic K-feldspar, pronounced peraluminous character, higher SiO2 content. Age evidence of these two granitic facies suggest that they are from the same magma.

  18. A generalized law for brittle deformation of Westerly granite

    USGS Publications Warehouse

    Lockner, D.A.

    1998-01-01

    A semiempirical constitutive law is presented for the brittle deformation of intact Westerly granite. The law can be extended to larger displacements, dominated by localized deformation, by including a displacement-weakening break-down region terminating in a frictional sliding regime often described by a rate- and state-dependent constitutive law. The intact deformation law, based on an Arrhenius type rate equation, relates inelastic strain rate to confining pressure Pc, differential stress ????, inelastic strain ??i, and temperature T. The basic form of the law for deformation prior to fault nucleation is In ????i = c - (E*/RT) + (????/a??o)sin-??(???? i/2??o) where ??o and ??o are normalization constants (dependent on confining pressure), a is rate sensitivity of stress, and ?? is a shape parameter. At room temperature, eight experimentally determined coefficients are needed to fully describe the stress-strain-strain rate response for Westerly granite from initial loading to failure. Temperature dependence requires apparent activation energy (E* ??? 90 kJ/mol) and one additional experimentally determined coefficient. The similarity between the prefailure constitutive law for intact rock and the rate- and state-dependent friction laws for frictional sliding on fracture surfaces suggests a close connection between these brittle phenomena.

  19. Comparative study of dark patinas on granitic outcrops and buildings.

    PubMed

    Prieto, B; Aira, N; Silva, B

    2007-08-01

    Formation of dark patinas on rocky surfaces is mainly related to the deposition of gases and particles and to sulphation mechanisms. In the present study, samples of dark patinas taken from granitic outcrops and from granitic buildings were examined in an attempt to understand the mechanisms of their formation. The outcrops are located in non-polluted areas and are characterized by the absence of any extraneous material that provides calcium, such as e.g. mortar. The buildings are located in areas with low levels of pollution. The climate in the study area favours proliferation of microorganisms. Important differences between the patinas sampled from outcrops and from buildings were observed, as the former are of biological origin and the latter of anthropogenic origin. Although the levels of pollution are low in the sampling area, sulphur was present in all of the samples from urban buildings. Sulphur was not present in patinas from outcrops or in patinas from monuments that are assumed to behave as outcrops (dolmens), although the latter are also of anthropogenic origin. Finally, the patinas were found to be formed by elements accumulated on the surface and not from elements contained within the rock itself.

  20. Characterization of bacterial community structure on a weathered pegmatitic granite.

    PubMed

    Gleeson, Deirdre B; Kennedy, Nabla M; Clipson, Nicholas; Melville, Karrie; Gadd, Geoffrey M; McDermott, Frank P

    2006-05-01

    This study exploited the contrasting major element chemistry of a pegmatitic granite to investigate mineralogical influences on bacterial community structure. Intact crystals of variably weathered muscovite, plagioclase, K-feldspar, and quartz were extracted, together with whole-rock granite. Environmental scanning electron microscopy revealed a diversity of bacterial structures, with rods and cocci clearly visible on surfaces of all mineral types. Bacterial automated ribosomal intergenic spacer analysis was used to generate a ribotype profile for each mineral. A randomization test revealed that community fingerprints differed between different mineral types, whereas canonical correspondence analysis (CCA) showed that mineral chemistry affected individual bacterial ribotypes. CCA also revealed that Al, Si, and Ca had a significant impact on bacterial community structure within the system, which contrasts with the finding within fungal communities that although Al and Si also had a significant impact, K rather than Ca was important. The bacterial populations associated with different minerals were different. Members of each of these populations were found almost exclusively on a single mineral type, as was previously reported for fungal populations. These results show that bacterial community structure was driven by the chemical composition of minerals, indicating selective pressure by individual chemical elements on bacterial populations in situ.

  1. Permeability Evolution of Granite Gneiss During Triaxial Creep Tests

    NASA Astrophysics Data System (ADS)

    Liu, L.; Xu, W. Y.; Wang, H. L.; Wang, W.; Wang, R. B.

    2016-09-01

    Permeability is an important factor for seepage analysis of rock material, and a key factor in ensuring the safety of underground works. In this study, the permeability evolution of granite gneiss during triaxial creep tests was investigated. In the context of an underground oil storage cavern in China, a series of hydro-mechanical coupling creep tests were conducted on rock cores of granite gneiss at three different pore pressures to reveal the effect of pore pressure on the permeability evolution and to investigate the correlation between the permeability and volumetric strain during the creep process. During the creep tests, the permeability decreases in the initial loading phase. At all deviatoric stress levels, the permeability remains stable in the steady creep stage and increases rapidly in the accelerated creep stage. Based on the test data, the initial permeability, steady permeability and peak permeability at various stress levels are defined. The effect of pore pressure on the permeability is captured by a linear model. In addition, the relationship between permeability and volumetric strain can be described as a process divided into three phases, with different functions in each phase.

  2. A petrologic assessment of internal zonation in granitic pegmatites

    NASA Astrophysics Data System (ADS)

    London, David

    2014-01-01

    Cameron et al. (1949) devised the nomenclature and delineated the patterns of internal zonation within granitic pegmatites that are in use today. Zonation in pegmatites is manifested both in mineralogy and in fabric (mineral habits and rock texture). Although internal zonation is a conspicuous and distinctive attribute of pegmatites, there has been no thorough effort to explain that mineralogical and textural evolution in relation to the zoning sequence presented by Cameron et al. (1949), or in terms of the comprehensive petrogenesis of pegmatite bodies (pressure, temperature, and whole-rock composition). This overview of internal zonation within granitic pegmatites consists of four principal parts: (1) a historic review of the subject, (2) a summary of the current understanding of the pegmatite-forming environment, (3) the processes that determine mineralogical and textural zonation in pegmatites, and (4) the applications of those processes to each of the major zones of pegmatites. Based on the concepts presented in London (2008), the fundamental determinates of the internal evolution of pegmatite zones are: (1) the bulk composition of melt, (2) the magnitude of liquidus undercooling prior to the onset of crystallization, (3) subsolidus isothermal fractional crystallization, by which eutectic or minimum melts fractionate by sequential, non-eutectic crystallization, (4) constitutional zone refining via the creation of a boundary layer liquid, chemically distinct from but continuous with the bulk melt at the crystallization front, and (5) far-field chemical diffusion, the long-range and coordinated diffusion of ions, particularly of alkalis and alkaline earths, through melt.

  3. Autoradiographic study of actinide sorption on climax stock granite

    SciTech Connect

    Beall, G.W.; O'Kelley, G.D.; Allard, B.

    1980-06-01

    An autoradiographic technique that employed an arrangement for placing in firm contact Polaroid sheet film, a scintillator screen, and the radioactive face of a specimen was applied to a study of the sorption of americium, neptunium, plutonium, and uranium on Climax Stock granite under varying conditions of pH and Eh. Qualitative agreement was found between the sorption of americium on crushed, pure minerals and on the minerals comprising the specimen of Climax Stock granite. The observations also supported a mechanism for reduction of Np(V) to Np(IV) and Pu(VI) to Pu(IV) by Fe(II)-containing minerals. There was no evidence for reduction of U(VI) by the Fe(II)-containing minerals, although the uranium, assumed to be present as UO/sub 2//sup 2 +/, appeared to be the only actinide species to exhibit sorption by a simple, cation-exchange mechanism at particular mineral sites. Some implications of these results for nuclear waste isolation are discussed briefly.

  4. Calcium isotopes in igneous rocks and the origin of granite

    SciTech Connect

    Marshall, B.D.; DePaolo, D.J. )

    1989-04-01

    The K-Ca radioactive parent-daughter system provides a tool for tracing the origins of igneous rocks. It is complementary to other isotopic systems because as stoichiometric constituents of major minerals, the concentrations of K and Ca, and the K/Ca ratio in rocks, are simply related to mineralogy. In this paper the authors report the first high-precision calcium isotopic analyses of continental granitic rocks, island arc rocks, and mid-ocean ridge basalts. These data show that mid-ocean ridge basalts have the low {sup 40}Ca/{sup 42}Ca ratios expected for the Earth's mantle, but that island arc rocks have slightly higher {sup 40}Ca/{sup 42}Co ratios indicative of crustal calcium in their magma sources. Many granitic rocks have high initial {sup 40}Ca/{sup 42}Ca ratios, and in conjunction with independent evidence for the age of the crustal sources, these ratios provide constraints on the K/Ca ratios, and in turn on the silica contents and residual mineralogy, of the deep crustal magma sources.

  5. Characterization of fungal community structure on a weathered pegmatitic granite.

    PubMed

    Gleeson, Deirdre B; Clipson, Nicholas; Melville, Karrie; Gadd, Geoffrey M; McDermott, Frank P

    2005-10-01

    This study exploited the contrasting major element chemistry of adjacent, physically separable crystals of framework and sheet silicates in a pegmatitic granite to investigate the mineralogical influences of fungal community structure on mineral surfaces. Large intact crystals of variably weathered muscovite, plagioclase, K-feldspar, and quartz were individually extracted, together with whole-rock granite. Environmental scanning electron microscopy (ESEM) revealed a diversity of fungal structures, with microcolonial fungi and fungal hyphae clearly visible on surfaces of all mineral types. Fungal automated ribosomal intergenic spacer analysis (FARISA) was used to generate a ribotype profile for each mineral sample and a randomization test revealed that ribotype profiles, or community fingerprints, differed between different mineral types. Canonical correspondence analysis (CCA) revealed that mineral chemistry affected individual fungal ribotypes, and strong relationships were found between certain ribotypes and particular chemical elements. This finding was further supported by analysis of variance (ANOVA) of the 16 most abundant ribotypes within the community. Significantly, individual ribotypes were largely restricted to single mineral types and ribotypes clustered strongly on the basis of mineral type. CCA also revealed that Al, Si, and Ca had a significant impact on fungal community structure within this system. These results show that fungal community structure was driven by the chemical composition of mineral substrates, indicating selective pressure by individual chemical elements on fungal populations in situ.

  6. Desorption of cesium from granite under various aqueous conditions.

    PubMed

    Wang, Tsing-Hai; Li, Ming-Hsu; Wei, Yuan-Yaw; Teng, Shi-Ping

    2010-12-01

    In this work the desorption of cesium ions from crushed granite in synthetic groundwater (GW) and seawater (SW) was investigated. Results were compared with those obtained in deionized water (DW) and in two kinds of extraction solutions, namely: MgCl(2) and NaOAc (sodium acetate). In general, the desorption rate of Cs from crushed granite increased proportionally with initial Cs loadings. Also, amounts of desorbed Cs ions followed the tendency in the order SW>GW>NaOAc approximately equal MgCl(2)>DW solutions. This indicated that the utilization of extraction reagents for ion exchange will underestimate the Cs desorption behavior. Fitting these experimental data by Langmuir model showed that these extraction reagents have reduced Cs uptake by more than 90%, while only less than 1% of adsorbed Cs ions are still observed in GW and SW solutions in comparison to those in DW. Further SEM/EDS mapping studies clearly demonstrate that these remaining adsorbed Cs ions are at the fracture areas of biotite.

  7. The compositional evolution of pollucite from African granitic pegmatites

    NASA Astrophysics Data System (ADS)

    Teertstra, David K.; Černiý, Petr

    1997-08-01

    Occurrences of pollucite are known from nine highly fractionated granitic pegmatites in Zimbabwe, Namibia and Mozambique. The pollucite is typically associated with spodumene, petalite, amblygonite, quartz and feldspar. The primary pollucite has {Si}/{Al} (at.) ratios of 2.47 to 2.57 and CRK = 100(Cs + Rb + K)/(Cs +, Rb + K + Na + Ca + Li) of 73.5 to 87.7. Extensive re-equilibration generated blebs and veins of (Cs, Al) rich pollucite with compositions trending towards end-member pollucite CsAIS 2O 6 with {Si}/{Al} = 2.00 and CRK = 100. Characteristic sequences of alteration by coarse veins of lepidolite, quartz and feldspars, fine veins of muscovite and spodumene, and replacement by feldspar and clay minerals are well-developed in African pollucite. The crystal chemistry, compositional ranges, character of subsolidus re-equilibration, and veining, alteration plus metasomatic features correspond to those observed at other pollucite localities, documenting general uniformity of pollucite crystallisation and subsolidus reactions in granitic pegmatites. Veining, replacement and cryptic processes such as analcimisation may significantly reduce Cs grades in apparently monomineralic pollucite ore, but late cation exchange to analcime is limited at the localities axamined. This suggests that leaching of Cs from undisturbed capsules of ceramic radwaste, which utilise a pollucite phase for containment of radioactive Cs isotopes, will be negligible in a Na poor environment.

  8. The Taitao Granites: I-type granites formed by subduction of the Chile Ridge and its implication in growth of continental crusts

    NASA Astrophysics Data System (ADS)

    Anma, Ryo

    2016-04-01

    Late Miocene to Early Pliocene granite plutons are exposed at the tip of the Taitao peninsula, the westernmost promontory of the Chilean coast, together with a contemporaneous ophiolite with a Penrose-type stratigraphy. Namely, the Taitao granites and the Taitao ohiolite, respectively, are located at ~30 km southeast of the Chile triple junction, where a spreading center of the Chile ridge system is subducting underneath the South America plate. This unique tectonic setting provides an excellent opportunity to study the generation processes of granitic magmas at a ridge subduction environment, and the complex magmatic interactions between the subducting ridge, overlying crust and sediments, and mantle. This paper reviews previous studies on the Taitao ophiolite/granite complex and use geochemical data and U-Pb age distributions of zircons separated from igneous and sedimentary rocks from the area to discuss the mechanism that formed juvenile magma of calc-alkaline I-type granites during ridge subduction. Our model implies that the magmas of the Taitao granites formed mainly due to partial melting of hot oceanic crust adjacent to the subducting mid-oceanic ridge that has been under influence of deep crustal contamination and/or metasomatized sub-arc mantle through slab window. The partial melting took place under garnet-free-amphibolite conditions. The juvenile magmas then incorporated a different amount of subducted sediments to form the I-type granites with various compositions. The Taitao granites provide an ideal case study field that shows the processes to develop continental crusts out of oceanic crusts through ridge subduction.

  9. Geochemistry and petrogenesis of Proterozoic granitic rocks from northern margin of the Chotanagpur Gneissic Complex (CGC)

    NASA Astrophysics Data System (ADS)

    Yadav, Bhupendra S.; Wanjari, Nishchal; Ahmad, Talat; Chaturvedi, Rajesh

    2016-07-01

    This study presents the geochemical characteristics of granitic rocks located on the northern margin of Chotanagpur Gneissic Complex (CGC), exposed in parts of Gaya district, Bihar and discusses the possible petrogenetic process and source characteristics. These granites are associated with Barabar Anorthosite Complex and Neo-proterozoic Munger-Rajgir group of rocks. The granitic litho-units identified in the field are grey, pink and porphyritic granites. On the basis of geochemical and petrographic characteristics, the grey and pink granites were grouped together as GPG while the porphyritic granites were named as PG. Both GPG and PG are enriched in SiO2, K2O, Na2O, REE (except Eu), Rb, Ba, HFSE (Nb, Y, Zr), depleted in MgO, CaO, Sr and are characterised by high Fe* values, Ga/Al ratios and high Zr saturation temperatures (GPGavg˜ 861 ∘C and PGavg˜ 835 ∘C). The REE patterns for GPG are moderately fractionated with an average (La/Yb)N˜ 4.55 and Eu/Eu* ˜ 0.58, than PG which are strongly fractionated with an average (La/Yb)N˜ 31.86 and Eu/Eu* ˜ 0.75. These features indicate that the granites have an A-type character. On the basis of geochemical data, we conclude that the granites are probably derived from a predominant crustal source with variable mantle involvement in a post-collisional setting.

  10. A reconnaissance of the Archean complex of the Granite Gorge, Grand Canyon, Arizona

    USGS Publications Warehouse

    Noble, L.F.; Hunter, J. Fred

    1917-01-01

    The field work upon which this article is based was done in March and April, 1914. From Garnet Canyon, near the west end of the Granite Gorge, the route followed the Tonto trail along the so-called lower plateau, or Tonto platform, to Red Canyon, at the east end of the Granite Gorge.

  11. Visualization of microcrack anisotropy in granite affected by afault zone, using confocal laser scanning microscope

    SciTech Connect

    Onishi, Celia T.; Shimizu, Ichiko

    2004-01-02

    Brittle deformation in granite can generate a fracture system with different patterns. Detailed fracture analyses at both macroscopic and microscopic scales, together with physical property data from a drill-core, are used to classify the effects of reverse fault deformation in four domains: (1) undeformed granite, (2) fractured granite with cataclastic seams, (3) fractured granite from the damage zone, and (4) foliated cataclasite from the core of the fault. Intact samples from two orthogonal directions, horizontal (H) and vertical (V), from the four domains indicate a developing fracture anisotropy toward the fault, which is highly developed in the damage zone. As a specific illustration of this phenomenon, resin impregnation, using a confocal laser scanning microscope (CLSM) technique is applied to visualize the fracture anisotropy developed in the Toki Granite, Japan. As a result, microcrack networks have been observed to develop in H sections and elongate open cracks in V sections, suggesting that flow pathways can be determined by deformation.

  12. Neo-tectonic fracturing after emplacement of quaternary granitic pluton in the Kakkonda geothermal field, Japan

    SciTech Connect

    Doi, N.; Kato, O.; Kanisawa, S.; Ishikawa, K.

    1995-12-31

    The fracture which occurs in the Kakkonda geothermal system was formed by neo-tectonic stress after the emplacement of the neo-granite (Quaternary Kakkonda Granite) at middle Pleistocene to recent. The characteristic contrast in permeability at ca.1.5 km is strongly controlled by the contact metamorphic zone, especially cordierite and higher grade metamorphic zones, in which the high temperature (320{degrees}C<) and low permeable deep reservoir was created. The five geothermal wells 2.5-3.0 km deep have clarified that a microearthquake zone below -1.0 km shows high permeability especially at the margin of the Kakkonda Granite, and low permeability outside of a microearthquake zone. The Kakkonda Granite is a composite pluton which has very few fractures inside of it. Thus, neo-tectonic fracturing has developed in the non-metamorphosed Tertiary formations and the margin of the Kakkonda Granite.

  13. Mobility of heavy metals through granitic soils using mini column infiltration test

    NASA Astrophysics Data System (ADS)

    Zarime, Nur'Aishah; Yaacob, W. Z. W.

    2014-09-01

    This study is about the mobility of cadmium through compacted granitic soils. Two granitic soils namely the Broga (BGR) and Kajang (KGR) granitic soils were collected in Selangor, Malaysia. Physical and chemical tests were applied for both granitic soils to determine the physical and chemical properties of soil materials. Physical test results shows granitic soils (BGR and KGR) have high percentage of sand ranging between 54%-63% and 46%-54% respectively, an intermediate and intermediate to high plasticity index as well as high specific gravity ie; 2.50-2.59 and 2.45-2.66 respectively. For chemical test, granitic soils shows acidic pH values ranged from 5.35-5.85 for BGR and pH 5.32-5.54 for KGR. For organic matter, SSA and CEC test, it shows low values ranged from 0.22%-0.34% and 0.39%- 0.50% respectively for organic matter test, 17.96 m2/g-21.93 m2/g and 25.76 m2/g-26.83 m2/g respectively for SSA test and 0.79 meq/100g-1.35 meq/100g and 1.31 meq/100g-1.35 meq/100g respectively for CEC test. Mini column infiltration test was conducted to determine the retention of cadmium while flowing through granite soils. This test conducted based on the falling head permeability concepts. Different G-force ranging from 231G to 1442G was used in this test. The breakthrough curves show the concentration of Cd becomes higher with the increasing of G-force for both granitic samples (BGR and KGR). The selectivity sorption for both granites ranked in the following decreasing order of; 231G>519G>923G>1442G. Results demonstrated that granitic soils also have low buffering capacity due to low resist of pH changes.

  14. Geochronology and sources of late Neoproterozoic to Cambrian granites of the Saldania Belt

    NASA Astrophysics Data System (ADS)

    Chemale, F.; Scheepers, R.; Gresse, P. G.; van Schmus, W. R.

    2011-04-01

    The Saldania Belt (SB), located in the southernmost part of South Africa, contains S-, I-, and A-type granites. Whole-rock Sm-Nd data for the Saldania granites indicate the presence of a juvenile as well as inherited crustal signature. The earlier S-type granites have ɛNd( t) values from -4.2 to -3.28 (for t = 550 Ma). In contrast, the intermediate I-type and youngest A-type and highly fractionated I-type granites display ɛNd values ranging from -1.44 to -3.68 (for t = 540 Ma) and from +3.66 to +5.1(for t = 530 Ma), respectively. The U-Pb single zircon data of A-type granites exposed in the Western Branch of the SB yielded dates from 524 ± 8 to 510 ± 4 Ma, whereas an S-type granite, situated in the Southern Branch of the SB and represented by the syn- to late-tectonic Rooiklip Granite, yielded an age of 527 ± 8 Ma. The volcano-sedimentary rocks intruded by these granites display Nd model ages from Ga to 1.67 Ga and ɛNd( t) values from -6.58 to +3.34 (for t = 560 Ma) with isotope signature similar to those of the granites. The S- and I-type granitic magmatism is mostly a product of melting of an earlier crust (Mesoproterozoic to Paleoproterozoic) with different degree of juvenile contribution. The obtained isotope data and field relationship support the hypothesis that the lithological units of the SB were affected by the late Neoproterozoic to Early Cambrian tectonism, related to compressive deformational processes at the southern margin of the Kalahari Plate and probably correlated with the Sierra La Ventana Belt basement.

  15. Mineralogical Control on Microbial Diversity in a Weathered Granite?

    NASA Astrophysics Data System (ADS)

    Gleeson, D.; Clipson, N.; McDermott, F.

    2003-12-01

    Mineral transformation reactions and the behaviour of metals in rock and soils are affected not only by physicochemical parameters but also by biological factors, particularly by microbial activity. Microbes inhabit a wide range of niches in surface and subsurface environments, with mineral-microbe interactions being generally poorly understood. The focus of this study is to elucidate the role of microbial activity in the weathering of common silicate minerals in granitic rocks. A site in the Wicklow Mountains (Ireland) has been identified that consists of an outcrop surface of Caledonian (ca. 400 million years old) pegmatitic granite from which large intact crystals of variably weathered muscovite, plagioclase, K-feldspar and quartz were sampled, together with whole-rock granite. Culture-based microbial approaches have been widely used to profile microbial communities, particularly from copiotrophic environments, but it is now well established that for oligotrophic environments such as those that would be expected on weathering faces, perhaps less than 1% of microbial diversity can be profiled by cultural means. A number of culture-independent molecular based approaches have been developed to profile microbial diversity and community structure. These rely on successfully isolating environmental DNA from a given environment, followed by the use of the polymerase chain reaction (PCR) to amplify the typically small quantities of extracted DNA. Amplified DNA can then be analysed using cloning based approaches as well as community fingerprinting systems such as denaturing gradient gel electrophoresis (DGGE), terminal restriction fragment length polymorphism (TRFLP) and ribosomal intergenic spacer analysis (RISA). Community DNA was extracted and the intergenic spacer region (ITS) between small (16S) and large (23S) bacterial subunit rRNA genes was amplified. RISA fragments were then electrophoresed on a non-denaturing polyacrylamide gel. Banding patterns suggest that

  16. 76 FR 60493 - Settlement Agreements for Recovery of Past Response Costs; Granite Timber Post and Pole Site...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-29

    ... AGENCY Settlement Agreements for Recovery of Past Response Costs; Granite Timber Post and Pole Site, Philipsburg, Granite County, MT AGENCY: Environmental Protection Agency (EPA). ACTION: Notice and Request for... Mark Metesh (Settling Party), regarding the Granite Timber Site (Site), located 5 miles south...

  17. 75 FR 16827 - Notice of Availability of the Draft Granite Mountain Wind, LLC Wind Energy Generation Project...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-02

    ... Report (EIR) for the proposed Granite Mountain Wind Energy Generation Project and by this notice is... related to the proposed Granite Mountain Wind Energy Generation Project by any of the following methods: Web site: http://www.blm.gov/ca/st/en/fo/barstow.html . E-mail: GraniteWindProject@blm.gov . Fax:...

  18. The geochemical characteristics of Haiyang A-type granite complex in Shandong, eastern China

    NASA Astrophysics Data System (ADS)

    Li, He; Ling, Ming-xing; Ding, Xing; Zhang, Hong; Li, Cong-ying; Liu, Dun-yi; Sun, Wei-dong

    2014-07-01

    Haiyang granite complex consists of K-feldspar granite and syenite, with a total exposure area of ~ 600 km2. The K-feldspar granite is metaluminous (A/CNK = 0.70 to 0.99) and the syenite is slightly peraluminous (A/CNK = 1.01 to 1.10), both of which have typical characteristics of A-type granite with high total alkali contents and FeOT/(FeOT + MgO) ratios. Zircon U-Pb age are 116.8 ± 1.7 Ma and 115.8 ± 2.2 Ma, for the K-feldspar granite and the syenite, respectively. This is consistent with field observation that the syenite intruded into the K-feldspar granite. Varied zircon O isotope (5.65-7.78‰ for K-feldspar granite and 4.68-7.08‰ for syenite) with peak values that are marginally higher than those of mantle zircon reflects important mantle contributions. These together with large variation of zircon εHf(t) values of K-feldspar granite (- 22.4 to - 15.6) and syenite (- 24.6 to - 13.5), can best be explained by the involvement of at least two components, e.g., enriched lithospheric mantle +/- subducted materials, and upwelling asthenosphere. Apatite has right decline REE pattern. The apatite from K-feldspar granite has higher Cl contents than those of syenite, implying more influence from a subduction released fluid in K-feldspar granite source. This distinction is supported by the systematically higher oxygen fugacity of K-feldspar granite as indicated by zircon Ce4 +/Ce3 + ratios. In the Yb/Ta-Y/Nb, Ce/Nb-Y/Nb diagrams, both K-feldspar granite and syenite plot in A1-type, with K-feldspar granite plotting closer to A2. In the Nb-Y-3Ga and Nb-Y-Ce charts, syenite plots near the boundary between A1 and A2, whereas some K-feldspar granite samples plot in A2 field, indicating a tendency of transition originally from A2 to A1. In general A1 granites form in intraplate settings, whereas A2 granite forms in post-collision. It is likely that mantle components metasomatized by subduction released fluids are easier to be partially melted, forming K-feldspar granite

  19. Petrogenesis and magmatic evolution of ∼130 Ma A-type granites in Southeast China

    NASA Astrophysics Data System (ADS)

    Sun, Fajun; Xu, Xisheng; Zou, Haibo; Xia, Yan

    2015-02-01

    A number of Late Mesozoic (∼130 Ma) A-type granitic plutons have been identified in Southeast China. Here we investigate the petrogenesis of one of these granitic plutons in Southeast China, the Sanqingshan-Damaoshan (SD) granites in northeastern Jiangxi Province, using zircon U-Pb geochronology, Hf isotopic analyses, and major and trace element analyses. The SD granites are metaluminous to weakly peraluminous and show typical A-type affinity, which is characterized by high SiO2, Na2O + K2O, rare earth element (REE), high field strength element (HFSE) contents, Ga/Al and Fe# [FeOt/(FeOt + MgO)] values. Zircon grains from the SD granites and some other ∼130 Ma A-type granites commonly contain oscillatory zoning "cores" surrounded by unzoned to weakly zoned "rims". Detailed studies of zircons from the SD granites show that "rims" are enriched in LREE, Th and U compared with "cores". Chondrite-normalized REE patterns of the "cores" increase steeply from La to Lu and show pronounced Ce and Eu anomalies, while REE patterns of the "rims" display higher REE abundances with flatter LREE patterns and moderate Ce anomalies. Nevertheless, Lu-Hf isotopic analyses and Ti-in zircon thermometer show similar characteristics between "rims" and "cores", indicating that the "rims" may crystallize under the effect of internal magmatic hydrothermal fluids. U-rich "rims" are more susceptible to Pb loss caused by self-irradiation, which may lead to significant younger U-Pb ages. As a result, U-Pb ages of zircon "cores" (∼130 Ma) represent crystallization ages of the SD granites. εHf(t) values of zircon grains from the SD granites are between -6.4 and -0.4 with Mesoproterozoic model ages (T2DM) ranging from 1.22 to 1.59 Ga, suggesting that the granites may be formed by partial melting of Proterozoic basement. Compared with other adjacent ∼130 Ma A-type granitic plutons in SE China, the SD granites have similar geochemical characteristics and Hf isotopic compositions to those of

  20. Orphan strontium-87 in abyssal peridotites: daddy was a granite.

    PubMed

    Snow, J E; Hart, S R; Dick, H J

    1993-12-17

    The (87)Sr/(86)Sr ratios in some bulk abyssal and alpine peridotites are too high to be binary mixtures of depleted mantle and seawater components. The apparent excess, or "orphan," (87)Sr appears to be separated from its radioactive parent. Such observations were widely held to be analytical artifacts. Study of several occurrences of orphan (87)Sr shows that the orphan component in abyssal peridotite is located in the alteration products of olivine and enstatite in the peridotite. The orphan (87)Sr is most likely introduced by infiltration of low-temperature (<200 degrees C) seawater bearing suspended detrital particulates. These particulates include grains of detrital clay that are partly derived from continental (that is, granitic) sources and thus are highly radiogenic. Orphan (87)Sr and other radiogenic isotopes may provide a tracer for low-temperature seawater penetrating into the oceanic crust. PMID:17829634

  1. 50. The apartment building on the left (164166 West Granite) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    50. The apartment building on the left (164-166 West Granite) was built about 1885-1886, and was used as a combination of residence and rooming house. It is one of the few remaining wood-frame structures dating from the beginning of Butte's economic and building development. Modifications, both interior and exterior, have been minimal, and the historic integrity of the structure has been retained. The Courthouse Grocery on the right (ca. 1887), is another early wood-frame building, and was also originally used as a residence and rooming house. It was modified in the early 20th century to accomodate commercial use on the ground floor, but the historic fabric of the structure is largely intact. - Butte Historic District, Bounded by Copper, Arizona, Mercury & Continental Streets, Butte, Silver Bow County, MT

  2. Changes in complex resistivity during creep in granite

    USGS Publications Warehouse

    Lockner, D.A.; Byerlee, J.D.

    1986-01-01

    A sample of Westerly granite was deformed under constant stress conditions: a pore pressure of 5 MPa, a confining pressure of 10 MPa, and an axial load of 170 MPa. Pore volume changes were determined by measuring the volume of pore fluid (0.01 M KClaq) injected into the sample. After 6 days of creep, characterized by accelerating volumetric stain, the sample failed along a macroscopic fault. Measurements of complex resistivity over the frequency range 0.001-300 Hz, taken at various times during creep, showed a gradual increase in both conductivity and permittivity. When analysed in terms of standard induced polarization (IP) techniques, the changing complex resistivity resulted in systematic changes in such parameters as percent frequency effect and chargeability. These results suggest that it may be possible to monitor the development of dilatancy in the source region of an impending earthquake through standard IP techniques. ?? 1986 Birka??user Verlag.

  3. Orphan strontium-87 in abyssal peridotites: daddy was a granite.

    PubMed

    Snow, J E; Hart, S R; Dick, H J

    1993-12-17

    The (87)Sr/(86)Sr ratios in some bulk abyssal and alpine peridotites are too high to be binary mixtures of depleted mantle and seawater components. The apparent excess, or "orphan," (87)Sr appears to be separated from its radioactive parent. Such observations were widely held to be analytical artifacts. Study of several occurrences of orphan (87)Sr shows that the orphan component in abyssal peridotite is located in the alteration products of olivine and enstatite in the peridotite. The orphan (87)Sr is most likely introduced by infiltration of low-temperature (<200 degrees C) seawater bearing suspended detrital particulates. These particulates include grains of detrital clay that are partly derived from continental (that is, granitic) sources and thus are highly radiogenic. Orphan (87)Sr and other radiogenic isotopes may provide a tracer for low-temperature seawater penetrating into the oceanic crust.

  4. Laboratory Simulation of Flow through Single Fractured Granite

    NASA Astrophysics Data System (ADS)

    Singh, K. K.; Singh, D. N.; Ranjith, P. G.

    2015-05-01

    Laboratory simulation on fluid flow through fractured rock is important in addressing the seepage/fluid-in-rush related problems that occur during the execution of any civil or geological engineering projects. To understand the mechanics and transport properties of fluid through a fractured rock in detail and to quantify the sources of non-linearity in the discharge and base pressure relationship, fluid flow experiments were carried out on a cylindrical sample of granite containing a `single rough walled fracture'. These experiments were performed under varied conditions of confining pressures, σ 3 (5-40 MPa), which can simulate the condition occurring about 1,000 m below in the earth crust, with elevated base pressure, b p (up to 25 MPa) and by changing fracture roughness. The details of the methodologies involved and the observations are discussed here. The obtained results indicate that most of the data in the Q verses b p plot, fall on the straight line and the flow through the single fracture in granite obeys Darcy's law or the well-known "cubic law" even at high value of b p (=4 MPa) and σ 3 (=5 MPa) combination. The Reynolds number is quite sensitive to the b p, σ 3 and fracture roughness, and there is a critical b p, beyond which transition in flow occurs from laminar to turbulent. It is believed that such studies will be quite useful in identifying the limits of applicability of well know `cubic law', which is required for precise calculation of discharge and/or aperture in any practical issues and in further improving theoretical/numerical models associated with fluid flow through a single fracture.

  5. The effect of elevated temperature on the physical properties of Mauthausen Granite (Austria) and Mórágy Granite (Hungary); a comparative study

    NASA Astrophysics Data System (ADS)

    Török, Anita; Török, Ákos

    2014-05-01

    Elevated temperature cause changes in the physical properties of rocks. The current study provides information on the behaviour of two granitic rocks that were subjected to high temperatures. The two studied lithologies were: i) grey Mauthausen Granite from Upper Austria and a ii) pinkish granite from Mórágy Granite Formation, southern Hungary. The latter one is the host rock of the Hungarian National Radioactive Waste Repository, which is located at Bátaapáti. To assess the changes in physical properties test were made in four conditions: air-dry room temperature (23°C); water saturated room temperature (23°C); after heat shock of 300°C and 600°C, respectively. For the heat tests a furnace was used, in which the temperature was hold on 300°C and 600°C for six hours. The physical parameters were measured according to EN standards or to ISRM guidelines. These included density, determination of ultrasound speed propagation (EN 14579:2005), uniaxial compressive strength (EN 1926:2007), indirect tensile strength (ISRM) and water absorption (EN 13755:2001). The results indicate that there were only minor changes in the densities of both granite types when the samples were heated up to 600°C. To the contrary, the strength parameters showed a clear trend. From room temperature until ~300°C, the uniaxial compressive strength, the modulus of elasticity and the indirect tensile strength showed a slight increase compared to the initial values. This elevated strength decreased significantly when the samples were heated to 600°C. This trend is in good agreement with the previous tests that were made on Indian granites (Dwivedi et al. 2008). Reference: Dwivedi, R. D., R. K. Goel, V.V.R. Prasad, A. Sinha 2008. Thermo-mechanical properties of Indian and other granites. Int. J. Rock Mech. Min. Sci., 45, 3, 303-315.

  6. Geochemistry of biotite granites from the Lamas de Olo Pluton, northern Portugal

    NASA Astrophysics Data System (ADS)

    Fernandes, Susana; Gomes, Maria; Teixeira, Rui; Corfu, Fernando

    2013-04-01

    In the Central Iberian Zone (CIZ) extensive crustal recycling occurred during the post-thickening extension stage of the Variscan orogeny (~330-290 Ma). After the ductile deformation phase D3 (~320-300 Ma), characterized by the intrusion of large volumes of highly peraluminous granitic magmas, rapid and drastic tectonic changes at about 300 Ma gave rise to the brittle phase of deformation D4 that controlled the emplacement of Fe-K subalkaline granites (296-290 Ma; Dias et al. 1998). The Lamas de Olo Pluton (LOP) is controlled by NE-SW and NW-SE fracture systems, probably related to the Régua-Verin fault zone (Pereira, 1989). The LOP is a medium to coarse-grained, porphyritic biotite granite, accompanied by medium- to fine grained, porphyritic biotite granite (Alto dos Cabeços- AC) and a more leucocratic, fine-grained, slightly porphyritic biotite-muscovite granite (Barragens- BA). The contacts between LO and AC are generally diffuse, whereas those to BA are sharp. In fact, the BA granite can occur in dykes and sills cutting LO and AC. Microgranular enclaves and xenoliths are very rare. The LOP intrudes the Douro Group, presumably of Precambrian to Cambrian age, and two-mica granites from the Vila Real composite massif. The LOP granites consist of quartz, microcline, plagioclase, biotite, zircon, titanite, tourmaline apatite, fluorite, ilmenite, magnetite, and rutile, with muscovite in BA granite and rare allanite in the LO and AC granites. The plagioclase composition is of oligoclase (An12) - andesine (An35) for LO granite, albite (An9) - andesine (An30) for CA granite and albite (An5) - oligoclase (An20) for BA granite. There are decreases in: a) anorthite content from phenocryst to matrix plagioclase; b) Ba content from phenocryst to matrix microcline in all granites. The Fe2+ biotite has a composition similar to that of biotite from calc-alkaline to sub-alkaline rock series. The LO and AC granites are meta- to peraluminous with ASI variable between 1.05 and 1

  7. Dirty or Tidy ? Contrasting peraluminous granites in a collapsing Orogen: Examples from the French Massif Central

    NASA Astrophysics Data System (ADS)

    Villaros, Arnaud; Pichavant, Michel; Moyen, Jean-François; Cuney, Michel; Deveaud, Sarah; Gloaguen, Eric; Melleton, Jérémie

    2013-04-01

    Post collisional collapse commonly enhances crustal melting. Such melting typically produces peraluminous granitic magmas. In the French Massif Central, a mid-crustal segment of the western Variscan belt, two large granitic bodies were produced during the collapse of the Variscan Belt. The St Sylvestre Leucogranitic Complex (SSyL) in the western part of the Massif Central and the Velay Migmatitic Complex (VMC) in the Eastern part. Although these two complexes are formed in similar geodynamic context they present meaningful petrological and geochemical differences. The VMC (~305 Ma) is clearly intrusive in migmatitic terranes. The migmatitic host recorded two successive melting events M3 (720 °C and 5kb) dated between 335 and 315 Ma and M4 (850°C and 4 kb) dated at 305 Ma. The compositions of the VMC are strictly H2O-undersaturated and ranges from leucogranitic to granodioritic. Three main successive granite types have been distinguished (1) A heterogeneous banded biotite granite, (2) A main biotite-cordierite granite, where cordierite can be prismatic, as cockade or pseudomorphic (3) a late magmatic with large K-feldspar phenocryst and prismatic cordierite. The compositions of the VMC granites are quite similar to typical Australian S-type granites in the sense that they also show a positive correlation between ferromagnesian abundance and aluminosity. The SSyL (~320 Ma) is intrusive in upper greenschist facies to upper amphibolite migmatitic metasediment and orthogneiss (~3kb). The compositional variety observed in the SSyL suggests a continuous trend from a moderately mafic, peraluminous magma (cd- and sill- granite) to a H2O saturated granite ("two-mica" granite) facies and finally to an extremely felsic, H2O-saturated magma. Three granitic units have been recognized in the SSyL: (1) the western "Brame Unit" composed of the less evolved cd- and sill- granite facies (2) the central "St Sylvestre Unit", composed mainly by U-rich two-mica granite, intruded by two

  8. Major magmatic events in Mt Meredith, Prince Charles Mountains: First evidence for early Palaeozoic syntectonic granites

    USGS Publications Warehouse

    Gongurov, N.A.; Laiba, A.A.; Beliatsky, B.V.

    2007-01-01

    Precambrian rocks at Mt Meredith underwent granulite-facies metamorphism M1. Zircon isotope dating for two orthogneisses revealed the following age signatures: 1294±3 and 957±4Ma; 1105±5 and 887±2Ma. The oldest ages could reflect the time of orthogneiss protolith crystallization and the latest age determinations date Grenvillian metamorphism. The metamorphic rocks were intruded by two-mica and garnet-biotite granites. The granites and host rocks underwent amphibolite-facies metamorphism M2. Zircon isotope analysis of the two-mica granites showed age estimation within 550-510Ma and zircon dating of the garnet-biotite granites revealed the ages of 1107±5, 953±8, and 551±4Ma. As Pan-African age signatures were obtained from only the granite samples, it is possible to suggest that the granites were formed at the time of 510-550Ma and the zircons with greater age values were captured by granites from the host rocks.

  9. Mineral dust and cell recovery from the bronchoalveolar lavage of healthy Vermont granite workers.

    PubMed

    Christman, J W; Emerson, R J; Graham, W G; Davis, G S

    1985-08-01

    We characterized the bronchoalveolar lavage (BAL) from healthy Vermont granite workers to investigate the pulmonary response to a chronic exposure to an injurious agent. Nine granite workers with 4 to 36 yr of employment in the industry and 27 unexposed volunteers were normal by history, physical examination, electrocardiogram, blood count, spirometry, and chest radiograph. Lavage cell recovery and percent neutrophils were not different. Lymphocyte recovery in BAL was increased in the granite-exposed population. Granite dust was present within the majority of alveolar macrophages from granite workers compared with those from control subjects, as determined by polarizing light microscopy and confirmed by scanning electron microscopy with X-ray energy spectrometry. There were no differences in phagocytic function or viability of macrophages from granite workers compared with those from unexposed volunteers. We conclude that in exposed populations, granite dust can be detected and semiquantitated in lavage specimens within the alveolar macrophages, macrophage function is preserved, and the response to this exposure involves an influx of lymphocytes.

  10. New U/Pb ages from granite and granite gneiss in the Ruby geanticline and southern Brooks Range, Alaska ( USA).

    USGS Publications Warehouse

    Patton, W.W.; Stern, T.W.; Arth, Joseph G.; Carlson, C.

    1987-01-01

    New U/Pb zircon ages from the Ray Mountains of central Alaska clarify the plutonic history of the Ruby geanticline and support earlier suggestions that the Ruby geanticline and S Brooks Range were once parts of the same tectonostratigraphic terrane. U/Pb zircon ages of 109 to 112 Ma from the Ray Mountains pluton confirm previously reported mid-Cretaceous K/Ar ages and rule out the possibility that the earliest intrusive phase of the pluton is older than mid-Cretaceous K/Ar ages and rule out the possibility that the earliest intrusive phase of the pluton is older than mid- Cretaceous. New U/Pb zircon ages from 4 granite gneiss samples in the Ray Mountains indicate a Devonian protolith age of 390+ or -12 Ma and suggest that the Ruby geanticline, like the S Brooks Range, underwent a major plutonic event in mid-Paleozoic time.-Authors

  11. Study of Magnetic Fabrics and Deformation across Meta-granite along Heping River, NE Taiwan

    NASA Astrophysics Data System (ADS)

    Yeh, E. C.; Yu-Kai, L.; Lee, T. Q.; Chou, Y. M.; Chen, C. C.; Chang, P. Y.

    2015-12-01

    Heping area of Hualien in the NE Taiwan is located at the region of subduction flip of oblique convergence between the Philippine Sea and Eurasian Plates. The ductile deformation in the region is consisted of the development of N65E-striking foliation and N60W-trending stretching lineation with top-to-southeastern shear. Distinguished mylonitic gneissosity is observed near the lithology contact between the marble and meta-granite but the flow occurrence of granite is still found in the downstream area of meta-granite core. To investigate the deformation pattern and the development of mylonization of meta-granite, study of magnetic fabrics across the meta-granite body is conducted via anisotropy of magnetic susceptibility (AMS) to evaluate the strain path of gneissosity development. AMS results show that the attitude of magnetic foliation and lineation is consistent with that of genissosity and stretching lineation. From the core to the lithology contact of meta-granite, generally anisotropy is increasing and susceptibility ellipsoids change from prolate to oblate. However due to different shearing on gneissosity, the anisotropy and magnetic ellipsoid vary pretty much even in the same site. Based on current analyses among meta-granitic and mylonitic samples, it suggested that strain path of mylonitization is evolved from prolate shape with low-anisotropy in the meta-granitic core through oblate shape with low-anisotropy in weakly gneissic samples to various ellipsoids from oblate to prolate with high-anisotropy in mylonitic samples. Our findings provide insights into understanding the deformation pattern across the meta-granite body and further establishing the strain path of mylonitic gneissosity development. Further studies of identifying magnetic carrier(s) and domain size to evaluate influences of magnetic minerals to the AMS pattern are needed.

  12. Contribution of Portuguese two-mica granites to stone built heritage

    NASA Astrophysics Data System (ADS)

    Almeida, Angela; Begonha, Arlindo

    2013-04-01

    The present study deals with the importance of the application of natural stone in monuments in urban setting, both as the main building material during the historical evolution of a city and as a means to increase the public awareness of the social role of geological resources of a specific region. The City of Oporto, World Heritage of the Humanity , has been selected to illustrate the use of the local granite since ancient times to the present day, a two-mica peraluminous granite ,classified as syn-tectonic relatively to the third tectonic deformation phase of the Hercynian orogeny, included in an expressive group that occurs extensively in northern Portugal . The Oporto granite has been the object of several geochemical, structural and geotechnical approaches. Despite the urban development, outcrops of this granite can be observed in different areas of the city, side by side with the urban constructions, and particularly in the imposing and intensely fractured escarpments carved by the river Douro. Oporto monumental heritage goes back to Roman occupation and the profile has been developed by the construction of granite buildings, following history and the social evolution, of an impressive grey architecture according to different styles of granite work that characterize the city in all its aspects, namely the old city wall, the medieval and baroque churches, the neoclassic houses but also the small humble habitations. The Oporto granite is always affected by weathering processes and the buildings exhibit various aspects of stone decay such as granular desintegration, plates, flakes, black crusts, thin black layers, efflorescences and biological colonization. The description of selected sites within the historical centre , where it is possible to recognize the importance of the granite in the character of the city, aims to call the attention to the inextricable role of geology in built heritage and in the culture, as well as to diagnose the deterioration

  13. Comparison of Proterozoic and Phanerozoic rift-related basaltic-granitic magmatism

    NASA Astrophysics Data System (ADS)

    Haapala, Ilmari; Rämö, O. Tapani; Frindt, Stephen

    2005-03-01

    This paper compares the 1.67-1.47 Ga rapakivi granites of Finland and vicinity to the 1.70-1.68 Ga rapakivi granites of the Beijing area in China, the anorogenic ˜130 Ma granites of western Namibia, and the 20-15 Ma granites of the Colorado River extensional corridor in the Basin and Range Province of southern Nevada. In Finland and China, the tectonic setting was incipient, aborted rifting of Paleoproterozoic or Archean continental crust, in Namibia it was continental rifting and mantle plume activity that led to the opening of southern Atlantic at ˜130 Ma. The 20-15 Ma granites of southern Nevada were related to rifting that followed the Triassic-Paleogene subduction of the Farallon plate beneath the southwestern United States. In all cases, extension-related magmatism was bimodal and accompanied by swarms of diabase and rhyolite-quartz latite dikes. Rapakivi texture with plagioclase-mantled alkali feldspar megacrysts occurs in varying amounts in the granites, and the latest intrusive phases are commonly topaz-bearing granites or rhyolites that may host tin, tungsten, and beryllium mineralization. The granites are typically ferroan alkali-calcic metaluminous to slightly peraluminous rocks with A-type and within-plate geochemical and mineralogical characteristics. Isotope studies (Nd, Sr) suggest dominant crustal sources for the granites. The preferred genetic model is magmatic underplating involving dehydration melting of intermediate-felsic deep crust. Juvenile mafic magma was incorporated either via magma mingling and mixing, or by remelting of newly hybridized lower crust. In Namibia, partial melting of subcontinental lithospheric mantle was caused by the Tristan mantle plume, in the other cases the origin of the mantle magmatism is controversial. For the Fennoscandian suites, extensive long-time mantle upwelling associated with periodic, migrating melting of the subcontinental lithospheric mantle, governed by heat flow and deep crustal structures, is

  14. Vapor phase exsolution as a controlling factor in hydrogen isotope variation in granitic rocks: the Notch Peak granitic stock, Utah

    USGS Publications Warehouse

    Nabelek, P.I.; O'Neil, J.R.; Papike, J.J.

    1983-01-01

    The Notch Peak granitic stock, western Utah, is comprised of three concentric sequentially intruded rock types, from granite at the rim, to quartz monzonite I, to quartz monzonite II at the core. The ??18O values of whole rocks vary about an average of 9.4 (SMOW), irrespective of the rock type and position relative to contact, suggesting that the three magmas had the same parent. The whole rock ??D values in the stock range from -100 to -55. ??D values increase toward the cores of both quartz monzonite I and quartz monzonite II, resulting in concentric contours. The ??D contours of quartz monzonite II cross-cut those of quartz monzonite I, suggesting little isotopic interaction between these bodies and the absence of a late pervasive fluid phase. There is a positive correlation between ??D values and water content of the samples, where samples from each body define a distinct field. The positive correlation is explained by isotopic fractionation attendant on vapor exsolution from the crystallizing magma. An observed increase in ??D with the degree of chloritization, a trend opposite to that observed in systems where participation of meteoric water has been demonstrated, is the result of subsolidus interaction with the exsolved fluids. These results show that large variations in the hydrogen isotope ratios of a granitoid can arise by exsolution of a vapor phase from the melt on crystallization. In general, magmas with larger modal amount of primary hydrous phases will tend to have higher ??D values than those with small amounts of hydrous phases. Furthermore, the relatively high ??D values of chlorites at Notch Peak confirm the applicability of classical concepts of closed-system deuteric alteration to some granitoid bodies. Thus, meteoric water interaction need not be always invoked to explain hydrogen isotope variation and deuteric alteration in granitoids. ?? 1983.

  15. Peralkaline and peraluminous granites and related mineral deposits of the Arabian Shield, Kingdom of Saudi Arabia

    USGS Publications Warehouse

    Elliott, James E.

    1983-01-01

    Existing geochemical and geologic data for many parts of the Arabian Shield were compiled as a basis for evaluating the resource potential of the granites of the Shield. Commodities associated with granites that have potential for economic mineral deposits include tin, tungsten, molybdenum, beryllium, niobium, tantalum, zirconium, uranium, thorium, rare-earth elements, and fluorite. Prospecting methods useful in discriminating those granites having significant economic potential include reconnaissance geologic mapping, petrographic and mineralogic studies, geochemical sampling of rock and wadi sediment, and radiometric surveying.

  16. Experiments and Simulations of Penetration into Granite by an Aluminum Shaped Charge

    SciTech Connect

    Murphy, M J; Randers-Pehrson, G; Kuklo, R M; Rambur, T A; Switzer, L L; Summes, M A

    2003-07-27

    This paper describes experimental results and numerical simulations of jet penetration into granite from an aluminum lined shaped charge. Several penetration versus standoff experiments were conducted into an in-situ granite formation located in the Climax Ridge region of the Nevada Test Site. Simulations of the jet penetration were modeled with a two dimensional arbitrary lagrange eulerian hydrocode. The effects of variations in the granite flow stress, porosity, and EOS have been evaluated. The work described in this paper is a continuation of our studies on jet penetration and modeling into high strength concrete.

  17. Experiments and simulations of penetration into granite by an aluminum shaped charge

    NASA Astrophysics Data System (ADS)

    Murphy, M. J.; Randers-Pehrson, G.; Kuklo, R. M.; Rambur, T. A.; Switzer, L. L.; Summers, M. A.

    2003-09-01

    This paper describes experimental results and numerical simulations of jet penetration into granite from an aluminum lined shaped charge. Several penetration versus standoff experiments were conducted into an in-situ granite formation located in the Climax Ridge region of the Nevada Test Site. Simulations of the jet penetration were modeled with a two dimensional arbitrary lagrange eulerian hydrocode. The effects of variations in the granite flow stress, porosity, and EOS have been evaluated. The work described in this paper is a continuation of our studies on jet penetration and modeling into high strength concrete[1].

  18. Geochemistry and petrogenesis of the Mesoarchean granites from the Canaã dos Carajás area, Carajás Province, Brazil: Implications for the origin of Archean granites

    NASA Astrophysics Data System (ADS)

    Feio, G. R. L.; Dall'Agnol, R.

    2012-12-01

    Four Mesoarchean (2.93 to 2.83 Ga) granite units, which encompass the Canaã dos Carajás, Bom Jesus, Cruzadão and Serra Dourada granites, were recognized in the Canaã dos Carajás area of the Archean Carajás Province. The Mesoarchean units are composed dominantly of biotite leucomonzogranites. They are compared with the Neoarchean Planalto suite (2.73 Ga) which encompasses biotite-hornblende monzogranites to syenogranites. The Canaã dos Carajás, Bom Jesus and the variety of the Cruzadão granite with higher (La/Yb)N are geochemically more akin to the calc-alkaline granites, whereas the other varieties of the Cruzadão granite are transitional between calc-alkaline and alkaline granites. The Serra Dourada granite has an ambiguous geochemical character with some features similar to those of calc-alkaline granites and other peraluminous granites. The Planalto granites have ferroan character, are similar geochemically to reduced A-type granites and show a strong geochemical contrast with the Mesoarchean studied granites. The Mesoarchean granites described in the Canaã dos Carajás area are geochemically distinct to those of the Rio Maria domain of the Carajás Province. The Canaã dos Carajás and Bom Jesus granites are similar to the high-Ca granites, whereas the Cruzadão and Serra Dourada are more akin to the low-CaO granites of the Yilgarn craton. The geochemical characteristics of the Mesoarchean studied granites approach those of the biotite granite group of Dharwar but the latter are enriched in HFSE and HREE compared to the Canaã dos Carajás granites. The Neoarchean Planalto suite granite has no counterpart in the Mesoarchean Rio Maria domain of the Carajás Province, neither in the Yilgarn and Dharwar cratons. Geochemical modeling suggests that partial melting of a source similar in composition to an Archean basaltic andesite of the Carajás Province could give origin to the Bom Jesus and Cruzadão granites. In the case of the Bom Jesus granite the

  19. Tectonic and source controls on granite melt chemistry

    NASA Astrophysics Data System (ADS)

    Brown, M.

    2012-12-01

    The composition and microstructure of the source, P-T evolution, degree of melting and number of melt extraction events, and whether melting is an equilibrium or disequilibrium process dictate the initial chemistry of granite melt at P and T, whereas this chemistry may be modified by physico-chemical processes during migration through the source and ascent through the crust. In addition to determining P-T evolution, tectonic setting determines any juvenile input to melt generation. Assuming melt extraction occurs at the melt connectivity transition (MCT), multiple cycles of melt build-up and loss are predicted along suprasolidus prograde P-T paths. Melt extraction changes the composition of the source and solid solution phases, so that successive melt batches have different chemistries. During migration, melt composition evolves by interaction with residue and crystallization-fractionation; glass compositions from melting experiments on crustal rocks do not match mafic granites, suggesting that natural melts selectively entrain peritectic minerals from the source, which equilibrate during ascent by dissolution-precipitation cycling. For CW P-T paths, decompression across hydrate-breakdown melting reactions is commonly invoked as important in the production of late orogenic granites, yet the amount of melt produced during decompression is dependent on the fertility of the crust at the T of interest and the amount may be quite small if melt is lost along the prograde P-T path. Rock-forming and accessory mineral behavior during melting is critical to the composition and isotopic fingerprint of the melt. Although various accessory minerals are the main hosts for Zr, U, Th and the REE it is not clear that breakdown of these under suprasolidus conditions necessarily will lead to saturation of the melt, since rock-forming minerals in the granulite facies become enriched these elements. Furthermore, in fluid absent melting, melt pockets may be located along hydrate grain

  20. Mantle hydrous-fluid interaction with Archaean granite.

    NASA Astrophysics Data System (ADS)

    Słaby, E.; Martin, H.; Hamada, M.; Śmigielski, M.; Domonik, A.; Götze, J.; Hoefs, J.; Hałas, S.; Simon, K.; Devidal, J.-L.; Moyen, J.-F.; Jayananda, M.

    2012-04-01

    Water content/species in alkali feldspars from late Archaean Closepet igneous bodies as well as growth and re-growth textures, trace element and oxygen isotope composition have been studied (Słaby et al., 2011). Both processes growth and re-growth are deterministic, however they differ showing increasing persistency in element behaviour during interaction with fluids. The re-growth process fertilized domains and didn't change their oxygen-isotope signature. Water speciation showed persistent behaviour during heating at least up to 600oC. Carbonate crystals with mantle isotope signature are associated with the recrystallized feldspar domains. Fluid-affected domains in apatite provide evidence of halide exchange. The data testify that the observed recrystallization was a high-temperature reaction with fertilized, halide-rich H2O-CO2 mantle-derived fluids of high water activity. A wet mantle being able to generate hydrous plumes, which appear to be hotter during the Archean in comparison to the present time is supposed by Shimizu et al. (2001). Usually hot fluids, which can be strongly carbonic, precede asthenospheric mantle upwelling. They are supposed to be parental to most recognized compositions, which can be derived by their immiscible separation into saline aqueous-silicic and carbonatitic members (Klein-BenDavid et al., 2007). The aqueous fractions are halogen-rich with a significant proportion of CO2. Both admixed fractions are supposed to be fertile. The Closepet granite emplaced in a major shear zone that delimitates two different terrains. Generally such shear zones, at many places, are supposed to be rooted deep into the mantle. The drain, that favoured and controlled magma ascent and emplacement, seemed to remain efficient after granite crystallization. In the southern part of the Closepet batholiths an evidence of intensive interaction of a lower crust fluid (of high CO2 activity) is provided by the extensive charnockitization of amphibolite facies (St

  1. Asyntectonic granites and the structural memory of plutonic rocks

    NASA Astrophysics Data System (ADS)

    de Saint-Blanquat, M.; Habert, G.; Law, R. D.; Morgan, S.; Tikoff, B.

    2003-04-01

    Because of their initial magmatic physical state, plutonic rocks are privileged recorders of their tectonic environment. Their structural memory, contained within the internal structure, and particularly within the fabric, is commonly used to reconstruct the tectonic context during and after emplacement. The main parameters which govern the internal structure are the regional strain regime, the local geometry, and the dynamics of magma infilling. As granitic magmatism is in general a short-lived event, this structural memory is short but precise. The combination of results obtained from various subcontemporaneous plutons could then allow to reconstruct the tectono-magmatic history of whole areas with very good time resolution. The main problem with the interpretation of the structural memory of granites is the difficulty to constrain the duration of its acquisition : the strain pattern within a pluton will not have the same meaning if the time of recording (= time of pluton construction) is 10 ky, 1 My, or significantly longer. A short recording time provides information on infinitesimal (or, in many cases, incremental) strain, whereas a longer time of emplacement will form fabrics which should be interpreted in terms of finite strain. Numerous recent studies have shown that the construction of plutons is discontinuous. The duration of pluton construction is then the total infilling time and the time between the successive pulses. The latter can be estimated using numerical simulations of the thermal history during pluton construction, constrained by textural relationships within and around the plutons. Our work on plutons emplaced in contrasted settings (transpression, extension, and absence of regional tectonics) permit us to quantify the duration of pluton construction, and shows that this duration depends primarily on the mechanism of emplacement, i.e. active (forceful) versus passive (permitted). We have obtained duration of pluton construction between 200 and

  2. Slow Slip Events on a 760 mm Long Granite Sample

    NASA Astrophysics Data System (ADS)

    Mclaskey, G.; Yamashita, F.

    2015-12-01

    We describe slow slip events and dynamic rupture events generated on a newly constructed large-scale biaxial friction apparatus at Cornell University that provide insights into the mechanisms of aseismic and seismic slip. We find that, under nominally similar experimental conditions, the 760 mm long granite sample sometimes slips in dynamic stick-slip events and sometimes relieves accumulated shear stress through slow slip events. To provide insights into this curious behavior and the underlying mechanisms, fault slip and shear stress are each measured at 8 locations along the 760 mm long fault. This allows us to map slow slip fronts and the nucleation and propagation of dynamic fault rupture. The granite sample is also instrumented with an array of piezoelectric sensors that are the laboratory equivalent of a seismic network. When the sample is loaded relatively slowly, at 0.03 MPa/s, slow slip occurs on large sections of the fault and the slow slipping region soon expands to the sample boundary. In this case, stress is released in a slow slip event with peak slip velocities < 2 mm/s. Alternatively, when one end of the sample is loaded rapidly (4 MPa/s), or the sample is allowed to heal in stationary contact for a few minutes, slow slip initiates near the load point and accelerates to slip velocities exceeding 200 mm/s before the slow slipping region expands all the way to the sample boundary. This produces a dynamic slip event (stick-slip). The dynamic slip events radiate seismic waves equivalent to a M = -2.5 earthquake. In contrast, the laboratory-generated slow slip events are predominantly aseismic and produce only bursts of tiny and discrete seismic events (M = -6) reminiscent of swarms of microseismicity. The experiments illustrate how a single fault can slide slowly and aseismically or rapidly and dynamically depending on stress state and loading conditions. We compare the behavior observed on this Cornell apparatus to the behavior of other large

  3. Petrography and physicomechanical properties of rocks from the Ambela granitic complex, NW Pakistan.

    PubMed

    Arif, Mohammad; Bukhari, S Wajid Hanif; Muhammad, Noor; Sajid, Muhammad

    2013-01-01

    Petrography and physicomechanical properties of alkali granites, alkali quartz syenite, and nepheline syenite from Ambela, NW Pakistan, have been investigated. Whereas the alkali quartz syenite and most of the alkali granites are megaporphyritic, the nepheline syenite and some of the alkali granites are microporphyritic. Their phenocryst shape and size and abundance of groundmass are also different. The values of unconfined compressive strength (UCS) are the lowest and highest for megaporphyritic alkali granite and alkali quartz syenite, respectively. However, all the four rock types are moderately strong. Correspondingly, their specific gravity and water absorption values are within the permissible range for use as construction material. The UCS for the alkali quartz syenite is the highest, most probably because (i) it has roughly equal amounts of phenocryst and groundmass, (ii) it displays maximum size contrast between phenocryst and groundmass, (iii) its phenocrysts are highly irregular, and (iv) it contains substantial amounts of quartz. PMID:23861654

  4. Quantum states of neutrons in the gravitational and centrifugal potentials in a new GRANIT spectrometer

    ScienceCinema

    None

    2016-07-12

    We will discuss the scientific program to be studied in a new gravitational spectrometer GRANIT in a broad context of quantum states (quantum behaviour) of ultracold neutrons (UCN) in gravitational [1] and centrifugal [2] potentials, as well as applications of these phenomena/spectrometer to various domains of physics, ranging from studies of fundamental short-range interactions and symmetries to neutron quantum optics and reflectometry using UCN. All these topics, as well as related instrumental and methodical developments have been discussed during dedicated GRANIT-2010 Workshop [3]. The GRANIT spectrometer has been recently installed at the Institut Laue-Langevin, Grenoble, France [4] and could become operational in near future. 1. V.V. Nesvizhevsky et al (2002), Nature 415, 297. 2. V.V. Nesvizhevsky et al (2010), Nature Physics 6, 114. 3. GRANIT-2010, Les Houches, 14-19 february 2010. 4. M. Kreuz et al (2009), NIM 611, 326.

  5. Petrography and Physicomechanical Properties of Rocks from the Ambela Granitic Complex, NW Pakistan

    PubMed Central

    Arif, Mohammad; Bukhari, S. Wajid Hanif; Muhammad, Noor; Sajid, Muhammad

    2013-01-01

    Petrography and physicomechanical properties of alkali granites, alkali quartz syenite, and nepheline syenite from Ambela, NW Pakistan, have been investigated. Whereas the alkali quartz syenite and most of the alkali granites are megaporphyritic, the nepheline syenite and some of the alkali granites are microporphyritic. Their phenocryst shape and size and abundance of groundmass are also different. The values of unconfined compressive strength (UCS) are the lowest and highest for megaporphyritic alkali granite and alkali quartz syenite, respectively. However, all the four rock types are moderately strong. Correspondingly, their specific gravity and water absorption values are within the permissible range for use as construction material. The UCS for the alkali quartz syenite is the highest, most probably because (i) it has roughly equal amounts of phenocryst and groundmass, (ii) it displays maximum size contrast between phenocryst and groundmass, (iii) its phenocrysts are highly irregular, and (iv) it contains substantial amounts of quartz. PMID:23861654

  6. Revisiting the block method for evaluating thermal conductivities of clay and granite

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Determination of thermal conductivities of porous media using the contact method is revisited and revalidated with consideration of thermal contact resistance. Problems that limit the accuracy of determination of thermal conductivities of porous media are discussed. Thermal conductivities of granite...

  7. Petrography and physicomechanical properties of rocks from the Ambela granitic complex, NW Pakistan.

    PubMed

    Arif, Mohammad; Bukhari, S Wajid Hanif; Muhammad, Noor; Sajid, Muhammad

    2013-01-01

    Petrography and physicomechanical properties of alkali granites, alkali quartz syenite, and nepheline syenite from Ambela, NW Pakistan, have been investigated. Whereas the alkali quartz syenite and most of the alkali granites are megaporphyritic, the nepheline syenite and some of the alkali granites are microporphyritic. Their phenocryst shape and size and abundance of groundmass are also different. The values of unconfined compressive strength (UCS) are the lowest and highest for megaporphyritic alkali granite and alkali quartz syenite, respectively. However, all the four rock types are moderately strong. Correspondingly, their specific gravity and water absorption values are within the permissible range for use as construction material. The UCS for the alkali quartz syenite is the highest, most probably because (i) it has roughly equal amounts of phenocryst and groundmass, (ii) it displays maximum size contrast between phenocryst and groundmass, (iii) its phenocrysts are highly irregular, and (iv) it contains substantial amounts of quartz.

  8. Introduction to special issue on granites and rhyolites: a commentary for the nonspecialist.

    USGS Publications Warehouse

    Barker, F.

    1981-01-01

    These 28 papers are a sample of modern research on granites and rhyolites. The studies include field relations, experimental aspects, mineralogy, major elements, minor elements, isotopic ratios and tectonics. (Following abstracts) -K.A.R.

  9. Assessment of terrestrial gamma radiation doses for some Egyptian granite samples.

    PubMed

    El Arabi, A M; Ahmed, N K; Salahel Din, K

    2008-01-01

    External exposures of population to ionising radiation due to naturally occurring radionuclides in sixty-three granite samples from three different locations in south eastern desert of Egypt were considered in this article. Average outdoor gamma dose rates in air were 190, 290 and 330 nGy h(-1) for Elba, Qash Amir and Hamra Dome granites, respectively. The corresponding doses in indoor air are 270, 400 and 470 nGy h(-1), respectively. These average values give rise to annual effective dose (outdoor, indoor and in total) 0.24, 1.4 and 1.6 mSv for Elba granite. For Qash Amir and Hamra Dome granites the corresponding values were 0.35, 2 and 2.3 mSv and 0.41, 2.3 and 2.7 mSv, respectively.

  10. Ulkan-Dzhugdzhur ore-bearing anorthosite-rapakivi granite-peralkaline granite association, Siberian Craton: Age, tectonic setting, sources, and metallogeny

    NASA Astrophysics Data System (ADS)

    Larin, A. M.

    2014-07-01

    The paper systematizes and integrates the results of geological, isotopic geochronological, and geochemical studies of the igneous rocks that make up the Ulkan-Dzhugdzhur anorthosite-rapakivi granite-peralkaline granite association and related mineralization. This association is a typical example of anorogenic igneous rocks that formed in the within-plate geodynamic setting most likely under effect of the mantle superplume, which was active in the territory of the Siberian Craton 1.75-1.70 Ga ago. The igneous rock association formed in a discrete regime that reflected the pulsatory evolution of a sublithospheric mantle source. The prerift (1736-1727 Ma) and rift proper (1722-1705 Ma) stages and a number of substages are distinguished. All igneous rocks pertaining to this association have mixed mantle-crustal origin. Basic rocks crystallized from the OIB-type basaltic magma, which underwent crustal contamination at various depths. Felsic rocks are products of mantle and crustal magma mixing. The contribution of mantle component progressively increased in a time-dependent sequence: moderately alkaline subsolvus granite → moderately alkaline and alkaline hypersolvus granites → peralkaline hypersolvus granite. All endogenic deposits in the studied district are related to a single source represented by the mantle plume and its derivatives. The Fe-Ti-apatite deposits hosted in anorthosite formed as a result of intense lower crustal contamination of basaltic magma near the Moho discontinuity and two stages of fractional crystallization at lower and upper crustal depth levels. The rare-metal deposits are genetically related to peralkaline granite. Formation of uranium deposits was most likely caused by Middle Riphean rejuvenation of the region, which also involved rocks of the Ulkan-Dzhugdzhur association.

  11. Determination of Granites' Mineral Specific Porosities by PMMA Method and FESEM/EDAX

    SciTech Connect

    Leskinen, A.; Penttinen, L.; Siitari-Kauppi, M.; Alanso, U.; Garcia-Gutierrez, M.; Missana, T.; Patelli, Alessandro

    2007-07-01

    Over extended periods, long-lived radionuclides (RN) or activation products within geologic disposal sites may be released from the fuel and migrate to the geo/biosphere. In the bedrock, contaminants will be transported along fractures by advection and retarded by sorption on mineral surfaces and by molecular diffusion into stagnant pore water in the matrix along a connected system of pores and micro-fissures. The objective of this paper was to determine the connective porosity and mineral-specific porosities for three granite samples by {sup 14}C methyl-methacrylate ({sup 14}C-PMMA) autoradiography. Scanning electron microscopy and energy-dispersive X-ray analyses (FESEM/EDAX) were performed in order to study the pore apertures of porous regions in greater detail and to identify the corresponding minerals. Finally, the porosity results were used to evaluate the diffusion coefficients of RNs from previous experiments which determined apparent diffusion coefficients for the main minerals in three granite samples by the Rutherford Backscattering technique. The total porosity of the Grimsel granite (0.75%) was significantly higher than the porosities of the El Berrocal and Los Ratones granites (0.3%). The porosities of the Grimsel granite feldspars were two to three times higher than the porosities of the El Berrocal and Los Ratones granites feldspars. However, there was no significant difference between the porosities of the dark minerals. A clear difference was found between the various quartz grains. Quartz crystals were non-porous in the El Berrocal and Los Ratones granites when measured by the PMMA method, but the quartz crystals in the Grimsel granite showed 0.5% intra granular porosity. The apparent diffusion coefficients calculated for uranium diffusion within Grimsel granite on different minerals were very similar (2.10{sup -13} {+-} 0.5 m{sup 2}/s), but differences within both Spanish granites were found from one mineral to another (9 {+-} 1.10{sup -14} m

  12. Geochronology and thermobarometry of the granitoid rocks within the Vaasa granite-migmatite complex, western Finland

    NASA Astrophysics Data System (ADS)

    Kurhila, Matti; Kotilainen, Anna; Tiljander, Mia; Hölttä, Pentti; Korja, Annakaisa

    2015-04-01

    The Vaasa granite-migmatite dome in west-central Finland has been formed in the Svecofennian orogeny, after the main collisional stage at ~1.9 Ga. The structure consists of a granite-migmatite core surrounded by metasedimentary rocks with outward decreasing metamorphic grade. The core comprises anatectic garnet-bearing granites, diatexites, pyroxene granites, and minor intrusive granodiorites. Geochemically, all of the rocks are peraluminous and magnesian. The Vaasa granites have close to average upper crustal compositions, and they show signs of titanite and plagioclase fractionation. The heavy REEs vary strongly according to garnet retention. Zircon U-Pb ages for these rock types indicate crystallization at 1875 Ma for the diatexites and garnet-bearing granites and at 1870 Ma for the pyroxene granites. Melt-forming temperatures are estimated by zircon and monazite saturation temperatures, and by Al/Ti ratios. No clear difference in the melting temperatures of the various rock types could be detected. However, while the monazite and zircon saturation temperatures point to temperatures around 800 ° C, the Al-Ti thermometer gives consistently about 100 ° C degrees higher results. Given the anatectic and felsic nature of the rocks, the lower temperature estimates seem more probable. Crystallization temperatures and pressures were calculated with the help of mineral chemical analyses. Garnet-biotite-plagioclase-quartz thermobarometry, and Al-in-hornblende barometry indicate pressures of 5.5-6 kbars for the diatexites, the pyroxene granites and an intrusive granodiorite. Significantly lower pressures of 2-4 kbars are recorded for the garnet-bearing granites. The garnet-biotite thermometer implies crystallization temperatures between 650 - 700 ° C for the pyroxene granites and the diatexites, and upto 600 ° C for the garnet-bearing granites. These results are markedly lower than those indicated by the whole-rock saturation temperatures of the same rocks. This may

  13. Petrogenesis of Malaysian tin granites: geochemistry, fractional crystallization, U-Pb zircon geochronology and tectonic setting

    NASA Astrophysics Data System (ADS)

    Wai-Pan Ng, Samuel; Searle, Mike; Whitehouse, Martin; Chung, Sun-Lin; Ghani, Azman; Robb, Laurence; Sone, Masatoshi; Oliver, Grahame; Gardiner, Nick; Roselee, Mohammad

    2014-05-01

    The Malaysian tin granites forming the backbone of the Thai-Malay Peninsula has been long recognized with two distinct granitic provinces:- 1. Early Permian to Late Triassic Eastern Province with mainly "I-type" (Hbl)-Bt granites with associated Cu-Au deposits, with subordinate Bt granites hosting limited Sn-W deposits, and 2. Late Triassic Main Range Province with mainly "S-type" Bt granites with associated Sn-W deposits, and subordinate (Hbl)-Bt granites. New geochemical data show that Chappell and White's (1974) I-S granite classification adopted in the existing model does not adequately distinguish the granites from one another as previously implied. Trace element geochemistry and Sr-Nd isotopic compositions show that the Malaysian tin granites in both provinces have transitional I-S characteristics. In addition, they inherited within-plate signature from Cambro-Ordovician Gondwana-related source rocks. Previous ages were obtained by whole rock Rb-Sr and biotite K-Ar geochronology in the 70s and 80s, dating methods that may not accurately represent the crystallization age of granites. We re-sampled the entire Malaysian Peninsula and 40 samples were collected for high-precision U-Pb SIMS dating on extracted zircon grains in order to better constrain the magmatic and tectonic evolution of Southeast Asia. The crystallization ages of the Eastern Province granitoids have been constrained ranging from 220 to 290 Ma, while the Main Range (Western) Province granitoids have ages ranging from 200 to 230 Ma. A progressive westward younging trend is apparent across the Eastern Province, but becomes less obvious in the Main Range Province. Our model suggests two east dipping subduction zones. We suggest that subduction roll-back along the Bentong-Raub suture might account for the westward younging trend, in the Eastern province. A second Late Triassic east-dipping subduction zone beneath western Malaysia is proposed in order to explain the "I-type" components to the Main

  14. Effects of magma mingling in the granites of Mount Desert Island, Maine

    SciTech Connect

    Seaman, S.J.; Ramsey, P.C. )

    1992-07-01

    Textures and compositional relationships associated with dark-colored, fine-grained enclaves in the Cadillac Mountain and Somesville granites, Mount Desert Island, Maine, preserve abundant evidence for contamination of host granitic magmas by enclave liquids. Fine-grained enclaves, which apparently represent chilled magmatic droplets, have affected the composition and texture of the host granites by three possible mechanisms: (1) crystallization of feldspar-quartz-hornblende pegmatite pods from fluids of enclave origin in the granite surrounding enclaves, and the disaggregation of the pods and dispersion of crystals into the granite; (2) ionic exchange between enclaves and granitic magmas; (3) the generation around enclaves of rinds consisting of an inner alkali feldspar-quartz zone and an outer zone of hornblende-enriched granite. Thermal calculations suggest that the alkali feldspar-quartz zones of the rinds surrounding enclaves may result from resorption of alkali feldspar and quartz crystals in the granitic magma by heat of cooling and crystallization of enclave material. The interaction between the hot enclave and the alkali feldspar-quartz composition liquid may be analogous to that between a pluton and meteoric water in a hydrothermal system. The segregation of alkali feldspar-quartz and hornblende-rich zones may result from the minimum melt composition fluid migrating toward the enclave, leaving behind unmelted hornblende, as part of a convection circuit set up by the enclave. Alternatively, hornblende-rich zones concentric to and outside of the alkali feldspar-quartz rinds may record limit of movement of a front of hydrous fluid driven from the enclave boundary down a thermal gradient.

  15. [Study on the spectra of granite of asbestos red and sesame white].

    PubMed

    Liu, X

    1998-10-01

    In this paper, the composition and spectra of granite of asbestos red and sesame white are studied by ICP-AES, XRF, IR and X-ray diffraction. According to the X-ray diffraction, the components were determined by computer. Comparing results, it is concluded that the red colour of asbestos red granite is caused by the red minerals of Fe contained in it.

  16. Rubidium-strontium date of possibly 3 billion years for a granitic rock from antarctica.

    PubMed

    Halpern, M

    1970-09-01

    A single total rock sample of biotite granite from Jule Peaks, Antarctica, has been dated by the rubidium-strontium method at about 3 billion years. The juxtaposition of this sector of Antarctica with Africa in the Dietz and Sproll continental drift reconstruction results in a possible geochronologic fit of the Princess Martha Coast of Antarctica with a covered possible notheastern extension of the African Swaziland Shield, which contains granitic rocks that are also 3 billion years old.

  17. Investigation of Naturally Occurring Radio Nuclides in Shir-kuh Granites

    SciTech Connect

    Mazarei, Mohammad Mehdi; Zarei, Mojtaba

    2011-12-26

    One of the principle natural radiation resources is Granite which can be dangerous for human because of its radiations. Based on this fact, in this research we attempt to specify the activity amount of these natural radio nuclides, existing in Shir-kuh Granite of Yazd state. To specify the activity amount of this natural radio nuclides, it has been applied the measurement method of Gamma spectroscopy using high purity Germanium (HPGe) detector.

  18. Igneous petrogenesis and tectonic setting of granitic rocks from the eastern Blue Ridge, Alabama Appalachians

    SciTech Connect

    Drummond, M.S. . Geology Dept.); Allison, D.T. . Geology Dept.); Tull, J.F. . Geology Dept.); Bieler, D.B. . Geology Dept.)

    1994-03-01

    A span of 150 my of orogenic activity is recorded within the granitic rocks of the eastern Blue Ridge of Alabama (EBR). Four discrete episodes of plutonism can be differentiated, each event exhibiting distinct field relations and geochemical signatures. (1) Penobscotian stage: this initial stage of plutonic activity is represented by the Elkahatchee Quartz Diorite (EQD), a premetamorphic (495 Ma) batholith and the largest intrusive complex (880 km[sup 2]) exposed in the Blue Ridge. Calc-alkaline I-type tonalite-granodiorite are the principal lithologies, with subordinate cumulate hbl-bt diorite, metadacite, granite and trondhjemite. The parental tonalitic magmas are interpreted to have been derived from a subducted MORB source under eclogite to get amphibolite conditions. (2) Taconic stage: the Kowaliga augen gneiss (KAG) and the Zana granite gneiss (ZG) are 460 Ma granitic bodies that reside in the SE extremity and structurally highest portion of the EBR. Both of these bodies are pre-metamorphic with strongly elongate sill- and pod-like shapes concordant with S[sub 1] foliation. Granite and granodiorite comprise the bulk of the KAG. (3) Acadian stage: Rockford Granite (RG), Bluff springs Granite (BSG, 366 Ma), and Almond Trondhjemite represent a suite of pre- to syn-metamorphic granitic intrusions. (4) late-Acadian stage: The Blakes Ferry pluton (BFP) is a post-kinematic pluton displaying spectacular by schlieren igneous flow structures, but no metamorphic fabric. The pluton's age can be bracketed between a 366 Ma age on the BSG and a 324 Ma K-Ar muscovite age on the BFP. BFP's petrogenesis has involved partial melting a MORB source followed by assimilation of metasedimentary host rock.

  19. A Spanish reference concept for a repository in granite -- The role of the barrier system

    SciTech Connect

    Nilsson, L.B.; Sellin, P.; Huertas, F.; Pusch, R.

    1993-12-31

    ENRESA, the organization responsible for radioactive waste management in Spain, is considering clay, salt and granite as optional host rocks for spent fuel disposal. The main features of a reference repository concept developed for the granite alternative is presented as well as a preliminary assessment of its long-term performance. Comments are given on issues, which should be studied more in depth in the continued R and D program.

  20. The transition from an Archean granite-greenstone terrain into a charnockite terrain in southern India

    NASA Technical Reports Server (NTRS)

    Condie, K. C.; Allen, P.

    1983-01-01

    In southern India, it is possible to study the transition from an Archean granite-greenstone terrain (the Karnataka province) into high grade charnockites. The transition occurs over an outcrop width of 20-35 km and appears to represent burial depths ranging from 15 to 20 km. Field and geochemical studies indicate that the charnockites developed at the expense of tonalites, granites, and greenstones. South of the transition zone, geobarometer studies indicate burial depths of 7-9 kb.

  1. Microhabitats and chemical microenvironments under saxicolous lichens growing on granite.

    PubMed

    de los Ríos, A; Wierzchos, J; Ascaso, C

    2002-01-01

    Lasallia hispanica, Parmelia omphalodes, and Cornicularia normoerica, saxicolous thalli growing on granite, show a close relationship with other lichens and microorganisms living in the lithic substrate beneath them. The lithobiontic community is an accumulation of microorganisms at an interface forming a biofilm, which interacts with the lithic substrate both geophysically and geochemically. Because of their fruticose and foliose morphology, the saxicolous species examined here are mainly involved in geophysical processes, but in the proximity of their attachment structures, geochemical processes may also be observed. On the other hand, fungi, algae and cyanobacteria forming crustose lichens, as well as free-living lithobiontic microorganisms, are known to show combined geophysical and geochemical action, mainly on laminar minerals. The substrate zone where the saxicolous lichens are attached is most affected by weathering reactions and shows the highest co-occurrence of lithobiontic microorganisms. The physical and chemical properties of the substrate, along with lichen and microorganism activity, determine different microenvironments and microhabitats. The ecological functioning of these lithobiontic communities is not yet fully understood, and research efforts similar to the present are needed to confirm that their development is influenced by interrelations between different community members and the substrate, as suggested here.

  2. Oral conditions among workers in the Danish granite industry.

    PubMed

    Petersen, P E; Henmar, P

    1988-10-01

    The purpose of the study was to evaluate the oral health situation of workers in the Danish granite industry, in particular, to describe the prevalence and severity of dental abrasion. Measurements of the work environment showed that the workers were exposed to abrasive quartz dust. A total of 39 workers (72%) completed a questionnaire on their dental health, work environment, and symptoms from the masticatory system. Only 10% had been treated by school dental services, and only 51% made regular visits to the dentist. Consequently, the clinical examinations revealed a high prevalence of dental caries (mean number of decayed, missing, and filled surfaces 87.2). The workers' periodontal conditions were poor; the mean percentage of teeth with gingivitis, calculus and pockets deeper than 5 mm was 13.4. The prevalence of dental abrasion was 100%; in particular, abrasion was observed on the front teeth. The severity of abrasion and the affection ratio increased by duration of exposure to dust. In conclusion, dental abrasion induced by work-related dust should be considered an occupational disease.

  3. Assessment of natural radioactivity in commercial granites used in Turkey.

    PubMed

    Onargan, Turgay; Gür, Filiz; Kaya, Erol; Güneri, Sinem

    2012-01-01

    The activity concentrations of (226)Ra, (232)Th and (40)K in twelve different domestic and imported tiling rocks (granites) used as building materials in Turkey were determined by employing high-resolution γ-ray spectrometry. The samples were evaluated to assess the radiation hazard for people by comparing the results with the control values recommended by the European Commission. The measured activity concentrations ranged from 7 to 136 Bq kg(-1), 9 to 138 Bq kg(-1) and 541 to 1277 Bq kg(-1) for (226)Ra, (232)Th and (40)K, respectively. Applying dose criteria recommended by the European Commission([15]), two of the samples showed higher Ra(eq) values than the limit dose of 370 Bq kg(-1), equivalent to a γ-dose of 1.5 mSv y(-1). The calculated gamma-index (I(γ)) values for all the 12 samples were lower than the recommended dose criterion. In some of the samples; however, the H(ex) and H(in) values were more than unity. The absorbed dose rates (D) for all the samples, except for four samples, were located within the range values recommended by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR)([3]). Annual effective dose (AED) values, except for one sample, were greater than the world average value of UNSCEAR([3]).

  4. Multispectral analysis of limestone, dolomite, and granite, Mill Creek, Oklahoma

    NASA Technical Reports Server (NTRS)

    Rowan, L. C.; Watson, K.

    1970-01-01

    Spectral reflectance and thermal emission data were collected at the Mill Creek, Oklahoma test site during NASA missions 132 and 133 in June 1970. The data were collected by three aircraft flown several times during the diurnal cycle at altitudes of 150 to 17,000 m above mean terrain. Reflectance of the main rock types (limestone, dolomite, and granite) was determined from the data collected using a 12-channel multispectral scanner during mission 133 and from thermal infrared images recorded during mission 132 on an RS-7 scanner from 17,000 m above terrain. A preliminary rock recognition map was generated automatically using data collected from 900 m above terrain. The discrimination provided by the map is reasonably accurate. Misidentification occurred in areas of unusually high dolomite reflectivity. High altitude thermal infrared (10 to 12 micrometers) images show regional folds and faults distinguished by the presence of thermally contrasting materials. Linear and curvilinear structural features two to three times smaller than the nominal 17 m resolution could be detected.

  5. Rapid technique for counting cracks in granitic rocks

    SciTech Connect

    Durham, W.B.; Beiriger, J.M.; Weed, H.C.

    1984-01-23

    Using a scanning electron microscope and an image analyzer, we have developed a technique for counting and measuring cracks in rocks which is more efficient than traditional techniques in which an operator performs all image analysis functions. The key aspect of the technique is that black-on-white tracings of fresh cracks, which can be made rather quickly by an operator, are fed to an image analyzer which then digitizes and tabulates data. The most time-consuming step in the process has now become the generation of SEM micrographs and pertinent chemical (mineralogical) information, not the quantification of crack structure. The technique has been applied to two studies involving nuclear waste isolation in a granitic rock, Climax Stock (Nevada Test Site) quartz monzonite, a rock which is structurally very inhomogeneous. One study detected a relationship between crack structure and distance from a hammer-drilled borehole; the other study was unable to detect a relationship between crack structure and gamma irradiation treatment in rocks loaded to near failure. 12 references, 6 figures, 3 tables.

  6. Weathering profiles in granites, Sierra Norte (Córdoba, Argentina)

    NASA Astrophysics Data System (ADS)

    Kirschbaum, Alicia; Martínez, Estela; Pettinari, Gisela; Herrero, Silvana

    2005-09-01

    Two weathering profiles evolved on peneplain-related granites in Sierra Norte, Córdoba province, were examined. Several weathering levels, of no more than 2 m thickness, were studied in these profiles. They had developed from similar parent rock, which had been exposed to hydrothermal processes of varying intensity. Fracturing is the most notable feature produced by weathering; iron oxides and silica subsequently filled these fractures, conferring a breccia-like character to the rock. The clay minerals are predominantly illitic, reflecting the mineral composition of the protolith. Smaller amounts of interstratified I/S RO type are also present, as well as scarce caolinite+chlorite that originated from the weathering of feldspar and biotite, respectively. The geochemical parameters define the weathering as incipient, in contrast to the geomorphological characteristics of Sierra Norte, which point to a long weathering history. This apparent incompatibility could be due to the probable erosion of the more weathered levels of the ancient peneplains, of which only a few relicts remain. Similar processes have been described at different sites in the Sierras Pampeanas. Reconstruction and dating of the paleosurfaces will make it possible to set time boundaries on the weathering processes studied and adjust the paleographic and paleoclimatic interpretations of this great South American region.

  7. Operation of the Lower Granite Dam Adult Trap, 2008.

    SciTech Connect

    Harmon, Jerrel R.

    2009-01-01

    During 2008 we operated the adult salmonid trap at Lower Granite Dam from 7 March through 25 November, except during a short summer period when water temperatures were too high to safely handle fish. We collected and handled a total of 20,463 steelhead Oncorhynchus mykiss and radio-tagged 34 of the hatchery steelhead. We took scale samples from 3,724 spring/summer Chinook salmon O. tshawytscha for age and genetic analysis. We collected and handled a total of 8,254 fall Chinook salmon. Of those fish, 2,520 adults and 942 jacks were transported to Lyons Ferry Hatchery on the Snake River in Washington. In addition, 961 adults and 107 jacks were transported to the Nez Perce Tribal Hatchery on the Clearwater River in Idaho. The remaining 3,724 fall Chinook salmon were passed upstream. Scales samples were taken from 780 fall Chinook salmon tagged with passive integrated transponder (PIT) tags and collected by the sort-by-code system.

  8. Granite rock outcrops: an extreme environment for soil nematodes?

    PubMed

    Austin, Erin; Semmens, Katharine; Parsons, Charles; Treonis, Amy

    2009-03-01

    We studied soil nematode communities from the surface of granite flatrock outcrops in the eastern Piedmont region of the United States. The thin soils that develop here experience high light intensity and extreme fluctuations in temperature and moisture and host unique plant communities. We collected soils from outcrop microsites in Virginia (VA) and North Carolina (NC) in various stages of succession (Primitive, Minimal, and Mature) and compared soil properties and nematode communities to those of adjacent forest soils. Nematodes were present in most outcrop soils, with densities comparable to forest soils (P > 0.05). Nematode communities in Mature and Minimal soils had lower species richness than forest soils (P < 0.05) and contained more bacterial-feeders and fewer fungal-feeders (P < 0.05). Primitive soils contained either no nematodes (NC) or only a single species (Mesodorylaimus sp., VA). Nematode communities were similar between Mature and Minimal soils, according to trophic group representation, MI, PPI, EI, SI, and CI (P > 0.05). Forest soils had a higher PPI value (P < 0.05), but otherwise community indices were similar to outcrop soils (P > 0.05). Outcrop nematode communities failed to group together in a Bray-Curtis cluster analysis, indicating higher variability in community structure than the Forest soils, which did cluster together. A high proportion of the nematodes were extracted from outcrop soils in coiled form (33-89%), indicating that they used anhydrobiosis to persist in this unique environment.

  9. Cavity Radius Scaling for Chemical Explosions in Granite

    NASA Astrophysics Data System (ADS)

    Stroujkova, A. F.; Vorobiev, O.; Carnevale, M.

    2015-12-01

    It was long argued that the far-field seismic amplitudes from explosions are determined by the volume change in the source region, mainly due to a formation of the explosive cavities (e.g. Denny and Johnson, 1991). Weston Geophysical performed measurements of the cavities left by small chemical explosions in hard rock in New England. The comparison of the measured cavity sizes with historical data from nuclear and chemical explosions in hard rock (e.g. granite) shows that the cavity radii scale as W1/3 and appear to be depth independent because the rock strength significantly exceeds the overburden pressure for all possible explosion depths. The cavity sizes produced by nuclear explosions in softer rock (e.g. alluvium) deviate from the cubic root scaling and depend on the confining pressure. Cavity size calculations as a function of yield using hydrodynamic simulations with GEODYN, an Eulerian hydrodynamic code developed at Lawrence Livermore National Laboratory, support these observations. We investigate the effects of the cavity size as well as the extent of the damage zones on seismic radiation.

  10. Study of the contaminant transport into granite microfractures using nuclear ion beam techniques.

    PubMed

    Alonso, Ursula; Missana, Tiziana; Patelli, Alessandro; Rigato, Valentino; Rivas, Pedro

    2003-03-01

    Hydrated bentonite is a very plastic material and it is expected to enter in the rock microfractures at the granite/bentonite boundary of a deep geological high-level waste repository. This process is enhanced by the high swelling pressure of the clay. Since bentonite has a very good sorption capability for many radionuclides, the displacement of the clay might lead to a "clay-mediated" contaminant transport into the rock. The aim of this work is to study the contaminant transport into granite microfractures using nuclear ion beam techniques, and to determine to what extent the clay can favour it. To do so, bentonite previously doped with uranium, cesium and europium was put in contact with the surface of granite sheets. Granite sheets contacted with non-doped bentonite and with radionuclide solutions were also prepared as references. This allowed analysing the differences in the diffusion behaviour of the three systems: clay, radionuclides and clay plus radionuclides. A combination of Rutherford backscattering spectrometry (RBS) and other nuclear ion-beam techniques such as particle-induced X-ray emission (PIXE) and microPIXE was used to study the depth and lateral distribution of clay and contaminants inside granite. It was also tried to evaluate not only the diffusion depth and diffusion coefficients but also the different areas of the granite where the diffusants have a preferential access.

  11. Weathering-associated bacteria from the Damma glacier forefield: physiological capabilities and impact on granite dissolution.

    PubMed

    Frey, Beat; Rieder, Stefan R; Brunner, Ivano; Plötze, Michael; Koetzsch, Stefan; Lapanje, Ales; Brandl, Helmut; Furrer, Gerhard

    2010-07-01

    Several bacterial strains isolated from granitic rock material in front of the Damma glacier (Central Swiss Alps) were shown (i) to grow in the presence of granite powder and a glucose-NH(4)Cl minimal medium without additional macro- or micronutrients and (ii) to produce weathering-associated agents. In particular, four bacterial isolates (one isolate each of Arthrobacter sp., Janthinobacterium sp., Leifsonia sp., and Polaromonas sp.) were weathering associated. In comparison to what was observed in abiotic experiments, the presence of these strains caused a significant increase of granite dissolution (as measured by the release of Fe, Ca, K, Mg, and Mn). These most promising weathering-associated bacterial species exhibited four main features rendering them more efficient in mineral dissolution than the other investigated isolates: (i) a major part of their bacterial cells was attached to the granite surfaces and not suspended in solution, (ii) they secreted the largest amounts of oxalic acid, (iii) they lowered the pH of the solution, and (iv) they formed significant amounts of HCN. As far as we know, this is the first report showing that the combined action of oxalic acid and HCN appears to be associated with enhanced elemental release from granite, in particular of Fe. This suggests that extensive microbial colonization of the granite surfaces could play a crucial role in the initial soil formation in previously glaciated mountain areas.

  12. Granites related to tin mineralization at Mt. Pleasant, New Brunswick, Canada: subvolcanic analogues of topaz rhyolites

    SciTech Connect

    Taylor, R.P.; Sinclair, W.D.

    1985-01-01

    Two type of fluorine-rich (>2000 ppm F) high-silica (>74 wt. % SiO/sub 2/) granite are present in the environs of the Mt. Pleasant Tungsten Mine. Both are subvolcanic in character and Devono-Carboniferous in age. An older fine-grained granite contains biotite (+/-chlorite) and is associated with the earlier W-Mo stockwork/breccia ore bodies. It is intruded by topaz- and fluorite-bearing granite porphyry/porphyritic granite to which later Sn-polymetallic base metal mineralization appears to be related. Major element characteristics (SiO/sub 2/ > 75 wt. %; Na/sub 2/O > 3.2 wt. %; K/sub 2/O/Na/sub 2/O > 1; TiO/sub 2/ < 0.2 wt. %; CaO < 0.7 wt. %; MgO < 0.2 wt. %; P/sub 2/O/sub 5/ < 0.05 wt. %) identify both phases as anorogenic granites. Trace element contents however permit their separation and identify the later granites with Rb > 800 ppm, Li > 100 ppm, Cs > 20 ppm, Ta > 15 ppm, F > 4000 ppm, and distinctive flat REE patterns with large negative Eu anomalies as the intrusive equivalents of topaz rhyolites. Such unique REE distributions suggest that melt depolymerization resulting from the enhanced solubility of fluorine may play a pivotal role in the evolution of these felsic magmas.

  13. 152Eu depth profiles in granite and concrete cores exposed to the Hiroshima atomic bomb.

    PubMed

    Shizuma, K; Iwatani, K; Hasai, H; Hoshi, M; Oka, T

    1997-06-01

    Two granite and two concrete core samples were obtained within 500 m from the hypocenter of the Hiroshima atomic bomb, and the depth profile of 152Eu was measured to evaluate the incident neutron spectrum. The granite cores were obtained from a pillar of the Motoyasu Bridge located 101 m from the hypocenter and from a granite rock in the Shirakami Shrine (379 m); the concrete cores were obtained from a gate in the Gokoku Shrine (398 m) and from a pillar top of the Hiroshima bank (250 m). The profiles of the specific activities of the cores were measured to a depth of 40 cm from the surface using low background germanium (Ge) spectrometers. According to the measured depth profiles, relaxation lengths of incident neutrons were derived as 13.6 cm for Motoyasu Bridge pillar (granite), 12.2 cm for Shirakami Shrine core (granite), and 9.6 cm for concrete cores of Gokoku Shrine and Hiroshima Bank. In addition, a comparison of the granite cores in Hiroshima showed good agreement with Nagasaki data. Present results indicates that the depth profile of 152Eu reflects incident neutrons not so high but in the epithermal region.

  14. Geochemical characteristics and origin of the Lebowa Granite Suite, Bushveld Complex

    USGS Publications Warehouse

    Hill, M.; Barker, F.; Hunter, D.; Knight, R.

    1996-01-01

    The ??? 2052-Ma Lebowa Granite Suite (LGS) represents the culminating phase of an Early Proterozoic magmatic cycle in the Central Transvaal area of the Kaapvaal Province. Following extrusion of at least 200,000 km3 of intermediate to acid volcanics (Rooiberg Felsite), mafic and ultramafic magmas intruded at 2065 Ma to form the Rustenburg Layered Suite (RLS). The LGS includes the Nebo, Makhutso, Bobbejaankop, Lease, and Klipkloof granites. The Nebo Granite intruded the Rooiberg Felsite as sheets up to 4 km thick above the RLS. Smaller stocks of the other granites crosscut the Nebo. We determined major- and trace-element compositions and oxygen, Rb-Sr, and Sm-Nd isotope ratios for samples of: Nebo Granite; Rooiberg Felsite; granophyre and granophyric granite; Makhutso, Bobbejaankop, and Lease granites; and feldspar porphyry from areas throughout the exposed area of the LGS (Dennilton, Verena Balmoral, Enkeldoorn, Sekhukhune Plateau, Zaaiplaats-Potgeitersrus, and Western Transvaal). Coherent floor-to-roof geochemical trends exist in some areas, although it is not possible to model them convincingly. Regional variations in geochemistry exist and likely are related to source variations in the estimated 200,000 km3 of the Nebo Granite sheets. ??18O for the LGS range from +5.9??? to +9.5???; if these are approximate primary magmatic values, pelitic sediments cannot have been an important source for the LGS. The Rb-Sr isotope system has been altered, a finding consistent with previous studies. A mineral isochron for Nebo Granite near Dennilton yields a York regression age of 1995 ?? 99 Ma, with initial 143Nd/144Nd = 0.50978??8 and ???CHUR=-5.12. Samples from the Sekhukhune Plateau have higher 143Nd/144Nd ratios than do Dennilton-area samples, suggesting that the former originated from older or less LREE-enriched sources. We suggest that intrusion of mafic to ultramafic magmas at depth in the continental crust triggered melting of Archean quartzofeldspathic crystalline

  15. Neutron porosity logging and core porosity measurements in the Beauvoir granite, Massif Central Range, France

    NASA Astrophysics Data System (ADS)

    Gallé, C.

    1994-08-01

    A large suite of geophysical logs have been run in the Beauvoir granite. The drillhole (900 m deep), first target of the French Deep Geology programme, is located in the Hercynian bedrock of Echassières in central France (Massif Central Range). After geochemical and petrological studies, the batholith was used for experiments pertaining to the storage of radioactive wastes. With its low porosity, its weak fracturing and its high homogeneity, the Beauvoir granite was chosen for the analysis of the relationship between logged data and the properties measured in the core. The study focused on neutron porosity and core water porosity. The Beauvoir granite has a total free water porosity of around 2% (average value of 54 core samples of rock mass) and an average neutron porosity of around 10%. We show that the origin of this significant difference is related to the neutron matrix effect of the granite. This phenomenon is partly due to the slowing-down effect of the combined water of clays and micas but also to the neutronic capture effect linked with the relatively high lepidolite (lithium mica) content of the granite. The Li 2O content controls 85% of the granite macroscopic capture cross-section. These two factors represent around 75% of the global neutron porosity of the Beauvoir granite. They have to be taken into consideration to get representative water contents of a low-porosity igneous rock from a neutron porosity log. Further investigations also demonstrated the necessity of choosing a better adapted neutron tool calibration for crystalline rocks. Instead of a standard calibration with limestone blocks, a calibration in granite blocks was simulated in order to obtain a better evaluation of the global neutron response of the granite. Then, by correcting this new neutron porosity for the matrix effect, it has been possible to determine water contents in accordance with laboratory water porosity values measured on core samples (2% average porosity). This

  16. Differential weathering of basaltic and granitic catchments from concentration-discharge relationships

    NASA Astrophysics Data System (ADS)

    Ibarra, Daniel E.; Caves, Jeremy K.; Moon, Seulgi; Thomas, Dana L.; Hartmann, Jens; Chamberlain, C. Page; Maher, Kate

    2016-10-01

    A negative feedback between silicate weathering rates and climate is hypothesized to play a central role in moderating atmospheric CO2 concentrations on geologic timescales. However, uncertainty regarding the processes that regulate the operation of the negative feedback limits our ability to interpret past variations in the ocean-atmosphere carbon cycle. In particular, the mechanisms that determine the flux of weathered material for a given climatic state are still poorly understood. Here, we quantify the processes that determine catchment-scale solute fluxes for two lithologic end-members-basalt and granite-by applying a recently developed solute production model that links weathering fluxes to both discharge and the reactivity of the weathering material. We evaluate the model against long-term monitoring of concentration-discharge relationships from basaltic and granitic catchments to determine the parameters associated with solute production in each catchment. Higher weathering rates in basaltic catchments relative to granitic catchments are driven by differing responses to increases in runoff, with basaltic catchments showing less dilution with increasing runoff. In addition, results from the solute production model suggest that thermodynamic constraints on weathering reactions could explain higher concentrations in basaltic catchments at lower runoff compared to granitic catchments. To understand how the response to changing discharge controls weathering fluxes under different climatic states, we define basalt/granite weatherability as the ratio of the basalt catchment flux to the granite catchment flux. This weatherability is runoff-dependent and increases with increasing runoff. For HCO3- and SiO2(aq) fluxes, for modern global runoff, the derived mean basalt/granite weatherability is 2.2 (1.3-3.7, 2σ) and 1.7 (1.6-2.1, 2σ), respectively. Although we cannot determine the array of individual processes resulting in differences among catchments, the relative

  17. Mobility of heavy metals through granitic soils using mini column infiltration test

    SciTech Connect

    Zarime, Nur 'Aishah; Yaacob, W. Z.W.

    2014-09-03

    This study is about the mobility of cadmium through compacted granitic soils. Two granitic soils namely the Broga (BGR) and Kajang (KGR) granitic soils were collected in Selangor, Malaysia. Physical and chemical tests were applied for both granitic soils to determine the physical and chemical properties of soil materials. Physical test results shows granitic soils (BGR and KGR) have high percentage of sand ranging between 54%–63% and 46%–54% respectively, an intermediate and intermediate to high plasticity index as well as high specific gravity ie; 2.50–2.59 and 2.45–2.66 respectively. For chemical test, granitic soils shows acidic pH values ranged from 5.35–5.85 for BGR and pH 5.32–5.54 for KGR. For organic matter, SSA and CEC test, it shows low values ranged from 0.22%–0.34% and 0.39%– 0.50% respectively for organic matter test, 17.96 m{sup 2}/g–21.93 m{sup 2}/g and 25.76 m{sup 2}/g–26.83 m{sup 2}/g respectively for SSA test and 0.79 meq/100g–1.35 meq/100g and 1.31 meq/100g–1.35 meq/100g respectively for CEC test. Mini column infiltration test was conducted to determine the retention of cadmium while flowing through granite soils. This test conducted based on the falling head permeability concepts. Different G-force ranging from 231G to 1442G was used in this test. The breakthrough curves show the concentration of Cd becomes higher with the increasing of G-force for both granitic samples (BGR and KGR). The selectivity sorption for both granites ranked in the following decreasing order of; 231G>519G>923G>1442G. Results demonstrated that granitic soils also have low buffering capacity due to low resist of pH changes.

  18. Rapakivi Granite: An architectural emblem of St Petersburg and its utilisation in other world cities

    NASA Astrophysics Data System (ADS)

    Bulakh, Andrey; Gavrilenko, Vladimir; Panova, Helen

    2015-04-01

    The wide-ranging utilisation of Rapakivi Granite in St Petersburg is typified by the the famous Alexander Column, and 114 stone columns of St Isaac's Cathedralas well as the pedestal of the Nicholas I monument, and portals and basements of buildings of the Admiralty, General Staff, Senate and Synod. The stone is also frequently seen among pavement slabs and in parapets of embankments and bridges around the city. This list of examples where Rapakivi Granite has been used could be expanded further. All Rapakivi Granites used in the buildings of St.Petersburg were quarried from the so-called Vyborg massif. At present it has been found that the massif occupies an area of about 18 000 km2. In the past granite of the Vyborg massif was worked from several quarries in the vicinity of Fredrikshamn (Hamina) in Finland for use in St Peterburg. The best known granite quarries are at Piterlaks (Piuterlahti) and Gimmekyul (Hämeenkylä). Sometimes Rapakivi Granite form Finland differs in appearance from typical varieties. Thus columns of a classical portal in the house at N 7 in Pochtamtskaya Street are hewn from this greyish variety. Other examples are the plinth of the General Staff and Trade Store buildings. After the 1960s varieties from the Leningrad district, and Korosten (Ukraine) massifs were used in St Petersburg. Today it is possible to find examples of Rapakivi Granite from Finland in cities in the USA, South Africa, United Kingdom and Germany. It is a long used stone as demonstrated by its cultural heritage. It is also used as an ornamental or decorative stone in modern architecture. References: 1) Bulakh, A.G., Abakumova, N.B., and Romanovsky, J.V. St Petersburg: a History in Stone. 2010. Print House of St Petersburg State University. 173 p. (In English). 2) Tutakova, A.Ya., Romanovskiy, A.Z., Bulakh, A.G., and Leer, V.I. Dimension Stone of the Leningrad Region. Granites of the Karelia Isthmus in Architecture of the Modern St Petersburg. 2011. St Petersburg. 78 p

  19. [Analysis of X-ray fluorescence spectroscopy and plasma mass spectrometry of the Guidong granite body and its implications to granite evolution].

    PubMed

    Li, Hong-Wei; Chen, Guo-Neng; Peng, Zhuo-Lun

    2013-07-01

    The Guidong composite granite body (CGB) located in the north Guangdong Province consists of numerous rock bodies formed respectively in the early and late Jurassic and early Cretaceous. Analysis of the granites of different period with X-ray fluorescence spectroscopy and plasma mass spectrometry indicates: (1) From the top of a granite body downwards, the felsic components of rock decrease, while the mafic and sigmaREE, LREE/HREE, (La/Yb)N, as well as delta Eu value increase, suggesting the material differentiation in the in-situ melting of crustal rocks and crystallisation of magma; (2) From old to young of the different period granite-massifs in the Guidong CGB, the felsic compositions totally decrease, and the mafic components, sigmaEE, LREE/HREE, (La/Yb)N, and delta Eu value increase as well, implying multiple crustal melting (remelting) events in the Mesozoic in this area; and (3) Primitive mantle-normalized spider diagram for trace elements of Guidong CGB suggests high maturity of the crust involved in the in-situ melting. PMID:24059211

  20. Crystallization and uplift path of late Variscan granites evidenced by quartz chemistry and fluid inclusions: Example from the Land's End granite, SW England

    NASA Astrophysics Data System (ADS)

    Drivenes, Kristian; Larsen, Rune Berg; Müller, Axel; Sørensen, Bjørn Eske

    2016-05-01

    The megacrystic, coarse-grained granite of the Land's End granitic complex, SW England, has been investigated by analyzing fluid inclusions, trace elements, and cathodoluminescence textures of quartz. By applying the TitaniQ geothermobarometer together with the cathodoluminescence textures, a two-stage emplacement process is proposed. K-feldspar and quartz phenocrysts crystallized in a deep magma chamber at ca. 18-20 km depth. The phenocrysts were transported together with the melt to a shallow emplacement depth at ca. 5-9 km in multiple intrusive events, causing the composite appearance of the granitic complex. This model of emplacement concurs with similar granites from the Erzgebirge. At the emplacement level, the magma exsolved an aqueous fluid with average salinity of 17.3% m/m NaCl and 9.7% m/m CaCl2. Fluids with higher salinities were exsolved deeper in the system, as the magma experienced stages of water saturation and water undersaturation during ascent from the deep magma chamber. The complex fluid inclusion textures are the results of multiple stages of entrapment of aqueous fluids in the host phases as multiple recharge events from the deeper magma chamber supplied fresh melts and aqueous volatiles. Titanium contents in quartz are closely related to the panchromatic cathodoluminescence intensity, and the Al/Ti ratio is reflected by the 3.26 eV/2.70 eV ratio of hyperspectral cathodoluminescence.

  1. [Analysis of X-ray fluorescence spectroscopy and plasma mass spectrometry of the Guidong granite body and its implications to granite evolution].

    PubMed

    Li, Hong-Wei; Chen, Guo-Neng; Peng, Zhuo-Lun

    2013-07-01

    The Guidong composite granite body (CGB) located in the north Guangdong Province consists of numerous rock bodies formed respectively in the early and late Jurassic and early Cretaceous. Analysis of the granites of different period with X-ray fluorescence spectroscopy and plasma mass spectrometry indicates: (1) From the top of a granite body downwards, the felsic components of rock decrease, while the mafic and sigmaREE, LREE/HREE, (La/Yb)N, as well as delta Eu value increase, suggesting the material differentiation in the in-situ melting of crustal rocks and crystallisation of magma; (2) From old to young of the different period granite-massifs in the Guidong CGB, the felsic compositions totally decrease, and the mafic components, sigmaEE, LREE/HREE, (La/Yb)N, and delta Eu value increase as well, implying multiple crustal melting (remelting) events in the Mesozoic in this area; and (3) Primitive mantle-normalized spider diagram for trace elements of Guidong CGB suggests high maturity of the crust involved in the in-situ melting.

  2. Radon emanation during compression, fracturing and heating of granites

    NASA Astrophysics Data System (ADS)

    Pili, E.; Nicolas, A.; Girault, F.; Schubnel, A.; Fortin, J.; Passelègue, F. X.; Richon, P.

    2013-12-01

    Radon emanation during compression, fracturing and heating of granites É. Pili1,2, A. Nicolas3, F. Girault3, A. Schubnel3, J. Fortin3, F. Passelègue3, P. Richon1 1CEA, DAM, DIF, F-91297 Arpajon, France 2Institut de Physique du Globe, Sorbonne Paris Cité, 1 rue Jussieu, F-75005 Paris, France 3Ecole Normale Supérieure, 24 rue Lhomond, F-75005 Paris, France Precursory radon emissions have been reported previously in various seismically active areas. Nevertheless such observations, only partially understood, are the subject of much skepticism. Radon-222 is a radioactive gas, daughter of radium-226 from alpha-decay in the uranium-238 decay chain that is naturally present in rocks and soils. Its escape is facilitated by preferential pathways such as fractures. Its half-life is 3.8 days only. As a consequence, radon may accumulate during short period only, and is thought to be released prior, during and after earthquakes as stress is discharged and new fluid pathways are made available. However, the physical processes involved in radon emanation during stress variations remain mostly unknown in the field and poorly studied in the laboratory. Here, we investigate radon emanation from various granite samples: Isla Craig, Westerly, La Peyratte and various leucogranites. Radon emanation and diffusion length, measured first on intact samples, are compared with measurements performed after heating at 850°C. Despite extensive thermal fracturing, radon emanation decreases irreversibly after heating compared to intact sample, and the higher the heating temperature the smaller the radon emanation. This is explained by the disappearance of water-film at grain boundaries, which plays an important role in radon percolation through the porous space, and then, at higher temperatures, by dehydration and melting of biotites where radium is concentrated. The recoil range of radon is likely shorter in melted biotites than in intact ones. The effect of mechanical fracturing on radon

  3. Lithium and boron in late-orogenic granites - Isotopic fingerprints for the source of crustal melts?

    NASA Astrophysics Data System (ADS)

    Romer, Rolf L.; Meixner, Anette; Förster, Hans-Jürgen

    2014-04-01

    Geochemically diverse late- and post-Variscan granites of the Erzgebirge-Vogtland, the Saxon Granulite Massif, and Thuringia (Germany) formed by anatectic melting of Palaeozoic sedimentary successions and associated mafic to felsic volcanic rocks. The compositional diversity of the least evolved of these granites is largely inherited from the protoliths. We present Li and B-isotopic data of these granites and compare them with the isotopic composition of their protoliths, to investigate whether (i) there exist systematic differences in the Li and B-isotopic composition among different granite types and (ii) Li and B-isotopic compositions provide information on the granite sources complementary to information from the isotopic composition of Sr, Nd, and Pb and the trace-element signatures. Low-F biotite and two-mica granite types have flat upper continental crust (UCC)-normalized trace-element pattern with variable enrichments in Li, Rb, Cs, Sn, and W and depletions in Sr, Ba, and Eu. These signatures are least pronounced for the Niederbobritzsch biotite granite, which has the largest contribution of mafic material, and most pronounced for the two-mica granites. The granites show a relatively narrow range of δ7Li values (-3.0 to -0.5) and a broad range of δ11B values (-13.4 to +20.1). The δ11B values are lower in rocks with distinctly higher contents of Li, Rb, Cs, and Sn. The high δ11B of the Niederbobritzsch granite may be explained by the melting of former altered oceanic crust in its source. Relative to UCC, intermediate-F to high-F low-P granites show strong depletions in Sr, Ba, Eu as well as Zr and Hf, strong enrichments in Li, Rb, and Cs as well as Nb, Sn, Ta, and W, and REE pattern with stronger enrichments for HREE than for LREE. These granites show narrow ranges of δ7Li (-2.0 to +1.6) and δ11B values (-14.7 to -9.1), reflecting the smaller variability of the Li and B-isotopic composition in their source lithologies. The anomalously high δ7Li value

  4. Highly evolved juvenile granites with tetrad REE patterns: the Woduhe and Baerzhe granites from the Great Xing'an Mountains in NE China

    NASA Astrophysics Data System (ADS)

    Jahn, Bor-ming; Wu, Fuyuan; Capdevila, R.; Martineau, F.; Zhao, Zhenhua; Wang, Yixian

    2001-12-01

    In NE China, voluminous granitoids were emplaced in late Paleozoic and Mesozoic times. We report here Sr-Nd-O isotopic and elemental abundance data for two highly evolved granitic plutons, Woduhe and Baerzhe, from the Great Xing'an Mountains. They show a rather "juvenile" Sr-Nd isotopic signature and a spectacular tetrad effect in their REE distribution patterns as well as non-CHARAC (charge-and-radius-controlled) trace element behavior. The emplacement ages are constrained at 130±4 Ma for the Woduhe and 122±5 Ma for the Baerzhe granites by Rb-Sr and Sm-Nd isotope analyses. Both granites are also characterized by low but imprecise initial 87Sr/ 86Sr ratios of about 0.703. The Nd-Sr isotope data argue for their generation by melting of dominantly juvenile mantle component with subordinate recycled ancient crust. This is largely compatible with the general scenario for much of the Phanerozoic granitoids emplaced in the Central Asian Orogenic Belt. The parental magmas for both the Woduhe and Baerzhe granites have undergone extensive magmatic differentiation, during which intense interaction of the residual melts with aqueous hydrothermal fluids (probably rich in F and Cl) resulted in the non-CHARAC trace element behavior and the tetrad effect of REE distribution. Both the Woduhe and Baerzhe granites show the characteristic trace element patterns of rare-metal granites, but their absolute abundances differ by as much as two orders of magnitude. The oxygen isotope compositions of the two granites have been severely disturbed. Significant 18O depletion in feldspar, but not so much in quartz, suggests that the hydrothermal alteration took place in a temperature condition of 300-500 °C. This subsolidus hydrothermal alteration is decoupled from the late-stage magma-fluid interaction at higher temperatures. Despite the two distinct and intense events of "water-rock" interaction, the Rb-Sr and Sm-Nd geochronological systems seem to have maintained closed, hence, suggesting

  5. Bioweathering and biotransformation of granitic rock minerals by actinomycetes.

    PubMed

    Abdulla, Hesham

    2009-11-01

    Actinomycetes inhabiting granitic rocks at St. Katherine, Egypt were investigated for their bioweathering potential. Actinomycete counts ranged between 174 and 360 colony forming units per gram. Counts were positively correlated to rock porosity (r = 0.65) and negatively correlated to rock salinity (r = -0.56). Sixty-six actinomycete isolates originating from rocks could be assigned into eight genera, with a high frequency of Nocardioides and Streptomyces. Organic acids were produced by 97% of the isolates. Strains belonging to Actinopolyspora, Actinomadura, Kitasatospora, Nocardioides, and Kibdelosporangium showed the highest acid production indices. Representatives from all eight genera could precipitate metals Cu, Fe, Zn, Cd, and Ag up to concentrations of 2.5 mM each. An actinomycete consortium of two Nocardioides strains and one Kibdelosporangium strain was studied for its potential to cause rock weathering in batch experiments. Results indicated a high ability of the consortium to leach the metals Cu, Zn, and Fe up to 2.6-, 2.1-, and 1.3-fold, respectively, compared to the control after 4 weeks. The pH significantly decreased after 1 week, which was parallel to an increased release of phosphate and sulfate reaching a 2.2- and 2.5-fold increase, respectively, compared to control. Highly significant weight loss (p = 0.005) was achieved by the consortium, indicating a potential multiple role of actinomycetes in weathering by acid production, metal leaching, and solubilization of phosphate and sulfate. This study emphasizes the diverse and unique abilities of actinomycetes inhabiting rock surfaces which could be of potential biotechnological applications, such as in the bioremediation of metal-contaminated environments and metal biorecovery.

  6. Groundwater chemistry of a nuclear waste reposoitory in granite bedrock

    SciTech Connect

    Rydberg, J.

    1981-09-01

    This report concerns the prediction of the maximum dissolution rate for nuclear waste stored in the ground. That information is essential in judging the safety of a nuclear waste repository. With a limited groundwater flow, the maximum dissolution rate coincides with the maximum solubility. After considering the formation and composition of deep granite bedrock groundwater, the report discusses the maximum solubility in such groundwater of canister materials, matrix materials and waste elements. The parameters considered are pH, Eh and complex formation. The use of potential-pH (Pourbaix) diagrams is stressed; several appendixes are included to help in analyzing such diagrams. It is repeatedly found that desirable basic information on solution chemistry is lacking, and an international cooperative research effort is recommended. The report particularly stresses the lack of reliable data about complex formation and hydrolysis of the actinides. The Swedish Nuclear Fuel Safety (KBS) study has been used as a reference model. Notwithstanding the lack of reliable chemical data, particularly for the actinides and some fission products, a number of essential conclusions can be drawn about the waste handling model chosen by KBS. (1) Copper seems to be highly resistant to groundwater corrosion. (2) Lead and titanium are also resistant to groundwater, but inferior to copper. (3) Iron is not a suitable canister material. (4) Alumina (Al/sub 2/O/sub 3/) is not a suitable canister material if groundwater pH goes up to or above 10. Alumina is superior to copper at pH < 9, if there is a risk of the groundwater becoming oxidizing. (5) The addition of vivianite (ferrous phosphate) to the clay backfill around the waste canisters improves the corrosion resistance of the metal canisters, and reduces the solubility of many important waste elements. This report does not treat the migration of dissolved species through the rock.

  7. Fault growth and acoustic emissions in confined granite

    USGS Publications Warehouse

    Lockner, David A.; Byerlee, James D.

    1992-01-01

    The failure process in a brittle granite was studied by using acoustic emission techniques to obtain three dimensional locations of the microfracturing events. During a creep experiment the nucleation of faulting coincided with the onset of tertiary creep, but the development of the fault could not be followed because the failure occurred catastrophically. A technique has been developed that enables the failure process to be stabilized by controlling the axial stress to maintain a constant acoustic emission rate. As a result the post-failure stress-strain curve has been followed quasi-statically, extending to hours the fault growth process that normally would occur violently in a fraction of a second. The results from the rate-controlled experiments show that the fault plane nucleated at a point on the sample surface after the stress-strain curve reached its peak. Before nucleation, the microcrack growth was distributed throughout the sample. The fault plane then grew outward from the nucleation site and was accompanied by a gradual drop in stress. Acoustic emission locations showed that the fault propagated as a fracture front (process zone) with dimensions of 1 to 3 cm. As the fracture front passed by a given fixed point on the fault plane, the subsequent acoustic emission would drop. When growth was allowed to progress until the fault bisected the sample, the stress dropped to the frictional strength. These observations are in accord with the behavior predicted by Rudnicki and Rice's bifurcation analysis but conflict with experiments used to infer that shear localization would occur in brittle rock while the material is still hardening.

  8. Seismic anisotropy in granite at the Underground Research Laboratory, Manitoba

    SciTech Connect

    Holmes, G.M.; Crampin, S.; Young, R.P.

    2000-05-01

    The Shear-Wave Experiment at Atomic Energy of Canada Limited's Underground Research Laboratory was probably the first controlled-source shear-wave survey in a mine environment. Taking place in conjunction with the excavation of the Mine-by test tunnel at 420 m depth, the shear-wave experiment was designed to measure the in situ anisotropy of the rockmass and to use shear waves to observe excavation effects using the greatest variety of raypath directions of any in situ shear-wave survey to date. Inversion of the shear-wave polarizations shows that the anisotropy of the in situ rockmass is consistent with hexagonal symmetry with an approximate fabric orientation of strike 023{degree} and dip 35{degree}. The in situ anisotropy is probably due to microcracks with orientations governed by the in situ stress field and to mineral alignment within the weak gneissic layering. However, there is no unique interpretation as to the cause of the in situ anisotropy as the fabric orientation agrees approximately with both the orientation expected from extensive-dilatancy anisotropy and that of the gneissic layering. Eight raypaths with shear waves propagating wholly or almost wholly through granodiorite, rather than granite, do not show the expected shear-wave splitting and indicate a lower in situ anisotropy, which may be due to the finer grain size and/or the absence of gneissic layering within the granodiorite. These results suggest that shear waves may be used to determine crack and mineral orientations and for remote monitoring of a rockmass. This has potential applications in mining and waste monitoring.

  9. New data on the age and geodynamic interpretation of the Kalba-Narym granitic batholith, eastern Kazakhstan

    NASA Astrophysics Data System (ADS)

    Kotler, P. D.; Khromykh, S. V.; Vladimirov, A. G.; Navozov, O. V.; Travin, A. V.; Karavaeva, G. S.; Kruk, N. N.; Murzintsev, N. G.

    2015-06-01

    Geological and new geochronological data are summarized for the Kalba-Narym granitic batholith in eastern Kazakhstan, and their geodynamic interpretation is suggested. In the structure of the batholith, we consider (from late to early) the Kunush plagiogranitic complex, the Kalguta granodiorite-granitic association, and the Kalba granitic, Monastery leucogranitic, and Kainda granitic complexes. The granitic complexes of the Kalba-Narym batholith were formed between the Carboniferous-Permian and the Early-Middle Permian (˜30 Ma). New data indicate that formation of the Kalba-Narym batholith was related to the activity of the Tarim mantle plume. Heating of the lithosphere by the plume coincided with postcollision collapse of the orogenic structure and led to the crust melting and formation of the studied granitic complexes in a relatively short period.

  10. Brother is high Sr/Y two-mica granite and sister is leucogranite: twin granites in the Northern Himalayan Gneiss Domes, southern Tibet

    NASA Astrophysics Data System (ADS)

    Zeng, L.; Gao, L.; Xie, K.

    2011-12-01

    Leucogranites in the Himalayan orogen is widely considered as the type example of crustal melts, which provides a probe to investigate the interplay among high-grade metamorphism, crustal anatexis, and tectonic transition in large-scale collisional belts. Whether the leucogranite was a daughter product from a more primitive granitic melt is an interesting question that deserves careful examination to address the above issue. We report a new suite of two-mica granite (TMG) and leucogranite (LG) in the Yardoi gneiss dome (YGD) in the easternmost of the Northern Himalayan Gneiss Domes (NHGD), south of the Yarlung-Tsangpo suture. SHRIMP and LA-ICP-MS zircon U/Pb dating show that TMG and LG formed at ~17.7 Ma to ~20.0 Ma and at ~17.1 Ma, respectively. Both suites of granite have high Na/K (>1.30) ratios. The TMGs are characterized by (1) high Sr (>450 ppm), low Rb (<95 ppm) and Y (<6 ppm), and high Sr/Y (>86) ratios; (2) no Eu anomalies; and (3) low initial 87Sr/86Sr ratios (<0.7098) and higher ɛNd (>-8.5) values. In contrast, the LGs have (1) lower Sr (<130 ppm) and higher Rb (92-130 ppm); (2) pronounced negative Eu anomalies with Eu/Eu*<0.55; and (3) relatively higher Sr (87Sr/86Sr(t) =0.7136-0.7148) and unradiogenic Nd (ɛNd(t)=-7.7~-11.1). These data demonstrate that these Mid-Miocene granites have major and trace element and radiogenic isotope compositions similar to those of >35 Ma granites, but significantly different from those granites of similar ages in the High Himalaya as well as in the NHGD. High Sr/Y and relatively unradiogenic Sr isotope compositions in the TMGs could be derived from partial melting of mafic materials formed during previous compressional thickening event which was triggered by the input of juvenile heat and material associated with the Miocene E-W extension. An AFC process (plagioclase fractional crystallization and contamination by crustal materials) could be a primary factor leading to the formation of these LGs. Concurrence of high Sr

  11. Oxygen isotope, fluid inclusion, microprobe and petrographic studies of the preCambrian granites from the southern Wind River range and the Granite Mountains, central Wyoming, U.S.A.: Constraints on origin, hydrothermal alteration and uranium genesis

    NASA Astrophysics Data System (ADS)

    Cheang, K. K.

    The Granite Mountain is comprised of the granite of Long Creek Mountain and the volumetrically dominant granite of Lankin Dome. Average delta 018 O values in per mil deg/00 of the granite of Long Creek Mountain is 8.2 + or - 0.3 deg/00 (N = 4) and average delta 018 8.5 + or - -0.5 deg/00 (N = 37), values of the two phases from the granite of Lankin Dome are: biotite granites = delta 018 8.5 + or 0.5 deg/00 (N = 37), leucocratic graphite = 8.4 + or - 0.3 deg/00 (N = 12). The average delta 018 values for Louis Lake Batholith are: hornblende-biotite granodiorite = 7.3 + or - 0.3 deg/00 (N = 13) and leucocratic biotite granite = 7.7 + or - 0.1 deg/00 (N = 6). It is concluded from the whole rock oxygen isotopic, mineralogical, chemical and strontium isotopic data that the unaltered granites in the Granite Mountains were probably derived from a uranium enriched source with some peraluminous metasedimentary component which favoured the preconcentration of uranium and thorium, whereas the Louis Lake Batholith was formed by partial melting of igneous source materials that are not strongly enriched in uranium.

  12. [Study on the fine structure of K-feldspar of Qichun granite].

    PubMed

    Du, Deng-Wen; Hong, Han-Lie; Fan, Kan; Wang, Chao-Wen; Yin, Ke

    2013-03-01

    Fine structure of K-feldspar from the Qichun granite was investigated using X-ray diffraction (XRD), Fourier infrared absorption spectroscopy (FTIR), and inductively coupled plasma mass spectrometry methods to understand the evolution of the granitic magmatism and its correlation to molybdenite mineralization. The XRD results showed that K-feldspar of the potassic alteration veins has higher ordering index and triclinicity and is namely microcline with triclinic symmetry. K-feldspar of the early cretaceous granite has relatively lower ordering index and has widening [131] peak and is locally triclinic ordering. K-feldspar of the late cretaceous granite has lowest ordering index and sharp [131] peak and is honiogeneously monoclinic. The FTIR results showed that the IR spectra of the Qichun K-feldspar are similar to that of orthoclase reported by Farmer (1974). The 640 cm-1 absorption band increases while the 540 cm-' absorption band decreases with increase in K-feldspar ordering index, also, the 1,010 cm-1 absorption band separates into 1,010 and 1,046 cm-1 absorption bands, with a change in the band shape from widening to sharp outline. The ICP-MS results suggested that K-feldspar of the early cretaceous granite has relatively higher metal elements and rare earth elements, and the granite exhibits better mineralization background, K-feldspar of the potassic alteration veins has markedly lower Sr and Ba, indicating that the alteration fluid originated from the granitic magmatism, and hence, potassic alteration is a good indicator for molybdenite exploration. PMID:23705418

  13. Granite disposal of U.S. high-level radioactive waste.

    SciTech Connect

    Freeze, Geoffrey A.; Mariner, Paul E.; Lee, Joon H.; Hardin, Ernest L.; Goldstein, Barry; Hansen, Francis D.; Price, Ronald H.; Lord, Anna Snider

    2011-08-01

    This report evaluates the feasibility of disposing U.S. high-level radioactive waste in granite several hundred meters below the surface of the earth. The U.S. has many granite formations with positive attributes for permanent disposal. Similar crystalline formations have been extensively studied by international programs, two of which, in Sweden and Finland, are the host rocks of submitted or imminent repository license applications. This report is enabled by the advanced work of the international community to establish functional and operational requirements for disposal of a range of waste forms in granite media. In this report we develop scoping performance analyses, based on the applicable features, events, and processes (FEPs) identified by international investigators, to support generic conclusions regarding post-closure safety. Unlike the safety analyses for disposal in salt, shale/clay, or deep boreholes, the safety analysis for a mined granite repository depends largely on waste package preservation. In crystalline rock, waste packages are preserved by the high mechanical stability of the excavations, the diffusive barrier of the buffer, and favorable chemical conditions. The buffer is preserved by low groundwater fluxes, favorable chemical conditions, backfill, and the rigid confines of the host rock. An added advantage of a mined granite repository is that waste packages would be fairly easy to retrieve, should retrievability be an important objective. The results of the safety analyses performed in this study are consistent with the results of comprehensive safety assessments performed for sites in Sweden, Finland, and Canada. They indicate that a granite repository would satisfy established safety criteria and suggest that a small number of FEPs would largely control the release and transport of radionuclides. In the event the U.S. decides to pursue a potential repository in granite, a detailed evaluation of these FEPs would be needed to inform site

  14. [Study on the fine structure of K-feldspar of Qichun granite].

    PubMed

    Du, Deng-Wen; Hong, Han-Lie; Fan, Kan; Wang, Chao-Wen; Yin, Ke

    2013-03-01

    Fine structure of K-feldspar from the Qichun granite was investigated using X-ray diffraction (XRD), Fourier infrared absorption spectroscopy (FTIR), and inductively coupled plasma mass spectrometry methods to understand the evolution of the granitic magmatism and its correlation to molybdenite mineralization. The XRD results showed that K-feldspar of the potassic alteration veins has higher ordering index and triclinicity and is namely microcline with triclinic symmetry. K-feldspar of the early cretaceous granite has relatively lower ordering index and has widening [131] peak and is locally triclinic ordering. K-feldspar of the late cretaceous granite has lowest ordering index and sharp [131] peak and is honiogeneously monoclinic. The FTIR results showed that the IR spectra of the Qichun K-feldspar are similar to that of orthoclase reported by Farmer (1974). The 640 cm-1 absorption band increases while the 540 cm-' absorption band decreases with increase in K-feldspar ordering index, also, the 1,010 cm-1 absorption band separates into 1,010 and 1,046 cm-1 absorption bands, with a change in the band shape from widening to sharp outline. The ICP-MS results suggested that K-feldspar of the early cretaceous granite has relatively higher metal elements and rare earth elements, and the granite exhibits better mineralization background, K-feldspar of the potassic alteration veins has markedly lower Sr and Ba, indicating that the alteration fluid originated from the granitic magmatism, and hence, potassic alteration is a good indicator for molybdenite exploration.

  15. Charnockites and granites of the western Adirondacks, New York, USA: a differentiated A-type suite

    USGS Publications Warehouse

    Whitney, P.R.

    1992-01-01

    Granitic rocks in the west-central Adirondack Highlands of New York State include both relatively homogeneous charnockitic and hornblende granitic gneisses (CG), that occur in thick stratiform bodies and elliptical domes, and heterogeneous leucogneisses (LG), that commonly are interlayered with metasedimentary rocks. Major- and trace-element geochemical analyses were obtained for 115 samples, including both types of granitoids. Data for CG fail to show the presence of more than one distinct group based on composition. Most of the variance within the CG sample population is consistent with magmatic differentiation combined with incomplete separation of early crystals of alkali feldspar, plagioclase, and pyroxenes or amphibole from the residual liquid. Ti, Fe, Mg, Ca, P, Sr, Ba, and Zr decrease with increasing silica, while Rb and K increase. Within CG, the distinction between charnockitic (orthopyroxene-bearing) and granitic gneisses is correlated with bulk chemistry. The charnockites are consistently more mafic than the hornblende granitic gneisses, although forming a continuum with them. The leucogneisses, while generally more felsic than the charnockites and granitic gneisses, are otherwise geochemically similar to them. The data are consistent with the LG suite being an evolved extrusive equivalent of the intrusive CG suite. Both CG and LG suites are metaluminous to mildly peraluminous and display an A-type geochemical signature, enriched in Fe, K, Ce, Y, Nb, Zr, and Ga and depleted in Ca, Mg, and Sr relative to I- and S-type granites. Rare earth element patterns show moderate LREE enrichment and a negative Eu anomaly throughout the suite. The geochemical data suggest an origin by partial melting of biotite- and plagioclase-rich crustal rocks. Emplacement occurred in an anorogenic or post-collisional tectonic setting, probably at relatively shallow depths. Deformation and granulite-facies metamorphism with some partial melting followed during the Ottawan phase

  16. Pulmonary function in granite dust exposure: a four-year follow-up.

    PubMed

    Musk, A W; Peters, J M; Wegman, D H; Fine, L J

    1977-05-01

    Pulmonary function studies were performed on 974 workers in Vermont granite sheds in 1974. Of these subjects, 668 had been studied 4 years earlier and had remained in jobs in which their exposure to granite dust had not changed based on dust concentrations measured during 1970. The yearly decrement in pulmonary function observed in the 668 granite shed workers was excessive (0.07 to 0.08 liter per year for forced vital capacity and 0.05 to 0.07 liter per year for forced expiratory volume in 1 sec). This exceeded the expected decrement derived from several other occupational and population groups. Studies from this laboratory and published cross-sectional and longitudinal data consistently indicate a decrement of no more than 0.03 to 0.04 liter per year in both forced vital capacity and forced expiratory volume in 1 sec. The observed decrements were independent of exposure groups and not accounted for by cigarette smoking. In 528 additional granite shed workers, decrements in ventilatory capacity had been measured for one, 2, or 3 years and were consistently of the same order of magnitude. Dust concentrations within defined jobs and between granite sheds showed great variability. Despite this, a suggestive relationship between exposure and decrement in ventilatory function was demonstrated at the end of 2 years; however, at the end of 4 years the relationship could no longer be shown with these exposure groupings. The difficulty in characterizing individual dust exposures and projecting dust concentrations for several years is considered to account for the absence of a dose-response relationship at the 4-year follow-up. The results of this study suggest that our previous estimates of annual deterioration in ventilatory capacity attributable to work in granite sheds are underestimates. We conclude that present dust concentrations in Vermont granite sheds cause excessive deterioration of lung capacity. To prevent these effects, dust concentrations must be lowered.

  17. Contamination in mafic mineral-rich calc-alkaline granites: a geochemical and Sr-Nd isotope study of the Neoproterozoic Piedade Granite, SE Brazil.

    PubMed

    Leite, Renato J; Janasi, Valdecir A; Martins, Lucelene

    2006-06-01

    The Piedade Granite (approximately 600 Ma) was emplaced shortly after the main phase of granite magmatism in the Agudos Grandes batholith, Apiaí-Guaxupé Terrane, SE Brazil. Its main units are: mafic mineral-rich porphyritic granites forming the border (peraluminous muscovite-biotite granodiorite-monzogranite MBmg unit) and core (metaluminous titanite-bearing biotite monzogranite BmgT unit) and felsic pink inequigranular granite (Bmg unit) between them. Bmg has high LaN/YbN (up to 100), Th/U (> 10) and low Rb, Nb and Ta, and can be a crustal melt derived from deep-seated sources with residual garnet and biotite. The core BmgT unit derived from oxidized magmas with high Mg# (approximately 45), Ba and Sr, fractionated REE patterns (LaN/YbN = 45), 87Sr/86Sr(t) approximately 0.710, epsilonNd(t) approximately -12 to -14, interpreted as being high-K calc-alkaline magmas contaminated with metasedimentary rocks that had upper-crust signature (high U, Cs, Ta). The mafic-rich peraluminous granites show a more evolved isotope signature (87Sr/86Sr(t) = 0.713-0.714; epsilonNd(t) = -14 to -16), similar to Bmg, and Mg# and incompatible trace-element concentrations intermediate between Bmg and BmgT. A model is presented in whichMBmgis envisaged as the product of contamination between a mafic mineral-rich magma consanguineous with BmgT and pure crustal melts akin to Bmg. PMID:16710571

  18. Chemical and isotopic studies of granitic Archean rocks, Owl Creek Mountains, Wyoming: Geochronology of an Archean granite, Owl Creek Mountains, Wyoming

    SciTech Connect

    Hedge, C.E.; Simmons, K.R.; Stuckless, J.S.

    1986-01-01

    Rubidium-strontium analyses of whole-rock samples of an Archean granite from the Owl Creek Mountains, Wyo., indicate an intrusive age of 2640 {plus minus} 125 Ma. Muscovite-bearing samples give results suggesting that these samples were altered about 2300 Ma. This event may have caused extensive strontium loss from the rocks as potassium feldspar was altered to muscovite. Alteration was highly localized in nature as evidence by unaffected rubidium-strontium mineral ages in the Owl Creek Mountains area. Furthermore, the event probably involved a small volume of fluid relative to the volume of rock because whole-rock {delta}{sup 18}O values of altered rocks are not distinct from those of unaltered rocks. In contrast to the rubidium-strontium whole-rock system, zircons from the granite have been so severely affected by the alteration event, and possibly by a late-Precambrian uplift event, that the zircon system yields little usable age information. The average initial {sup 87}Sr/{sup 86}Sr (0.7033 {plus minus} 0.0042) calculated from the isochron intercept varies significantly. Calculated initial {sup 87}Sr/{sup 86}Sr ratios for nine apparently unaltered samples yield a range of 0.7025 to 0.7047. These calculated initial ratios correlate positively with whole-rock {delta}{sup 18}O values; and, therefore, the granite was probably derived from an isotopically heterogeneous source. The highest initial {sup 87}Sr/{sup 86}Sr ratio is lower than the lowest reported for the metamorphic rocks intruded by the granite as it would have existed at 2640 Ma. Thus, the metamorphic sequence, at its current level of exposure, can represent no more than a part of the protolith for the granite.

  19. Contamination in mafic mineral-rich calc-alkaline granites: a geochemical and Sr-Nd isotope study of the Neoproterozoic Piedade Granite, SE Brazil.

    PubMed

    Leite, Renato J; Janasi, Valdecir A; Martins, Lucelene

    2006-06-01

    The Piedade Granite (approximately 600 Ma) was emplaced shortly after the main phase of granite magmatism in the Agudos Grandes batholith, Apiaí-Guaxupé Terrane, SE Brazil. Its main units are: mafic mineral-rich porphyritic granites forming the border (peraluminous muscovite-biotite granodiorite-monzogranite MBmg unit) and core (metaluminous titanite-bearing biotite monzogranite BmgT unit) and felsic pink inequigranular granite (Bmg unit) between them. Bmg has high LaN/YbN (up to 100), Th/U (> 10) and low Rb, Nb and Ta, and can be a crustal melt derived from deep-seated sources with residual garnet and biotite. The core BmgT unit derived from oxidized magmas with high Mg# (approximately 45), Ba and Sr, fractionated REE patterns (LaN/YbN = 45), 87Sr/86Sr(t) approximately 0.710, epsilonNd(t) approximately -12 to -14, interpreted as being high-K calc-alkaline magmas contaminated with metasedimentary rocks that had upper-crust signature (high U, Cs, Ta). The mafic-rich peraluminous granites show a more evolved isotope signature (87Sr/86Sr(t) = 0.713-0.714; epsilonNd(t) = -14 to -16), similar to Bmg, and Mg# and incompatible trace-element concentrations intermediate between Bmg and BmgT. A model is presented in whichMBmgis envisaged as the product of contamination between a mafic mineral-rich magma consanguineous with BmgT and pure crustal melts akin to Bmg.

  20. Geothermal potential of Caledonian granites underlying Upper Palaeozoic sedimentary basins astride the Iapetus Suture Zone in Ireland

    NASA Astrophysics Data System (ADS)

    Fritschle, Tobias; Daly, J. Stephen; Whitehouse, Martin J.; McConnell, Brian; Buhre, Stephan

    2014-05-01

    Upper Palaeozoic sedimentary basins in Ireland overlie crystalline rocks within the Caledonian Iapetus Suture Zone. Beneath these basins, Lower Palaeozoic rocks, formed and deformed during the Caledonian orogenic cycle, were intruded by c. 420-390 Ma late-tectonic granites at various tectonic levels. These include the subsurface Kentstown and Glenamaddy granites discovered by mineral exploration drilling. While these granites comprise actual targets for Enhanced Geothermal System (EGS) exploration, several others likely exist based on geophysical considerations. In order to test the regional geothermal potential, the buried granites as well as analogue exposed rocks are being investigated geochemically. The geothermal potential of the intrusives depends on their heat production rate (HPR), which is calculated using rock density and concentrations of the heat producing elements (HPE) uranium, thorium and potassium. In spite of their close spacing and similar ages, the whole-rock geochemistry of the granites varies significantly, but with no obvious geographical control (Fritschle et al., 2013; 2014). The granite HPR values range from 1.4 μW/m3 for the Dhoon Granite (Isle of Man) to 4.9 μW/m3 for the Drogheda Granite (Ireland). This compares with the average HPR for a 'typical' granite of 2.7 μW/m3 (Goldstein et al., 2009). It is demonstrated that an elevated HPR of a granite can be related to enrichment in one of the HPE alone (e.g., uranium-enrichment in the Foxdale Granite (Isle of Man), or thorium-enrichment in the Drogheda Granite). Enrichment in HPE in a granite may occur due to different reasons including hydrothermal (re-) distribution of uranium, or the assimilation of thorium-rich wall-rocks. Hence, the distribution of the HPE in particular minerals, veins and source lithologies, along with the petrophysical characteristics of the sedimentary basins and the granites' petrogenesis, are currently being investigated as possible mechanisms controlling their

  1. Reconnaissance geology and geochronology of the Precambrian of the Granite Mountains, Wyoming

    USGS Publications Warehouse

    Peterman, Zell E.; Hildreth, Robert A.

    1978-01-01

    The Precambrian of the western part of the Granite Mountains, Wyoming, contains a metamorphic complex of gneisses, schists, and amphibolites that were derived through amphibolite-grade metamorphism from a sedimentary-volcanic sequence perhaps similar to that exposed in the southeastern Wind River Mountains. Whole-rock Rb-Sr dating places the time of metamorphism at 2,860?80 million years. A high initial 87Sr/ 86 S r ratio of 0.7048 suggests that either the protoliths or the source terrane of the sedimentary component is several hundred million years older than the time of metamorphism. Following an interval of 300:t100 million years for which the geologic record is lacking or still undeciphered, the metamorphic complex was intruded by a batholith and satellite bodies of medium- to coarse-grained, generally massive biotite granite and related pegmatite and aplite. The main body of granite is dated at 2,550?60 million years by the Rb-Sr method. Limited data suggest that diabase dikes were emplaced and nephrite veins were formed only shortly after intrusion of the granite. Emplacement of the granite at about 2,550 million years ago appears to be related to a major period of regional granitic plutonism in the Precambrian of southern and western Wyoming. Granites, in the strict sense, that are dated between 2,450 and 2,600 million years occur in the Teton Range, the Sierra Madre, the Medicine Bow Mountains and the Laramie Range. This episode of granitic plutonism occured some 50 to 100 million years later than the major tonalitic to granitic plutonism in the Superior province of northern Minnesota and adjacent Ontario-the nearest exposed Precambrian W terrane that is analogous to the Wyoming province. Initial 87Sr / 86Sr ratios of some of the Wyoming granites are higher than expected if the rocks had been derived from juvenile magmas and it is likely that older crustal rocks were involved to some degree in the generation of these granites. Slightly to highly disturbed

  2. Origin of miarolitic pegmatites in the Königshain granite/Lusatia

    NASA Astrophysics Data System (ADS)

    Thomas, Rainer; Davidson, Paul

    2016-09-01

    In this study we examine an interesting occurrence of miarolitic pegmatites in the Königshain granite of the Lusatia region of the Bohemian Massif. This granite is characterized by the extensive development of micro-sized miarolitic pegmatites (typically with diameters of 5 to 15 mm) irregularly distributed through its upper levels, and larger miarolitic pegmatites (up to 1 m) in the uppermost levels. This granite also shows evidence of varied forms of transport of extremely volatile rich residual melts/fluids, in the form of more or less discrete inter-granular melt bodies, and associated magmatic quartz veins formed in tectonic fissures. Together, these provide evidence for the origin of miarolitic pegmatites, both in the specific case of Königshain, and more generally. Our evidence suggests that miarolitic pegmatites form from volatile- and alkali-rich residual melts, ranging from 10 to 50% H2O, far more than typical granitic melts, but far more silicate components than aqueous fluids or vapor suggested by some authors. Using melt inclusions in quartz from the aplitic and graphic granite zones in miarolitic pegmatites in the Königshain granite, we show that two different inclusion populations are present. We provide evidence that the first inclusion population are those related to the primary granite at the level of intrusion, and the second were trapped during the re-crystallization of the granite wall rocks by silicate-rich supercritical fluids moving through the solid crystal framework with a porosity < 25 and a permeability > 0 (see Clarke et al., 2013). Our results show that a significant volume fraction of the miarolitic pegmatites was not created by a pegmatite-forming fluid, but formed in-situ by re-crystallization of wall-rocks, triggered by highly reactive volatiles exsolved from the pegmatite-forming melts. Evidence is also presented which suggests the nature and speed of emplacement of the Königshain granite. This evidence may explain the unusual

  3. Oxygen and hydrogen isotope compositions as indicators of granite genesis in the New England Batholith, Australia

    USGS Publications Warehouse

    O'Neil, J.R.; Shaw, S.E.; Flood, R.H.

    1977-01-01

    Oxygen and hydrogen isotope studies of a number of granite suites and mineral separates from the New England Batholith indicate that ??O18 can be used to discriminate the major granite protoliths. The granite suites previously subdivided on the basis of mineralogical and geochemical criteria into S-type (sedimentary) and I-type (igneous) have ??O18 values consistently higher in the S-type granites (10.4-12.5) than in the spatially related I-type plutons (7.7-9.9). There appears to be a systematic variation in ??O18 from the most S-type to the most I-type granites, the dividing point between the two occuring at ??O18 equal to 10. A group of leucocratic granites that form about half of the batholith and difficult to classify mineralogically and geochemically is found to have low ??O18 values (6.4-8.1), suggesting an affinity to the most I-type granites. A single leucogranite pluton with minor muscovite has a ??O18 of 9.6 which is significantly higher than other leucogranites indicating a different origin perhaps involving amphibole fractionation. The behavior of ??D in the plutonic rocks is much less systematic than ??O18. Excluding samples collected adjacent to major faults, the ??D values show a rough positive correlation with water content similar to, but less pronounced than, the trend previously observed in the Berridale Batholith, southeastern Australia. This relation is considered to reflect an interaction between meteoric water and the granites, the largest effect being observed in samples with the least amount of water. Of note is the generally lower ??D values of the upper Paleozoic New England Batholith compared with the Silurian Berridale Batholith. This difference may be related to a near equatorial paleolatitude of 22 ??S in the Silurian and near polar paleolatitudes in the late Carboniferous that have been inferred for these regions. Granite samples collected from near major faults, and one ignimbrite sample of rhyodacite composition, have very low ??D

  4. Geochronology, geochemistry, and petrology of the Precambrian Sandia granite, Albuquerque, New Mexico

    SciTech Connect

    Majumdar, A.

    1985-01-01

    The Precambrian Sandia granite of north-central New Mexico belongs to the 1.2-1.6 Ga crustal province of the western USA. The granite shows an intrusive contact with the metamorphic country rocks. The Rb-Sr whole rock isochron age of the country rocks is 1.61 +/- 0.06 Ga, (/sup 87/Sr//sup 86/Sr)/sub 0/ = 0.705 +/- 0.001. The culmination of the intrusion of the Sandia granite took place at 1.44 +/- 0.04 GA. (/sup 87/Sr//sup 86/)/sub 0/ = 0.7054 +/- 0.0005. Rb-Sr ages on biotite-whole rock pairs and an /sup 40/Ar//sup 39/Ar dating of a biotite from the granite indicate final cooling to 300-350/sup 0/C at 1.33 Ga. This suggests slow cooling of the granite at rates which averaged 4/sup 0/C/Ma for about 100 Ma after its emplacement; during this period the Rb-Sr isotope system perhaps remained partially open. The Sandia granite shows compositional variation from granodiorite to quartz monzonite in both the northern and southern blocks. The field geology, petrology, and geochemistry of the two blocks suggest that they form a single pluton. Both the Sandia granite and mesocratic, two pyroxene granulite xenoliths therein give an ..delta../sup 18/O value of +8.0 +/- 0.5% indicating (meta)igneous source ricks for each of them. These values tend to rule out Condie's (1978) favored hypothesis for magma generation of 30-50% partial melting of siliceous gradulites. Rather, they favor an alternative hypothesis, equally satisfactory from the geochemical viewpoint, involving 5-10% melt of a gabbroic or two-pyroxene granulite parent rock in the lower crust. The Sandia granite, and by implication, the other high-Ca granitic rocks of the western USA thus do not seem to represent addition of new mantle-derived materials to the middle-late Proterozoic crust of this section of the continent.

  5. Nagarparker granites showing Rodinia remnants in the southeastern part of Pakistan

    NASA Astrophysics Data System (ADS)

    Khan, Tahseenullah; Murata, Mamoru; Rehman, Hafiz Ur; Zafar, Muhammad; Ozawa, Hiraoki

    2012-10-01

    The Nagarparker area of the Trans-Aravalli Belt comprises Precambrian igneous and metamorphic basement rocks, predominantly granites. These granites are subalkalic to alkalic A-type containing riebeckite, ferro-richterite, ferro-edenite ± arvedsonite amphiboles, and rutile, zircon, apatite, allanite, titanite, titano-magnetite, ilmenite, magnetite and fluorite accessory minerals. The variations in Nb, Y, Ce and Ga and Ga/Al ratios typify the granites of the area as post-orogenic A2-type, formed possibly by partial melting of the island arc crust in a rift-related within plate tectonic setting. The granites of the area yielded U-Th-Pb EPMA zircon and monazite radiometric ages between 1100 and 700 Ma, mostly concentrating around ˜750 Ma. Based on petrological, geochemical and geochronological resemblance of granites of the Nagarparker area with those of the Seychelles islands and the Malani Igneous Suite, it is inferred that being part of Trans-Aravalli Belt of the Indian shield, the Nagarparker area might have shouldered the Seychelles islands towards the western side of the Rodinia before the supercontinent rifted in Neoproterozoic.

  6. [Spectral characteristics and implication of granite from pozaiying molybdenite deposits in west of Guangdong].

    PubMed

    An, Yan-Fei; Zhong, Li-li; Zhou, Yang-Zhang; Chen, Qing; Li, Xing-yuan

    2014-06-01

    Some granite samples from Pozaiying molybdenite deposits in the west of Guangdong were retrieved to characterize the spectral signature of XRD, FT-NIR and Raman. The results show that compared to the Porphyry granite and granite in the far zone, the signal of XRD and Raman of granite in near zone is weaker while the signal of FT-NIR is stronger. The authors' analyses indicate that the FWHM of quartz (101) peak in XRD, Sericite peak (4 529 cm(-1)) in FT-NIR and quartz peak in Raman shift from the latter are higher than those of former two. Those spectral characteristics indicate that compared with other samples, the content of petrogenetic mineral in samples from near zone is lower while the content of alteration mineral is higher, and its crystallinity and crystallization temperatures are both lower. The authors' studies suggest that there may be an alteration zone, embracing the granite-porphyry, which comprised low temperature mineral, and the quartz-porphyry which related to molybdenite mineralization belongs to the zone near Guanshanzhang mass. PMID:25358146

  7. Measurements of natural radioactivity and the resulting radiation doses from commercial granites.

    PubMed

    Aydarous, A Sh; Zeghib, Sadek; Al-Dughmah, Mohammed

    2010-12-01

    Saudi Arabia is becoming a relatively large market for local and foreign marble and granite use in dwellings. Due to increasing concern about environmental radiological protection, different types of locally widely used granite tiles were collected from different suppliers in the Jeddah province, Saudi Arabia. The analysis for these granite tiles for gamma radiation was conducted by means of a high-resolution HPGe gamma-spectroscopy system. The activity concentrations of (232)Th, (226)Ra and 40K in the selected granite samples ranged from 4.9 to 144, 9.7 to 133 and 168 to 1806 Bq kg(-1), respectively. The data were compared with other granite types and building materials used all over the world. The absorbed dose rates, effective dose rates, radium equivalent activities as well as the radiation hazard indices were estimated. The radium equivalent activities (Ra(eq)) are lower than the limit of 370 Bq kg(-1) set by the Organisation for Economic Cooperation and Development (Exposure to radiation from the natural radioactivity in building materials. Report by a Group of Experts of the OECD, Nuclear Energy Agency, OECD, Paris, 1979) except in three samples.

  8. Raised immunoglobulin concentrations in bronchoalveolar lavage fluid of healthy granite workers.

    PubMed

    Calhoun, W J; Christman, J W; Ershler, W B; Graham, W G; Davis, G S

    1986-04-01

    Immunoglobulin concentrations and lymphocyte counts were determined in bronchoalveolar fluid obtained from nine symptomless, healthy, non-smoking granite workers (mean age 45.6, range 22-56 years) and nine normal, non-smoking, non industrial controls (mean age 22.8, range 21-32 years). The proteins were measured in unconcentrated lavage fluid by means of a solid phase, enzyme linked immunosorbent assay. IgG and IgA concentrations were three times greater in lavage fluid from granite workers than the samples from non-industrial controls (p less than 0.02). Eight of nine normal volunteers (89%) had no detectable IgM (less than 30 ng/ml) in the lavage fluid whereas eight of nine (89%) granite workers had detectable IgM (chi 2 = 8, p less than 0.01). Lymphocyte counts in lavage fluid from the workers were significantly greater (15.5%) than control counts (5.6%; p less than 0.05). The normal albumin concentration suggests that differences in permeability do not account for all of the increased immunoglobulin concentrations found in granite workers' lavage fluid and that some immunoglobulin is locally synthesised. It is concluded that occupational exposure to granite dust is associated with an increased proportion of lymphocytes and an increased concentration of immunoglobulin in lavage fluid that may reflect a subclinical immune inflammatory response.

  9. Hydrogen analysis for granite using proton-proton elastic recoil coincidence spectrometry.

    PubMed

    Komatsubara, T; Sasa, K; Ohshima, H; Kimura, H; Tajima, Y; Takahashi, T; Ishii, S; Yamato, Y; Kurosawa, M

    2008-07-01

    In an effort to develop DS02, a new radiation dosimetry system for the atomic bomb survivors of Hiroshima and Nagasaki, measurements of neutron-induced activities have provided valuable information to reconstruct the radiation situation at the time of the bombings. In Hiroshima, the depth profile of (152)Eu activity measured in a granite pillar of the Motoyasu Bridge (128 m from the hypocenter) was compared with that calculated using the DS02 methodology. For calculation of the (152)Eu production due to the thermal-neutron activation reaction, (151)Eu(n,gamma)(152)Eu, information on the hydrogen content in granite is important because the transport and slowing-down process of neutrons penetrating into the pillar is strongly affected by collisions with the protons of hydrogen. In this study, proton-proton elastic recoil coincidence spectrometry has been used to deduce the proton density in the Motoyasu pillar granite. Slices of granite samples were irradiated by a 20 MeV proton beam, and the energies of scattered and recoil protons were measured with a coincidence method. The water concentration in the pillar granite was evaluated to be 0.30 +/- 0.07%wt. This result is consistent with earlier data on adsorptive water (II) and bound water obtained by the Karl Fisher method. PMID:18509666

  10. Time-Dependent Behaviors of Granite: Loading-Rate Dependence, Creep, and Relaxation

    NASA Astrophysics Data System (ADS)

    Hashiba, K.; Fukui, K.

    2016-07-01

    To assess the long-term stability of underground structures, it is important to understand the time-dependent behaviors of rocks, such as their loading-rate dependence, creep, and relaxation. However, there have been fewer studies on crystalline rocks than on tuff, mudstone, and rock salt, because the high strength of crystalline rocks makes the detection of their time-dependent behaviors much more difficult. Moreover, studies on the relaxation, temporal change of stress and strain (TCSS) conditions, and relations between various time-dependent behaviors are scarce for not only granites, but also other rocks. In this study, previous reports on the time-dependent behaviors of granites were reviewed and various laboratory tests were conducted using Toki granite. These tests included an alternating-loading-rate test, creep test, relaxation test, and TCSS test. The results showed that the degree of time dependence of Toki granite is similar to other granites, and that the TCSS resembles the stress-relaxation curve and creep-strain curve. A viscoelastic constitutive model, proposed in a previous study, was modified to investigate the relations between the time-dependent behaviors in the pre- and post-peak regions. The modified model reproduced the stress-strain curve, creep, relaxation, and the results of the TCSS test. Based on a comparison of the results of the laboratory tests and numerical simulations, close relations between the time-dependent behaviors were revealed quantitatively.

  11. [Spectral characteristics and implication of granite from pozaiying molybdenite deposits in west of Guangdong].

    PubMed

    An, Yan-Fei; Zhong, Li-li; Zhou, Yang-Zhang; Chen, Qing; Li, Xing-yuan

    2014-06-01

    Some granite samples from Pozaiying molybdenite deposits in the west of Guangdong were retrieved to characterize the spectral signature of XRD, FT-NIR and Raman. The results show that compared to the Porphyry granite and granite in the far zone, the signal of XRD and Raman of granite in near zone is weaker while the signal of FT-NIR is stronger. The authors' analyses indicate that the FWHM of quartz (101) peak in XRD, Sericite peak (4 529 cm(-1)) in FT-NIR and quartz peak in Raman shift from the latter are higher than those of former two. Those spectral characteristics indicate that compared with other samples, the content of petrogenetic mineral in samples from near zone is lower while the content of alteration mineral is higher, and its crystallinity and crystallization temperatures are both lower. The authors' studies suggest that there may be an alteration zone, embracing the granite-porphyry, which comprised low temperature mineral, and the quartz-porphyry which related to molybdenite mineralization belongs to the zone near Guanshanzhang mass.

  12. Hydrogen analysis for granite using proton-proton elastic recoil coincidence spectrometry.

    PubMed

    Komatsubara, T; Sasa, K; Ohshima, H; Kimura, H; Tajima, Y; Takahashi, T; Ishii, S; Yamato, Y; Kurosawa, M

    2008-07-01

    In an effort to develop DS02, a new radiation dosimetry system for the atomic bomb survivors of Hiroshima and Nagasaki, measurements of neutron-induced activities have provided valuable information to reconstruct the radiation situation at the time of the bombings. In Hiroshima, the depth profile of (152)Eu activity measured in a granite pillar of the Motoyasu Bridge (128 m from the hypocenter) was compared with that calculated using the DS02 methodology. For calculation of the (152)Eu production due to the thermal-neutron activation reaction, (151)Eu(n,gamma)(152)Eu, information on the hydrogen content in granite is important because the transport and slowing-down process of neutrons penetrating into the pillar is strongly affected by collisions with the protons of hydrogen. In this study, proton-proton elastic recoil coincidence spectrometry has been used to deduce the proton density in the Motoyasu pillar granite. Slices of granite samples were irradiated by a 20 MeV proton beam, and the energies of scattered and recoil protons were measured with a coincidence method. The water concentration in the pillar granite was evaluated to be 0.30 +/- 0.07%wt. This result is consistent with earlier data on adsorptive water (II) and bound water obtained by the Karl Fisher method.

  13. Damage and Plastic Deformation Modeling of Beishan Granite Under Compressive Stress Conditions

    NASA Astrophysics Data System (ADS)

    Chen, L.; Wang, C. P.; Liu, J. F.; Liu, J.; Wang, J.; Jia, Y.; Shao, J. F.

    2015-07-01

    Based on experimental investigations, we propose a coupled elastoplastic damage model to simulate the mechanical behavior of granite under compressive stress conditions. The granite is taken from the Beishan area, a preferable region for China's high-level radioactive waste repository. Using a 3D acoustic emission monitoring system in mechanical tests, we focus on the cracking process and its influence on the macroscopic mechanical behavior of the granite samples. It is verified that the crack propagation coupled with fractional sliding along the cracks is the principal mechanism controlling the failure process and nonlinear mechanical behavior of granite under compressive stress conditions. Based on this understanding, the coupled elastoplastic damage model is formulated in the framework of the thermodynamics theory. In the model, the coupling between damage and plastic deformation is simulated by introducing the independent damage variable in the plastic yield surface. As a preliminary validation of the model, a series of numerical simulations are performed for compressive tests conducted under different confining pressures. Comparisons between the numerical and simulated results show that the proposed model can reproduce the main features of the mechanical behavior of Beishan granite, particularly the damage evolution under compressive stress conditions.

  14. Glacial modification of granite tors in the Cairngorms, Scotland

    USGS Publications Warehouse

    Hall, A.M.; Phillips, W.M.

    2006-01-01

    A range of evidence indicates that many granite tors in the Cairngorms have been modified by the flow of glacier ice during the Pleistocene. Comparisons with SW England and the use of a space-time transformation across 38 tor groups in the Cairngorms allow a model to be developed for progressive glacial modification. Tors with deeply etched surfaces and no, or limited, block removal imply an absence of significant glacial modification. The removal of superstructure and blocks, locally forming boulder trains, and the progressive reduction of tors to stumps and basal slabs represent the more advanced stages of modification. Recognition of some slabs as tor stumps from which glacial erosion has removed all superstructure allows the original distribution of tors to be reconstructed for large areas of the Cairngorms. Unmodified tors require covers of non-erosive, cold-based ice during all of the cold stages of the Middle and Late Pleistocene. Deformation beneath cold-based glacier ice is capable of the removal of blocks but advanced glacial modification requires former wet-based glacier ice. The depth of glacial erosion at former tor sites remains limited largely to the partial or total elimination of the upstanding tor form. Cosmogenic nuclide exposure ages (Phillips et al., 2006) together with data from weathering pit depths (Hall and Phillips, 2006), from the surfaces of tors and large erratic blocks require that the glacial entrainment of blocks from tors occurred in Marine Isotope Stages (MIS) 4-2, 6 and, probably, at least one earlier phase. The occurrence of glacially modified tors on or close to, the main summits of the Cairngorms requires full ice cover over the mountains during these Stages. Evidence from the Cairngorms indicates that tor morphology can be regarded as an important indicator of former ice cover in many formerly glaciated areas, particularly where other evidence of ice cover is sparse. Recognition of the glacial modification of tors is important

  15. Trace-element compositions and Br/Cl ratios of fluid inclusions in the Tsushima granite, Japan: Significance for formation of granite-derived fluids

    NASA Astrophysics Data System (ADS)

    Kurosawa, Masanori; Sasa, Kimikazu; Shin, Ki-Choel; Ishii, Satoshi

    2016-06-01

    Fluid inclusions in quartz samples from a miarolitic cavity, two quartz veins, and a hydrothermal ore vein in the Tsushima granite, Japan, were analyzed by particle-induced X-ray emission to examine the chemistry and process of formation of hydrothermal fluids in an island-arc granite. Most of the inclusions were polyphase or vapor, and there were smaller numbers of two-phase aqueous inclusions. The inclusions contained Cl, K, Ca, Ti, Mn, Fe, Cu, Zn, Ge, Br, Rb, Sr, Ba, and Pb. For each inclusion, there was a strong positive correlation between Cl content and contents of other elements identified. Concentration ranges for most elements (other than Rb and Ge) in polyphase inclusions from the miarolitic cavity were comparable to those from cavities in alkaline granites; those from the ore vein were comparable to large-scale continental hydrothermal ore deposits. The lower Rb and higher Ge contents in the polyphase inclusions of the Tsushima granite may be characteristic of hydrothermal fluids from calc-alkaline granites in an island-arc setting. Br/Cl ratios (by weight) for the vapor and two-phase inclusions were 0.0013-0.0030 and differed among the three geological settings. Br/Cl ratios of polyphase inclusions increased with increasing Cl content in single-crystal and polycrystalline quartz, and high values of more than 0.0100 were found. The high Br/Cl ratios and the differences among the geological settings sampled may be due to pressure dependences of partitioning of Cl and Br between fluid and magma during fluid segregation and between liquid and vapor during boiling. Using a simple model based on these dependences, we calculated Br/Cl ratios greater than 0.01 in brine generated at pressures <0.89 kbar. Differences in Br/Cl ratios in polyphase and vapor inclusions from each geological setting were attributed to mixing between two end-member fluids: a high Br/Cl fluid generated at low pressure and a low Br/Cl fluid generated at high pressure. Br/Cl ratios of

  16. The Late Precambrian Timna igneous complex, Southern Israel: Evidence for comagmatic-type sanukitoid monzodiorite and alkali granite magma

    NASA Astrophysics Data System (ADS)

    Beyth, Michael; Stern, Robert J.; Altherr, Rainer; Kröner, Alfred

    1994-01-01

    New data from a geochemical, geochronological and isotopic study of the Late Precambrian Timna igneous complex suggest the formation of alkali granites from a LIL-enriched, mantle derived, sanukitoid-type monzodiorite (a silica oversaturated rock with Mg# >60). These data also provide new insights into the petrology, timing and regional tectonic control of the transition from the calc-alkaline to the alkaline magmatic activity in the northern Arabian-Nubian Shield (ANS) during the Late Precambrian. The Timna alkali granite was formed by fractional crystallization from the monzodioritic magma in a quasi-stratified magmatic cell which formed 610 Ma ago in the 625 Ma old calc-alkaline, porphyritic granite crust. These monzodiorites are mantle-derived, as demonstrated by their high Mg# (63), Cr (230 ppm), and Ni (120 ppm). They are characterized by initial {87Sr}/{86Sr} of 0.7034, ɛ-Nd (610 Ma) = +3.4, and are enriched in K 2O (2.9%), Sr (840 ppm), Ba (1290 ppm) and LREE [ ( {La}/{Lu}) n= 10-25 ]. The chemical characteristics and REE patterns of the monzodiorites and andesitic dykes of Timna are very similar to Dokhan andesites from northeastern Egypt and the Archean sanukitoids from Canada. The isotopic, geochemical and geochronologic data all indicate that Timna monzodiorites are comagmatic with the alkali granite. The alkali granite is a typical post-orogenic, borderline A-type granite. It is enriched in potassium (K 2O=4.68-6.64%), has a negative europium anomaly ( {Eu}/{Eu∗}=0.058-0.38 ) and ɛ-Nd (610 Ma) of +3.9. The calc-alkaline granite is a typical I-type granite with a small positive europium anomaly ( {Eu}/{Eu∗}=1.02-1.16 ). Its age and the Sr, Nd and Pb isotopic characteristics with ɛ-Nd (625 Ma) of +5.6 to +5.9 are significantly different from these of the alkali granite and monzodiorites, and indicate little interaction with the monzodiorite during the formation of the alkali granite. The alkali granites are correlative with the post

  17. Metasomatism of ferroan granites in the northern Aravalli orogen, NW India: geochemical and isotopic constraints, and its metallogenic significance

    NASA Astrophysics Data System (ADS)

    Kaur, Parampreet; Chaudhri, Naveen; Hofmann, Albrecht W.; Raczek, Ingrid; Okrusch, Martin; Skora, Susanne; Koepke, Jürgen

    2014-06-01

    The late Palaeoproterozoic (1.72-1.70 Ga) ferroan granites of the Khetri complex, northern Aravalli orogen, NW India, were extensively metasomatised ~900 Ma after their emplacement, at around 850-830 Ma by low-temperature (ca. 400 °C) meteoric fluids that attained metamorphic character after exchanging oxygen with the surrounding metamorphic rocks. Albitisation is the dominant metasomatic process that was accompanied by Mg and Ca metasomatism. A two-stage metasomatic model is applicable to all the altered ferroan intrusives. The stage I is represented by a metasomatic reaction interface that developed as a result of transformation of the original microcline-oligoclase (An12-14) granite to microcline-albite (An1-3) granite, and this stage is rarely preserved. In contrast, the stage II metasomatic reaction front, where the microcline-bearing albite granite has been transformed to microcline-free albite granite, is readily recognisable in the field and present in most of the intrusives. Some of them lack an obvious reaction interface due to the presence of stage II albite granites only. When studied in isolation, these intrusives were incorrectly classified and their tectonic setting was misinterpreted. Furthermore, our results show that the mafic mineralogy of metasomatised granites has a significant impact on the characterisation of such rocks in the magmatic classification and discrimination diagrams. Nevertheless, the stage I metasomatised granites can be appropriately characterised in these diagrams, whereas the characterisation of the stage II granites will lead to erroneous interpretations. The close spatial association of these high heat producing ferroan granites with iron oxide-copper-gold (IOCG), U and REE mineralisation in the region indicates a genetic link between the metasomatism and the mineralisation. World-class IOCG, U and REE deposits are associated with metasomatised ferroan granites, suggesting that such a relationship may act as a critical

  18. Mineralogy and geochemistry of the Paleoproterozoic, tin-mineralized Bom Jardim granite of the Velho Guilherme Suite, eastern Amazonian craton

    NASA Astrophysics Data System (ADS)

    Lamarão, Claudio Nery; Cordovil Pinho, Sabrina Cristina; de Paiva, Antonio Lima; Galarza, Marco Antônio

    2012-10-01

    The Bom Jardim granite is located to the south of São Felix do Xingu town and is intrusive in the intermediate to felsic volcanic rocks of the Uatumã Group. It is formed dominantly of coarse- to medium-grained isotropic monzogranite and syenogranite, both affected by intense late- to post-magmatic alteration. Biotite, generally chloritized, is the main primary mafic phase, with rare amphibole being found in the monzogranite. Hydrothermally altered and greisenized rocks, containing small primary concentrations of cassiterite + wolframite, as well as quartz veins with millimeter- to centimeter-sized crystals of wolframite + pyrite + fluorite occur in pervasively altered cupolas. Presently, alluvial cassiterite and wolframite (±columbite, tantalite) are mined in the Pedra Preta mine, located in the northern part of the pluton. SEM data showed that Sn-W mineralization is dominantly associated with syenogranite and greisenized rocks. EDS Semi-quantitative analysis revealed that the zircon crystals of the Bom Jardim granite are characteristically enriched in Hf, Y, U, and Th and display Zr/Hf ratios decreasing from monzogranite/leucomonzogranite toward syenogranite and greisenized syenogranite rocks, suggesting that magmatic differentiation significantly contributed for this particular feature. The Bom Jardim granite is slightly peraluminous and displays geochemical affinities with A-type granites. The Bom Jardim granite varieties evolved dominantly by fractional crystallization and their REE patterns are similar to those of the tin-specialized granites of the Velho Guilherme suite. It is concluded that the more evolved granites and associated greisenized rocks of the Bom Jardim pluton are tin-specialized granites. The similarities observed between the granites of the Velho Guilherme suite and the Bom Jardim granite allow to include the latter in this important granite suite.

  19. Subaerial biofilms on granitic historic buildings: microbial diversity and development of phototrophic multi-species cultures.

    PubMed

    Vázquez-Nion, D; Rodríguez-Castro, J; López-Rodríguez, M C; Fernández-Silva, I; Prieto, B

    2016-07-01

    Microbial communities of natural subaerial biofilms developed on granitic historic buildings of a World Heritage Site (Santiago de Compostela, NW Spain) were characterized and cultured in liquid BG11 medium. Environmental barcoding through next-generation sequencing (Pacific Biosciences) revealed that the biofilms were mainly composed of species of Chlorophyta (green algae) and Ascomycota (fungi) commonly associated with rock substrata. Richness and diversity were higher for the fungal than for the algal assemblages and fungi showed higher heterogeneity among samples. Cultures derived from natural biofilms showed the establishment of stable microbial communities mainly composed of Chlorophyta and Cyanobacteria. Although most taxa found in these cultures were not common in the original biofilms, they are likely common pioneer colonizers of building stone surfaces, including granite. Stable phototrophic multi-species cultures of known microbial diversity were thus obtained and their reliability to emulate natural colonization on granite should be confirmed in further experiments. PMID:27192622

  20. Seismogenic faulting in the Meruoca granite, NE Brazil, consistent with a local weak fracture zone.

    PubMed

    Moura, Ana Catarina A; Oliveira, Paulo H S DE; Ferreira, Joaquim M; Bezerra, Francisco H R; Fuck, Reinhardt A; Nascimento, Aderson F DO

    2014-10-24

    A sequence of earthquakes occurred in 2008 in the Meruoca granitic pluton, located in the northwestern part of the Borborema Province, NE Brazil. A seismological study defined the seismic activity occurring along the seismically-defined Riacho Fundo fault, a 081° striking, 8 km deep structure. The objective of this study was to analyze the correlation between this seismic activity and geological structures in the Meruoca granite. We carried out geological mapping in the epicentral area, analyzed the mineralogy of fault rocks, and compared the seismically-defined Riacho Fundo fault with geological data. We concluded that the seismically-defined fault coincides with ∼E-W-striking faults observed at outcrop scale and a swarm of Mesozoic basalt dikes. We propose that seismicity reactivated brittle structures in the Meruoca granite. Our study highlights the importance of geological mapping and mineralogical analysis in order to establish the relationships between geological structures and seismicity at a given area. PMID:25352370

  1. Seismogenic faulting in the Meruoca granite, NE Brazil, consistent with a local weak fracture zone.

    PubMed

    Moura, Ana Catarina A; De Oliveira, Paulo H S; Ferreira, Joaquim M; Bezerra, Francisco H R; Fuck, Reinhardt A; Do Nascimento, Aderson F

    2014-12-01

    A sequence of earthquakes occurred in 2008 in the Meruoca granitic pluton, located in the northwestern part of the Borborema Province, NE Brazil. A seismological study defined the seismic activity occurring along the seismically-defined Riacho Fundo fault, a 081° striking, 8 km deep structure. The objective of this study was to analyze the correlation between this seismic activity and geological structures in the Meruoca granite. We carried out geological mapping in the epicentral area, analyzed the mineralogy of fault rocks, and compared the seismically-defined Riacho Fundo fault with geological data. We concluded that the seismically-defined fault coincides with ∼E-W-striking faults observed at outcrop scale and a swarm of Mesozoic basalt dikes. We propose that seismicity reactivated brittle structures in the Meruoca granite. Our study highlights the importance of geological mapping and mineralogical analysis in order to establish the relationships between geological structures and seismicity at a given area. PMID:25590704

  2. Silica exposure and rheumatoid arthritis: a follow up study of granite workers 1940-81.

    PubMed

    Klockars, M; Koskela, R S; Järvinen, E; Kolari, P J; Rossi, A

    1987-04-18

    The incidence and prevalence of subjects awarded disability pensions and the prevalence of subjects receiving free medicines because of rheumatoid arthritis were studied in a Finnish cohort of 1026 granite workers hired between 1940 and 1971 and followed up until 31 December 1981. The incidence of awards of disability pensions because of rheumatoid arthritis during 1969-81, the prevalence of rheumatoid arthritis on 31 December 1981, and the prevalence of subjects receiving free medicines for rheumatoid arthritis at the end of 1981 were significantly higher among the granite workers than in the general male population of the same age. Retrospective analysis of the records of all patients with rheumatoid arthritis in the cohort showed a predominance of a severe, serologically positive and erosive form of rheumatoid arthritis, usually with an age at onset of 50 or over. The possible aetiological or pathophysiological role of granite dust in rheumatoid arthritis may be based on the effects of quartz on the immune system.

  3. Biodeterioration of granite monuments by Ochrolechia parella (L.) mass: an FT Raman spectroscopic study.

    PubMed

    Prieto, B; Seaward, M R; Edwards, H G; Rivas, T; Silva, B

    1999-01-01

    Ochrolechia parella is one of the most abundant lichens colonizing granite monuments in the region of Galicia (N.W. Spain). Its interaction with granite used in the construction of four ancient monuments was studied using FT Raman spectroscopy to evaluate the production of calcium oxalate by this lichen and the relationship of this production with different environmental conditions, particularly humidity. The results obtained showed that Ochrolechia parella is an aggressive colonizer, causing chemical disturbances to the granite through the formation of both calcium oxalate monohydrate and dihydrate. Apothecial development appears to be related to the production of calcium oxalate, and humidity determines the state of hydration of the calcium oxalate in the thallus.

  4. Pippard relation close to the alpha - beta transition for quartz in granite

    NASA Astrophysics Data System (ADS)

    Yurtseven, Hamit; Tari, Özlem; Gümüş, Ayşegül

    2016-03-01

    In this study, we examine variation of the thermal expansion αp with the isothermal compressibility κT at various temperatures (1 atm) close to the α-β transition in quartz using the experimental data from the literature. We obtain the pressure dependence of the thermal expansion for dry granite quartz at room temperature. Variation of αp with the κT is also studied as a function of temperature for constant pressures of 0.1, 100, 200 and 300 MPa close to the α-β transition of dry granite quartz. Our results show that volumetric expansion increases as functions of temperature (1 atm) and pressure (room temperature), as observed experimentally for dry granite quartz.

  5. Extra-terrestrial igneous granites and related rocks: A review of their occurrence and petrogenesis

    NASA Astrophysics Data System (ADS)

    Bonin, Bernard

    2012-11-01

    The telluric planets and the asteroid belt display the same internal structure with a metallic inner core and a silicate outer shell. Experimental data and petrological evidence in silicate systems show that granite can be produced by extreme igneous differentiation through various types of igneous processes. On Moon, 4.4-3.9 Ga granite clasts display dry mineral assemblages. They correspond to at least 8 discrete intrusive events. Large K/Ca enrichment and low REE abundances in granite relative to KREEP are consistent with silicate liquid immiscibility, a process observed in melt inclusions within olivine of lunar basalts and in lunar meteorites. Steep-sided domes identified by remote sensing can represent intrusive or extrusive felsic formations. On Mars, black-and-white rhythmic layers observed on the Tharsis rise along the flanks of the peripheral scarps of the Tharsis Montes giant volcanoes suggest the possible eruption of felsic pyroclastites. Though no true granites were found so far in the Martian SNC meteorites, felsic glasses and mesostases were identified and a component close to terrestrial continental (granitic) crust is inferred from trace element and isotope systematics. Venus has suffered extensive volcanic resurfacing, whereas folded and faulted areas resemble terrestrial continents. Near large shield volcanoes, with dominant basaltic compositions, steep-sided domes have been interpreted as non-degassed silicic extrusions. The hypothesis of a granitic component is "tantalising". Extra-terrestrial granite is frequently found as clasts and mesostases in asteroidal meteorites. Porphyritic textures, with alkali feldspar crystals up to several centimetres in size, were observed in silicate enclaves within iron meteorites. In the chondrite clan, polymict breccias can contain granitic clasts, whose provenance is debated. One clast from the Adzhi-Bogdo meteorite yields a 4.53 ± 0.03 Ga Pb-Pb age, making it the oldest known granite in the solar system. The

  6. Seismogenic faulting in the Meruoca granite, NE Brazil, consistent with a local weak fracture zone.

    PubMed

    Moura, Ana Catarina A; Oliveira, Paulo H S DE; Ferreira, Joaquim M; Bezerra, Francisco H R; Fuck, Reinhardt A; Nascimento, Aderson F DO

    2014-10-24

    A sequence of earthquakes occurred in 2008 in the Meruoca granitic pluton, located in the northwestern part of the Borborema Province, NE Brazil. A seismological study defined the seismic activity occurring along the seismically-defined Riacho Fundo fault, a 081° striking, 8 km deep structure. The objective of this study was to analyze the correlation between this seismic activity and geological structures in the Meruoca granite. We carried out geological mapping in the epicentral area, analyzed the mineralogy of fault rocks, and compared the seismically-defined Riacho Fundo fault with geological data. We concluded that the seismically-defined fault coincides with ∼E-W-striking faults observed at outcrop scale and a swarm of Mesozoic basalt dikes. We propose that seismicity reactivated brittle structures in the Meruoca granite. Our study highlights the importance of geological mapping and mineralogical analysis in order to establish the relationships between geological structures and seismicity at a given area.

  7. Seismogenic faulting in the Meruoca granite, NE Brazil, consistent with a local weak fracture zone.

    PubMed

    Moura, Ana Catarina A; De Oliveira, Paulo H S; Ferreira, Joaquim M; Bezerra, Francisco H R; Fuck, Reinhardt A; Do Nascimento, Aderson F

    2014-12-01

    A sequence of earthquakes occurred in 2008 in the Meruoca granitic pluton, located in the northwestern part of the Borborema Province, NE Brazil. A seismological study defined the seismic activity occurring along the seismically-defined Riacho Fundo fault, a 081° striking, 8 km deep structure. The objective of this study was to analyze the correlation between this seismic activity and geological structures in the Meruoca granite. We carried out geological mapping in the epicentral area, analyzed the mineralogy of fault rocks, and compared the seismically-defined Riacho Fundo fault with geological data. We concluded that the seismically-defined fault coincides with ∼E-W-striking faults observed at outcrop scale and a swarm of Mesozoic basalt dikes. We propose that seismicity reactivated brittle structures in the Meruoca granite. Our study highlights the importance of geological mapping and mineralogical analysis in order to establish the relationships between geological structures and seismicity at a given area.

  8. Subaerial biofilms on granitic historic buildings: microbial diversity and development of phototrophic multi-species cultures.

    PubMed

    Vázquez-Nion, D; Rodríguez-Castro, J; López-Rodríguez, M C; Fernández-Silva, I; Prieto, B

    2016-07-01

    Microbial communities of natural subaerial biofilms developed on granitic historic buildings of a World Heritage Site (Santiago de Compostela, NW Spain) were characterized and cultured in liquid BG11 medium. Environmental barcoding through next-generation sequencing (Pacific Biosciences) revealed that the biofilms were mainly composed of species of Chlorophyta (green algae) and Ascomycota (fungi) commonly associated with rock substrata. Richness and diversity were higher for the fungal than for the algal assemblages and fungi showed higher heterogeneity among samples. Cultures derived from natural biofilms showed the establishment of stable microbial communities mainly composed of Chlorophyta and Cyanobacteria. Although most taxa found in these cultures were not common in the original biofilms, they are likely common pioneer colonizers of building stone surfaces, including granite. Stable phototrophic multi-species cultures of known microbial diversity were thus obtained and their reliability to emulate natural colonization on granite should be confirmed in further experiments.

  9. Strain behavior of a granite and a graywacke sandstone in tension

    SciTech Connect

    Schock, R.N.; Louis, H.

    1982-09-10

    Westerly granite and Lance graywacke sandstone were deformed with one of the principal stresses tensile at the same time that the principal strains were monitored. Both rocks exhibited inelastic behavior prior to failure. Pronounced dilatancy and softening in shear took place in the granite. When Young's modulus varied, it did so continuously between compression and tensile stress states with no apparent discontinuity at zero axial stress, implying that cracks played the same role in tension as in compression. Failure was observed whenever the tensile stress exceeded a critical value, in agreement with predictions from Griffiths' failfure criterion. The sandstone exhibited approximately twice as much strain per unit stress change as the granite and showed evidence of grain-to-grain movement as well as crack closure, results consistent with comparisons determined earlier when all stresses are compressive.

  10. Strain behavior of a granite and a Graywacke sandstone in tension

    NASA Astrophysics Data System (ADS)

    Schock, R. N.; Louis, H.

    1982-09-01

    Westerly granite and Lance graywacke sandstone were deformed with one of the principal stresses tensile at the same time that the principal strains were monitored. Both rocks exhibited inelastic behavior prior to failure. Pronounced dilatancy and softening in shear took place in the granite. When Young's modulus varied, it did so continuously between compression and tensile stress states with no apparent discontinuity at zero axial stress, implying that cracks played the same role in tension as in compression. Failure was observed whenever the tensile stress exceeded a critical value, in agreement with predictions from Griffiths' failure criterion. The sandstone exhibited approximately twice as much strain per unit stress change as the granite and showed evidence of grain-to-grain movement as well as crack closure, results consistent with comparisons determined earlier when all stresses are compressive.

  11. Chronology and petrogenesis of a 1.8 g lunar granitic clast:14321,1062

    NASA Technical Reports Server (NTRS)

    Shih, C.-Y.; Bansal, B. M.; Wiesmann, H.; Nyquist, L. E.; Bogard, D. D.; Wooden, J. L.

    1985-01-01

    Geochronological, isotopic, and trace element data for a pristine granite clast from Apollo 14 breccia 14321 obtained using Rb-Sr, Sm-Nd, and (Ar-39)-(Ar-40) methods are presented. Trace element data for a possibly related evolved rock, the quartz-monodiorite clast from breccia 15404 are also presented, and the relationship between these two rock types is discussed. The concordancy of the Rb-Sr and Sm-Nd internal isochron ages and especially the Rb-Sr model age strongly suggest that the granite clast formed 4.1 AE ago. It probably crystallized slowly in the crust and was later excavated and brecciated about 3.88 AE ago, as indicated by the Ar-Ar age. A two-stage model involving crystal fractionation followed by silicate liquid immiscibility is proposed for the lunar granite genesis.

  12. Radiation dose to workers due to the inhalation of dust during granite fabrication.

    PubMed

    Zwack, L M; McCarthy, W B; Stewart, J H; McCarthy, J F; Allen, J G

    2014-03-01

    There has been very little research conducted to determine internal radiation doses resulting from worker exposure to ionising radiation in granite fabrication shops. To address this issue, we estimated the effective radiation dose of granite workers in US fabrication shops who were exposed to the maximum respirable dust and silica concentrations allowed under current US regulations, and also to concentrations reported in the literature. Radiation doses were calculated using standard methods developed by the International Commission on Radiological Protection. The calculated internal doses were very low, and below both US occupational standards (50 mSv yr(-1)) and limits applicable to the general public (1 mSv yr(-1)). Workers exposed to respirable granite dust concentrations at the US Occupational Safety and Health Administration (OSHA) respirable dust permissible exposure limit (PEL) of 5 mg m(-3) over a full year had an estimated radiation dose of 0.062 mSv yr(-1). Workers exposed to respirable granite dust concentrations at the OSHA silica PEL and at the American Conference of Governmental Industrial Hygienists Threshold Limit Value for a full year had expected radiation doses of 0.007 mSv yr(-1) and 0.002 mSv yr(-1), respectively. Using data from studies of respirable granite dust and silica concentrations measured in granite fabrication shops, we calculated median expected radiation doses that ranged from <0.001 to 0.101 mSv yr(-1). PMID:24270240

  13. Sorption of Eu(III) on granite: EPMA, LA-ICP-MS, batch and modeling studies.

    PubMed

    Fukushi, Keisuke; Hasegawa, Yusuke; Maeda, Koushi; Aoi, Yusuke; Tamura, Akihiro; Arai, Shoji; Yamamoto, Yuhei; Aosai, Daisuke; Mizuno, Takashi

    2013-11-19

    Eu(III) sorption on granite was assessed using combined microscopic and macroscopic approaches in neutral to acidic conditions where the mobility of Eu(III) is generally considered to be high. Polished thin sections of the granite were reacted with solutions containing 10 μM of Eu(III) and were analyzed using EPMA and LA-ICP-MS. On most of the biotite grains, Eu enrichment up to 6 wt % was observed. The Eu-enriched parts of biotite commonly lose K, which is the interlayer cation of biotite, indicating that the sorption mode of Eu(III) by the biotite is cation exchange in the interlayer. The distributions of Eu appeared along the original cracks of the biotite. Those occurrences indicate that the prior water-rock interaction along the cracks engendered modification of biotite to possess affinity to the Eu(III). Batch Eu(III) sorption experiments on granite and biotite powders were conducted as functions of pH, Eu(III) loading, and ionic strength. The macroscopic sorption behavior of biotite was consistent with that of granite. At pH > 4, there was little pH dependence but strong ionic strength dependence of Eu(III) sorption. At pH < 4, the sorption of Eu(III) abruptly decreased with decreased pH. The sorption behavior at pH > 4 was reproducible reasonably by the modeling considering single-site cation exchange reactions. The decrease of Eu(III) sorption at pH < 4 was explained by the occupation of exchangeable sites by dissolved cationic species such as Al and Fe from granite and biotite in low-pH conditions. Granites are complex mineral assemblages. However, the combined microscopic and macroscopic approaches revealed that elementary reactions by a single mineral phase can be representative of the bulk sorption reaction in complex mineral assemblages. PMID:24171426

  14. Structure and emplacement of granite plutons in the Paleoproterozoic crust of Eastern Burkina Faso: rheological implications

    NASA Astrophysics Data System (ADS)

    Vegas, Nestor; Naba, Seta; Bouchez, Jean Luc; Jessell, Mark

    2008-11-01

    The Fada N'Gourma area in Burkina Faso is underlain by Paleoproterozoic rocks that make the northeastern West-African Craton. This region is composed of NE-trending volcano-sedimentary belts and foliated tonalites, affected by several shear zones. A generation of younger, ˜2100 Ma-old, non-foliated biotite-bearing granites intrudes the former rock units. We have investigated the younger granite pluton of Kouare that was previously considered as forming a single body with the pluton of Satenga to the west, a pluton which likely belongs to the ˜20 Ma more recent Tenkodogo-Yamba batholith. Magnetic fabric measurements have been combined with microstructural observations and the analysis of field and aeromagnetic data. The granite encloses angular enclaves of the host tonalites. Magmatic microstructures are preserved inside the pluton and solid-state, high-temperature deformation features are ubiquitous at its periphery. The presence of steeply plunging lineations in the pluton of Kouare and its adjacent host-rocks suggests that large volumes of granitic magmas became crystallized while they were ascending through the crust that was softened and steepened close to the contact. Around Kouare, the foliation in the host tonalites conforms with a map-scale, Z-shaped fold in between NNE-trending shear zones, implying a bulk clockwise rotation of the material contained in-between the shear zones, including the emplacing pluton. Regionally, the Fada N'Gourma area is concluded to result from NW-shortening associated with transcurrent shearing and vertical transfer of granitic magmas. This study concludes that the ˜2200 Myears old juvenile crust of Burkina Faso was brittle before the intrusion of the biotite-granites, became softened close to them and that gravity-driven and regional scale wrench tectonics were active together.

  15. "Gris Quintana": a Spanish granite from the Past into the Future.

    NASA Astrophysics Data System (ADS)

    José Tejado, Juan; Mota, M. Isabel; Pereira, Dolores

    2014-05-01

    "Gris Quintana" is a medium-grained, biotite and amphibole granodiorite extracted in the Pluton of Quintana de la Serena (Extremadura, Spain). It is a constant light grey granite from the Hercynian geologic with excellent physicomechanical and physicochemical properties. The granodiorite is composed of plagioclase, biotite, quartz and alkali feldspar, with accessory allanite, titanite, apatite, zircon and ilmenite, mostly as inclusions within the biotite crystals. This commercial variety is extracted from many quarries in the late Hercynian plutons located in the Iberian Massif in Spain period (transition between Central Iberian and Ossa-Moren Zones), having large reserves of granite. Many of the quarries have their own transformation factory (high production zone), with which the sector is offered an endless variety of finishes and constructive rock typologies. A wide range of solutions to architects and designers are offered. Gris Quintana granite is one of the materials with highest technological benefits that are used in arquitecture. "Gris Quintana" granite has been used since ancient times, not only at a regional, but also at national and international level: paving, building (structural, exterior façadas, interior uses), urban decoration and funeral art. It can be found in monuments and more recently, in buildings of different styles and uses, that stand out in beauty and splendor, lasting in time. Some singular works in "Gris Quintana" granite all over the world: extension to the "Congreso de Diputados" (Parliament) in Madrid, "Puerta de San Vicente" in Madrid, Andalucia Parliament columns in Sevilla, New Senate Buiding in Madird, "Gran Vía" pavement in Madrid, "Teatro Real façade" in Madrid… "Gris Quintana" granite accomplishes all the requirements for its nomination as Global Heritage Stone Resource, for both its use in construction and for artistic purposes.

  16. Sorption of Eu(III) on granite: EPMA, LA-ICP-MS, batch and modeling studies.

    PubMed

    Fukushi, Keisuke; Hasegawa, Yusuke; Maeda, Koushi; Aoi, Yusuke; Tamura, Akihiro; Arai, Shoji; Yamamoto, Yuhei; Aosai, Daisuke; Mizuno, Takashi

    2013-11-19

    Eu(III) sorption on granite was assessed using combined microscopic and macroscopic approaches in neutral to acidic conditions where the mobility of Eu(III) is generally considered to be high. Polished thin sections of the granite were reacted with solutions containing 10 μM of Eu(III) and were analyzed using EPMA and LA-ICP-MS. On most of the biotite grains, Eu enrichment up to 6 wt % was observed. The Eu-enriched parts of biotite commonly lose K, which is the interlayer cation of biotite, indicating that the sorption mode of Eu(III) by the biotite is cation exchange in the interlayer. The distributions of Eu appeared along the original cracks of the biotite. Those occurrences indicate that the prior water-rock interaction along the cracks engendered modification of biotite to possess affinity to the Eu(III). Batch Eu(III) sorption experiments on granite and biotite powders were conducted as functions of pH, Eu(III) loading, and ionic strength. The macroscopic sorption behavior of biotite was consistent with that of granite. At pH > 4, there was little pH dependence but strong ionic strength dependence of Eu(III) sorption. At pH < 4, the sorption of Eu(III) abruptly decreased with decreased pH. The sorption behavior at pH > 4 was reproducible reasonably by the modeling considering single-site cation exchange reactions. The decrease of Eu(III) sorption at pH < 4 was explained by the occupation of exchangeable sites by dissolved cationic species such as Al and Fe from granite and biotite in low-pH conditions. Granites are complex mineral assemblages. However, the combined microscopic and macroscopic approaches revealed that elementary reactions by a single mineral phase can be representative of the bulk sorption reaction in complex mineral assemblages.

  17. Radiation dose to workers due to the inhalation of dust during granite fabrication.

    PubMed

    Zwack, L M; McCarthy, W B; Stewart, J H; McCarthy, J F; Allen, J G

    2014-03-01

    There has been very little research conducted to determine internal radiation doses resulting from worker exposure to ionising radiation in granite fabrication shops. To address this issue, we estimated the effective radiation dose of granite workers in US fabrication shops who were exposed to the maximum respirable dust and silica concentrations allowed under current US regulations, and also to concentrations reported in the literature. Radiation doses were calculated using standard methods developed by the International Commission on Radiological Protection. The calculated internal doses were very low, and below both US occupational standards (50 mSv yr(-1)) and limits applicable to the general public (1 mSv yr(-1)). Workers exposed to respirable granite dust concentrations at the US Occupational Safety and Health Administration (OSHA) respirable dust permissible exposure limit (PEL) of 5 mg m(-3) over a full year had an estimated radiation dose of 0.062 mSv yr(-1). Workers exposed to respirable granite dust concentrations at the OSHA silica PEL and at the American Conference of Governmental Industrial Hygienists Threshold Limit Value for a full year had expected radiation doses of 0.007 mSv yr(-1) and 0.002 mSv yr(-1), respectively. Using data from studies of respirable granite dust and silica concentrations measured in granite fabrication shops, we calculated median expected radiation doses that ranged from <0.001 to 0.101 mSv yr(-1).

  18. Petrochemical and isotopic studies of Transhimalayan granites in Ladakh, NW India

    SciTech Connect

    Srimal, N.; Basu, A.R.; Sinha, A.K.

    1985-01-01

    The India-Asia collision zone in the Transhimalayan Indus and Shyok Tectonic Belts (STB) of Ladakh, NW India is characterized by two major granitic batholiths. The northern, Karakoram Granitic batholith and the southern, Ladakh Granitic batholith are separated by thrust-bound belts of ophiolite, flysch and calc-alkaline volcanics of Mesozoic to Tertiary age. The KGC can be divided into three zones: a northern zone of metaluminous to mildly peraluminous granodiorite, diorite and tonalite with normative corundum, a southern zone of peraluminous two-mica and garnet bearing granites with normative corundum 1.8-3.3%, K/Rb=200-310, Rb/Sr > 0.3 and initial /sup 87/Sr/ /sup 86/Sr > 0.7113, and a central zone with variable K/Rb, Rb/Sr and initial /sup 87/Sr//sup 86/Sr ratios showing characteristics of both the northern and the southern zones. Field and characteristics of both the northern and the southern zones. Field and geochemical data indicate that: 1) the northern granites of the KGC represent an older magmatic arc derived largely from igneous sources with a small admixture of evolved crustal components and 2) the southern granites of the KGC are derived by partial melting of mature crustal material. Preliminary work in the LGC indicate varying source contamination reflected in variable initial /sup 87/Sr//sup 86/Sr ratios (.7041-.7072) and in correlated /sup 87/Sr//sup 86/Sr vs. delta /sup 18/O plot. The authors data suggest: 1) multiple accretion of Gondwanic fragments in the Mesozoic and Tertiary along the southern margin of Asia, 2) absence of extensive crustal anatexis in the source region of the Ladakh batholith, and 3) remobilization of old sutures and crustal anatexis as a result of India-Asia collision.

  19. Conventional U-Pb dating versus SHRIMP of the Santa Barbara Granite Massif, Rondonia, Brazil

    USGS Publications Warehouse

    Sparrenberger, I.; Bettencourt, Jorge S.; Tosdal, R.M.; Wooden, J.L.

    2002-01-01

    The Santa Ba??rbara Granite Massif is part of the Younger Granites of Rondo??nia (998 - 974 Ma) and is included in the Rondo??nia Tin Province (SW Amazonian Craton). It comprises three highly fractionated metaluminous to peraluminous within-plate A-type granite units emplaced in older medium-grade metamorphic rocks. Sn-mineralization is closely associated with the late-stage unit. U-Pb monazite conventional dating of the early-stage Serra do Cicero facies and late-stage Serra Azul facies yielded ages of 993 ?? 5 Ma and 989 ?? 13 Ma, respectively. Conventional multigrain U-Pb isotope analyses of zircon demonstrate isotopic disturbance (discordance) and the preservation of inherited older zircons of several different ages and thus yield little about the ages of Sn-granite magmatism. SHRIMP U-Pb ages for the Santa Ba??rbara facies association yielded a 207Pb/206Pb weighted-mean age of 978 ?? 13 Ma. The textural complexity of the zircon crystals of the Santa Ba??rbara facies association, the variable concentrations of U, Th and Pb, as well as the mixed inheritance of zircon populations are major obstacles to using conventional multigrain U-Pb isotopic analyses. Sm-Nd model ages and ??Nd (T) values reveal anomalous isotopic data, attesting to the complex isotopic behaviour within these highly fractionated granites. Thus, SHRIMP U-Pb zircon and conventional U-Pb monazite dating methods are the most appropriate to constrain the crystallization age of the Sn-bearing granite systems in the Rondo??nia Tin Province.

  20. Analyses of SRS waste glass buried in granite in Sweden and salt in the United States

    SciTech Connect

    Williams, J.P. ); Wicks, G.G. ); Clark, D.E. ); Lodding, A.R. )

    1991-01-01

    Simulated Savannah River Site (SRS) waste glass forms have been buried in the granite geology of the Stirpa mine in Sweden for two years. Analyses of glass surfaces provided a measure of the performance of the waste glasses as a function of time. Similar SRS waste glass compositions have also been buried in salt at the WIPP facility in Carlsbad, New Mexico for a similar time period. Analyses of the SRS waste glasses buried in-situ in granite will be presented and compared to the performance of these same compositions buried in salt at WIPP.

  1. Analyses of SRS waste glass buried in granite in Sweden and salt in the United States

    SciTech Connect

    Williams, J.P.; Wicks, G.G.; Clark, D.E.; Lodding, A.R.

    1991-12-31

    Simulated Savannah River Site (SRS) waste glass forms have been buried in the granite geology of the Stirpa mine in Sweden for two years. Analyses of glass surfaces provided a measure of the performance of the waste glasses as a function of time. Similar SRS waste glass compositions have also been buried in salt at the WIPP facility in Carlsbad, New Mexico for a similar time period. Analyses of the SRS waste glasses buried in-situ in granite will be presented and compared to the performance of these same compositions buried in salt at WIPP.

  2. Orbicular granite near Jelenia Góra in southwestern Poland: the first outcrops?

    NASA Astrophysics Data System (ADS)

    Kennan, Pádhraig S.; Lorenc, Marek W.

    2008-01-01

    In 1802, Leopold von Buch described some outcrops of orbicular granite in the Karkonosze granite, Lower Silesia, Poland. In that publication, Abraham Gottlieb Werner wrote a foreword dated 1800. The Silesian discovery predates that of the well-known orbicular diorite (Napoleonite) in outcrop on Corsica and, thus, may be the first ever record of this distinctive rock type in its geological context. The characterizing, closely-packed, simple orbs comprise K-feldspar cores surrounded by rims of radiating K-feldspar and quartz. Rapid growth from a hydrous, pegmatitic melt is indicated. The Karkonosze outcrop, in the timing of its discovery, is a unique part of the geological heritage.

  3. Map Showing Quaternary Geology and Geomorphology of the Granite Park Area, Grand Canyon, Arizona

    USGS Publications Warehouse

    Hereford, Richard; Burke, Kelly J.; Thompson, Kathryn S.

    2000-01-01

    View to west-northwest showing map area and setting of Granite Park; Grand Canyon, Arizona. The Colorado River flows from right to left. Granite Park Wash is the light-colored area in foreground of photograph. The debris fan of 209 Mile Canyon is at left center. Pleistocene gravel is exposed in the steep, light-colored bank above 209 Mile Rapids at left edge of photograph. The black-colored ledge that forms the dark cliff at upper right of photograph is the basalt flow of Hamblin (1994). Sand dunes, debris fans, and terraces of the Colorado River cover the lower half of this area shown in this photograph.

  4. Effect of Pressure and Stress on Water Transport in Intact and Fractured Gabbro and Granite

    SciTech Connect

    Trimmer, D.; Bonner, B.; Heard, H.C.; Duba, A.

    1980-12-10

    New laboratory data are reported on the effect of confining pressure (to 60 MPa), pore-water pressure (to 30 MPa), and stress difference (to 0.88 of the fracture stress) on permeability of intact and fractured White Lake gneissic granite. Westerly granite, and Creighton gabbro. Permeabilities as low as 10/sup -24/ m/sup 2/ (10/sup -2/ darcy) have been measured using a transient technique. Fracture displacement, electrical conductance, compressional velocity, and pulse amplitude are determined simultaneously. The loads applied to the 0.15-m-diameter by 0.28-m-length test sample are controlled automatically, and most data are taken by microprocessor. Tests on the intact gneissic granite indicated permeabilities of 10/sup -22/ to 10/sup -24/ m/sup 2/ that appeared to be unaffected either by effective pressure or by stress. The granite yielded permeabilities of 4 +- 10/sup -20/ m/sup 2/ that decreased by a factor of 2 as effective pressure increased to 25 MPa and varied by a factor of 2 as stress was increased to 0.5 of the fracture stress. Permeability of the gabbro linearly decreased from 2 x 10/sup -22/ to 8 x 10/sup -24/ m/sup 2/ with effective pressures to 25 MPa. Loading of the gabbro up to 0.88 of the fracture stress increased permeability by a factor of 7. The introduction of a throughgoing fracture increased the apparent permeability by 10/sup 6/ to 10/sup 9/ over the intact values in both granite and gabbro. When compared to the initial value, compressional velocities increased by 5% with pressure to 30 MPa in the gneissic granite. For granite, pressurization from 2 to 25 MPa increased the velocity and pulse amplitude by 5 and 30%, and decreased the conductance by 50%. Velocity, amplitude, and conductance were weakly dependent on pressure in gabbro. The addition of stress decreased velocity and amplitude while increasing conductance markedly on both granite and gabbro.

  5. Chemical and isotopic studies of granitic Archean rocks, Owl Creek Mountains, Wyoming: Uranium-thorium-lead systematics of an Archean granite from the Owl Creek Mountains, Wyoming

    SciTech Connect

    Stuckless, J.S.; Nkomo, I.T.; Butt, K.A.

    1986-01-01

    Isotopic analyses of apparently unaltered whole-rock samples of a granite from the Owl Creek Mountains, Wyo., yield a lead-lead isochron age of 2730 {plus minus} 35 Ma, which is somewhat older than the age obtained by the rubidium-strontium whole-rock method. Thorium-lead data for the same samples deviate markedly from an isochronal relation; however, calculated initial {sup 208}Pb/{sup 204}Pb ratios correlate with whole-rock {delta}{sup 18}O values and lead to the conclusion that the {sup 232}Th-{sup 208}Pb data are not colinear because of an originally heterogeneous granitic magma. Relationships in the {sup 207}Pb/{sup 235}U-{sup 206}Pb/{sup 238}U system show that uranium was mobilized during early Laramide time or shortly before, such that most surface and shallow drill-core samples lost 60-80 percent of their uranium, and some fractured, deeper drill-core samples gained from 50 to 10,000 percent uranium. Fission-track maps show that much uranium is located along edges and cleavages of biotite and magnetic where it is readily accessible to oxidizing ground water. Furthermore, qualitative comparisons of uranium distribution in samples with excess radiogenic lead and in samples with approximately equilibrium amounts of uranium and lead suggest that the latter contain more uranium in these readily accessible sites. Unlike other granites that have uranium distributions and isotopic systematics similar to those observed in this study, the granite of the Owl Creek Mountains is not associated with economic uranium deposits.

  6. Pattern of elemental release during the granite dissolution can be changed by aerobic heterotrophic bacterial strains isolated from Damma Glacier (central Alps) deglaciated granite sand.

    PubMed

    Lapanje, Aleš; Wimmersberger, Celine; Furrer, Gerhard; Brunner, Ivano; Frey, Beat

    2012-05-01

    Colonisation and weathering of freshly deglaciated granite are key processes in initial soil formation and development. We have obtained 438 isolates from granite sand covering glacial toe, 284 isolates at 22°C and 154 at 4°C incubation temperatures, respectively, to obtain cultures for the investigation of their weathering capabilities under laboratory conditions. The isolation of bacteria from granite sand was performed on rich-, intermediate- and low-nutrient-content solid media. Isolates were identified by 16S rRNA gene sequencing. According to the genera-associated weathering capabilities described in the literature and according to their abundance in our culture collection, we selected eight strains to analyse their effects on the weathering dynamics of granite sand during the batch culture experiment. Analysis of culturable bacteria showed higher species richness among isolates from 22°C than from 4°C incubations. In the R2A and 1/100 Ravan media, we observed the highest species richness of isolates obtained at 22°C and 4°C incubation temperatures, respectively. The obtained 16S rRNA sequences revealed the presence of alpha-, beta- and gamma-proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes. The most numerous group of isolates was distantly related to Collimonas representatives, and according to the sequences of the 16S rRNA genes, they can form a new genus. Isolates from this group had the capability of causing increased dissolution rates for Fe, W, Ni and Rb. In general, at each sampling during the 30-day experiment, every strain showed a unique weathering profile resulting from differential rates of the dissolution and the precipitation of different minerals in the batch culture. Consequently, the presence of different strains, their growth stage and changes in proportions of strains in the bacterial community can affect further soil development and the successive colonisation by plants.

  7. 76 FR 40722 - Granite Reliable Power, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-11

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Granite Reliable Power, LLC; Supplemental Notice That Initial Market-Based... above-referenced proceeding of Granite Reliable Power, LLC's application for market-based rate...

  8. Geochemical characteristics of the Bulgarmarse Granite of the Fall River Pluton in the Avalonian Superterrane of southeastern New England

    SciTech Connect

    Mancuso, C.I.; Puffer, J.H. . Dept. of Geological Sciences)

    1993-03-01

    The 600 m.y. Bulgarmarsh Granite of the Fall River Pluton crops out along the SE margin of the Pennsylvanian-age Narragansett Basin in the Dedham terrane of the New England Avalonian Superterrane. The Bulgarmarsh is a coarse-grained, quartz-rich, very leucooratic granite, in which mafic minerals, generally less than 5--8%, occur chiefly as chlorite, biotite and garnet disequilibrium intergrowths. Most of the granite is very slightly deformed, but there are many localized zones of deformation, both brittle and plastic, that vary in degree of intensity. The Bulgarmarsh intrudes Basin margin metavolcanics similar to those of Price Neck Formation that crop out within the Basin in Newport and on Gould Island. The Bulgarmarsh Granite has many of the mineralogical and geochemical characteristics of an A-type granite. Its geochemistry places it in the post-orogenic classification of Maniar and Piccoli (1989). New major and minor element geochemical data clearly discriminate between the Bulgarmarsh Granite and the adjacent calc-alkaline Metacom Granite Gneiss. Avalonian Orogeny, occupying a place in geologic history similar to that of the Newport Granite.

  9. Sorption and diffusion of selenium oxyanions in granitic rock.

    PubMed

    Ikonen, Jussi; Voutilainen, Mikko; Söderlund, Mervi; Jokelainen, Lalli; Siitari-Kauppi, Marja; Martin, Andrew

    2016-09-01

    The processes controlling diffusion and sorption of radionuclides have been studied extensively in the laboratory, whereas, only a few in-situ experiments have been carried out in order to study in-situ diffusion over the long-term (several years). This is largely due to the fact that in-situ experiments are typically time consuming and cost intensive, and it is commonly accepted that laboratory scale tests are well-established approaches to characterizing the properties of geological media. In order to assess the relevance of laboratory experiments, the Swiss National Cooperative for Disposal of Radioactive Waste (Nagra) have been conducting extensive experiments in the Underground Rock Laboratory (URL) at the Grimsel Test Site (GTS) in order to study radionuclide transport and retention in-situ. One of the elements used in these experiments is non-radioactive selenium, as an analog for the radiotoxic isotope Se-79, which is present in radioactive waste. In this work, two laboratory through-diffusion experiments using selenium as a tracer were carried out in block (decimeter) scale rock specimens to support one of the ongoing radionuclide transport and retention in-situ experiment at the GTS mentioned above. The though-diffusion tests of selenium were performed under atmospheric conditions in both Kuru grey granite (KGG) and Grimsel granodiorite (GG). The decrease of selenium concentration in an inlet hole drilled into each of the rock samples and the breakthrough of selenium into sampling holes drilled around the inlet were analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The effective diffusion (De) and distribution coefficients (Kd) of selenium were then determined from the changes of selenium concentration in the inlet and sampling holes using a Time-Domain Diffusion (TDD) simulations. In addition, Kd of selenium was measured by batch sorption experiments as a function of pH and Se concentration in atmospheric conditions and nitrogen

  10. Sorption and diffusion of selenium oxyanions in granitic rock

    NASA Astrophysics Data System (ADS)

    Ikonen, Jussi; Voutilainen, Mikko; Söderlund, Mervi; Jokelainen, Lalli; Siitari-Kauppi, Marja; Martin, Andrew

    2016-09-01

    The processes controlling diffusion and sorption of radionuclides have been studied extensively in the laboratory, whereas, only a few in-situ experiments have been carried out in order to study in-situ diffusion over the long-term (several years). This is largely due to the fact that in-situ experiments are typically time consuming and cost intensive, and it is commonly accepted that laboratory scale tests are well-established approaches to characterizing the properties of geological media. In order to assess the relevance of laboratory experiments, the Swiss National Cooperative for Disposal of Radioactive Waste (Nagra) have been conducting extensive experiments in the Underground Rock Laboratory (URL) at the Grimsel Test Site (GTS) in order to study radionuclide transport and retention in-situ. One of the elements used in these experiments is non-radioactive selenium, as an analog for the radiotoxic isotope Se-79, which is present in radioactive waste. In this work, two laboratory through-diffusion experiments using selenium as a tracer were carried out in block (decimeter) scale rock specimens to support one of the ongoing radionuclide transport and retention in-situ experiment at the GTS mentioned above. The though-diffusion tests of selenium were performed under atmospheric conditions in both Kuru grey granite (KGG) and Grimsel granodiorite (GG). The decrease of selenium concentration in an inlet hole drilled into each of the rock samples and the breakthrough of selenium into sampling holes drilled around the inlet were analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The effective diffusion (De) and distribution coefficients (Kd) of selenium were then determined from the changes of selenium concentration in the inlet and sampling holes using a Time-Domain Diffusion (TDD) simulations. In addition, Kd of selenium was measured by batch sorption experiments as a function of pH and Se concentration in atmospheric conditions and nitrogen

  11. Sorption and diffusion of selenium oxyanions in granitic rock.

    PubMed

    Ikonen, Jussi; Voutilainen, Mikko; Söderlund, Mervi; Jokelainen, Lalli; Siitari-Kauppi, Marja; Martin, Andrew

    2016-09-01

    The processes controlling diffusion and sorption of radionuclides have been studied extensively in the laboratory, whereas, only a few in-situ experiments have been carried out in order to study in-situ diffusion over the long-term (several years). This is largely due to the fact that in-situ experiments are typically time consuming and cost intensive, and it is commonly accepted that laboratory scale tests are well-established approaches to characterizing the properties of geological media. In order to assess the relevance of laboratory experiments, the Swiss National Cooperative for Disposal of Radioactive Waste (Nagra) have been conducting extensive experiments in the Underground Rock Laboratory (URL) at the Grimsel Test Site (GTS) in order to study radionuclide transport and retention in-situ. One of the elements used in these experiments is non-radioactive selenium, as an analog for the radiotoxic isotope Se-79, which is present in radioactive waste. In this work, two laboratory through-diffusion experiments using selenium as a tracer were carried out in block (decimeter) scale rock specimens to support one of the ongoing radionuclide transport and retention in-situ experiment at the GTS mentioned above. The though-diffusion tests of selenium were performed under atmospheric conditions in both Kuru grey granite (KGG) and Grimsel granodiorite (GG). The decrease of selenium concentration in an inlet hole drilled into each of the rock samples and the breakthrough of selenium into sampling holes drilled around the inlet were analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The effective diffusion (De) and distribution coefficients (Kd) of selenium were then determined from the changes of selenium concentration in the inlet and sampling holes using a Time-Domain Diffusion (TDD) simulations. In addition, Kd of selenium was measured by batch sorption experiments as a function of pH and Se concentration in atmospheric conditions and nitrogen

  12. Geochemistry and Rb-sr geochronology of associated proterozoic peralkaline and subalkaline anorogenic granites from Labrador

    NASA Astrophysics Data System (ADS)

    Collerson, Kenneth D.

    1982-12-01

    Anorogenic granites of middle to late Proterozoic age in the Davis Inlet — Flowers Bay area of Labrador are subdivided on the basis of petrology and geochemistry into three coeval suites. Two of these are high-temperature anhydrous hypersolvus granites: a peralkaline aegirine-sodic-calcic to sodic amphibole-bearing suite and a non-alkaline fayalite-pyroxene-bearing suite. The third is a group of non-alkaline subsolvus hornblende-biotite-bearing granites. Associated with the hypersolvus peralkaline suite is a group of genetically related syenites and quartz syenites. The granites cut ca. 3,000 Ma old Archaean gneisses as well as Elsonian layered basic intrusions of the Nain Complex. One of these, a crudely layered mass which ranges in composition from gabbro to diorite and monzonite, appears to be related to the syenites. The peralkaline granites and some of the syenites are extremely enriched in the high field-strength elements such as Y, Zr, Nd, as well as Rb, Ga and Zn, and have low abundances of Ba, Sr and most of the transition elements. In contrast, the non-alkaline hypersolvus and subsolvus granites do not show the same degree of enrichment. Concentration of the highly charged cations in the peralkaline suite is believed to be the result of halogen-rich fluid activity during fractionation of the magma. The sodic evolution trend in the peralkaline suite is reflected mineralogically by the development of aegirine and aegirine-hedenbergite solid solutions, and by a spectacular amphibole compositional range from katophorite through winchite, richterite, riebeckite to arfvedsonite and ferro eckermannite. Accessory phases which are ubiquitous in these rocks include aenigmatite, astrophyllite, fluorite, monazite and zircon. The non-alkaline hypersolvus granites typically contain iron-rich phases such as fayalite, eulite, ferrosilite-hedenbergite, and annite rich biotite. In the subsolvus granites, amphiboles range in composition from edenite through common

  13. Biofouling of granite-rapakivi in St. Petersburg monuments and in the quarry in Russia and Finland

    NASA Astrophysics Data System (ADS)

    Vlasov, Dmitry; Panova, Elena; Alampieva, Elena; Olhovaya, Elena; Popova, Tatyana; Vlasov, Alexey; Zelenskaya, Marina

    2013-04-01

    Granite-rapakivi was widely used in the architecture of St. Petersburg: the facades of buildings, embankments of rivers and canals, bridges, sculptural monuments, pedestals, facing the metro stations. This stone is rapidly destroyed due to the peculiarities of its structure. Biofouling of granite is insufficiently studied. Cause the destruction of granite can be bacteria, microscopic algae, fungi, mosses, lichens, higher plants, invertebrates and vertebrates. They often form specific lithobiotic communities that contribute to the destruction of granite-rapakivi. The objects of research were monuments of St. Petersburg (granite sculpture, facades, facing embankments) as well as granite-rapakivi quarries in Russia and Finland, where the stone was quarried for use in St. Petersburg. Sampling was carried out from the most typical biofouling sites. Different methods were applied for the study of damaged granite: petrographic analysis, light and scanning electron microscopy, methods for detection and identification of microorganisms, X-ray microprobe analysis. As result the main forms of granite destruction were described: fractures, ovoid weathering, granular disintegration, surface films, crusts and layers, pitting and fouling. Lichens, mosses, herbaceous and micromycetes were dominated on the granite-rapakivi in quarries. For example, in a Monferran quarry (Virolahti region) the complicated lithobiotic community was revealed. It included 30 species of micromycetes, 31 species of lichens, 10 species of moss. Bacteriological analysis showed the dominance of bacteria Bacillus, and actinomycetes in microbial biofilms. More than 100 species of plants were found on the granite embankments in St. Petersburg. They were confined to the cracks, seams of granite blocks. Plants and mosses were common to the granite embankments of rivers and canals in the central (historical) part of the city. Dimensions of mosses depend on the area of the deepening which they occupy. The most

  14. Pegmatoid schlieren with tourmaline in granitoids of eastern russia as an attribute of intrusive series completed by ore-bearing Li-F granites

    NASA Astrophysics Data System (ADS)

    Alekseev, V. I.; Marin, Yu. B.

    2014-12-01

    Tourmaline schlieren in pegmatoids and host granites are widespread in Cretaceous granitoid plutons occurring in tin districts of eastern Russia. These schlieren were formed under the action of fluoricboron fluids, which are considered to be forerunners of rare-metal granite magmatism. The tourmaline schlieren in adamellites, biotite, and two-mica granites are reliable attributes of intrusive series completed by emplacement of ore-bearing Li-F granites.

  15. Trace-element geochemistry of postorogenic granites from the northeastern Arabian Shield, Kingdom of Saudi Arabia

    USGS Publications Warehouse

    Stuckless, John S.; Knight, R.J.; VanTrump, G.; Budahn, J.R.

    1983-01-01

    Concentrations determined for all of the trace elements included in this study of postorogenic granites from the northeastern Arabian Shield are best described by log-normal distributions. The trace elements are divided into two groups: (1) compatible lithophile and siderophile elements (strontium, cobalt, scandium, manganese, europium, and titanium) and (2) incompatible lithophile elements (uranium, thorium, tantalum, rubidium, and rare-earth elements, except europium). The compatible elements exhibit greatest concentrations in the metaluminous postorogenic granites, and concentrations decrease with increasing degree of magma evolution. Economic potential for these elements and other geochemically similar elements is considered to be low. The concentrations of the incompatible elements increase with increasing degree of magma evolution and are greatest in the peralkaline and peraluminous granites. There is some geologic evidence that pegmatite and vein-forming processes were operative toward the end stage of postorogenic magmatism in the northeastern Arabian Shield, and therefore there is some probability for economic potential for these elements. It is suggested that such potential is greatest where highly evolved postorogenic granites intruded volatile (generally water )-rich country rocks.

  16. Continuous improvement for winning in the marketplace: the Granite Rock experience.

    PubMed

    Ramalingam, P R

    1996-11-01

    Leadership and the employee involvement approach are features of continuous improvement (CI). The experiences of Granite Rock with the strategy and practices for quality improvements are presented. The major factors to be focused on to move quality from the dismal levels that exist today toward world-class quality status are examined.

  17. Radioactivity and gamma-dose rates observed at the Morungaba granites, Southeastern Brazil.

    PubMed

    Lucas, Fabio de Oliveira; Ribeiro, Fernando Brenha

    2013-07-01

    A ground gamma-ray survey was conducted over part of a large granitic body located near the city of Campinas, eastern São Paulo State, Brazil. The dominant rock types are K-feldspar porphyries-rich granites, porphyritic biotite and hornblend-bearing granites, fine to medium-grained monzogranites and medium to gross grained, biotite and muscovite-bearing monzogranites. The radioactive element distribution reflects local geology, in part re-worked by weathering, and the most radioactive rocks are the K-feldspar-rich granites. The rate of the absorbed dose by the air reflects the integrated effects of the radioactive elements distribution. Most of the observed values vary between 67 and 130 nGy h(-1) and with localised spots with the absorbed dose rate values up to 193 nGy h(-1) and low values of ∼25 nGy h(-1). The mean air absorbed dose rate for the studied area is 77 nGy h(-1).

  18. Estimation of the indoor radon and the annual effective dose from granite samples

    NASA Astrophysics Data System (ADS)

    Sola, P.; Srinuttrakul, W.; Kewsuwan, P.

    2015-05-01

    Inhalation of radon and thoron daughters increases the risk of lung cancer. The main sources of indoor radon are building materials. The aim of this research is to estimate the indoor radon and the annual effective dose from the building materials. Eighteen granite samples bought from the markets in Thailand were measured using an ionization chamber (ATMOS 12 DPX) for the radon concentration in air. Radon exhalation rates were calculated from the radon concentration in chamber. The indoor radon from the granite samples ranged from 10.04 to 55.32 Bq·m-2·h-1 with an average value of 20.30 Bq·m-2·h-1 and the annual effective dose ranged from 0.25 to 1.39 mSv·y-1 with an average value of 0.48 mSv·y-1. The results showed that the annual effective doses of three granite samples were higher than the annual exposure limit for the general public (1 mSv·y-1) recommended by the International Commission on Radiological Protection (ICRP). In addition, the relationship between the colours and radon exhalation rates of granite samples was also explained.

  19. Impact of environmental dewatering of Lower Granite and Little Goose reservoirs on benthic invertebrates and macrophytes

    SciTech Connect

    Cushing, C.E.

    1993-09-01

    An investigation into the effects of dewatering on the benthic fauna in Lower Granite and Little Goose reservoirs was undertaken. Benthos in both the soft bottom regions of the reservoirs as well as those inhabiting the rock rip-rap along the shoreline were studied. These organisms provide an important food resource for both migrating salmonids and resident fish species; thus, impacts of contemplated dewatering schemes require evaluation. The results of these studies indicate that there were no significant, long-term impacts to the soft bottom benthos as a result of dewatering in Little Goose Reservoir. In fact, higher numbers of some taxa indicate that there may have been a washout of these organisms from Lower Granite Reservoir with subsequent deposition in the upper reaches of Little Goose Reservoir. This should be accompanied by a coincident decrease in these organisms in Lower Granite Reservoir. However, we did not have pre-dewatering samples from Lower Granite Reservoir with which we could compare post-filling samples to determine if the dewatering resulted in lower benthic populations.

  20. Trace-element contents of postorogenic granites of the eastern Arabian Shield, Kingdom of Saudi Arabia

    USGS Publications Warehouse

    Stuckless, J.S.; Vaughn, R.B.; VanTrump, George

    1986-01-01

    The regional trends for the chemical data and geochemical correlations over the large area sampled, suggest that the postorogenic granites were derived from a single protolith that formed by the mixing of oceanic sediments from the west, continental sediments from the east.

  1. The Advanced Placement English Program in Salt Lake and Granite School Districts.

    ERIC Educational Resources Information Center

    Stratopoulos, Irene Chachas

    The main purposes in examining and evaluating the Advanced Placement English Program in Salt Lake and Granite School Districts were to identify the essential curriculum features of the program, to make suggestions for curriculum improvement, and to determine whether or not the quality of the AP English Program surpassed that of the conventional…

  2. Building Capacity through Sustainable Engagement: Lessons for the Learning Community from the "GraniteNet" Project

    ERIC Educational Resources Information Center

    Arden, Catherine; McLachlan, Kathryn; Cooper, Trevor

    2009-01-01

    This paper reports an exploration into critical success factors for the sustainability of the partnership between the University of Southern Queensland and the Stanthorpe community during the GraniteNet Phoenix Project--the first phase of a three-phase participatory action research project conducted during 2007-2008. The concepts of learning…

  3. A comparison of fracture transmissivities in granite water wells before and after hydrofracturing

    NASA Astrophysics Data System (ADS)

    Hart, David

    2016-02-01

    In many regions of the world, crystalline bedrock aquifers are the only choice for groundwater supply. This is the case in northern Wisconsin, located in the upper Midwest of the continental United States. Here, groundwater flow to wells occurs only through fractures in the granitic basement. Although hydrofracturing of these wells is common and generally increases well yield, the precise mechanism for the increased yields remained unknown. Stressed and ambient flow logs were obtained in two 305-m-deep granitic boreholes in northern Wisconsin prior to hydrofracturing. From those logs, it was determined that nearly all of the groundwater flow to the boreholes occurred in less than 10 fractures in the upper 80 m, with no measureable contribution below that depth. Following hydrofracturing of the boreholes, stressed and ambient flow logs were again obtained. The transmissivity of the two boreholes increased by factors of 8.6 and 63 times. It was found that (1) the fractures that had contributed flow to the boreholes increased in transmissivity, (2) although the applied pressures were large enough in some instances to create new fractures, those new fractures did not increase the borehole transmissivities significantly, and (3) fractures without measureable flow before hydrofracturing remained without measureable flow. Hydrofracturing increases yield in granitic boreholes; however, that increase seems to only occur in fractures where flow was pre-existing and in the upper 80 m of the boreholes. These observations suggest that efforts to enhance yield in granitic aquifers should be focused on the upper part of the borehole.

  4. Geochronology of the Xihuashan composite granitic body and tungsten mineralization, Jiangxi province, south China.

    USGS Publications Warehouse

    McKee, E.H.; Rytuba, J.J.; Xu, Keqin

    1987-01-01

    One of the goals of this visit was to collect samples of different granitic rocks in the pluton for radiometric dating to establish the geochronology of intrusion, alteration, and mineralization. This report summarises geochronologic studies during a visit by Chinese and US scientists to the Xihuashan mine.-after Authors

  5. Pioneering fungi from the Damma glacier forefield in the Swiss Alps can promote granite weathering.

    PubMed

    Brunner, I; Plötze, M; Rieder, S; Zumsteg, A; Furrer, G; Frey, B

    2011-05-01

    Fungi were isolated from fine granitic sediments, which were collected at 15 sampling points within a 20 m × 40 m area in front of the Damma glacier in the central Swiss Alps. From the 45 fungal isolates grown on nutrient-rich agar media at 4 °C, 24 isolates were selected for partial sequencing and identification based on the small subunit ribosomal DNA. Sequencing data revealed that the isolated fungi represented three fungal phyla and 15 species. The weathering potential of 10 of the 15 fungal species was tested with dissolution experiments using powdered granite material (<63 μm). The results showed that the zygomyceteous species Mucor hiemalis, Umbelopsis isabellina and Mortierella alpina dissolved the granite powder most efficiently due to the release of a variety of organic acids, mainly citrate, malate and oxalate. In particular, the high concentrations of Ca, Fe, Mg and Mn in the solutions clustered well with the high amounts of exuded citrate. This is the first report on fungi that were isolated from a non-vegetated glacier forefield in which the fungi's capabilities to dissolve granite minerals were examined.

  6. Chemical migration by contact metamorphism between granite and silt/carbonate system

    SciTech Connect

    Laul, J.C.; Papike, J.J.

    1981-01-01

    Comparison of trace element signatures between the metamorphosed and unmetamorphosed samples from granite-silt/carbonate system suggests that some elements do migrate during contact metamorphism. The relative degree of migration varies depending on the element. The evidence of chemical migration in silt and carbonate is convincing on a several-meter scale.

  7. Dependency of hydromechanical properties of monzonitic granite on confining pressure and fluid pressure under compression

    NASA Astrophysics Data System (ADS)

    Wang, Huanling; Xu, Weiya; Lui, Zaobao; Chao, Zhiming; Meng, Qingxiang

    2016-05-01

    Monzonitic granite is a low-permeability rock. Monzonitic granite formations are ideal for underground storage of oil due to their low permeability and high mechanical strength. In this study, a series of coupled hydromechanical triaxial tests are carried out using monzonitic granite specimens. The influence of confining and fluid pressures on stress, strain, and permeability is investigated. Failure characteristics under different confining and fluid pressures are discussed based on the analysis of macro fracture planes and micro scanning electron microscopy (SEM). The test results show that the change of permeability with stress and strain reflects the deformation stages of compaction, compression, crack propagation, coalesce, and failure of cracks. Due to the low porosity, the change of permeability is small in the initial phases of compaction and compression, whereas there is a significant increase in permeability when new cracks start to develop and coalesce. Confining pressures have a significant impact on the strength and permeability, particularly the crack damage stress of the rock. Compared with confining pressure, the effect of fluid pressure on rock strength and crack damage stress is small. For the monzonitic granite specimens tested, changing the confining pressure results in different failure modes, whereas the fluid pressure has a relatively small effect on the failure modes.

  8. Evaluation of the effectiveness of laser crust removal on granites by means of hyperspectral imaging techniques

    NASA Astrophysics Data System (ADS)

    Pozo-Antonio, J. S.; Fiorucci, M. P.; Ramil, A.; López, A. J.; Rivas, T.

    2015-08-01

    In this paper, we present a study of the application of the hyperspectral imaging technique in order to non-destructively evaluate the laser cleaning of the biogenic patina and the sulphated black crust developed on a fine-grained granite used in the construction of Cultural Heritage in NW Spain. The grained polymineral texture of the granite hinders the adjustment of laser irradiation parameters during the cleaning, and therefore the in situ process control. The cleaning was performed with a nanosecond pulsed Nd:YVO4 laser at 355 nm. A hyperspectral camera was used to in situ assess the effectiveness of cleaning by recording images of the rock surfaces before and during the laser treatment. Different analytical techniques were used to test the ability of the hyperspectral imaging technique to evaluate the cleaning process of the granite samples: optical microscopy, scanning electron microscopy with energy dispersive X-ray spectrometry (SEM - EDX), Fourier transform infrared spectroscopy (FTIR) and spectrophotometer colour measurements. The results indicated that hyperspectral imaging technique is a reliable and more affordable technique to in situ evaluate the process of laser cleaning of the biogenic patina and the sulphated black crust in fine-grained granites.

  9. Petrology and chemistry of two 'large' granite clasts from the moon

    NASA Technical Reports Server (NTRS)

    Warren, P. H.; Taylor, G. J.; Keil, K.; Shirley, D. N.; Wasson, J. T.

    1983-01-01

    Pristine granite clasts in Apollo-14 breccias 14321 and 14303 have estimated masses of 1.8 and 0.17 g, respectively. The 14321 clast is about 60 percent K-feldspar and 40 percent quartz, with traces of extremely Mg-poor mafic silicates and ilmenite. The 14303 clast is roughly 33 percent plagioclase, 32 percent K-feldspar, 23 percent quartz, 11 percent pyroxene, and 1 percent ilmenite; pyroxene and ilmenite are moderately Mg-rich; plagioclase and pyroxene are strongly zoned. Both clasts are severely brecciated, but monomict (pristine). Both have abundant graphic integrowths of K-feldspar with quartz. Unlike the majority of similar earth rocks, both clasts are devoid of hydrous phases. The bulk composition of the 14321 clast is similar to those of several other lunar granitic samples, but the 14303 clast is unique: it bears as close a resemblance to KREEP as it does to other lunar granites. Silicate liquid immiscibility may explain why the granites are low in REE relative to KREEP.

  10. Estimating the elastic modulus and REV of Inada Granite using a homogenization analysis method

    NASA Astrophysics Data System (ADS)

    Chae, B.; Choi, J.; Seo, Y.

    2013-12-01

    The elastic behavior of granite, which is a composite of various minerals, was calculated with consideration of fracture distribution using the homogenization theory. Microscopic and photographic analyses were conducted to measure the random distribution of the minerals and microcracks in Inada granite. A modal analysis was conducted simultaneously with the photographic analysis. The elastic homogenization theory was applied to calculate the elastic modulus of Inada granite using the results of the modal analysis. The elastic modulus that was determined using the homogenization analysis became constant when the size of the model was larger than 254.3 mm2 (1,156 elements). The elastic modulus, which was calculated as 94.1 GPa, was lower than the experimental value by 7.3 GPa. After the distribution of the rock-forming elements and the elastic modulus were calculated, the representative elementary volume (REV) of the fine-grained Inada granite was estimated to be 254.3 mm2 (1,156 elements).

  11. An example of trondhjemite genesis by means of alkali metasomatism: Rockford Granite, Alabama Appalachians

    NASA Astrophysics Data System (ADS)

    Drummond, Mark S.; Ragland, Paul C.; Wesolowski, David

    1986-03-01

    A model for trondhjemite genesis is proposed where granite is transformed to trondhjemite via infiltration by a Na-rich metamorphic fluid. The Rockford Granite of the Northern Alabama Piedmont serves as the case example for this process and is characterized as a synmetamorphic, peraluminous trondhjemite-granite suite. The major process operative in the conversion of granite to trondhjemite involves cation exchange of Na for K in the feldspar and mica phases through a volatile fluid medium. Whole-rock δ 18O values for the trondhjemites are negatively correlated with atomic proportion K/Na ratio indicating a partial reequilibration of the altered granitoids with a Na- and18O-rich metamorphically derived fluid. Biotite decomposition to an Al-epidote-paragonitic muscovite-secondary quartz assemblage is also associated with the sodium metasomatism, as are apatite replacement by Al-epidote and secondary zircon crystallization. Rare albitization of primary magmatic plagioclase and discontinuous grossularite reaction rim growth on magmatic garnet are present in the trondhjemites indicating the mobility of Ca during alkali metasomatism. The replacement of magmatic phases by me tasomatic phases exemplifies the chemical changes produced during infiltration metasomatism where the trondhjemites are depleted in P2O5, Th, Rb, U, K2O, V, Sn, F, MgO, Pb, TiO2, FeO* and Li and enriched in CaO, Na2O, Zr and Sr relative to the granites. Other elements, such as Cr, MnO, Cu, Zn, Co, Ba, SiO2, Ni, Al2O3, are shown to be relatively immobile during the metasomatism. The infiltration metasomatism probably occurred during prograde regional metamorphism, when a discrete fluid phase was produced in the surrounding amphibolite-grade metasediments. Foliation planes in the granite apparently served as conduits for fluid flow with reaction-enhanced permeability accompanying the 8% molar volume reduction during Na-for-K exchange in the feldspars. A source for the Na and Sr in the metamorphic fluid

  12. Experimental constraints on the Qitianling granite in south China: phase equilibria and petrogenetic implications

    NASA Astrophysics Data System (ADS)

    Huang, Fangfang; Scaillet, Bruno; Wang, Rucheng; Erdmann, Saskia; Chen, Yan; Faure, Michel; Liu, Hongsheng; Xie, Lei; Wang, Bo; Zhu, Jinchu

    2016-04-01

    In South China, the huge distribution of the Mesozoic metallogenic province reflects the abundant magmatism and associated mineralizations which occurred during that period. Building up the phase equilibrium diagrams of representative Mesozoic granites allows us to better understand Mesozoic magmatic events, an approach so far little applied to granites of South China. The Qitianling ganite is a representative Jurassic A-type metaluminous pluton which is associated with tin mineralization in South China. The dominant rock-types are hornblende-biotite monzonitic granites, biotite±hornblende bearing granites and fine-grained biotite-bearing granites. Three metaluminous granite samples (QTL38C, QTL14A and QTL13), of varying mafic character but all bearing hornblende, were chosen for constraining crystallization and magma generation conditions of the Qitianling composite batholith. Crystallization experiments were performed in the 100-700 MPa range, albeit mainly at 200 MPa, at an fO2 at NNO-1 or NNO +2.5, in a temperature range 700°C to 900°C. At 200 MPa, the water content in melt varies between 3 wt% and 6.5 wt% (water-saturated). Experimental results show that under H2O-saturated conditions and at NNO-1, ilmenite, magnetite and pyroxene are the liquidus phases, followed by hornblende, biotite and plagioclase. Hornblende is present only in the most mafic sample (QTL38C), below 900°C and above 5 wt% H2O. In contrast, for H2O-saturated conditions and at NNO+2.5, magnetite, pyroxene crystallize first, followed by biotite while ilmenite is rarely observed. Petrographic observations of natural samples show that magnetite and ilmenite coexist, whereas pyroxene is never observed. The Fe# value (Fe/Mg+Fe) of natural amphibole goes up to 0.69, being on average at 0.67. Experiments indicate that the crystallization of pyroxene occurs at early magmatic stages, but it breaks down to hornblende and biotite at low temperatures, explaining its absence in natural assemblages

  13. Experimental determination of liquidus H2O contents of simple granites at deep crustal conditions

    NASA Astrophysics Data System (ADS)

    Makhluf, A. R.; Newton, R. C.; Manning, C. E.

    2014-12-01

    The liquidus water content of a granitic melt at high pressure (P) and temperature (T) is important because it constrains the volume of granite that could be produced by melting of the deep crust. Previous estimates based on melting experiments at low P (≤0.5 GPa) show substantial scatter when extrapolated to deep crustal P and T (700-1000˚C, 0.6-1.5 GPa). To improve the high-P constraints on water concentration at the granite liquidus, we preformed experiments in piston-cylinder apparatus at 1 GPa using a range of granite compositions. In each experiment, granite glass + H2O was homogenized well above the liquidus T, then T was lowered by increments until quartz and alkali feldspar crystalized from the liquid. To establish reversed equilibrium, we crystallized the homogenized melt at the lower T, then raised the T until we found that the crystalline phases were resorbed into the liquid. Four different bulk compositions were studied (ab-ksp-qz, in wt%): 40-40-20, 37.5-37.5-25, 36.25-36.25-27.5, 35-35-30. Quenched charges were analyzed by petrographic microscope, SEM and electron microprobe. Microprobe analysis of all-glass charges reproduced our intended starting compositions. The minimum temperature of the 1 GPa liquidus at a given water content occurs at 27.5±0.3 wt% quartz, regardless of H2O content. The reversed liquidus temperatures at 3.0, 4.1, 5.85, 7.95 wt% water are respectively 935-985, 850-915, 775-825 and 700-750˚C. Our results conform closely to the extrapolation of Holtz 2001, which give significantly higher water contents than used by most dehydration melting models. This presents a challenge for producing voluminous amounts of metaluminous granites from lower crustal biotite-amphibole gneisses by dehydration melting. For example, a deep-crustal tonalitic gneiss with 0.6-0.8 wt% H2O would yield less than 20 vol% granitic liquid for complete dehydration and perfect extractability, neither of which are likely to be realized in deep crustal melting.

  14. Late-Archaean Potassic Granite from the Bundelkhand Craton, Central India

    NASA Astrophysics Data System (ADS)

    Sarkar, Saheli; Saha, Lopamudra; Nasipuri, Pritam; Pati, Jayanta Kumar; Patole, Vishal

    2014-05-01

    Late-Archaean granitoids, show wide range of compositional variation: (i) TTG like granitoids with strongly fractionated REE patterns, which can be both Na-rich and K-Mg-rich (Sanukitoids) (ii) K-rich, Mg-poor biotite granites with less fractionated REE patterns and showing negative Eu-anomalies (type area, the Closepet Granite, Eastern Dharwar Craton, India). Amongst them Late-Archaean Sanukitoid or K-rich Closepet-type granitoids are most widely reported from the Archaean Cratons world-wide: Superior Province, Canada, Pilbara Craton, Yilgarn Craton, Antarctica, Limpopo Belt, Dharwar Craton. Several models proposed so far for the origin of these granitoids mostly include partial melting of hydrated basalts, reaction of slab melts with mantle wedge peridotites, re-melting of an enriched mantle and then mixing of the resulting melt with the anatectic melt generated during the melting of continental crust in subduction zone settings. The Closepet-type potassic biotite-rich granites were mostly produced by re-melting of TTG-like continental basements most likely in a subduction zone setting. Most of the proposed models suggest such partial melting to have taken place in garnet-stability field and some in orthopyroxene-stability field. In this study we report late-Archaean (~2.61-2.5 Ga) potassic granite from the Bundelkhand Craton in central India. The Late-Archaean granitoids recorded from the craton are intrusive into the high-grade supracrustal rocks of the craton. They are classified as coarse grained grey, pink porphyritic granite, medium granied pink granite, granite porphyry and fine-grained pink granite. The supracrustal rocks of the craton have been metamorphosed at ~2.78 Ga under high-pressure conditions (~17-18 kbar)- medium temperature (600ºC) in a subduction zone setting. The intrusions of the granitoids at ~2.6-2.5 Ga mark the stability of the craton. The pink-porphyritic granite studied here preserves plagioclase-potash feldspar

  15. Behaviour of Sr, Ca, Nd and Li Isotopes During Granite Weathering: the Margeride Massif, France

    NASA Astrophysics Data System (ADS)

    Negrel, P.; Bullen, T. D.; Millot, R.

    2008-12-01

    The Massif Central region of France contains numerous mineral water springs with salinities up to 6 g/L. These high salinities develop due to water-rock interaction processes accompanying weathering of granitic rocks such as the Margeride massif, a 5 km-deep laccolith having an age of 323 ± 12 Ma and consisting mainly of granitoid and gneiss. In order to better constrain weathering processes, we have determined the Sr, Nd, Ca and Li-isotope compositions of the Margeride granite, weathered granite (arene) and saprolite, sediment and soil overlying the granite, and groundwater samples (e.g., mineral water springs) associated with the massif. 87Sr/86Sr ratios increase in the order apatite-plagioclase-K-feldspar-arene- sediments and soils-biotite, and are well correlated with Rb/Sr ratios. Mineral waters have 87Sr/86Sr ratios similar to that of plagioclase, but have higher Rb/Sr ratios. 44Ca/40Ca ratios of plagioclase and apatite are similar to that of the whole rock, while those of K-feldspar and biotite are significantly less. 44Ca/40Ca ratios of arene, soil and sediment are similar to or less than that of K- feldspar, reflecting complete loss of Ca from plagioclase and apatite during weathering. In contrast, 44Ca/40Ca ratios for the mineral waters are similar to or substantially greater than that of plagioclase, reflecting extensive calcium carbonate precipitation during ascent of the waters along the rock fracture network. 44Ca/40Ca ratios of the waters are as much as 3.5 per mil greater than that of seawater, and thus contain the heaviest Ca yet reported for terrestrial materials. 7Li/6Li ratios differ by a few per mil among the granite minerals; of the weathering products, arene and soils have the least 7Li/6Li ratios, while river bank sediment and arene surface sediment have progressively greater ratios. 7Li/6Li ratios of the mineral waters have the greatest values, reflecting preferential retention of 6Li in the weathering products. 143Nd/144Nd ratios are

  16. Contrasting evolution of low-P rare metal granites from two different terranes in the Hoggar area, Algeria

    NASA Astrophysics Data System (ADS)

    Kesraoui, Mokrane; Nedjari, Samia

    2002-05-01

    Two mineralogically different rare metal granites located in two distinct terranes from the Tuareg area are compared: the Tin-Amzi granite in the north of the Laouni Terrane and the Ebelekan granite in the Assodé-Issalane Terrane. The Tin-Amzi granite is enclosed within Eburnean granulitic gneisses, and consists of albite, quartz, protolithionite, K-feldspar and topaz granite (PG). The accessory minerals include columbite tantalite, U- and Hf-rich zircon, Th-uraninite, wolframoixiolite and wolframite. This facies is characterised by a mineralogical evolution from the bottom to the top underlined by a strong resorption of K-feldspar and albite and the crystalliK-feldspar of more abundant topaz and protolithionite II which is further altered in muscovite and Mn-siderite. It is underlain by an albite, K-feldspar, F-rich topaz, quartz and muscovite granite (MG), with W-Nb-Ta oxides, wolframite, Nb-rutile, zircon and scarce uranothorite as accessories. The Ebelekan granite intrudes into a coarse-grained biotite granite enclosed within upper amphibolite-facies metasediments. It comprises a zinnwaldite, albite, topaz porphyritic granite (ZG) with "snow ball" quartz and K-feldspar. The accessories are zircon, monazite, uranothorite, Ta bearing cassiterite, columbite tantalite and wodginite. It is capped by a banded aplite-pegmatite (AP). The geochemistry of Tin-Amzi and Ebelekan granites is nearly comparable. Both are peraluminous (A/CNK=1.10-1.29; ASI=1.17-1.31), sodolithic and fluorine rich with high SiO 2, Al 2O 3, Na 2O+K 2O, Rb, Ga, Li, Ta, Nb, Sn and low FeO, MgO, TiO 2, Ba, Sr, Y, Zr and REE contents. These rare metal Ta bearing granites belong to the P-poor subclass, relating to their P 2O 5 content ( 0.03-0.15 wt.%). Nevertheless, they are distinguished by their concentration of W, Sn and Ta. The Tin-Amzi granite is W-Ta bearing with high W/Sn ratio whereas the Ebelekan granite is Ta-Sn bearing with insignificant W content. At Tin-Amzi the W-Nb-Ta minerals define

  17. Origin, distribution and glaciological implications of Jurassic high heat production granites in the Weddell Sea rift, Antarctica

    NASA Astrophysics Data System (ADS)

    Leat, Phil T.; Jordan, Tom A. R. M.; Ferraccioli, Fausto; Flowerdew, Michael; R, Riley, Teal; Vaughan, Alan P. M.; Whitehouse, Martin

    2013-04-01

    The distribution of heat flow in Antarctic continental crust is critical to understanding ice sheet nucleation, growth and basal rheology and hydrology. We identify a group of High Heat Production granites intruded into Palaeozoic sedimentary sequences which may contribute to locally high heat flow beneath the central part of the West Antarctic Ice Sheet. Four of the granite plutons are exposed above ice sheet level at Pagano Nunatak, Pirrit Hills, Nash Hills and Whitmore Mountains. A new U-Pb zircon age from Pirrit Hills of 177.9 ± 2.3 Ma confirms earlier Rb-Sr dating that suggested an Early-Middle Jurassic age for the granites, coincident with the Karoo-Ferrar large igneous province and the first stage of Gondwana break-up. Our recently-acquired aerogeophysical data indicate that the plutons are distributed unevenly over 1000 km2 and were intruded into the actively extending, locally transcurrent, Jurassic Weddell Sea Rift [1]. In the NW part of the rift, the Pirrit Hills, Nash Hills and Whitmore Mountains granites form small isolated intrusions within weakly deformed upper crust. In the SE part of the rift, where granite intrusion was strongly structurally controlled within transtensional structures, the Pagano Nunatak granite is the only outcrop of a probably multiphase, ca 180 km long granite intrusion. The granites are weakly peraluminous, S-type and have Th and U abundances up to 61 and 19 ppm respectively. Heat production of analysed granite samples is ca. 2.9-9.1 µWm-3, toward the upper limit of values for High Heat Production granites globally. The granites are thought to have been generated during mafic underplating of the Weddell Rift during eruption of the contemporaneous Karoo-Ferrar magmatism [2]. The high Th and U abundances may be related to fractionation of the high Th-U Ferrar basaltic magmas combined with assimilation of pelitic sedimentary rocks. The granites correspond to an area of West Antarctica that may have heat flow significantly above

  18. The Pan-African high-K calc-alkaline peraluminous Elat granite from southern Israel: geology, geochemistry and petrogenesis

    NASA Astrophysics Data System (ADS)

    Eyal, M.; Litvinovsky, B. A.; Katzir, Y.; Zanvilevich, A. N.

    2004-10-01

    Calc-alkaline leucocratic granites that were emplaced at the late post-collision stage of the Pan-African orogeny are abundant in the northern half of the Arabian-Nubian Shield. Commonly, they are referred to as the Younger Granite II suite. In southern Israel such rocks are known as Elat granite. Studies of these rocks enable to recognize two types of granites: coarse-grained, massive Elat granite (EG), and fine- to medium-grained Shahmon gneissic granite (SGG). Both granite types are high-K and peraluminous ( ASI ranges from 1.03 to 1.16). They are similar in modal composition, mineral and whole-rock chemistry. Within the EG, a noticeable distinction in whole-rock chemistry and mineral composition is observed between rocks making up different plutons. In particular, the granite of Wadi Shelomo, as compared to the Rehavam pluton, is enriched in SiO 2, FeO∗, K 2O, Ba, Zr, Th, LREE and impoverished in MgO, Na 2O, Sr, and HREE. The Eu/Eu∗ values in the granite are low, up to 0.44. Mass-balance calculations suggest that chemical and mineralogical variations were caused by fractionation of ˜16 wt.% plagioclase from the parental Rehavam granite magma at temperature of 760-800 °C (muscovite-biotite geothermometer). The Rb-Sr isochrons yielded a date of 623 ± 24 Ma for the EG, although high value of age-error does not allow to constrain time of emplacement properly. The Rb-Sr date for SGG is 640 ± 9 Ma; however, it is likely that this date points to the time of metamorphism. A survey of the literature shows that peraluminous, high-K granites, similar to the EG, are abundant among the Younger Granite II plutons in the Sinai Peninsula and Eastern Desert, Egypt. They were emplaced at the end of the batholithic (late post-collision) stage. The most appropriate model for the generation of the peraluminous granitic magma is partial melting of metapelite and metagreywacke.

  19. The pulmonary toxicity of talc and granite dust as estimated from an in vivo hamster bioassay.

    PubMed

    Beck, B D; Feldman, H A; Brain, J D; Smith, T J; Hallock, M; Gerson, B

    1987-02-01

    A short-term animal bioassay was used to assess the toxicity of occupational dusts. We quantified pulmonary responses in hamsters exposed to granite (12% quartz) and talc (quartz and asbestos-free) dust collected from worksites. Personal samples collected on workers showed similar quartz content and particle-size distributions to the high-volume samples collected for bioassays, thus demonstrating that the particulates were representative of worker exposure. We measured biochemical and cellular indicators of injury in bronchoalveolar lavage fluid (BAL) of animals exposed to dust suspensions by intra-tracheal instillation. The assays measured release of cytoplasmic and lysosomal enzymes into the cell-free supernatant of BAL; levels of albumin and red blood cells; changes in macrophage and polymorphonuclear neutrophil cell numbers; and in situ macrophage phagocytosis. Dose-response (0.15, 0.75, and 3.75 mg/100 g body wt) and time-course (1-14 days postexposure) studies were performed. One day after exposure, both talc and granite dust resulted in elevated enzyme levels, pulmonary edema, and increased cell numbers in BAL. Macrophage phagocytosis was also inhibited. Based on earlier studies, response levels were either intermediate between nontoxic iron oxide and toxic alpha-quartz or comparable with alpha-quartz. The response to granite dust diminished fairly rapidly over time. By contrast, after talc exposure, there was a more persistent elevation in enzyme levels, and macrophage phagocytosis remained depressed. These results indicate that, when a similar mass was deposited in the lungs, talc caused more lung injury than did granite. Better estimates of exposure-dose relationships in talc and granite workers as well as longer-term animal studies are required to evaluate the harmfulness of these work environments at present-day exposure levels.

  20. A thermal model for the distribution in space and time of the Himalayan granites

    NASA Astrophysics Data System (ADS)

    Pinet, Christophe; Jaupart, Claude

    1987-06-01

    In southern Tibet, crustal thickening due to the India-Asia collision has led to the formation of two granite belts. One is located at the southern edge of the accretionary wedge of Tethyan sedimentary rocks, close to the contact with basement gneisses of the Tibetan slab. The other is found within the wedge itself, close to the Kangmar thrust trace. Available ages suggest that the granites appeared first in the southern belt and then in the Kangmar belt. This sequence seems to violate the chronology of thrusting. Another feature of the Himalayas is that melting started only about 20 Ma after the onset of thickening, which is much less than the thermal time constant of thick crust. We give a thermal model, based on the assumption of conductive heat transfer, which explains these features. The model relies on the geometry of a sedimentary accretionary wedge bounded by low-angle thrust faults and on the existence of a thermal conductivity contrast between old basement and young sedimentary rocks. The wedge of sedimentary rocks acts as an insulating cap and its southern edge heats up along the contact with basement rocks. On a horizontal cross-section, there is a temperature maximum along this southern edge, which explains why melting starts there. The early thermal evolution is sensitive to local conditions and granites first appear in the vicinity of the most radiogenic parts of the basement. The distribution of granites in space and time is seemingly random, reflecting different melting events in different radiogenic environments in the heterogeneous basement. This model predicts a relationship between radioactivity and age which is compatible with available data. The results emphasize that there are large horizontal temperature variations across a thickened region and that granite ages are not related simply to the timing of tectonic phases.

  1. Soft computing modeling for indirect determination of the weathering degrees of a granitic rock

    NASA Astrophysics Data System (ADS)

    Dagdelenler, G.; Sezer, E.; Gokceoglu, C.

    2010-05-01

    Determination of weathering degrees of intact rock has been one of the difficult problems in engineering geology. Additionally, granitic rocks are commonly used as building and ornamental stones and pavement material in various civil engineering structures. For this reason, correct determination of weathering degree of the granitic rocks has a crucial importance in engineering geology. Up to now, some approaches for the determination of weathering degree of granitic rocks have been proposed. Some soft computing methods have been used for the determination of the weathering degree of the granitic rocks. However, in literature, the adaptive neuro-fuzzy inference system has not been used for the weathering classification yet. For this reason, the main purpose of the present study is to apply some soft computing methods such as artificial neural networks and adaptive neuro-fuzzy inference system on the determination of weathering degree of a granitic rock selected from Turkey by using some index and mechanical properties. The study is formed by four main stages such as sampling, testing, modeling and assessment of the model performances. During the modeling stage, two weathering prediction models with multi-inputs are developed with two soft computing techniques such as artificial neural networks and the adaptive neuro-fuzzy inference system. The general performances of models developed in this study are close; however the adaptive neuro-fuzzy inference system exhibits the best performance considering the performance index and the degree of consistency. Finally, both models developed in this present study can be used when determining the weathering degree. The results obtained from this study revealed that the soft computing techniques used in the study are highly useful tools to solve some complex problems encountered frequently in engineering geology.

  2. Garnet-bearing granite from the Třebíč pluton, Bohemian Massif (Czech Republic)

    NASA Astrophysics Data System (ADS)

    René, M.; Stelling, J.

    2007-09-01

    Garnet occurs as a significant mineral constituent of felsic garnet-biotite granite in the southern edge of the Třebíč pluton. Two textural groups of garnet were recognized on the basis of their shape and relationship to biotite. Group I garnets are 1.5-2.5 mm, euhedral grains which have no reaction relationship with biotite. They are zoned having high XMn at the rims and are considered as magmatic. Group II garnets form grain aggregates up to 2.5 cm in size, with anhedral shape of individual grains. The individual garnet II grains are usually rimmed by biotite and have no compositional zoning. The core of group I garnets and group II garnets contains 67-80 mol% of almandine, 5-19 mol% of pyrope, 7-17 mol% of spessartine and 2-4 mol% of grossular. Biotite occurs in two generations; both are magnesian siderophyllites with Fe/(Fe + Mg) = 0.50-0.69. The matrix biotite in granites (biotite I) has high Ti content (0.09-0.31 apfu) and Fe/(Fe + Mg) ratio between 0.50 and 0.59. Biotite II forms reaction rims around garnet, is poor in Ti (0.00-0.06 apfu) and has a Fe/(Fe + Mg) ratio between 0.61 and 0.69. The textural relationship between biotite and garnet indicates that garnet reacted with granitic melt to form Ti-poor biotite and a new granitic melt, depleted in Ti and Mg and enriched in Fe and Al. In contrast to the host durbachites (hornblende-biotite melagranites), which originated by mixing of crustal melts and upper mantle melts, the origin of garnet-bearing granites is related to partial melting of the aluminium-rich metamorphic series of the Moldanubian Zone.

  3. Field investigation and modeling of runoff generation in a granitic catchment in Zhuhai, China

    NASA Astrophysics Data System (ADS)

    Fu, Congsheng; Chen, Jianyao; Dong, Linyao; Jiang, Huabo

    2012-08-01

    SummaryRainwater percolation into bedrock and the contribution of bedrock groundwater flow to streamflow have been reported for several experimental catchments in China, Japan and the US. On the basis of previous studies, the particular runoff characteristics of granitic catchments were determined: (i) fast rainwater infiltration, (ii) obviously saturated throughflow (interflow) at the soil-bedrock interface, and (iii) obvious rainwater percolation into the bedrock and a substantial contribution of bedrock groundwater flow to streamflow. Next, the runoff generation characteristics of a small granitic catchment (0.99 km2) in southern China were analyzed, based on long-term monitoring of rainfall, runoff at the catchment outlet and at different depths in two plots, along with monitoring of soil suction and soil water content at different depths in these two plots (5 m × 10 m). According to the monitoring results, the maximum soil infiltration rate in this granitic catchment was larger than 4.45 × 10-4 m/s. Interflow was found at the soil-bedrock interface in plot B with a soil depth ⩽1 m. In plot A overlain by a thick soil layer ⩾2 m, interflow was mainly generated within an aquitard at a shallow depth (˜1 m). The plot interflow hydrograph was similar, but slightly slimmer and sharper, than that of streamflow, illustrating that interflow is the main source of catchment streamflow at the storm scale. A semi-distributed model was constructed based on a digital elevation model, and the ratio of rainwater percolation into bedrock to precipitation in the study catchment from 1 April 2007 to 31 March 2008 was 0.33-0.47, in agreement with results for other granitic catchments. These results can aid in understanding the particular runoff generation characteristics of granitic catchments.

  4. Reutilization of granite powder as an amendment and fertilizer for acid soils.

    PubMed

    Barral Silva, M T; Silva Hermo, B; García-Rodeja, E; Vázquez Freire, N

    2005-11-01

    The properties of granite powders--a granite manufacturing waste product-were analyzed to assess their potential use as amendments and fertilizers on acid soils. Two types of powders were characterized: one produced during cutting of granite with a diamond-edged disc saw, comprising only rock powder, the other produced during cutting with a multi-blade bandsaw, containing calcium hydroxide and metal filings added during the cutting procedure. The acid neutralizing capacity of the granite powders was assessed in short- (2-3 h) and medium-term (1-30 d) experiments. The powders showed a buffering capacity at around pH 8, which corresponded to the rapid dissolution of basic cations, and another buffering effect at pH<4.5, attributable to the dissolution of Fe and Al. The acid neutralizing capacity (ANC) determined in the short-term experiments, to a final pH of 4.5, varied between 5 and 61 cmol H+kg(-1) powder. The ANC to pH 4.5 obtained in the medium-term experiments was much higher than that obtained in the short-term experiments, reaching a maximum ANC value of 200 cmol H+kg(-1) powder. There was no great difference in the neutralizing capacity determined at between 1 and 30 d. The most abundant elements in acid solutions obtained at the end of medium-term experiments were Mg and Ca for disc saw powders, whereas Ca and Fe (at pH<5) were the most soluble elements in the bandsaw powders. The rapid release of these cations suggests the possible effective use of the granite powders as a source of nutrients on being added to acid soils.

  5. Ultrasonic characterization of granites obtained from industrial quarries of Extremadura (Spain).

    PubMed

    del Río, L M; López, F; Esteban, F J; Tejado, J J; Mota, M; González, I; San Emeterio, J L; Ramos, A

    2006-12-22

    The industry of ornamental rocks, such as granites, represents one of the most important industrial activities in the region of Extremadura, SW Spain. A detailed knowledge of the intrinsic properties of this natural stone and its environmental evolution is a required goal in order to fully characterize its quality. In this work, two independent NDT acoustic techniques have been used to measure the acoustic velocity of longitudinal waves in different prismatic granitic-samples of industrial quarries. A low-frequency transceiver set-up, based on a high-voltage BPV Steinkamp instrument and two 50 kHz probes, has been used to measure pulse travel times by ultrasonic through-transmission testing. In complementary fashion, an Erudite MK3 test equipment with an electromagnetic vibrator and two piezoelectric sensors has also been employed to measure ultrasonic velocity by means of a resonance-based method, using the same types of granite varieties. In addition, a comprehensive set of physical/mechanical properties have also been analyzed, according to Spanish regulations in force, by means of alternative methods including destructive techniques such as strength, porosity, absorption, etc. A large number of samples, representing the most important varieties of granites from quarries of Extremadura, have been analyzed using the above-mentioned procedures. Some results obtained by destructive techniques have been correlated with those found using ultrasonic techniques. Our experimental setting allowed a complementary characterization of granite samples and a thorough validation of the different techniques employed, thus providing the industry of ornamental rocks with a non-destructive tool that will facilitate a more detailed insight on the properties of the rocks under study.

  6. Geochronology, geochemistry and tectonic implications of Late Triassic granites in the Mongolian Altai Mountains

    NASA Astrophysics Data System (ADS)

    Dash, Batulzii; Boldbaatar, Enkhjargal; Zorigtkhuu, Oyun-Erdene; Yin, An

    2016-03-01

    Although the closure of the Paleo-Asian Ocean in western China and western Mongolia occurred in the Late Carboniferous and Early Permian, widespread intra-continental magmatism continued to occur across this region from the Late Permian to the end of the Triassic. In this study we document field relationships and geochemical characterization of a Late Triassic felsic intrusive complex in the western Mongolian Altai. The plutonic complex occurs as sills, dikes, and small stocks and its composition varies from biotite granite, two-mica granite, to leucogranite. Structurally, the plutonic complex occurs in the hanging wall of a segment of the regionally extensively (>1500 km long) Irtysh-Ertix-Bulgan thrust zone. As the plutonic bodies both cut and are deformed by the shear fabrics in this regional thrust shear zone, the duration of felsic magmatism and regional thrusting was temporally overlapping. This suggests that magmatism was coeval with crustal thickening. Major- and trace-element data and isotopic analysis of granitoid samples from our study area indicate that the felsic intrusions were derived from partial melting of meta-sediments, with the biotite and two-mica granite generated through vapor-absent melting and the leucogranite from flux melting. Although the Mongolian Altai intrusions were clearly originated from anatexis, coeval granite in the Chinese Altai directly west of our study area in the hanging wall of the Irtysh-Ertix-Bulgan thrust was derived in part from mantle melting. To reconcile these observations, we propose a Himalayan-style intracontinental-subduction model that predicts two geologic settings for the occurrence of felsic magmatism: (1) along the intracontinental thrust zone where granite was entirely generated by anatexis and (2) in the hanging wall of the intracontinental thrust where convective removal and/or continental subduction induced mantle melting.

  7. Adsorption of Se species on crushed granite: a direct linkage with its internal iron-related minerals.

    PubMed

    Jan, Yi-Lin; Wang, Tsing-Hai; Li, Ming-Hsu; Tsai, Shih-Chin; Wei, Yuan-Yaw; Teng, Shi-Ping

    2008-01-01

    The adsorption of selenium species on crushed granite is investigated directly linking to its internal iron-related minerals. Experimental results demonstrated that granite has higher affinity toward Se(IV) adsorption than Se(VI) adsorption. Se(IV) adsorption on granite is insensitive to background electrolytes while the effect of ionic strength on Se(VI) adsorption is not observed, which is attributed to the overloading of Se(VI) ions. Results of chemical sequential extraction showed that the removal of crystalline iron oxides dramatically reduces Se(IV) adsorption, which corresponds to the disappearance of goethite signal within XRD pattern. Based on our results, it is proposed that goethite within granite dominates Se adsorption in crushed granite. Although these goethites probably stem from some sample preparation processes including drilling in situ, crushing, washing and drying granite samples in laboratory, the formation of goethite enhances the granite affinity toward Se species adsorption. Images of SEM/EDS furthermore revealed that goethite is embedded within the fractures. In addition, quantification by standard addition method by spiking goethite suspension indicates that only around 20% of goethite minerals are available during Se(IV) adsorption.

  8. Mineralogy and Petrology of Basement Granites of the Cooper Basin, Central Australia

    NASA Astrophysics Data System (ADS)

    van Zyl, Jaco; Gasparon, Massimo; Uysal, Tonguc

    2010-05-01

    Mineralogy and Petrology of Basement Granites of the Cooper Basin, Central Australia Although the Australian continent is tectonically relatively stable in comparison with other continental settings, the radiogenic heat production within the Australian continental crust is significantly high. One region with particularly elevated heat production is the Cooper Basin. The Cooper basin is an intra-cratonic basin that contains Late Carboniferous to middle Triassic sedimentary rocks which is mainly comprised of non marine sediments. The Cooper Basin overlies granites which have intruded the Warburton Basin Sediments. The Cooper basin in turn is overlain by the Eromanga Basin. This paper focuses on four deep wells in which granites have been intersected. The aim of this study is to characterize the mineralogy and petrology of the granites to further the understanding of heat production. Ten petrographic thin-sections were made from the granites and sampled at different depths in the four geothermal wells. Eight (Big Lake-3507; McLeod-1-3745.2, 3745.9, 3748.3; Moomba-1 2847.75, 2848.7, 2851, 2847.4) of the ten samples exhibit minor to strong alteration, with the other two remaining samples (Jolokia-1 4905 and Moomba-1 2857.4) showing only slight alteration. The predominant mineral in the altered samples is quartz, and a highly birefringent clay mineral (illite from EPMA and XRD) with minor oxides (Goethite, Rutile) sulphides (Galena, Pyrite) and REE-rich silicates (Thorite, Zircon) and phosphates (Apatite, Monazite and Xenotime). The sections exhibiting minor alteration contain plagioclase and K-feldspar in varying stages of decomposition. These feldspars contain varying amounts of illite crystallites. The only altered mineral in the two slightly altered samples is biotite. In Jolokia 1- 4905 the biotite has been completely replaced by a Fe-bearing illite. In Moomba 1- 2857.4 the biotite is only in the early stages of alteration, with the alteration product being Fe

  9. Crustal structure of the Archaean granite-greenstone terrane in the northern portion of the Kaapvaal Craton

    NASA Technical Reports Server (NTRS)

    Debeer, J. H.; Stettler, E. H.; Barton, J. M., Jr.; Vanreenen, D. D.; Bearncombe, J. R.

    1986-01-01

    Recent investigations of the electrical resistivity, gravity and aeromagnetic signatures of the various granite-greenstone units in the northern portion of the Kaapvaal craton have revealed three features of significance: (1) the Archean greenstone belts are shallow features, rarely exceeding 5 km in depth; (2) the high resistivity upper crustal layer typical of the lower grade granite-greenstone terranes is absent in the granulite facies terrane; and (3) the aeromagnetic lineation patterns allow the granite-greenstone terrane to be subdivided into geologically recognizable tectono-metamorphic domains on the basis of lineation frequency and direction. A discussion follows.

  10. The Riviera Deposit: Endo-skarn and Vein-hosted W-MO-REE Mineralization in I-type Granites of the Cape Granite Suite, South Africa

    NASA Astrophysics Data System (ADS)

    Rozendaal, A.; Moyen, J.

    2009-05-01

    The blind Riviera deposit is located in the western Cape Province and was discovered by stream sediment sampling in the mid 1970's. Resources total 46 million metric tons assaying 0,216 per cent tungsten and 200 parts per million molybdenum, a marginal grade that has prohibited development into an open cast mine. Mineralization is mainly hosted by granitoids of the Riviera Pluton which intruded the regionally metamorphosed volcano-sedimentary Malmesbury Group. These granitoids form part of the Cape Granite Suite, a series of batholiths and plutons with S-, I- and A-type characteristics. The composite Riviera Pluton comprises a suite of metaluminous to slightly peraluminous granitoids. The rocks least affected by hydrothermal alteration are granodioritic to adamelitic in composition whereas the more altered host rocks include quartz-monzonite, granite and quartz syenite. As a whole the suite is subalkaline to K-calcalkaline and conforms to the characteristics of I-type granites. The pluton was emplaced into a dome-shaped interference structure, late in the Neoproterozoic Saldanian orogenic cycle. Alteration, particularly prevalent in the roof or cupola of the pluton, occurs as zones of pervasive sericitization, argillization, silicification and potassic alteration. Their spatial and temporal relationship is complex and indicates several superimposed alteration events. Wall rocks display limited alteration and have acted as an impermeable cap. The cross-cutting granitoid intrusions produced wall rock xenoliths of various dimensions consisting mainly of meta-carbonates displaying various stages of digestion. Economic concentrations of scheelite are spatially linked to these assimilations, particularly proximal to the wall rock contact. The occurrence of diagnostic minerals such as vesuvianite, hornblende, hedenbergite, grandite garnets define a typical endo-skarn association. Accessory minerals include pyrite, pyrrhotite, chalcopyrite, sphalerite and the LREE enriched

  11. Measurement of radioactivity and radon exhalation rate in different kinds of marbles and granites.

    PubMed

    El-Dine, N W; El-Shershaby, A; Ahmed, F; Abdel-Haleem, A S

    2001-12-01

    Geological materials usually contaminated with naturally occurring radioactive materials (NORM) have become a focus of great attention. These NORM under certain conditions can reach hazardous contamination levels. Some contamination levels may be sufficiently severe that precautions must be taken. The present study deals with 60 geological samples (marble and granite) from both Egyptian and foreign locations. The studied samples were analyzed and the concentrations in Bq/kg dry weight of radioisotopes were determined by gamma-ray spectrometry using hyper-pure germanium (HPGe) detector in Bq/kg dry weight. The absorbed dose rate due to the natural radioactivity in the samples under investigation ranged from 2.45 +/- 0.07 to 64.44 +/- 1.93 nGy/h for marble and from 41.55 +/- 1.25 to 111.94 +/- 3.36 nGy/h for granite. The radium equivalent activity varied from 5.46 +/- 0.16 to 150.52 +/- 4.52 Bq/kg for marble samples and from 229.52 +/- 6.89 to 92.16 +/- 2.76 Bq/kg for granite. The representative external hazard index values for the corresponding samples are also estimated and given. The radon exhalation rates for marble and granite samples were also calculated by using solid state nuclear track detector (CR-39). The value of radium exhalation rate varied from 8.0 +/- 2.39 to 30.20 +/- 5.06 Bq/m2/d for marble and 6.89 +/- 1.72 to 25.79 +/- 4.38 Bq/m2/d for granite and the effective radium content was found to vary from 1.700 +/- 0.51 to 6.42 +/- 1.08 Bq/kg for marble and 1.29 +/- 0.32 to 5.63 +/- 0.96 Bq/kg for granite. The values of the radon exhalation rate and effective radium content are found to correspond with the values of uranium concentration measured by the HPGe detector in the corresponding sample.

  12. Hydrothermal alterations in the Echassières granitic cupola (Massif central, france)

    NASA Astrophysics Data System (ADS)

    Merceron, Thierry; Vieillard, Philippe; Fouillac, Anne-Marie; Meunier, Alain

    1992-11-01

    Detailed petrographic and mineralogic investigations of an albite-lepidolite granite at Echassières (Massif Central, France; scientific deep drill program) shows the existence of hydrothermal stages which are closely related to the magmatic and structural history. According to fluid inclusion data, K-Ar datations and 18O/16O-D/H compositions of secondary minerals, two successive hydrothermal periods have been recognized. The early one (273 268 million years) produced a series of aluminous phyllosilicates: muscovite, pyrophyllite, donbassite, tosudite, kaolinite which are observed as vein deposits (<10 mm wide) and alteration products of primary minerals in wall-rocks. The vein system was sealed by monomineralic assemblages during a cooling period (400 150°C). This early hydrothermal alteration stage was controlled by interactions of rock with low salinity (1 10 wt% NaCl equivalent) fluids expelled from the granitic body during the cooling processes. The chemical properties of these fluids were the following: low pH, very low Mg and Fe and high Li, Na and K contents. Thermodynamic calculations show that the sequence pyrophyllite, Li-bearing donbassite, tosudite is mostly temperature dependent. From the chemical composition of secondary minerals and isotopic data it can be deduced that these fluids, which have a meteoric origin, have been expelled from the granite body during its cooling period and after interaction with it at high temperature. The late hydrothermal stage corresponds to deposits of fluorite and Fe-Mg rich illite (151 million years) in subvertical fractures. Temperature conditions did not exceed 250° C and fluids came through the surrounding metamorphic rocks into the granitic body. IIlite/smectite mixed-layer minerals have been identified in subvertical fractures which were opened during Tertiary periods. In the host micaschists, successive hydrothermal alterations took place during the cooling of the Beauvoir granite. Early magmatic fluids

  13. Effects of slip, slip rate, and shear heating on the friction of granite

    USGS Publications Warehouse

    Blanpied, M.L.; Tullis, T.E.; Weeks, J.D.

    1998-01-01

    The stability of fault slip is sensitive to the way in which frictional strength responds to changes in slip rate and in particular to the effective velocity dependence of steady state friction ????ss/?? ln V. This quantity can vary substantially with displacement, temperature and slip rate. To investigate the physical basis for this behavior and the possible influence of shear heating, we slid initially bare granite surfaces in unconfined rotary shear to displacements of hundreds of millimeters at normal stresses, ??n, of 10 and 25 MPa and at room temperature. We imposed step changes in slip rate within the range 10-2 to 103.5 ??m/s and also monitored frictional heating with thermistors embedded in the granite. The transient response of ?? to slip rate steps was fit to a rate- and state-dependent friction law using two state variables to estimate the values of several parameters in the constitutive law. The first 20 mm of slip shows rising friction and falling ????ss/?? ln V; further slip shows roughly constant friction, ????ss/?? ln V and parameter values, suggesting that a steady state condition is reached on the fault surface. At V ??? 10 ??m/s, ????ss/?? ln V = -0.004 ?? 0.001. At higher rates the response is sensitive to normal stress: At ??n = 25 MPa granite shows a transition to effective velocity strengthening (????ss/?? ln V = 0.008 ?? 0.004) at the highest slip rates tested. At 10 MPa granite shows a less dramatic change to ????ss/?? ln V ??? 0 at the highest rates. The maximum temperature measured in the granite is ???60??C at 25 MPa and 103.5 ??m/s. Temperatures are in general agreement with a numerical model of heat conduction which assumes spatially homogeneous frictional heating over the sliding surface. The simplest interpretation of our measurements of ????ss/?? ln V is that the granite is inherently veocity weakening (?????ss/??? In V 0 mimics velocity strengthening. These results have implications for the frictional behavior of faults during

  14. Deep drilling at the Siljan Ring impact structure: oxygen-isotope geochemistry of granite

    USGS Publications Warehouse

    Komor, S.C.; Valley, J.W.

    1990-01-01

    The Siljan Ring is a 362-Ma-old impact structure formed in 1700-Ma-old I-type granites. A 6.8-km-deep borehole provides a vertical profile through granites and isolated horizontal diabase sills. Fluid-inclusion thermometry, and oxygen-isotope compositions of vein quartz, granite, diabase, impact melt, and pseudotachylite, reveal a complex history of fluid activity in the Siljan Ring, much of which can be related to the meteorite impact. In granites from the deep borehole, ??18O values of matrix quartz increase with depth from near 8.0 at the surface to 9.5??? at 5760 m depth. In contrast, feldspar ??18O values decrease with depth from near 10 at the surface to 7.1??? at 5760 m, forming a pattern opposite to the one defined by quartz isotopic compositions. Values of ??18O for surface granites outside the impact structure are distinct from those in near-surface samples from the deep borehole. In the deep borehole, feldspar coloration varies from brick-red at the surface to white at 5760 m, and the abundances of crack-healing calcite and other secondary minerals decrease over the same interval. Superimposed on the overall decrease in alteration intensity with depth are localized fracture zones at 4662, 5415, and 6044 m depth that contain altered granites, and which provided pathways for deep penetration of surface water. The antithetic variation of quartz and feldspar ??18O values, which can be correlated with mineralogical evidence of alteration, provides evidence for interaction between rocks and impact-heated fluids (100-300?? C) in the upper 2 km of the pluton. Penetration of water to depths below 2 km was restricted by a general decrease in impact-fracturing with depth, and by a 60-m-thick diabase sill at 1500 m depth that may have been an aquitard. At depths below 4 km in the pluton, where water/rock ratios were low, oxygen isotopic compositions preserve evidence for limited high-temperature (>500?? C) exchange between alkali feldspar and fluids. The high

  15. Use of markers of paleo-circulations to characterize the porous network of fractured granite.

    NASA Astrophysics Data System (ADS)

    Bertrand, L.; LeGarzic, E.; Géraud, Y.; Diraison, M.

    2012-04-01

    Fractured reservoirs in crystalline rocks are well studied nowadays for their application in water resources, oil exploitation or geothermics. In this king of rock, the matrice has a very low permeability and the fluid flow is localized in the fracture pattern. Thus, the characterization and the modeling of such reservoirs require the good knowledge of the fractures, in particular the orientation, density or spatial distribution. In actual fractured reservoirs, the access on those parameters are with seismic and borehole data. The two prospection techniques are at different scale and dimensions, and correlations between them are difficult to make. In consequence, it is necessary to study field rocks analogues on the underground fractured reservoirs. Tamariu's granite, Catalunya, is one of those fields' analogues. Previous studies have highlighted a structuration of the granite in structural blocs of different sizes, separated by faults, and internal fracture patterns in each bloc. Markers of intense paleofluids circulations have been seen in the faults and fractures of those blocs. This study follows the structural characterization of the fracture pattern and as the aim to study the fluid circulation in those fractures. With precise fracture maps, we have analyzed the principal flow direction and the nature of the hydrothermal deposits. Aside from primary hydrothermal quartz, the main secondary minerals are calcite and dolomite, and a little part of iron oxides. This observation, combined on the fracture maps, has allowed us to try a semi-quantification of the usable volume by the fluid in the granite at the circulations time. The fracture pattern has been the host of fluids of around 3% of their volume. Therefore, we have identified a diffuse flow in the grain matrice and which creates primary minerals alteration. The volume of alteration represent around 0,1-0,3% of the rock. In consequence, this study highlights a double-porosity behavior of the granite. On one

  16. Igneous phenocrystic origin of K-feldspar megacrysts in granitic rocks from the Sierra Nevada batholith

    USGS Publications Warehouse

    Moore, J.G.; Sisson, T.W.

    2008-01-01

    Study of four K-feldspar megacrystic granitic plutons and related dikes in the Sierra Nevada composite batholith indicates that the megacrysts are phenocrysts that grew in contact with granitic melt. Growth to megacrystic sizes was due to repeated replenishment of the magma bodies by fresh granitic melt that maintained temperatures above the solidus for extended time periods and that provided components necessary for K-feldspar growth. These intrusions cooled 89-83 Ma, are the youngest in the range, and represent the culminating magmatic phase of the Sierra Nevada batholith. They are the granodiorite of Topaz Lake, the Cathedral Peak Granodiorite, the Mono Creek Granite, the Whitney Granodiorite, the Johnson Granite Porphyry, and the Golden Bear Dike. Megacrysts in these igneous bodies attain 4-10 cm in length. All have sawtooth oscillatory zoning marked by varying concentration of BaO ranging generally from 3.5 to 0.5 wt%. Some of the more pronounced zones begin with resorption and channeling of the underlying zone. Layers of mineral inclusions, principally plagioclase, but also biotite, quartz, hornblende, titanite, and accessory minerals, are parallel to the BaO-delineated zones, are sorted by size along the boundaries, and have their long axes preferentially aligned parallel to the boundaries. These features indicate that the K-feldspar megacrysts grew while surrounded by melt, allowing the inclusion minerals to periodically attach themselves to the faces of the growing crystals. The temperature of growth of titanite included within the K-feldspar megacrysts is estimated by use of a Zr-in-titanite geothermometer. Megacryst-hosted titanite grains all yield temperatures typical of felsic magmas, mainly 735-760 ??C. Titanite grains in the granodiorite hosts marginal to the megacrysts range to lower growth temperatures, in some instances into the subsolidus. The limited range and igneous values of growth temperatures for megacryst-hosted titanite grains support the

  17. From migmatites to granites in the Pan-African Damara orogenic belt, Namibia

    NASA Astrophysics Data System (ADS)

    Toé, W.; Vanderhaeghe, O.; André-Mayer, A.-S.; Feybesse, J.-L.; Milési, J.-P.

    2013-09-01

    The Swakop River exposes a unique structural section into the root of the Pan-African Damara orogenic belt (DOB) in Namibia formed as a result of collision between the Congo and the Kalahari cratons from ca. 550 to 500 Ma. The Central Zone of the Damara orogenic belt is characterized by amphibolite to granulite facies metamorphism accompanied by intense partial melting. Three tectonic units are defined in the Central Zone based on the proportion and distribution of the granitic fraction, namely (1) a lower unit dominated by diatexites and comprising plutons of homogeneous granites, (2) a middle unit composed by metatexites with mainly a metasedimentary protolith, and (3) an upper unit corresponding to metamorphic rocks with intrusive leucogranitic sills and laccoliths. The increase in the granitic fraction with structural depth is suggesting an increase in the degree of partial melting and implies a relative inefficiency of magma mobility from the source to higher structural levels. The transition from metatexites of the middle unit to diatexites and granites of the lower unit is interpreted as reflecting the former transition from partially molten rocks to a crustal-scale magmatic layer. Mushroom-shaped granitic plutons in the lower unit are consistent with their emplacement as diapirs and the development of gravitational instabilities within the magmatic layer. In the middle unit, granitic veins concordant and discordant to the synmigmatitic foliation localized in structurally-controlled sites (foliation, boudin's necks, shear zones, fold hinges) indicate that, within the partially molten zone, deformation plays the dominant role in melt segregation and migration at the outcrop scale. Melt migration from the partially molten zone to the intrusive zone is related to the build-up of an interconnected network of dikes and sills with diffuse contacts with the migmatitic hosts in the middle unit. In contrast, the upper unit is characterized by homogeneous

  18. Origin of Mesozoic and Tertiary granite in the western United States and implications for Pre-Mesozoic crustal structure: 2. Nd and Sr isotopic studies of unmineralized and Cu- and Mo-mineralized granite in the Precambrian Craton

    NASA Astrophysics Data System (ADS)

    Farmer, G. Lang; Depaolo, Donald J.

    1984-11-01

    In the Cordilleran region of the western United States, Mesozoic and Tertiary peraluminous granitic rocks display regional variations in initial 143Nd/144Nd (ɛNd); ɛNd = -10 to -12 in southern Arizona, - 17 to -19 in the northern Great Basin (NGB), and -30 in the northern Rocky Mountains. Initial 87Sr/86Sr values are between 0.710 and 0.721 and show no regional pattern. Metaluminous granitic rocks have a wider range of ɛNd values extending from values similar to those of the peraluminous granites to much higher values. The 87Sr/86Sr values are mostly fairly low, between 0.705 and 0.710 except in the NGB where values as high as 0.7157 are observed. No systematic differences between the ɛNd or 87Sr/86Sr values of Cu- or Mo-mineralized and Unmineralized granite were discerned, except for Cu-mineralized granite in eastern Nevada and Mo-mineralized granite in Colorado, which have ɛNd values higher (˜0) and lower ( ˜-10.0), respectively, than Unmineralized granite in the same region. Comparison to ɛNd values of exposed Precambrian rock suggests that the peraluminous granite, and the Mo granite in Colorado, were derived exclusively from felsic Precambrian basement rocks and that the regional variations in the ɛNd values reflect the regional variation in the average crustal age. The Nd data confirm that the Precambrian basement underlying the NGB and eastern California is isotopically distinct from Precambrian crust in the remainder of the western United States. The similarity between the ɛNd values of peraluminous granite and Precambrian crust also suggests that the high 147Sm/144Nd (>0.13) and the low total light rare earth element (LREE) abundances characteristic of peraluminous granite in southern Arizona were imposed during the chemical evolution of the magmas. Metaluminous granite are interpreted to have formed via mixing of mantle-derived magma and large proportions of low 87Sr/86Sr (granulite facies) lower crust, except in the eastern NGB where the mantle

  19. Metasomatism and metallogeny of A-type granites of the Mt Painter-Mt Babbage Inliers, South Australia

    NASA Astrophysics Data System (ADS)

    Elburg, Marlina A.; Andersen, Tom; Bons, Paul D.; Weisheit, Anett; Simonsen, Siri L.; Smet, Ingrid

    2012-10-01

    The Mount Painter and Mount Babbage Inliers (South Australia) are largely composed of Mesoproterozoic A-type granitoids that intruded marginally older metasediments. Metasomatic activity has had a pronounced influence on the granites in the southerly Mt Painter Inlier. U-Pb dating and Hf isotope ratios of zircons from granites and hyperaluminous rocks show the latter to be heavily metasomatised equivalents of the granitoids. Similar metasomatic processes are likely to have been responsible for the formation of Fe-oxide-U-REE ores. These ores formed more than 1100 Ma after intrusion of the Mesoproterozoic A-type granites, and elemental remobilisation may have been associated with a new phase of granitoid magmatism around 455 Ma. The ferroan and incompatible element-rich nature of A-type granites makes them a suitable source for ores that can be tapped whenever thermal and fluid conditions are favourable.

  20. Multiseasonal and geobotanical approach in remote detection of greisenization areas in the Serra da Pedra Branca Granite, Goias State, Brazil

    NASA Technical Reports Server (NTRS)

    Parada, N. D. J. (Principal Investigator); Almeidafilho, R.

    1983-01-01

    Multiseasonal analysis of LANDSAT multispectral images in CCT format permitted the mapping of lithologic facies in the Pedra Branca Granite, using geobotanical associations, which occur in the form of variations in the density of cerrado vegetation, as well as the predominance of certain distinctive vegetation species. Dry season images did not show very good results in lithological differentiation due to anomalous illumination conditions related to the low solar elevation and the homogeneity in the vegetation cover, specially the grasses that become dry during this season. Rainy season image, on the other hand, allowed the separation of the lithological types, a fact that can be attributed to a greater differentiation among the geobotanical associations. As a result of this study, the muscovite-granite facies with greisenization zones, which are lithological indicators of important tin mineralization within the Serra da Pedra Branca Granite, were mapped. This methodology can be sucessfully applied to similar known granite bodies elsewhere in the Tin Province of Goias.

  1. Characterisation of Australian Verdelho wines from the Queensland Granite Belt region.

    PubMed

    Sonni, Francesca; Moore, Evan G; Chinnici, Fabio; Riponi, Claudio; Smyth, Heather E

    2016-04-01

    Verdelho is a white-grape-vine, growing well in the Granite Belt region of Queensland. Despite its traditional use in Madeira wine production, there is scant literature on the flavour characteristics of this variety as a dry wine. In this work, for the first time, volatile compounds of Verdelho wines from the Granite Belt have been isolated by solid phase extraction (SPE), and analysed using gas chromatography-mass spectrometry (GC-MS). A corresponding sensory characterisation of this distinctive wine style has also been investigated, using sensory descriptive analysis. Chemical compounds that mostly contribute to the flavour of these wines were related to fruity sweet notes (ethyl esters and acetates), grassy notes (3-hexenol), floral aromas (2-phenylethanol and β-linalool) and cheesy aromas (fatty acids). Sensory analysis confirmed that the Verdelho wines were characterised by fruity aroma attributes, especially "tree-fruit" and "rockmelon", together with "herbaceous", while significant differences in the other attributes were found. PMID:26593603

  2. Uranium mineralization in the two mica granite of gabal Ribdab area, South Eastern Desert, Egypt.

    PubMed

    Ibrahim, M E; Saleh, G M; Abd El-Naby, H H

    2001-12-01

    Among the different rock units in the Gabal Ribdab area, the two-mica leucogranite and muscovite pegmatitic granite are the most favourable host rocks for uranium and thorium mineralization. The muscovite pegmatitic granite shows evidence of post-magmatic alteration, e.g. Na- and K-metasomatism, whereas the two-mica leucogranite could be regarded as being fresh. The spectrometric survey revealed the presence of three enriched zones with a maximum eU content of 140 ppm and the maximum eTh is 36 ppm. Uranophane, zippeite and becquerelite are the most abundant uranium minerals. The origin of these secondary minerals is mainly related to alteration of primary minerals by the action of oxidizing fluids, mobilization of uranium and then redeposition in other forms. Redistribution by circulating meteoric waters might have taken place.

  3. Natural radioactivity and evaluation of effective dose equivalent of granites in Turkey.

    PubMed

    Osmanlioglu, Ahmet Erdal

    2006-01-01

    Annual effective dose equivalent due to natural gamma radiation from (238)U, (232)Th and (40)K have been evaluated from granites in Turkey. Forty samples were taken for spectrometric analysis. Specific concentrations of (238)U, (232)Th and (40)K in granite samples were determined. Spectroscopy system was used with 1.8 keV (FWHM) coaxial high purity germanium (HPGe) detector. Average values of concentrations of (238)U, (232)Th and (40)K were detected at 15.85, 33.76 and 359 Bq kg(-1), respectively. The average value of radon varies from 0.073 to 0.185 Bq m(-2) h(-1) exhalation depends on the specific concentration of uranium. The dose rate due to this highest activity which have been evaluated by a Monte Carlo transport calculations does not exceed 0.4 mSv a(-1).

  4. Monitoring ground anchor using non-destructive ground anchor integrity test (NDT-GRANIT)

    SciTech Connect

    Robbany, Z. Handayani, G.

    2015-09-30

    Monitoring at ground anchor commonly uses a pull out test method, therefor we developing a non-destructive ground anchor integrity testing (NDT-GRANIT). NDT-GRANIT using the principle of seismic waves that have been modified into form of sweep signal, the signal will be demodulated, filtered, and Fourier transformation (inverse discrete Fourier transform) so the data can be interpreted reflected wave from the ground anchor. The method was applied to determine whether the ground anchor still gripped in the subsurface by looking the attenuation of the wave generated sources. From the result we can see that ground anchor does not grip. To validate the results of the comparison method of measurement used pile integrity test.

  5. Effects of temperature and sliding rate on frictional strength of granite

    USGS Publications Warehouse

    Lockner, D.A.; Summers, R.; Byerlee, J.D.

    1986-01-01

    Layers of artificial granite gouge have been deformed on saw-cut granite surfaces inclined 30?? to the sample axes. Samples were deformed at a constant confining pressure of 250 MPa and temperatures of 22 to 845??C. The velocity dependence of the steady-state coefficient of friction (??ss) was determined by comparing sliding strengths at different sliding rates. The results of these measurements are consistent with those reported by Solberg and Byerlee (1984) at room temperature and Stesky (1975) between 300 and 400??C. Stesky found that the slip-rate dependence of (??ss) increased above 400??C. In the present study, however, the velocity dependence of (??ss) was nearly independent of temperature. ?? 1986 Birkha??user Verlag.

  6. New insights into the origin of two contrasting Himalayan granite belts

    NASA Astrophysics Data System (ADS)

    Harrison, T. Mark; Lovera, Oscar M.; Grove, Marty

    1997-10-01

    The two parallel belts of Miocene granite that extend along much of the Himalaya differ in age, petrogenesis, and emplacement style. We suggest that their origin is linked to shear heating on a continuously active decollement that cuts through previously metamorphosed Indian supracrustal rocks that were transformed into basement during the initial stages of the Indian-Asian collision. Numerical simulations assuming a shear stress of 30 MPa indicate that initiation of slip on the Himalayan thrust at 24 Ma could trigger discontinuous melting reactions leading to formation of the High Himalayan granite chain from 24 to 20 Ma and the North Himalayan belt from 18 to 12 Ma. This model result agrees well with observation as do model predictions regarding emplacement style and location.

  7. Characterisation of Australian Verdelho wines from the Queensland Granite Belt region.

    PubMed

    Sonni, Francesca; Moore, Evan G; Chinnici, Fabio; Riponi, Claudio; Smyth, Heather E

    2016-04-01

    Verdelho is a white-grape-vine, growing well in the Granite Belt region of Queensland. Despite its traditional use in Madeira wine production, there is scant literature on the flavour characteristics of this variety as a dry wine. In this work, for the first time, volatile compounds of Verdelho wines from the Granite Belt have been isolated by solid phase extraction (SPE), and analysed using gas chromatography-mass spectrometry (GC-MS). A corresponding sensory characterisation of this distinctive wine style has also been investigated, using sensory descriptive analysis. Chemical compounds that mostly contribute to the flavour of these wines were related to fruity sweet notes (ethyl esters and acetates), grassy notes (3-hexenol), floral aromas (2-phenylethanol and β-linalool) and cheesy aromas (fatty acids). Sensory analysis confirmed that the Verdelho wines were characterised by fruity aroma attributes, especially "tree-fruit" and "rockmelon", together with "herbaceous", while significant differences in the other attributes were found.

  8. Sedimentology and Stratigraphy of the Granite Wash: Contact Rapids and Keg River Sandstone (Red Earth Area)

    NASA Astrophysics Data System (ADS)

    Balshaw, Kevin Ewart

    The Granite Wash is comprised of diachronous, Cambrian to Devonian sandstone deposits, which include the Devonian Contact Rapids and Keg River sandstones of which this study will focus. Prolific oil production from the Granite Wash has fueled exploration since the 1950s and as a result substantial core and wireline data is available. Mapping of the Precambrian subcrop suggests that palaeo-highs, known as inselbergs, strongly influenced sedimentation transport, volume, rate and ultimately preservation after marine transgression. Several distinct surfaces identified from wireline data and cores indicate an overall marine transgression throughout Keg River time. The facies observed represent continental, shallow marine and sabkha environments and a climatic shift from arid to semi-arid to arid. This detailed sedimentological and stratigraphic study provided the depositional framework that allowed for palaeogeographic maps to be constructed.

  9. The ‘granite encapsulation’ route to the safe disposal of Pu and other actinides

    NASA Astrophysics Data System (ADS)

    Gibb, F. G. F.; Taylor, K. J.; Burakov, B. E.

    2008-03-01

    Waste actinides, including plutonium, present a long-term management problem and a serious security issue. Immobilisation in mineral or ceramic waste forms for interim storage is a widely proposed first step. The safest, most secure geological disposal for Pu is in very deep boreholes and we propose that the key step to combination of these immobilisation and disposal concepts is encapsulation of the waste form in cylinders of recrystallized granite. We discuss the underpinning science, focusing on experimental work, and consider implementation. Finally, we present and discuss analyses of zircon, UO 2 and Ce-doped cubic zirconia from high pressure and temperature experiments in granitic melts that demonstrate the viability of this solution and that actinides can be isolated from the environment for millions, maybe hundreds of millions, of years.

  10. Source regions of granites and their links to tectonic environment: examples from the western United States

    NASA Astrophysics Data System (ADS)

    Anthony, Elizabeth Y.

    2005-03-01

    This review, in honor of Ilmari Haapala's retirement, reflects on lessons learned from studies of three granitic systems in western North America: (1) Mesoproterozoic samples from west Texas and east New Mexico; (2) Laramide granitic systems associated with porphyry-copper deposits in Arizona; and (3) granites of the Colorado Mineral Belt. The studies elucidate relationships amongst tectonic setting, source material, and magma chemistry. Mesoproterozoic basement samples are from two different felsic suites with distinct elemental and isotopic compositions. The first suite, the "plutonic province", is dominantly magnesian, calc-alkalic to alkali-calcic, and metaluminous. It has low K 2O/Na 2O and Rb/Sr, and Nd model ages of 1.56 to 1.40 Ga. The second suite, the "Panhandle igneous complex", is magnesian, metaluminous, alkalic, and is part of the Mesoproterozoic belt of magmatism that extends from Finland to southwestern United States. Samples from the Panhandle igneous complex demonstrate three episodes of magmatism: the first pulse was intrusion of quartz monzonite at 1380 to 1370 Ma; the second was comagmatic epizonal granite and rhyolite at 1360 to 1350 Ma. Both of these rock types are high-K to slightly ultra-high-K. The third pulse at 1338 to 1330 Ma was intrusion of ultra-high-K quartz syenite. Nd model ages (1.94 to 1.52 Ga) are distinct from those of the "plutonic province" and systematically older than crystallization ages, implying a substantial crustal input to the magmas. At the Sierrita porphyry-copper deposit in the Mazatzal Province of southeastern Arizona, trace element, Sr, and Nd isotopic compositions were determined for a suite of andesitic and rhyolitic rocks (67 Ma) intruded by granodiorite and granite. Isotopic composition and chemical evolution are well correlated throughout the suite. Andesite has the least negative initial ɛNd (-4.3) and lowest 87Sr/ 86Sr i (0.7069). It is also the oldest and chemically most primitive, having low

  11. Laser ablation of iron-rich black films from exposed granite surfaces

    NASA Astrophysics Data System (ADS)

    Delgado Rodrigues, J.; Costa, D.; Mascalchi, M.; Osticioli, I.; Siano, S.

    2014-10-01

    Here, we investigated the potential of laser removal of iron-rich dark films from weathered granite substrates, which represents a very difficult conservation problem because of the polymineralic nature of the stone and of its complex deterioration mechanisms. As often occurs, biotite was the most critical component because of its high optical absorption, low melting temperature, and pronounced cleavage, which required a careful control of the photothermal and photomechanical effects to optimize the selective ablation of the mentioned unwanted dark film. Different pulse durations and wavelengths Nd:YAG lasers were tested and optimal irradiation conditions were determined through thorough analytical characterisations. Besides addressing a specific conservation problem, the present work provides information of general valence in laser uncovering of encrusted granite.

  12. Distinction between S-type and peraluminous I-type granites: Zircon versus whole-rock geochemistry

    NASA Astrophysics Data System (ADS)

    Gao, Peng; Zheng, Yong-Fei; Zhao, Zi-Fu

    2016-08-01

    Biotite and two-mica granites are common in continental crust. Although they are generally peraluminous in lithochemistry, their petrogenesis has been controversial. Because they often show a negative correlation between P2O5 and SiO2 and a positive correlation between A/CNK and SiO2, they are commonly considered as the I-type granites of metaigneous origin. However, such lithochemical consideration is not certain in view of their other geochemical characteristics. To constrain the source nature of peraluminous granites, we performed a combined study of in situ U-Pb age, O isotope, and trace element for synmagmatic and relict zircons from Triassic biotite and two-mica granites in the Nanling Range, South China. Zircon U-Pb dating yields concordant ages of 230 ± 3 to 237 ± 3 Ma for synmagmatic zircons, and 335-2379 Ma for relict zircons with two clusters at ca. 440 Ma and ca. 800 Ma, respectively. Both the synmagmatic zircons and the ~ 440 Ma relict zircons are characterized by high δ18O values of 8.8-11.4‰ and 8.6-10.3‰, respectively. In contrast, the majority of the other relict zircons show relatively low δ18O values of 5.1-7.9‰. The high δ18O values for synmagmatic zircons indicate that the Triassic granites were originated from metasedimentary sources. The two age clusters for relict zircons overlap with two episodes of granitic magmatism, respectively, in the early Paleozoic and the middle Neoproterozoic in South China, suggesting their inheritance from the metasedimentary sources. Thus, these Triassic granites were derived from partial melting of metasedimentary rocks rather than metaigneous rocks; they belong to S-type granite although their lithochemical relationships are akin to common I-type granites. As such, the zircon in situ geochemical analyses have the capacity to unravel the source nature of controversial granites. Our data indicate that fractional crystallization of heterogeneous magmas is the possible mechanism for the decoupling

  13. A study on the usage of respirators among granite quarry workers in Singapore.

    PubMed

    Chia, S E

    1989-06-01

    The frequency and correctness of respirators were studied in 5 granite quarries in Singapore involving 201 workers. The overall prevalence of usage of correct respirators was 45.8%. 10.4% of the workers were found to be using the wrong respiratory protective devices. Age, years of exposure and types of occupations were found to affect the usage of respirators. Some common reasons given by workers for not wearing the respirators were 'breathing difficulty', 'hot & sweaty', and 'respirator smells after a while'.

  14. A joint TEM-HLEM geophysical approach to borehole sitting in deeply weathered granitic terrains.

    PubMed

    Meju, M A; Fontes, S L; Ulugergerli, E U; La Terra, E F; Germano, C R; Carvalho, R M

    2001-01-01

    The accurate location of aquiferous fracture zones in granite beneath a > 50 m thick weathered mantle in semi-arid regions is a major hydrogeological problem. It is expected that the zone of intensive fracturing will be more susceptible to weathering and thus be characterized by the thickest development of saprolite, a good electrically conductive target for deep-probing electromagnetic systems. The single-loop transient electromagnetic (TEM) technique is well known to have the capability for detecting concealed steep mineralized targets in mining environments and can be adapted to this hydrogeological problem. We propose that combining the conventional frequency-domain horizontal-loop electromagnetic (HLEM) and single-loop TEM is an effective practical approach to locating concealed aquiferous fracture zones. In the supporting case studies presented here, we deployed multifrequency HLEM profiling (with 50 m transmitter-receiver separation) and TEM soundings with contiguous 10 or 20 m sided loops along the survey lines in a granitic terrain affected by deep (> 50 m) weathering in northeast Brazil. A somewhat layered structure consisting of resistive hardpan/leached zone, conductive saprolite, and resistive basement is identifiable in the typical TEM depth sounding data. We obtained coincident HLEM and TEM anomalies at all the sites, enabling a relatively straightforward selection of potential drilling positions. Simple resistivity-depth transformation of the TEM data was done for each site, yielding an approximate section from which drilling depths were estimated. All of the boreholes located were successful. Although our results appear to indicate that the single-loop TEM method could be used independently for borehole sitting in deeply weathered granitic terrains and that the weathering profile over granite can be mapped using TEM depth soundings of appropriate observational bandwidth, we recommend a joint electromagnetic approach for optimal well sitting.

  15. Example of trondhjemite genesis by means of alkali metasomatism: Rockford Granite, Alabama Appalachians

    SciTech Connect

    Drummond, M.S.; Wesolowski, D.; Ragland, P.C.; Ragland, J.

    1985-01-01

    An alternative model for trondhjemite genesis is proposed where granite is transformed to trondhjemite via infiltration by a Na-rich metamorphic fluid. The Rockford Granite serves as the case example for this process and is characterized as a synmetamorphic, peraluminous trondhjemite-granite suite. The major process operative in the conversion of granite to trondhjemite involves cation exchange of Na for K in the feldspar and mica phases through a volatile fluid medium. Whole-rock delta/sup 18/O values for the trondhjemites are negatively correlated with the atomic prop. K/Na ratio indicating a partial reequilibration of the altered granitoids with a Na- and /sup 18/O-rich metamorphically derived fluid. Biotite decomposition to an Al-epidote-paragonitic muscovite-quartz assemblage is also associated with the Na-metasomatism, as are apatite replacement by Al-epidote and secondary zircon crystallization. The replacement of magmatic phases by metasomatic phases exemplifies the chemical changes produced during infiltration metasomatism where the trondhjemites are depleted in all REE's. The timing of the infiltration metasomatism is thought to have occurred during regional metamorphism, producing a discrete fluid phase in the surrounding amphibolite-grade metasediments. Foliation planes in the granitoid apparently served as conduts for fluid flow with reaction enhanced permeability accompanying the 8% molar volume reduction during Na for K exchange in the feldspars. A model is proposed where metamorphic fluids migrated updip and along strike from their source and were buffered by the presence or absence of two feldspars in the metasediments.

  16. Origin and age of the Eisenkappel gabbro to granite suite (Carinthia, SE Austrian Alps)

    PubMed Central

    Miller, C.; Thöni, M.; Goessler, W.; Tessadri, R.

    2011-01-01

    The northern part of the Karawanken plutonic belt is a gabbro–granite complex located just north of the Periadriatic lineament near the Slovenian–Austrian border. Petrographic and geochemical studies of the Eisenkappel intrusive complex indicate that this multiphase plutonic suite developed by a combination of crystal accumulation, fractional crystallization and assimilation processes, magma mixing and mingling. The mafic rocks are alkaline and have within-plate geochemical characteristics, indicating anorogenic magmatism in an extensional setting and derivation from an enriched mantle source. The mafic melts triggered partial melting of the crust and the formation of granite. The granitic rocks are alkalic, metaluminous and have the high Fe/Fe + Mg characteristics of within-plate plutons. Temperature and pressure conditions, derived from amphibole-plagioclase and different amphibole thermobarometers, suggest that the analysed Eisenkappel gabbros crystallized at around 1000 ± 20 °C and 380–470 MPa, whereas the granitic rock crystallized at T ≤ 800 ± 20 °C and ≤ 350 MPa. Mineral-whole rock Sm–Nd analyses of two cumulate gabbros yielded 249 ± 8.4 Ma and 250 ± 26 Ma (εNd: + 3.6), garnet-whole rock Sm–Nd analyses of two silicic samples yielded well-constrained ages of 238.4 ± 1.9 Ma and 242.1 ± 2.1 Ma (εNd: − 2.6). PMID:26525511

  17. Origin and interaction of some alkalic and silicic plutons in the Vermilion Granitic Complex, NE Minnesota

    SciTech Connect

    McCall, G.W.; Nabelek, P.I.; Bauer, R.L.; Glascock, M.D.

    1985-01-01

    Alkalic gabbros and tonalites comprise a significant portion of the Archaean crust in the Vermilion Granitic Complex of NE Minnesota. The origin of these and associated rocks has been modeled using major and trace element approaches. Samples of the alkalic gabbro collected from three different intrusions have similar major element, REE, and transition metal concentrations. The REE patterns of these rocks can be modeled as the result of 1% to 3% melting of an undepleted garnet herzolite mantle with REE concentrations three times that of chondrites. However, their Al/sub 2/O/sub 3//CaO ratios of 2 - 3, Sr content of 900-1400 ppm and Ba of 100 - 1600 ppm suggest that the source may have been an enriched, metasomatized mantle. The hornblendites associated with these alkalic rocks have REE patterns which are consistent with crystallization and accumulation from the gabbroic magma. Major and trace element modeling suggest that the granitic dikes which are common throughout the area may be residual liquids formed by 60% crystallization of plagioclase, biotite, hornblende and apatite from the nearby tonalites such as the Burntside of Wakemup Bay plutons. Porphyritic hornblende monzonites composed of centimeter sized hornblende crystals floating in a granitic matrix occur locally. The field relations as well as the major and trace element data are consistent with the formation of these monzonitic rocks by mixing of the granite with partially consolidated hornblendite. These results suggest a complex interaction between alkalic gabbros and tonalites involving fractionation and mixing during the development of the Archaean crust of NE Minnesota.

  18. Cesium adsorption and distribution onto crushed granite under different physicochemical conditions.

    PubMed

    Tsai, Shih-Chin; Wang, Tsing-Hai; Li, Ming-Hsu; Wei, Yuan-Yaw; Teng, Shi-Ping

    2009-01-30

    The adsorption of cesium onto crushed granite was investigated under different physicochemical conditions including contact time, Cs loading, ionic strength and temperature. In addition, the distribution of adsorbed Cs was examined by X-ray diffraction (XRD) and EDS mapping techniques. The results showed that Cs adsorption to crushed granite behaved as a first-order reaction with nice regression coefficients (R(2) > or = 0.971). Both Freundlich and Langmuir models were applicable to describe the adsorption. The maximum sorption capacity determined by Langmuir model was 80 micromol g(-1) at 25 degrees C and 10 micromol g(-1) at 55 degrees C. The reduced sorption capacity at high temperature was related to the partial enhancement of desorption from granite surface. In general, Cs adsorption was exothermic (DeltaH<0, with median of -12 kJ mol(-1)) and spontaneous (DeltaG<0, with median of -6.1 at 25 degrees C and -5.0 kJ mol(-1) at 55 degrees C). The presence of competing cations such as sodium and potassium ions in synthetic groundwater significantly reduces the Cs adsorption onto granite. The scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM/EDS) mapping method provided substantial evidences that micaceous minerals (biotite in this case) dominate Cs adsorption. These adsorbed Cs ions were notably distributed onto the frayed edges of biotite minerals. More importantly, the locations of these adsorbed Cs were coincided with the potassium depletion area, implying the displacement of K by Cs adsorption. Further XRD patterns displayed a decreased intensity of signal of biotite as the Cs loading increased, revealing that the interlayer space of biotite was affected by Cs adsorption.

  19. The effects of confining pressure and stress difference on static fatigue of granite

    NASA Technical Reports Server (NTRS)

    Kranz, R. L.

    1980-01-01

    Samples of Barre granite have been creep tested at room temperature at confining pressures up to 2 kbar. Experimental procedures are described and the results of observations and analysis are presented. It is noted that the effect of pressure is to increase the amount of inelastic deformation the rock can sustain before becoming unstable. It is also shown that this increased deformation is due to longer and more numerous microcracks.

  20. Indoor radon risk associated to post-tectonic biotite granites from Vila Pouca de Aguiar pluton, northern Portugal.

    PubMed

    Martins, L M O; Gomes, M E P; Teixeira, R J S; Pereira, A J S C; Neves, L J P F

    2016-11-01

    At Vila Pouca de Aguiar area, northern Portugal, crops out a post-tectonic Variscan granite pluton, related with the Régua-Vila Real-Verín fault zone, comprising three types of biotite granites. Among these granites, PSG granite yield the highest average contents of U, probably due to its enrichment in accessory U-bearing minerals such as zircon. In the proximity of faults and joints, these granites are often affected by different degrees of hydrothermal alteration, forming reddish altered rocks, commonly known as "episyenites". These altered rocks are probably associated to the occurrence of hydrothermal processes, which led to uranium enrichment in the most advanced stages of episyenitization. In these granites, both average gamma absorbed dose rates in outdoor and indoor air are higher than those of the world average. Furthermore, even in the worst usage scenario, all these granites can be used as a building material, since their annual effective doses are similar to the limit defined by the European Commission. The geometric mean of radon activity of 91 dwellings located at the Vila Pouca de Aguiar pluton is 568Bqm(-3), exceeding that of other northern Portuguese granites. Measurements carried out during a winter season, indicate that 62.6% of the analysed dwellings yield higher indoor radon average values than the Portuguese legislation limit (400Bqm(-3)), and annual effective doses due higher than the world's average value (1.2mSvy(-1)). The interaction of geogenic, architectural and anthropogenic features is crucial to explain the variance in the geometric mean of radon activity of dwellings from Vila Pouca de Aguiar pluton, but the role of geologic faults is probably the most important decisive factor to increase the indoor radon concentration in dwellings. Hence, the development of awareness campaigns in order to inform population about the incurred radiological risks to radon exposure are highly recommended for this specific area. PMID:27448957

  1. Indoor radon risk associated to post-tectonic biotite granites from Vila Pouca de Aguiar pluton, northern Portugal.

    PubMed

    Martins, L M O; Gomes, M E P; Teixeira, R J S; Pereira, A J S C; Neves, L J P F

    2016-11-01

    At Vila Pouca de Aguiar area, northern Portugal, crops out a post-tectonic Variscan granite pluton, related with the Régua-Vila Real-Verín fault zone, comprising three types of biotite granites. Among these granites, PSG granite yield the highest average contents of U, probably due to its enrichment in accessory U-bearing minerals such as zircon. In the proximity of faults and joints, these granites are often affected by different degrees of hydrothermal alteration, forming reddish altered rocks, commonly known as "episyenites". These altered rocks are probably associated to the occurrence of hydrothermal processes, which led to uranium enrichment in the most advanced stages of episyenitization. In these granites, both average gamma absorbed dose rates in outdoor and indoor air are higher than those of the world average. Furthermore, even in the worst usage scenario, all these granites can be used as a building material, since their annual effective doses are similar to the limit defined by the European Commission. The geometric mean of radon activity of 91 dwellings located at the Vila Pouca de Aguiar pluton is 568Bqm(-3), exceeding that of other northern Portuguese granites. Measurements carried out during a winter season, indicate that 62.6% of the analysed dwellings yield higher indoor radon average values than the Portuguese legislation limit (400Bqm(-3)), and annual effective doses due higher than the world's average value (1.2mSvy(-1)). The interaction of geogenic, architectural and anthropogenic features is crucial to explain the variance in the geometric mean of radon activity of dwellings from Vila Pouca de Aguiar pluton, but the role of geologic faults is probably the most important decisive factor to increase the indoor radon concentration in dwellings. Hence, the development of awareness campaigns in order to inform population about the incurred radiological risks to radon exposure are highly recommended for this specific area.

  2. Adsorption, desorption and fractionation of As(V) on untreated and mussel shell-treated granitic material

    NASA Astrophysics Data System (ADS)

    Seco-Reigosa, N.; Cutillas-Barreiro, L.; Nóvoa-Muñoz, J. C.; Arias-Estévez, M.; Álvarez-Rodríguez, E.; Fernández-Sanjurjo, M. J.; Núñez-Delgado, A.

    2014-12-01

    As(V) adsorption and desorption were studied on granitic material, coarse and fine mussel shell, and granitic material amended with 12 and 24 t ha-1 fine shell, investigating the effect of different As(V) concentrations and different pH, as well as the fractions where the adsorbed As(V) was retained. As(V) adsorption was higher on fine than on coarse shell. Mussel shell amendment increased As(V) adsorption on granitic material. Adsorption data corresponding to the un-amended and shell-amended granitic material were satisfactory fitted to the Langmuir and Freundlich models. Desorption was always < 19% when the highest As(V) concentration (100 mg L-1) was added. Regarding the effect of pH, the granitic material showed its highest adsorption (66%) at pH < 6, and it was lower as pH increased. Fine shell presented notable adsorption in the whole pH range between 6 and 12, with a maximum of 83%. The shell-amended granitic material showed high As(V) adsorption, with a maximum (99%) at pH near 8, but decreasing as pH increased. Desorption varying pH was always < 26%. In the granitic material, desorption increased progressively when pH increased from 4 to 6, contrary to what happened to mussel shell. Regarding the fractionation of the adsorbed As(V), most of it was in the soluble fraction (weakly bound). Globally, the granitic material did not show high As(V) retention capacity, which implies risks of water pollution and transfer to the food chain; however, the mussel shell amendment increased As(V) retention, making this practice recommendable.

  3. Adsorption, desorption and fractionation of As(V) on untreated and mussel shell-treated granitic material

    NASA Astrophysics Data System (ADS)

    Seco-Reigosa, N.; Cutillas-Barreiro, L.; Nóvoa-Muñoz, J. C.; Arias-Estévez, M.; Álvarez-Rodríguez, E.; Fernández-Sanjurjo, M. J.; Núñez-Delgado, A.

    2015-03-01

    As(V) adsorption and desorption were studied on granitic material, coarse and fine mussel shell and granitic material amended with 12 and 24 t ha-1 fine shell, investigating the effect of different As(V) concentrations and different pH as well as the fractions where the adsorbed As(V) was retained. As(V) adsorption was higher on fine than on coarse shell. Mussel shell amendment increased As(V) adsorption on granitic material. Adsorption data corresponding to the unamended and shell-amended granitic material were satisfactory fitted to the Langmuir and Freundlich models. Desorption was always <19% when the highest As(V) concentration (100 mg L-1) was added. Regarding the effect of pH, the granitic material showed its highest adsorption (66%) at pH <6, and it was lower as pH increased. Fine shell presented notable adsorption in the whole pH range between 6 and 12, with a maximum of 83%. The shell-amended granitic material showed high As(V) adsorption, with a maximum (99%) at pH near 8, but decreased as pH increased. Desorption varying pH was always <26%. In the granitic material, desorption increased progressively when pH increased from 4 to 6, contrary to what happened to mussel shell. Regarding the fractionation of the adsorbed As(V), most of it was in the soluble fraction (weakly bound). The granitic material did not show high As(V) retention capacity, which could facilitate As(V) transfer to water courses and to the food chain in case of As(V) compounds being applied on this material; however, the mussel shell amendment increased As(V) retention, making this practice recommendable.

  4. Darkfield reflection visible microspectroscopy equipped with a color mapping system of a brown altered granite.

    PubMed

    Onga, Chie; Nakashima, Satoru

    2014-01-01

    Visible darkfield reflectance spectroscopy equipped with a color mapping system has been developed and applied to a brown-colored Rokko granite sample. Sample reflectance spectra converted to Kubelka-Munk (KM) spectra show similar features to goethite and lepidocrocite. Raman microspectroscopy on the granite sample surface confirms the presence of these minerals. Here, L*a*b* color values (second Commission Internationale d'Eclairage [CIELab] 1976 color space) were determined from the sample reflection spectra. Grey, yellow, and brown zones of the granite show different L*, a*, and b* values. In the a*-b* diagram, a* and b* values in the grey and brown zones are on the lepidocrocite/ferrihydrite trends, but their values in the brown zone are larger than those in the grey zone. The yellow zone shows data points close to the goethite trend. Iron (hydr)oxide-rich areas can be visualized by means of large a* and b* values in the L*, a*, and b* maps. Although the present method has some problems and limitations, the visible darkfield reflectance spectroscopy can be a useful method for colored-material characterization. PMID:25014840

  5. Abundance and distribution of boron in the Hauzenberg (Bavaria) granite complex

    SciTech Connect

    Sauerer, A.; Troll, G. )

    1990-01-01

    Hercynian S-type granites from the Hauzenberg igneous complex show a range of boron concentration from 1 to 12 ppm. The whole-rock boron data are not significantly correlated with concentrations of other trace elements (Zr, Rb, Ba, Sr, Ni, V, Co, Cu, Zn, F); neither is boron correlated with the major elements (except with sodium) or with the differentiation index (DI). The boron budget in the rock-forming minerals (plagioclase, alkali feldspar, quartz, biotite, muscovite) of the tourmaline-free granites reveals that the highest concentrations of boron occur in muscovite, whereas the greatest amount of boron is incorporated in plagioclase (57-69%) due to its high modal amount. Boron in plagioclase increases with the extent of of sericitization (obtained by X-ray diffractometry). Muscovite in a pegmatite contains more than 50% of the total boron. The areal distribution of boron within the complex is neither uniform nor random; an increase of boron concentrations from granodioritic to granitic rocks is indicated, whereas the late differentiates are depleted in boron.

  6. Determination of trace elements in granites by inductively coupled plasma mass spectrometry.

    PubMed

    Liang, Q; Jing, H; Gregoire, D C

    2000-03-01

    Proposed is a simple and reliable method for the dissolution of granite and the determination of 38 elements by inductively coupled plasma mass spectrometry. One hundred milligrams of sample are digested with 1 ml of HF and 0.5 ml of HNO(3) in screw top PTFE-lined stainless steel bombs at 190 degrees C for 12 h. Insoluble residues are dissolved using 8 ml of 40% HNO(3) (v/v) heated to 110 degrees C for 3 h. Six granite standard reference materials (GSR-1, JG-2, G-2, NIM-G, SG-3, SG-1a) were studied. Analytical calibration was accomplished using aqueous standard solutions. Rhodium was used as an internal standard to correct for matrix effects and instrument drift. We report data for: Li, Be, Sc, V, Cr, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb, Mo, Cs, Ba, Hf, Ta, W, Pb, Th, U and 14 of the rare earth elements. The recoveries for most of these elements in granite ranged from 90 to 110%.

  7. Southern complex: geology, geochemistry, mineralogy, and mineral chemistry of selected uranium- and thorium-rich granites

    SciTech Connect

    Hoffman, M.A.

    1987-01-01

    Four major rock groups are defined in the Southern Complex: the Bell Creek Granite (BCG), the Clotted Granitoids (CGR), the Albite Granite (AGR), and the Migmatite Complex. Metatexites of the Migmatite Complex are the oldest rocks and include paleosome of a metasedimentary and metavolcanic protolith represented by Banded Iron Formation, Banded Amphibolite, and Banded Gneisses, and interlayered or crosscutting leucogranites. The CGR span the range from metatexite to diatexite and represent in-situ partial melting of metapelitic layers in the protolith during intrusion of the BCG. The BCG cuts the migmatites, is locally cut by the CGR, and was derived by partial melting of a dominantly metasedimentary protolith at some depth below the presently exposed migmatites during a regional tectonothermal event. The Albite Granite is a 2km diameter, muscovite-fluorite-columbite-bearing intrusive stock that cuts all other major units. The thorium history of the BCG is a function of the history of monazite. The thorium history of the CGR is also dominated by monazite but the thorium content of this unit cannot be entirely accounted for by original restite monazite. The uranium history of the BCG and CGR was dominated by magmatic differentiation and post magmatic, metamorphic and supergene redistributions and is largely independent of the thorium history. The thorium and uranium history of the AGR was dominated by magmatic/deuteric processes unlike the BCG and CGR.

  8. Gas chromatography applied to cultural heritage. Analysis of dark patinas on granite surfaces.

    PubMed

    Aira, N; Jurado, V; Silva, B; Prieto, B

    2007-04-13

    The formation of dark patinas has been mainly related with deposition of gases and particles, and sulphation mechanisms particularly in calcareous rocks. However, in granitic monuments located in Galicia (northwest of Spain), especially in rural areas, this origin is unlikely since granite is a very poor calcium-containing rock and the atmospheric pollution in this area is negligible. A biological origin seems to be most probable. In order to know the importance of biological and atmospheric factors in the formation of dark patinas on granitic monuments, a number of analyses using several techniques are needed. The characterization of fatty acids in patinas by gas chromatography has established clear differences among samples. Thus, all of the samples having a biological origin displayed a similar fatty acid pattern, with unsaturated fatty acids predominating, especially oleic and linoleic acids; these were followed in abundance by the branched fatty acid 18:00 anteiso, and palmitic acid. Different patterns of fatty acid allowed establishment of an anthropogenic origin of the some of the patinas analysed.

  9. RADIOACTIVITY DOSAGE OF ORNAMENTAL GRANITIC ROCKS BASED ON CHEMICAL, MINERALOGICAL AND LITHOLOGICAL DATA

    SciTech Connect

    Salas, H.T.; Nalini, H.A. Jr.; Mendes, J.C.

    2004-10-03

    One hundred samples of granitic rock were collected from granite traders in Belo Horizonte. Autoradiography, optical microscopy, diffractometry, and chemical analysis (X-ray spectrometry, X-ray fluorescence, neutron activation, gravimetry and electron probe microanalysis) were used to determine the mineral assemblages and lithotypes. Autoradiographic results for several samples showed the presence of monazite, allanite and zircon. Chemical analysis revealed concentrations of uranium of {le} 30ppm, and thorium {le} 130ppm. Higher concentrations generally correlated with high concentrations of light rare earths in silica-rich rocks of granitic composition. Calculations were made of radioactive doses for floor tiles in a standard room for samples with total concentration of uranium and thorium greater than 60ppm. On the basis of calculations of {sup 232}Th, {sup 40}K and {sup 226}Ra from Th, K and U analysis, the doses calculated were between 0.11 and 0.34 mSv/year, which are much lower than the acceptable international exposure standard of 1.0 mSv/year.

  10. Natural radioactivity in granite stones used as building materials in Iran.

    PubMed

    Asgharizadeh, F; Abbasi, A; Hochaghani, O; Gooya, E S

    2012-04-01

    Due to increasing concern about environmental radiological protection, specific radioactivity concentrations of (226)Ra, (232)Th and (40)K in different types of commonly used granite stone samples collected from the Tehran city of Iran have been determined by means of a high-resolution HPGe gamma-spectroscopy system. The activity concentrations of (232)Th, (226)Ra and (40)K in the selected granite samples ranged from 18 to 178, 6 to 160 and 556 to 1539 Bq kg(-1), respectively. The radium equivalent activities (Ra(eq)) are lower than the limit of 370 Bq kg(-1) set by NEA-OECD [Nuclear Energy Agency. Exposure to radiation from natural radioactivity in building materials. Report by NEA Group of Experts. OECD (1979)], except in two samples. The internal hazard indexes have been found well below the acceptable limit in most of the samples. Five samples of investigated commercial granite stones do not satisfy the safety criterion illustrated by UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation. Exposure from natural sources of radiation. Report to the General Assembly (1993). Applying dose criteria recently recommended by the EC [European Commission Report on Radiological Protection Principles Concerning the Natural Radioactivity of Building Materials. Radiation Protection 112 (1999)] for superficial materials, all investigated samples meet the exemption dose limit of 0.3 mSv y(-1).

  11. Darkfield reflection visible microspectroscopy equipped with a color mapping system of a brown altered granite.

    PubMed

    Onga, Chie; Nakashima, Satoru

    2014-01-01

    Visible darkfield reflectance spectroscopy equipped with a color mapping system has been developed and applied to a brown-colored Rokko granite sample. Sample reflectance spectra converted to Kubelka-Munk (KM) spectra show similar features to goethite and lepidocrocite. Raman microspectroscopy on the granite sample surface confirms the presence of these minerals. Here, L*a*b* color values (second Commission Internationale d'Eclairage [CIELab] 1976 color space) were determined from the sample reflection spectra. Grey, yellow, and brown zones of the granite show different L*, a*, and b* values. In the a*-b* diagram, a* and b* values in the grey and brown zones are on the lepidocrocite/ferrihydrite trends, but their values in the brown zone are larger than those in the grey zone. The yellow zone shows data points close to the goethite trend. Iron (hydr)oxide-rich areas can be visualized by means of large a* and b* values in the L*, a*, and b* maps. Although the present method has some problems and limitations, the visible darkfield reflectance spectroscopy can be a useful method for colored-material characterization.

  12. Spectrophotometric color measurement for early detection and monitoring of greening on granite buildings.

    PubMed

    Sanmartín, P; Vázquez-Nion, D; Silva, B; Prieto, B

    2012-01-01

    This paper addresses the detection and monitoring of the development of epilithic phototrophic biofilms on the granite façade of an institutional building in Santiago de Compostela (NW Spain), and reports a case study of preventive conservation. The results provide a basis for establishing criteria for the early detection of phototrophic colonization (greening) and for monitoring its development on granite buildings by the use of color changes recorded with a portable spectrophotometer and represented in the CIELAB color space. The results show that parameter b* (associated with changes of yellowness-blueness) provides the earliest indication of colonization and varies most over time, so that it is most important in determining the total color change. The limit of perception of the greening on a granite surface was also established in a psycho-physical experiment, as Δb*: +0.59 CIELAB units that correspond, in the present study, to 6.3 μg of biomass dry weight cm(-2) and (8.43 ± 0.24) × 10(-3) μg of extracted chlorophyll a cm(-2).

  13. Weathering pits as indicators of the relative age of granite surfaces in the Cairngorm mountains, Scotland

    USGS Publications Warehouse

    Hall, A.M.; Phillips, W.M.

    2006-01-01

    Weathering pits 1-140 cm deep occur on granite surfaces in the Cairngorms associated with a range of landforms, including tors, glacially exposed slabs, large erratics and blockfields. Pit depth is positively correlated with cosmogenic exposure age, and both measures show consistent relationships on individual rock landforms. Rates of pit deepening are non-linear and a best fit is provided by the sigmoidal function D = b1+ exp(b2+b3/t). The deepest pits occur on unmodified tor summits, where 10 Be exposure ages indicate that surfaces have been exposed to weathering for a minimum of 52-297 ka. Glacially exposed surfaces with pits 10-46 cm deep have given 10 Be exposure durations of 21-79 ka, indicating exposure by glacial erosion before the last glacial cycle. The combination of cosmogenic exposure ages with weathering pit depths greatly extends the area over which inferences can be made regarding the ages of granite surfaces in the Cairngorms. Well-developed weathering pits on glacially exposed surfaces in other granite areas are potential indicators of glacial erosion before the Last Glacial Maximum. ?? Swedish Society for Anthropology and Geography.

  14. Laser cleaning of graffiti in Rosa Porriño granite

    NASA Astrophysics Data System (ADS)

    Fiorucci, M. P.; Lamas, J.; López, A. J.; Rivas, T.; Ramil, A.

    2011-05-01

    This paper presents preliminary results in determining the optimum parameters for graffiti removal in a ornamental granite, Rosa Porriño, by means of Nd:YVO4 laser at the wavelength of 355 nm and different fluences. The spray-paints (black, blue, red and silver) tested in this work were chemically characterized by means of elemental analysis, XRF, SEM/EDX and FTIR. The assessment of cleaning and characterization of the stone substrate before and after irradiation was performed by means of optical microscopy, SEM-EDX, and confocal microscopy. The analysis of the irradiated samples showed in some cases, damage in the granite substrate associated to thermal effects. The severity and kind of damage, depends on the laser fluence delivered, the constituent mineral irradiated, and the color used to paint the stone. So, at the highest levels of fluence the laser beam is able to scratch the surface, being the depth of the grooves in the stone measured by confocal microscopy. Moreover, SEM images show the differential damage caused in mineral constituents of granite i.e., quartz, feldspars, and biotite, the latter providing to be the most affected mineral, reaching melting even at low levels of fluence. It was appreciated that the color of the spray-paint affects the results of cleaning, and observed differences could be attributed to different organic constituents in the paints or the presence of metallic particles in its composition, as occurs with silver paint.

  15. Localisation of deformation in the thermal contrast at a granite batholith margin, New Zealand

    NASA Astrophysics Data System (ADS)

    Scott, J. M.; Borcovsky, D. A.; Palin, J. M.; Toy, V. G.

    2014-07-01

    The Wainui Shear Zone is a ˜ 1.2 km wide steeply dipping ductile shear zone that is intimately associated with the western margin of a very extensive granite batholith in central New Zealand. Shear sense indicators and lineation orientations within the central high-strain portion of shear zone consistently show a reverse dip-slip east-side-up sense of motion. Shallower foliation in the margins of the shear zone is interpreted to pre-date the central high-strain zone. However, U-Pb and Ar-Ar data reveal that all ductile deformation occurred between ˜114 and 109 Ma (and probably between 114 and 111 Ma) requiring: (1) that deformation kinematics within the shear zone changed over a short time period, and (2) the shear fabrics formed immediately after emplacement of the voluminous granite batholith. The temporal and spatial link between the deformation and plutonism is hypothesised to be a result of thermal weakening of the cooler Paleozoic crust by Cretaceous granite intrusion, which promoted localisation of deformation onto the intrusive contact. Deformation was initially distributed over a wide zone but became focused into a central mylonite zone. Continental-scale shortening is recorded as a network of ductile shear zones that formed on thermal contrasts within the upper, middle and lower crust along the New Zealand Gondwana margin.

  16. Hydrothermal fluids responsible for the formation of precious minerals in the Nigerian Younger Granite Province

    NASA Astrophysics Data System (ADS)

    Abaa, S. I.

    1991-04-01

    Preliminary investigations in the Younger Granite Province of Nigeria have revealed that precious and semi-precious minerals like rubies, sapphires, emeralds, aquamarine, zircon and fluorite can be found in the region. The gem minerals are shown to have been produced either by direct deposition along fissures, veins and greisens by hydrothermal fluids or as a result of hydrothermal fluids reacting with wall-rocks. These wall rocks are either biotite granites from which the hydrothermal fluids originated or basement rocks or any other rocks which the biotite granites intrude and their residual hydrothermal fluids have invaded. The hydrothermal fluids appear to have been rich in alkalis (Na+, K+, etc.), rare elements (Be, Zr, F, REE, etc.) and siliceous. As these fluids rose through fractures and channel ways through the rocks, they either deposited the gem minerals in the fractures at the appropriate stability conditions or reacted with the wall-rocks producing the gem minerals at the expense of elements like Ca and A1 in the minerals of these rocks.

  17. Petrology and mineral chemistry of peraluminous Marziyan granites, Sanandaj-Sirjan metamorphic belt (NW Iran)

    NASA Astrophysics Data System (ADS)

    Darvishi, Esmaiel; Khalili, Mahmoud; Beavers, Roy; Sayari, Mohammad

    2015-10-01

    The Marziyan granites are located in the north of Azna and crop out in the Sanandaj-Sirjan metamorphic belt. These rocks contain minerals such as quartz, K-feldspars, plagioclase, biotite, muscovite, garnet, tourmaline and minor sillimanite. The mineral chemistry of biotite indicates Fe-rich (siderophyllite), low TiO2, high Al2O3, and low MgO nature, suggesting considerable Al concentration in the source magma. These biotites crystallized from peraluminous S-type granite magma belonging to the ilmenite series. The white mica is rich in alumina and has muscovite composition. The peraluminous nature of these rocks is manifested by their remarkably high SiO2, Al2O3 and high molar A/CNK (> 1.1) ratio. The latter feature is reflected by the presence of garnet and muscovite. All field observations, petrography, mineral chemistry and petrology evidence indicate a peraluminous, S-type nature of the Marziyan granitic rocks that formed by partial melting of metapelite rocks in the mid to upper crust possibly under vapour-absent conditions. These rocks display geochemical characteristics that span the medium to high-K and calc-alkaline nature and profound chemical features typical of syn-collisional magmatism during collision of the Afro-Arabian continental plate and the Central Iranian microplate.

  18. High-temperature microstructures and rheology of deformed granite, Erzgebirge, Bohemian Massif

    NASA Astrophysics Data System (ADS)

    Schulmann, Karel; Mlčoch, Bedřich; Melka, Radek

    1996-06-01

    Three stages of granite deformation were recognized in porphyric granitoids sheared under amphibolite facies conditions in the Erzgebirge Mts: (1) weakly deformed granite in lozenge-shaped pods, (2) S—C orthogneiss, and (3) thin zones of banded mylonites. Weakly deformed granite forms a load-bearing framework (LBF) structure in which quartz and feldspar aggregates exhibit similar strain intensities and shapes. K-feldspar deforms by fracturing and onset of dynamic recrystallization along clast margins, plagioclase recrystallizes completely and quartz shows effects of grain boundary migration recrystallization and activity of basal (a) slip. S—C orthogneiss is interpreted as an interconnected weak layer (IWL) structure with high viscosity contrast between quartz and both feldspars. Concentration of deformation into thin quartz layers is indicated by intense strain of quartz, grain size variations of recrystallized quartz and dominant prism (a) slip. Feldspars show well annealed structures and slip on (010)(001). Banded mylonite is marked by similar strain intensity of quartz and feldspar aggregates and low viscosity contrast between constituent phases. Quartz shows evidence for grain size increase and rhomb (a + c) slip. Fully recrystallized feldspars show evidence for (010)(100) slip. The whole microstructural sequence and the transitions from LBF structure to IWL structures show the dependence of microstructural evolution of different materials on the bulk strain intensity.

  19. Origin of Meter-Size Granite Basins in the Southern Sierra Nevada, California

    USGS Publications Warehouse

    Moore, James G.; Gorden, Mary A.; Robinson, Joel E.; Moring, Barry C.

    2008-01-01

    Meter-size granite basins are found in a 180-km belt extending south from the South Fork of the Kings River to Lake Isabella on the west slope of the southern Sierra Nevada, California. Their origin has long been debated. A total of 1,033 basins have been inventoried at 221 sites. The basins occur on bedrock granitic outcrops at a median elevation of 1,950 m. Median basin diameter among 30 of the basin sites varies from 89 to 170 cm, median depth is 12 to 63 cm. Eighty percent of the basin sites also contain smaller bedrock mortars (~1-2 liters in capacity) of the type used by Native Americans (American Indians) to grind acorns. Features that suggest a manmade origin for the basins are: restricted size, shape, and elevation range; common association with Indian middens and grinding mortars; a south- and west-facing aspect; presence of differing shapes in distinct localities; and location in a food-rich belt with pleasant summer weather. Volcanic ash (erupted A.D. 1240+-60) in the bottom of several of the basins indicates that they were used shortly before ~760 years ago but not thereafter. Experiments suggest that campfires built on the granite will weaken the bedrock and expedite excavation of the basins. The primary use of the basins was apparently in preparing food, including acorns and pine nuts. The basins are among the largest and most permanent artifacts remaining from the California Indian civilization.

  20. Chemical reactions accompanying fluid flow through granite held in a temperature gradient

    USGS Publications Warehouse

    Moore, Diane E.; Morrow, C.A.; Byerlee, J.D.

    1983-01-01

    Distilled water was passed at a low rate down a temperature gradient through cylinders of Barre and Westerly Granite. Temperatures ranged from 80-100??C at the outer edges of the cylinders to 250-300??C in central, drilled holes which housed the heating coils. The measured permeabilities of the granite cylinders decreased by as much as two orders of magnitude in experiments of 1-3 weeks' duration. The amount of permeability decrease varied directly with temperature and inversely with the rate of fluid flow. The compositions of the fluids discharged from the granites were functions of temperature and flow rate as well as mineral composition, with dissolved silica concentrations showing trends different from those of the other analyzed species. Fluids from experiments run at higher temperatures but at much lower initial rates of fluid flow had higher concentrations of most ions but substantially lower dissolved silica contents. In contrast, an increase in temperature at similar rates of fluid flow resulted in higher silica concentrations. In the experiments, the distilled water acquired enough dissolved materials at high temperatures to become supersaturated with respect to several minerals at the low-temperature edges of the cylinders. Some of this material, particularly silica, was deposited along grain boundaries and microfractures, causing the observed permeability decreases. The very low rates of fluid flow in some high-temperature experiments significantly increased the rates of SiO2 precipitation and reduced dissolved silica concentrations relative to other species in the discharged fluids. ?? 1983.

  1. Sources of granite magmatism in the Embu Terrane (Ribeira Belt, Brazil): Neoproterozoic crust recycling constrained by elemental and isotope (Sr-Nd-Pb) geochemistry

    NASA Astrophysics Data System (ADS)

    Alves, Adriana; Janasi, Valdecir de Assis; Campos Neto, Mario da Costa

    2016-07-01

    Whole rock elemental and Sr-Nd isotope geochemistry and in situ K-feldspar Pb isotope geochemistry were used to identify the sources involved in the genesis of Neoproterozoic granites from the Embu Terrane, Ribeira Belt, SE Brazil. Granite magmatism spanned over 200 Ma (810-580 Ma), and is dominated by crust-derived relatively low-T (850-750 °C, zircon saturation) biotite granites to biotite-muscovite granites. Two Cryogenian plutons show the least negative εNdt (-8 to -10) and highest mg# (30-40) of the whole set. Their compositions are strongly contrasted, implying distinct sources for the peraluminous (ASI ∼ 1.2) ∼660 Ma Serra do Quebra-Cangalha batholith (metasedimentary rocks from relatively young upper crust with high Rb/Sr and low Th/U) and the metaluminous (ASI = 0.96-1.00) ∼ 630 Ma Santa Catarina Granite. Although not typical, the geochemical signature of these granites may reflect a continental margin arc environment, and they could be products of a prolonged period of oceanic plate consumption started at ∼810 Ma. The predominant Ediacaran (595-580 Ma) plutons have a spread of compositions from biotite granites with SiO2 as low as ∼65% (e.g., Itapeti, Mauá, Sabaúna and Lagoinha granites) to fractionated muscovite granites (Mogi das Cruzes, Santa Branca and Guacuri granites; up to ∼75% SiO2). εNdT are characteristically negative (-12 to -18), with corresponding Nd TDM indicating sources with Paleoproterozoic mean crustal ages (2.0-2.5 Ga). The Guacuri and Santa Branca muscovite granites have the more negative εNdt, highest 87Sr/86Srt (0.714-0.717) and lowest 208Pb/206Pb and 207Pb/206Pb, consistent with an old metasedimentary source with low time-integrated Rb/Sr. However, a positive Nd-Sr isotope correlation is suggested by data from the other granites, and would be consistent with mixing between an older source predominant in the Mauá granite and a younger, high Rb/Sr source that is more abundant in the Lagoinha granite sample. The

  2. Predicted indoor radon concentrations from a Monte Carlo simulation of 1,000,000 granite countertop purchases.

    PubMed

    Allen, J G; Zwack, L M; MacIntosh, D L; Minegishi, T; Stewart, J H; McCarthy, J F

    2013-03-01

    Previous research examining radon exposure from granite countertops relied on using a limited number of exposure scenarios. We expanded upon this analysis and determined the probability that installing a granite countertop in a residential home would lead to a meaningful radon exposure by performing a Monte Carlo simulation to obtain a distribution of potential indoor radon concentrations attributable to granite. The Monte Carlo analysis included estimates of the probability that a particular type of granite would be purchased, the radon flux associated with that type, the size of the countertop purchased, the volume of the home where it would be installed and the air exchange rate of that home. One million countertop purchases were simulated and 99.99% of the resulting radon concentrations were lower than the average outdoor radon concentrations in the US (14.8 Bq m(-3); 0.4  pCi l(-1)). The median predicted indoor concentration from granite countertops was 0.06 Bq m(-3) (1.59 × 10(-3) pCi l(-1)), which is over 2000 times lower than the US Environmental Protection Agency's action level for indoor radon (148 Bq m(-3); 4 pCi l(-1)). The results show that there is a low probability of a granite countertop causing elevated levels of radon in a home. PMID:23295242

  3. Age, duration of formation, and geotectonic position of the Zavitaya lithium granite-pegmatite system, Eastern Transbaikalia

    NASA Astrophysics Data System (ADS)

    Zagorsky, V. Ye.; Shokalsky, S. P.; Sergeev, S. A.

    2015-01-01

    The Zavitaya granite-pegmatite system with a lithium deposit is localized in the northern marginal part of the Onon terrane (Aginskii massif) and ajoins to the Ingoda-Shilka branch of the Mongol-Okhotsk suture in the south. This paper presents the first U-Pb (SHRIMP) age of granites and barren and spodumene pegmatites of the Zavitaya field. The Zavitaya polychronous granite-pegmatite system evolved through 40 million years: porphyritic biotite granites (169.0 ± 3 Ma), two mica granites-leucogranites (147.5 ± 3.1 Ma), muscovite leucogranites (140.0 ± 3.0 Ma), barren pegmatites (139.6 ± 3.1 Ma), and lithium spodumem pegmatites (129.6 ± 2.7 Ma). The formation of the system coincides with the change in geodynamic regimes of the region at the Middle Jurassic-Early Cretaceous boundary: the age of the early granites of the system and spodumene pegmatites corresponds to the termination of collision and to the beginning of the Early Cretaceous rifting, respectively.

  4. Relations of zoned pegmatites to other pegmatites, granite, and metamorphic rocks in the southern Black Hills, South Dakota

    USGS Publications Warehouse

    Norton, J.J.; Redden, J.A.

    1990-01-01

    The pegmatite field and the Harney Peak Granite of the southern Black Hills, South Dakota, form an igneous system that progresses from slightly biotitic muscovite granite through layered pegmatitic granite, with alternating sodic and potassic rocks, to simple plagioclase-quartz-perthite pegmatites, and on to zoned pegmatites. Most of the country rocks are Lower Proterozoic mica schists. At 1700 Ga, intrusion of the Harney Peak Granite created a large dome in these rocks, a thermal aureole with a staurolite, a first sillimanite isograd, and a small area of metamorphism above the second sillimanite isograd. The zoned pegmatites have a strong tendency to occur in clusters, and the types of pegmatites are different in different clusters. A less obvious tendency is a regional zonation in which rare-mineral pegmatites become more abundant and muscovite pegmatites less abundant toward the outskirts of the region. The composition of the granite indicates that its magma originated by partial melting of metasedimentary mica schists similar to those at the present surface. The pegmatitic nature of most of the granite probably reflects exsolution of an aqueous phase. -from Authors

  5. Re-examination of models for the origin of granite-rhyolite provinces in the midcontinent region, USA

    SciTech Connect

    Van Schmus, W.R. . Dept. of Geology)

    1993-03-01

    New isotopic data for the 1.47 Ga Eastern Granite-Rhyolite Province and the 1.37 Ga Southern Granite-Rhyolite Province require re-examination of models for the origin of these suites of rock. For the most part, eNd(t) values for the granite-rhyolite provinces and A-type plutons intrusive into adjacent Early proterozoic basement are compatible with origin through melting of 1.8 Ga continental crust. However, new data shows that southeastern parts of the granite-rhyolite provinces yield positive [var epsilon]Nd(t) data is an E-W trending belt of intermediate values in northern Oklahoma; [var epsilon]Nd(t) data south of this belt, in s. Oklahoma, are equivalent to that in Kansas and Nebraska, reflecting cal 1.8 Ga lower crust. The granite-rhyolite provinces are not related to any well defined tectonic event, and they have commonly been referred to as anorogenic. The thermal event responsible for producing the silicic melts may have been associated with an extensional regime, in view of the a-type character of the granites.

  6. Weathering-Associated Bacteria from the Damma Glacier Forefield: Physiological Capabilities and Impact on Granite Dissolution ▿

    PubMed Central

    Frey, Beat; Rieder, Stefan R.; Brunner, Ivano; Plötze, Michael; Koetzsch, Stefan; Lapanje, Ales; Brandl, Helmut; Furrer, Gerhard

    2010-01-01

    Several bacterial strains isolated from granitic rock material in front of the Damma glacier (Central Swiss Alps) were shown (i) to grow in the presence of granite powder and a glucose-NH4Cl minimal medium without additional macro- or micronutrients and (ii) to produce weathering-associated agents. In particular, four bacterial isolates (one isolate each of Arthrobacter sp., Janthinobacterium sp., Leifsonia sp., and Polaromonas sp.) were weathering associated. In comparison to what was observed in abiotic experiments, the presence of these strains caused a significant increase of granite dissolution (as measured by the release of Fe, Ca, K, Mg, and Mn). These most promising weathering-associated bacterial species exhibited four main features rendering them more efficient in mineral dissolution than the other investigated isolates: (i) a major part of their bacterial cells was attached to the granite surfaces and not suspended in solution, (ii) they secreted the largest amounts of oxalic acid, (iii) they lowered the pH of the solution, and (iv) they formed significant amounts of HCN. As far as we know, this is the first report showing that the combined action of oxalic acid and HCN appears to be associated with enhanced elemental release from granite, in particular of Fe. This suggests that extensive microbial colonization of the granite surfaces could play a crucial role in the initial soil formation in previously glaciated mountain areas. PMID:20525872

  7. Elemental analysis of granite by instrumental neutron activation analysis (INAA) and X-ray fluorescence analysis (XRF).

    PubMed

    El-Taher, A

    2012-01-01

    The instrumental neutron activation analysis technique (INAA) was used for qualitative and quantitative analysis of granite samples collected from four locations in the Aswan area in South Egypt. The samples were prepared together with their standards and simultaneously irradiated in a neutron flux of 7×10(11)n/cm(2)s in the TRIGA Mainz research reactor. Gamma-ray spectra from an hyper-pure germanium detector were analyzed. The present study provides the basic data of elemental concentrations of granite rocks. The following elements have been determined Na, Mg, K, Fe, Mn, Sc, Cr, Ti, Co, Zn, Ga, Rb, Zr, Nb, Sn, Ba, Cs, La, Ce, Nd, Sm, Eu, Yb, Lu, Hf, Ta, Th and U. The X-ray fluorescence (XRF) was used for comparison and to detect elements, which can be detected only by XRF such as F, S, Cl, Co, Cu, Mo, Ni, Pb, Se and V. The data presented here are our contribution to understanding the elemental composition of the granite rocks. Because there are no existing databases for the elemental analysis of granite, our results are a start to establishing a database for the Egyptian granite. It is hoped that the data presented here will be useful to those dealing with geochemistry, granite chemistry and related fields.

  8. Predicted indoor radon concentrations from a Monte Carlo simulation of 1,000,000 granite countertop purchases.

    PubMed

    Allen, J G; Zwack, L M; MacIntosh, D L; Minegishi, T; Stewart, J H; McCarthy, J F

    2013-03-01

    Previous research examining radon exposure from granite countertops relied on using a limited number of exposure scenarios. We expanded upon this analysis and determined the probability that installing a granite countertop in a residential home would lead to a meaningful radon exposure by performing a Monte Carlo simulation to obtain a distribution of potential indoor radon concentrations attributable to granite. The Monte Carlo analysis included estimates of the probability that a particular type of granite would be purchased, the radon flux associated with that type, the size of the countertop purchased, the volume of the home where it would be installed and the air exchange rate of that home. One million countertop purchases were simulated and 99.99% of the resulting radon concentrations were lower than the average outdoor radon concentrations in the US (14.8 Bq m(-3); 0.4  pCi l(-1)). The median predicted indoor concentration from granite countertops was 0.06 Bq m(-3) (1.59 × 10(-3) pCi l(-1)), which is over 2000 times lower than the US Environmental Protection Agency's action level for indoor radon (148 Bq m(-3); 4 pCi l(-1)). The results show that there is a low probability of a granite countertop causing elevated levels of radon in a home.

  9. Origin of the fluorine-rich highly differentiated granites from the Qianlishan composite plutons (South China) and implications for polymetallic mineralization

    NASA Astrophysics Data System (ADS)

    Chen, Bin; Ma, Xinghua; Wang, Zhiqiang

    2014-10-01

    Many composite granite plutons occur in South China, accompanied by large-scale polymetallic mineralization. Each composite pluton is composed of main-phase granite and late-stage highly differentiated granite. Traditionally, the highly differentiated granite is thought to be residual melt of the former via fractionation, and ore-forming materials and fluids are from granite magma itself. We propose a different model for the origin of the granites and related mineralization, based on petrological and geochemical studies on the Qianlishan composite plutons that host the supergiant Shizhuyuan W-Sn-Bi-Mo deposit. The main-phase granite shows features of normal granites, while the highly differentiated granite is characterized by F-rich, water-deficient, low fO2, alkalinity, REE tetrad effect, and modified behavior of some trace elements, e.g., very high K/Ba and low K/Rb and Zr/Hf ratios. We suggest that the parent magma of the highly differentiated granite was derived from melting of dominantly lower crustal rocks, triggered by underplating of a new pulse of basaltic magmas; small amounts of basaltic magmas and volatiles such as fluorine were involved in the source of the granite. Addition of fluorine lowered the solidus temperature and viscosity of granite magma, and thus prolonged the process of magma evolution. This resulted in extreme fractional crystallization, and intense interaction between melt and circulating waters from country rocks, forming the unusual geochemical features of the granite. The high temperature circulating waters, along with metamorphic fluids released from deep crustal rocks, subsequently, extract ore-forming metals from country rocks through forming F-bearing complexation, forming the polymetallic deposits.

  10. Highly fractionated I-type granites in NE China (I): geochronology and petrogenesis

    NASA Astrophysics Data System (ADS)

    Wu, Fu-yuan; Jahn, Bor-ming; Wilde, Simon A.; Lo, Ching-Hua; Yui, Tzen-Fu; Lin, Qiang; Ge, Wen-chun; Sun, De-you

    2003-02-01

    Northeastern (NE) China is the easternmost part of the Central Asian Orogenic Belt (CAOB), which is celebrated for its accretionary tectonics and the world's most important juvenile crust production in the Phanerozoic era. Abundant granitoids occur in the Great Xing'an, Lesser Xing'an and Zhangguangcai Ranges in NE China. This paper presents partial results of a series of studies on the granitoids from this region, aiming to understand their role in the building of new continental crust in eastern Asia. Three composite granite plutons (Xinhuatun, Lamashan and Yiershi) were chosen for geochemical and isotopic study in order to determine their emplacement ages and petrogenesis. Petrographically, they range from granodiorite (minor), monzogranite, syenogranite to alkali-feldspar granite. Quartz and perthitic feldspar are principal phases, accompanied by minor amounts of plagioclase, biotite (<5%) and other accessory minerals. In addition, many contain abundant miarolitic cavities which suggest that they were emplaced at shallow levels with extensive fractional crystallization. Geochemically, the granites are silica-rich, peraluminous and have high contents of alkalis. They invariably show enrichment in light rare earth elements (LREE) and significant negative Eu anomalies. All the granitic rocks demonstrate the characteristic negative anomalies in Ba, Nb, Sr, P, Eu, and Ti, and a positive anomaly in Pb in the spidergram. The emplacement of the Xinhuatun pluton took place at 184±4 Ma as revealed by zircon SHRIMP U-Pb data. This is also supported by the slightly younger Rb-Sr whole-rock (WR) isochron age of 173±3 Ma. A whole-rock (WR) Rb-Sr isochron age of 154±3 Ma was obtained for the Lamashan pluton, which is interpreted as close to the time of emplacement. The Yiershi pluton was intruded at about 140 Ma as evidenced by a zircon U-Pb age of 137±2 Ma and WR Rb-Sr isochron age of 143±5 Ma. Biotite-WR Rb-Sr isochrons and 40Ar/ 39Ar ages of feldspars allow us to

  11. Characterization of elemental release during microbe granite interactions at T = 28 °C

    NASA Astrophysics Data System (ADS)

    Wu, Lingling; Jacobson, Andrew D.; Hausner, Martina

    2008-02-01

    This study used batch reactors to characterize the mechanisms and rates of elemental release (Al, Ca, K, Mg, Na, F, Fe, P, Sr, and Si) during interaction of a single bacterial species ( Burkholderia fungorum) with granite at T = 28 °C for 35 days. The objective was to evaluate how actively metabolizing heterotrophic bacteria might influence granite weathering on the continents. We supplied glucose as a C source, either NH 4 or NO 3 as N sources, and either dissolved PO 4 or trace apatite in granite as P sources. Cell growth occurred under all experimental conditions. However, solution pH decreased from ˜7 to 4 in NH 4-bearing reactors, whereas pH remained near-neutral in NO 3-bearing reactors. Measurements of dissolved CO 2 and gluconate together with mass-balances for cell growth suggest that pH lowering in NH 4-bearing reactors resulted from gluconic acid release and H + extrusion during NH 4 uptake. In NO 3-bearing reactors, B. fungormum likely produced gluconic acid and consumed H + simultaneously during NO 3 utilization. Over the entire 35-day period, NH 4-bearing biotic reactors yielded the highest release rates for all elements considered. However, chemical analyses of biomass show that bacteria scavenged Na, P, and Sr during growth. Abiotic control reactors followed different reaction paths and experienced much lower elemental release rates compared to biotic reactors. Because release rates inversely correlate with pH, we conclude that proton-promoted dissolution was the dominant reaction mechanism. Solute speciation modeling indicates that formation of Al-F and Fe-F complexes in biotic reactors may have enhanced mineral solubilities and release rates by lowering Al and Fe activities. Mass-balances further reveal that Ca-bearing trace phases (calcite, fluorite, and fluorapatite) provided most of the dissolved Ca, whereas more abundant phases (plagioclase) contributed negligible amounts. Our findings imply that during the incipient stages of granite

  12. Fractured reservoir analogs: case study of paelocirculation markers on Tamariu's Granite.

    NASA Astrophysics Data System (ADS)

    Bertrand, Lionel; Legarzic, Edouard; Geraud, Yves; Diraison, Marc

    2013-04-01

    In fractured crystalline reservoirs, the grain matrix has in general a very low permeability and the fluid flow is localized in the fracture pattern. The flow in such fracture network is generally complicated to characterize, in on hand because many parameters (length, connectivity, aperture, tortuosity,…) are acting on the fluid flow, in other hand because the fractures at a reservoir scale using seismic data are not easy to characterize. In fact, the only information we have on fracture in buried reservoir are at a local scale with boreholes and at a kilometric scale with seismic. The study of field analogs is one way to establish a better comprehension of the fracture pattern between those two scales. Regional and outcrop studies on Tamariu's granite, which outcrops on the Catalonian Coastal Ranges, has permit the characterization of the faults and fractures at different scales. The faults network defines different sizes of structural blocks bordered by faults. In an unfaulted structural block, the granite exhibits a fracture network filled with hydrothermal carbonates, markers of important paleofluid circulation. These carbonates were analysed at different scales using fracture mapping, calcimetry and microscopy on thin- sections in order to define the location and the volume of the carbonates precipitation and to have an estimation of the paleo-porosity used by the fluids in the fracture network. With precise fracture maps, we analysed the principal flow direction and the nature of the hydrothermal deposits. The same maps, combined with calcimetry measurements, allow us to quantify the 2D volume of porosity used by the paleofluids. We have quantified the carbonates in different areas of percolation: the main veins, breccias cimented by carbonates, fractured granite and poorly fractured granite. The percentage of paleofluids markers reaches to 3% of the granitic rock, and the main part of them are localized in some fractured corridor composed of mains veins

  13. "Petit Granit": a Belgian limestone used in heritage, construction and sculpture.

    NASA Astrophysics Data System (ADS)

    Pereira, Dolores; Touneur, Francis; Bernáldez, Lorenzo; García Blázguez, Ana

    2014-05-01

    "Petit Granit" is a Lower Carboniferous (Tournaisian) grey-bluish crinoidal limestone that becomes shiny black when polished. The rock is known under several other names like Pierre Bleue (Blue Stone), but at the same time it should not be confused with other natural stones having a similar commercial name (e.g. Chinese Bluestone or Irish Bluestone) which are superficially similar limestones. It consists of around 96% microcrystalline calcite and a high proportion of fossils, mainly crinoids. In addition some dolomite, quartz, pyrite, marcasite and fluorite are present. Around fifteen quarries are active these days, employing almost one thousand people and thus is an important part of the natural stone economy in Belgium. "Petit Granit" has an Appellation d'Origine Locale (Local Appellation of Origin) designation since 1999. It has been extracted in several regions of South Belgium since the Middle Ages. In a sense the name is misleading because it is not an igneous rock and therefore not a true granite, but it derives from the profusion of numerous white fossil fragments in a dark carbonaceous matrix which look similar to feldspar crystals in a granitic background. The stone characterizes many façades of the urban architecture of Brussels and other Belgian cities, and since the second half of the 19th century it has been used in various countries in Europe and overseas. Its high density and uniformity mean that it takes an excellent polish and thus has versatile use as a dimension stone. "Petit Granit" has also been used widely in sculpture and architecture by several well known artists (e.g. Mateo Hernández, Michel Smolders, Tom Blatt, Elise Delbrassinne, Benoît Luyckx, Santiago Calatrava, among others). However, deterioration has been observed when it has been used for exterior purposes, and appropriate measures need to be taken to prevent this. This stone can be considered as Global Heritage Stone Resource in Europe, for both its use in construction and for

  14. Scaling the Teflon Peaks: Granite, Glaciers, and the Highest Relief in North America

    NASA Astrophysics Data System (ADS)

    Ward, D.; Anderson, R. S.; Haeussler, P. J.

    2010-12-01

    We use a combination of field observations, remote sensing, and digital elevation data to demonstrate how the topographic character of the Alaska Range (Alaska, USA) has been influenced by the exhumation of Tertiary granitic plutons among more erodible sedimentary and metamorphic rocks. Observations that the mean elevations of many tectonically active mountain ranges follow closely the elevation of the mean Cenozoic snowline or glacial equilibrium line (ELA), rather than rates of tectonic rock uplift, have led to the “glacial buzzsaw hypothesis” - that terrain raised above the ELA is rapidly denuded by glaciers. The Alaska Range stands in prominent exception to this observation. Much of the range is developed on pervasively fractured sedimentary and metamorphic rocks and has local relief of 1000-1500 m. In contrast, early and mid-Tertiary plutons of relatively intact granite support most of the range's impressive mountains (including Mt. McKinley, or Denali, the highest mountain in North America at 6194 m), with 2500-5000 m of local relief. Moreover, these plutons are where the range's modern glaciers originate, as the high peaks protrude in some cases kilometers above modern snowlines. These glaciers flow off of the plutons onto the surrounding, softer rocks, where mean summit elevations are similar to modern snowline elevations. We exploit the Denali massif and the Kichatna Mountains to its west to illustrate the direct ways in which exhumation of granite plutons affects glacial erosion, glacier long profiles, the glacial drainage network, and the effectiveness of periglacial processes. We use simple scaling calculations to explore the potential feedbacks of relief enhancement - specifically, that of avalanching from steep valley walls - on the health of the glaciers occupying the valleys, and describe ways in which peaks can be preserved and allowed to grow to great heights. Our work indicates that most of the Alaska Range has developed in accordance with

  15. Petrology and textural evolution of granites associated with tin and rare-metals mineralization at the Pitinga mine, Amazonas, Brazil

    NASA Astrophysics Data System (ADS)

    Lenharo, Sara Lais Rahal; Pollard, Peter J.; Born, Helmut

    2003-01-01

    The Água Boa and Madeira igneous complexes at the Pitinga mine were emplaced into acid volcanic rocks of the Paleoproterozoic Iricoumé Group, and host major tin, rare-metal (Zr, Nb, Ta, Y, REE) and cryolite mineralization. The igneous complexes are elongate NE-SW and each is composed of three major facies that, in order of emplacement, include porphyritic and equigranular rapakivi granite and biotite granite in both igneous complexes, followed by topaz granite in the Água Boa igneous complex (ABIC) and albite granite in the Madeira igneous complex (MIC). Rapakivi, porphyritic and granophyric textures observed in the granites are interpreted to reflect multiple stages of crystallization at different pressures (depths). Decompression during ascent shifted the magmas into the plagioclase stability field, causing partial resorption of quartz, with subsequent growth at lower pressure. Fluid saturation and separation probably occurred after final emplacement at shallow levels. Temperature and pressure estimates based on phase relations and zircon concentrations range from a maximum of 930 °C and 5 kbar for the rapakivi granites to below 650 °C and 1 kbar for the peralkaline albite granite. This suggests initial crystallization of early intrusive phases at around 15 km depth, with final emplacement of more volatile-rich crystal-mush at a depth of 0.5-1 km. Accessory minerals, including zircon, thorite, monazite, columbite-tantalite, cassiterite, bastnaesite and xenotime are present in almost all facies of the Água Boa and Madeira igneous complexes, attesting to the highly evolved character of the magmas. The presence of magnetite and/or primary cassiterite indicate crystallization under oxidizing conditions above the NNO buffer. The evolutionary sequence and Nd isotope characteristics ( TDM=2.2-2.4 Ga) of the Pitinga granites are similar to those of other Proterozoic rapakivi granites. However, petrographic, geochemical and Nd isotopic data ( ɛNd initial=-2.1 to +0

  16. The chemical and isotopic record of rock-water interaction in the Sherman Granite, Wyoming and Colorado

    USGS Publications Warehouse

    Zielinski, R.A.; Peterman, Z.E.; Stuckless, J.S.; Rosholt, J.N.; Nkomo, I.T.

    1982-01-01

    Chemical, isotopic, radiographic, and rock-leaching data are combined to describe the effects of rock-water interactions in core samples of petrographically fresh, 1.43 b.y.-old Sherman Granite. The data serve to identify sensitive indicators of incipient alteration and to estimate the degree, pathways, and timing of element mobilization. Unfractured core samples of Sherman Granite are remarkably fresh by most chemical or isotopic criteria, but incipient alteration is indicated by the abundance and distribution of uranium and the degree of radioactive equilibration of uranium with its decay products. Uranium abundances which are out of equilibrium with lead decay products indicate remobilization of a portion (3 to 60 percent) of original uranium in late Phanerozoic time. Association of uranium with minor but pervasive secondary alteration products also indicates some remobilization. The amount of apparent uranium mobility in unfractured Sherman Granite (3 to 60 percent) is small compared to the results of similar studies of Archean granites from nearby localities. Chemical and isotopic data evaluated as a function of core-sample depth suggest a uranium migrational pathway involving near-surface leaching and reconcentration at depth. Movement of solutions through the upper 200 ft (60 m) of Sherman Granite is fracture controlled, and brecciated granite shows more obvious petrographic, chemical, and isotopic evidence of alteration and multi-element redistribution. Laboratory experiments using freshly crushed Sherman Granite confirm that uranium is leached in preference to elements such as Si, Mg, Ca, and K, and that leachable uranium is situated close to the solid-liquid interface; perhaps as uranium along grain boundaries, in crystal defects, or on cleavage traces of minerals that exclude uranium from their structure. ?? 1981 Springer-Verlag.

  17. Health assessment of natural radioactivity and radon exhalation rate in granites used as building materials in Lebanon.

    PubMed

    Kobeissi, M A; El-Samad, O; Rachidi, I

    2013-03-01

    Measurements of specific activities (Bq kg(-1)) of gamma-emissions from radioactive nuclides, (238)U, (226)Ra, (214)Bi, (232)Th, (212)Pb and (40)K, contained in 28 granite types, used as building materials in indoors in Lebanon, were performed on the powdered granites. The concentration of the nuclides, (226)Ra, (232)Th and (40)K, in the granites varied from below detection level (BDL) to 494 Bq kg(-1), BDL to 157.2 Bq kg(-1) and BDL to 1776 Bq kg(-1), respectively. (226)Ra concentration equivalents, C(Raeq), were obtained and ranged between 37 and 591 Bq kg(-1), with certain values above the allowed limit of 370 Bq kg(-1). Calculated annual gamma-absorbed dose in air, D(aR), varied from 17.7 to 274.5 (nGy h(-1)). Annual effective dose, E (mSv y(-1)), of gamma radiations related to the studied granites and absorbed by the inhabitants was evaluated. E (mSv y(-1)) ranged from 0.09 to 1.35 mSv y(-1). Some granite types produced E above the allowed limit of 1 mSv y(-1) set by ICRP. Values of (222)Rn mass exhalation rate, E(M) (mBq kg(-1)h(-1))(,) in granite powder were obtained using the CR-39 detector technique. Diffusion factors, f, in 23 granite types were calculated with f ranging between (0.1 ± 0.02)×10(-2) and (6.6 ± 1.01)×10(-2).

  18. An evaluation of compliance with occupational exposure limits for crystalline silica (quartz) in ten Georgia granite sheds.

    PubMed

    Wickman, Arthur R; Middendorf, Paul J

    2002-06-01

    Since the 1920s, industrial hygiene studies have documented granite shed workers' exposures to crystalline silica, and the data from these studies have contributed to a better understanding of the relationship between silica exposures and adverse health effects, such as silicosis. The majority of these studies were conducted in the Barre, Vermont, granite sheds. However, a second major granite processing region is located in Elberton, Georgia, where approximately 1800 workers are employed in 150 granite sheds and 45 quarries. The current study reports the exposures of 40 workers in 10 granite sheds in Elberton, Georgia. The arithmetic mean exposure to silica for all monitored employees was 0.052 mg/m3. Employees were classified into one of seven job task groups. The job task group with the greatest exposure was the top polish group, which had a mean exposure of 0.085 mg/m3. Among the top polish workers, the greatest percentage of exposures above the Occupational Safety and Health Administration's permissible exposure limit (OSHA PEL) occurred among the workers who used dry grinders. Wet methods were effective in reducing these exposures to below the OSHA PEL. The mean exposure of Elberton granite shed workers was less than the OSHA PEL, but was not below the threshold limit value of the American Conference of Industrial Hygienists (ACGIH TLV), which was lowered in the year 2000 to 0.05 mg/m3. The Elberton granite shed workers provide a valuable cohort for research on the effects of exposure to crystalline silica at levels between the ACGIH TLV and the OSHA PEL. They are a relatively permanent worker population, are concentrated geographically, and have a quantitatively documented exposure to crystalline silica over the past twenty years.

  19. The chemical and isotopic record of rock-water interaction in the Sherman Granite, Wyoming and Colorado

    NASA Astrophysics Data System (ADS)

    Zielinski, R. A.; Peterman, Z. E.; Stuckless, J. S.; Rosholt, J. N.; Nkomo, I. T.

    1982-01-01

    Chemical, isotopic, radiographic, and rock-leaching data are combined to describe the effects of rock-water interactions in core samples of petrographically fresh, 1.43 b.y.-old Sherman Granite. The data serve to identify sensitive indicators of incipient alteration and to estimate the degree, pathways, and timing of element mobilization. Unfractured core samples of Sherman Granite are remarkably fresh by most chemical or isotopic criteria, but incipient alteration is indicated by the abundance and distribution of uranium and the degree of radioactive equilibration of uranium with its decay products. Uranium abundances which are out of equilibrium with lead decay products indicate remobilization of a portion (3 to 60 percent) of original uranium in late Phanerozoic time. Association of uranium with minor but pervasive secondary alteration products also indicates some remobilization. The amount of apparent uranium mobility in unfractured Sherman Granite (3 to 60 percent) is small compared to the results of similar studies of Archean granites from nearby localities. Chemical and isotopic data evaluated as a function of core-sample depth suggest a uranium migrational pathway involving near-surface leaching and reconcentration at depth. Movement of solutions through the upper 200 ft (60 m) of Sherman Granite is fracture controlled, and brecciated granite shows more obvious petrographic, chemical, and isotopic evidence of alteration and multi-element redistribution. Laboratory experiments using freshly crushed Sherman Granite confirm that uranium is leached in preference to elements such as Si, Mg, Ca, and K, and that leachable uranium is situated close to the solid-liquid interface; perhaps as uranium along grain boundaries, in crystal defects, or on cleavage traces of minerals that exclude uranium from their structure.

  20. Environmental Radioactivity : a case study in HHP granitic region of Tusham ring complex Haryana, India

    NASA Astrophysics Data System (ADS)

    Bajwa B., S.; Singh, H.; Singh, J.; Singh, S.; Sonikawade R., G.

    2010-05-01

    The paper presents the results of investigations of radon levels in the soil-gas, groundwater and indoor-air in the dwellings of the high heat producing (HHP)-granitic region of Tusham ring complex, Bhiwani District, Haryana. Radon release from soil and groundwater was found to be comparatively higher than the values observed in the nearby non-HHP/non-granitic regions of Punjab. The soil-gas and the groundwater radon concentration of HHP region of Tusham ring conmplex varies from 42.8±0.7 - 71.5±3.2 kBq m-3 with an average value of 61 kBq m-3, and 17.4±1.3 - 49.7±1.7 Bq l-1 with an average of 26.2 Bq l-1respectively, whereas in non-granitic/non-HHP regions the average value 31.5 (16.3±0.8-44.1±1.8) kBq m-3 and 7.9 (4.7±0.7-14.0±1.2) Bql-1 respectively have been observed. Indoor radon concentration in around 155 traditional dwellings in a wide range of villages situated in this HHP region has also been measured using the SSNTDs (LR-115) for two continuous years. Indoor radon levels in these dwellings in these dwellings have been found to be varying from 109 ± 80 to 1006 ± 55 Bq m-3 whereas the annual average radon values vary from 60 ±37 to 235 ±55 Bq m-3 for the dwellings of the villages studied in a non-HHP region of Amritsar District, Punjab. A positive correlation has been observed between the soil-gas and indoor radon levels particularly in the periphery of the exposed HHP rock formations, which may likely be the result of the imfluence of imbeded and exposed HHP granitic rocks and thus the active-soil formations. In the present study, uranium concentration and radon exhalation rate in the wide range of soil/rock samples collected from this region, known to be composed of acid volcanics & associated HHP granites have been estimated. For comparative analysis, the soil samples from some districts of Punjab have also been analyzed for uranium estimation and radon exhalation rate. The ‘ CAN ' technique using plastic track detector LR-115 type-II has

  1. Smolt Monitoring at the Head of Lower Granite Reservoir and Lower Granite Dam; Smolt Monitoring by Federal and Non-Federal Entities, 2001-2002 Annual Report.

    SciTech Connect

    Buettner, Edwin W.; Putnam, Scott A.

    2003-06-01

    This project monitored the daily passage of chinook salmon Oncorhynchus tshawytscha, steelhead trout O. mykiss, and sockeye salmon smolts O. nerka during the 2001 spring out-migration at migrant traps on the Snake River and Salmon River. In 2001 fish management agencies released significant numbers of hatchery chinook salmon and steelhead trout above Lower Granite Dam that were not marked with a fin clip or coded-wire tag. Generally, these fish were distinguishable from wild fish by the occurrence of fin erosion. Total annual hatchery chinook salmon catch at the Snake River trap was 11% of the 2000 numbers. The wild chinook catch was 3% of the previous year's catch. Hatchery steelhead trout catch was 49% of 2000 numbers. Wild steelhead trout catch was 69% of 2000 numbers. The Snake River trap collected 28 age-0 chinook salmon. During 2001 the Snake River trap captured zero hatchery and zero wild/natural sockeye salmon and six hatchery coho salmon O. kisutch. Differences in trap catch between years are due to fluctuations not only in smolt production, but also differences in trap efficiency and duration of trap operation associated with flow. The significant reduction in catch during 2001 was due to a reduction in hatchery chinook production (60% of 2000 release) and due to extreme low flows. Trap operations began on March 11 and were terminated on June 29. The trap was out of operation for a total of two days due to mechanical failure or debris. Hatchery chinook salmon catch at the Salmon River trap was 47% and wild chinook salmon catch was 67% of 2000 numbers. The hatchery steelhead trout collection in 2001 was 178% of the 2000 numbers. Wild steelhead trout collection in 2001 was 145% of the previous year's catch. Trap operations began on March 11 and were terminated on June 8 due to the end of the smolt monitoring season. There were no days where the trap was out of operation due to high flow or debris. The decrease in hatchery chinook catch in 2001 was due to a

  2. The nature and barium partitioning between immiscible melts - A comparison of experimental and natural systems with reference to lunar granite petrogenesis

    NASA Technical Reports Server (NTRS)

    Neal, C. R.; Taylor, L. A.

    1989-01-01

    Elemental partitioning between immiscible melts has been studied using experimental liquid-liquid Kds and those determined by analysis of immiscible glasses in basalt mesostases in order to investigate lunar granite petrogenesis. Experimental data show that Ba is partitioned into the basic immiscible melt, while probe analysis results show that Ba is partitioned into the granitic immiscible melt. It is concluded that lunar granite of significant size can only occur in a plutonic or deep hypabyssal environment.

  3. Granitoid magmatism of Alarmaut granite-metamorphic dome, West Chukotka, NE Russia

    NASA Astrophysics Data System (ADS)

    Luchitskaya, M. V.; Sokolov, S. D.; Bondarenko, G. E.; Katkov, S. M.

    2009-04-01

    Main tectonic elements of West Chukotka are Alazey-Oloy, South-Anyui and Anyui-Chukotka fold systems, formed as a result of collision between structures of North-Asian continent active margin and Chukotka microcontinent [1-3]. South-Anyui fold system, separating Alazey-Oloy and Anyui-Chukotka systems, is considered as suture zon, formed as a result of oceanic basin closing [4-6]. Continent-microcontinent collision resulted in formation of large orogen with of northern and southern vergent structures, complicated by strike-slip deformations [7, 8]. Within Anyui-Chukotka fold system several rises, where most ancient deposits (crystalline basement and Paleozoic cover of Chukotka microcontinent) are exposed, were distinguished [2, 9-11]. Later they were considered as granite-metamorphic domes [12-14]. Alarmaut dome is located at West Chukotka to the north from Bilibino city and is traced from south to north in more than 120 km. General direction of structure is discordant to prevailing NW extensions of tectonic elements of the region. Paleozoic-Triassic deposits are exposed within the Alarmaut dome: 1) D3-C1 - crystalline schists, quartz-feldspar metasandstones, quartzites, marbles (700 m) [11]; 2) C1 - marblized limestones, quartz-feldspar metasandstones, quartzites, amphibole-pyroxene crystalline schists. Limestones contain corals, indicating Visean age of deposits [11]. Metamorphism reaches amphibolite facies, maximum P-T conditions are 660°С and 5 kbar. Migmatites, indicating in situ partial melting, are observed. Intensity of deformations of Paleozoic rocks increases at the boundary with Triassic deposits [11]; in the western part of dome slices of Pz rocks are separated by blastomylonite horizons [14]. Within Alramaut dome granitoids of Lupveem batholith (central part of dome), Bystrinsky pluton (southeastern part), and small Koyvel' and Kelil'vun plutons were studied. New U-Pb SHRIMP zircon data indicate Early Cretaceous (117-112 m.a.) age of granitoids [15

  4. The role of external fluid in the Shanggusi dynamic granitic magma system, East Qinling, China: Quantitative integration of textural and chemical data

    NASA Astrophysics Data System (ADS)

    Yang, Zong-Feng; Luo, Zhao-Hua; Lu, Xin-Xiang; Huang, Fan; Chen, Bi-He; Zhou, Jiu-Long; Cheng, Li-Lu

    2014-11-01

    It is well recognized that various degrees of mantle-derived materials are incorporated in the formation of granite, and mantle-derived mafic melts are generally considered to mix with crustal felsic melt. Here, however, we provide an example of the Shanggusi leucocratic granite where external mantle-derived hydrous fluid, rather than mafic melt, might be incorporated into a nearly pure crustal granitic melt system. Field observations suggest that the Shanggusi granite consists of granite porphyry, granite dyke and granitic pegmatite and they have consistent zircon U-Pb ages and molybdenite Re-Os ages. The marginal pegmatite, interconnected miarolitic cavities, heterogeneous molybdenite mineralization and significant variation of micro-texture of the Shanggusi granite physically indicate that strong fluid activities occurred in the granitic system. Accumulation of quartz and K-feldspar and bulk-rock major element data imply that fractional crystallization played an important role in the evolution of the granitic system which, however, cannot reasonably explain the significant trace elements fractionation, non-CHARAC trace elements behavior and simultaneous concave and convex REE tetrad effect of the Shanggusi granite, but which can be best explained by the influence of external fluorine-rich hydrous fluid. Importantly, the chemical fractionation, including bulk-rock trace elements and isotopes, is closely correlated with quantitative textural parameter Lmax (the average length of the four largest quartz crystals in each sample), indicating that the vast majority of physical and chemical characteristics of the granitic system were most likely controlled by the wholesale fluid flow. The Shanggusi granite is highly siliceous (SiO2 = 74.91-79.50 wt.%, except granitic pegmatite with SiO2 = 67.41 wt.%), extremely poor in mafic minerals, and with relative homogeneous bulk-rock major element chemistry and mineralogy, which approximate experimentally pure crustal melt that

  5. A tin-mineralized topaz rhyolite dike with coeval topaz granite enclaves at Qiguling in the Qitianling tin district, southern China

    NASA Astrophysics Data System (ADS)

    Xie, Lei; Wang, Rucheng; Chen, Jun; Zhu, Jinchu; Zhang, Wenlan; Lu, Jianjun; Zhang, Rongqing

    2013-06-01

    The Qiguling topaz rhyolite is present as a dike within the Qitianling biotite granite batholith of the Nanling Range of southern China. Here, the rhyolitic dike, 4.5 m wide and 500 m long, contains enclaves of topaz granite. These rhyolites contain up to 72 wt.% SiO2, have alumina saturation index (ASI) > 1.1, and have groundmasses with estimated fluorine contents of approximately 1.5 wt.%. Textural relationships provide evidence of a quenched silicate melt that contains quartz, K-feldspar, albite, and zinnwaldite phenocrysts in a groundmass containing abundant topaz. The rhyolites in the study area are also strongly enriched in tin (90-2700 ppm), and generally have a close association between cassiterite and zinnwaldite, although cassiterite is also present as sponge-textured fills between rock-forming minerals. Granite enclaves and their hosted rhyolite have similar major geochemical compositions and mineralogies to each other. Zircon U-Pb dating indicates that the topaz rhyolite (147-150 Ma) and topaz granite enclaves (154 Ma) were formed contemporaneously, with ages that overlap within analytical uncertainty. In addition, the major and trace element compositions of the rhyolite and their granite enclaves are dissimilar to those of the hosting Qitianling biotite granite. This discovery of granite enclaves within rhyolite dikes suggests the presence of a topaz-bearing granite body at depth that may host tin mineralization. The expected hidden tin granite may be of great interest in the further exploration.

  6. Alteration and arenization processes of granitic waste rock piles from former uranium Mines in Limousin, France.

    NASA Astrophysics Data System (ADS)

    Kanzari, Aisha; Boekhout, Flora; Gérard, Martine; Galoisy, Laurence; Phrommavanh, Vannapha; Descostes, Michael

    2014-05-01

    France counts approximately 200 former uranium mines, 50 of which are located in the Limousin region. Mining activities between 1945 and 2001 have generated close to 200 000 tons of waste rocks in the Limousin, with uranium levels corresponding essentially to the geological background. Waste rock piles from three former mining sites in this region, were selected according to their age, uranium content and petrological signature. These sites are part of the two-mica granitic complex of St Sylvestre massif, formed 324 million years ago. Granitic blocks that build up the waste rock piles have experienced different processes and intensities of alteration before their emplacement at the surface. These processes are responsible for the petrological heterogeneity throughout the waste rock pile at the time of construction. It is important to make a distinction within waste rocks between natural-cut-off waste rocks and economic-cut-off waste rocks. The latter represents a minority and is linked to stock prices. Natural-cut-off waste rocks contain about 20 ppm of uranium; economic-cut-off waste rocks contain about 100 to 300 ppm of uranium. The aims of this study are to 1) assess the neo-formation of U-bearing minerals hosted by these rocks, and 2) to characterize the weathering processes since the construction of the rock piles, including both mechanical and chemical processes. The structure of the waste rocks piles, from metric blocks to boulders of tens centimeters, induces an enhanced weathering rate, compared to a granitic massif. Mechanical fracturing and chemical leaching by rainwater (arenization) of the waste rocks produce a sandy-silty alteration phase. Silty-clay weathering aureoles of submetric-granitic blocks evolving into technic soil are mainly located below growing birch trees. Sampling on the rock piles was restricted to surface rocks. Samples collected consist mainly of granites, and rare lamprophyres with a high radiometric signal, thereby especially

  7. The role of felsic microgranular enclaves on the evolution of some Neoproterozoic granite plutons in SE Brazil

    NASA Astrophysics Data System (ADS)

    Alves, Adriana; Janasi, Valdecir A.; Pereira, Giovanna

    2010-05-01

    Recent studies of granite petrogenesis are strongly influenced by the finding that mafic microgranular enclaves (mme) witness frequent and volumetrically significant contribution of mantle-derived magmas to the origin and evolution of granitic melts, be it as a heat source and/or as a source compositional diversity. On the other hand, the origin of felsic microgranular enclaves (fme) is still a matter of debate; current hypotheses consider them as fragments of chilled margins, products of protracted hybridization between invading basic magmas and resident granite mushes or products of interaction between fairly similar melts. Felsic microgranular enclaves are widespread in various granite plutons from SE Brazil, in many cases surpassing mme in size and volume. Two groups of occurrences are studied in more detail illustrate different scenarios, with and without clear connections with mafic magmas. In the Mauá and Mogi das Cruzes plutons, made up of (muscovite)-biotite monzogranite, only fme occur, and the participation of more mafic melts is not evident from field structures or from whole rock and mineral chemical/isotope data. Our preferred model relate the fme to self-mixing events, suggesting mingling/mixing between highly viscous and chemically similar felsic endmembers. In the Itu Batholith, mme enclaves occur, albeit in very different volumes, in three chemically distinct plutons, all with A-type chemical affinities, In the rapakivi Salto Pluton, fme are large (dm to meter-sized) and widespread, except in a central body of porphyry granite. Scattered cm-sized mme of variable composition, some clearly brought as inclusions in the fme, are thought to represent different stages of hybridization, as indicated by disequilibrum features common also in the host syenogranites (rapakivi texture; mafic-rimmed quartz). The enclave assemblage of the Cabreúva Pluton is similarly dominated by fme, but larger mme and small diorite occurrences are evidence that basic magmas

  8. The Paleoproterozoic Singo granite in south-central Uganda revealed as a nested igneous ring complex using geophysical data

    NASA Astrophysics Data System (ADS)

    Abdelsalam, Mohamed G.; Katumwehe, Andrew B.; Atekwana, Estella A.; Le Pera, Alan K.; Achang, Mercy

    2016-04-01

    We used high-resolution airborne magnetic and radiometric data and satellite gravity data to investigate the form of occurrence of the Paleoproterozoic Singo granite in west-central Uganda. This granitic body covers an area of ∼700 km2, intrudes Paleoproterozoic crystalline rocks and overlain by Paleoproterozoic-Mesoproterozoic sedimentary rocks, both of which belong to the Rwenzori terrane, and it is host to hydrothermally-formed economic minerals such as gold and tungsten. Our analysis provided unprecedented geometrical details of the granitic body and revealed the following: (1) the margins of the Singo granite are characterized by a higher magnetic signature compared to the interior of the granitic body as well as the surroundings. These anomalies are apparent in both the total magnetic field and horizontal derivative images and define eight overlapping ring features. (2) the depth continuation of these magnetic anomalies define outward but steeply-dipping features as indicated by the tilt images extracted from the airborne magnetic data. This is further supported by forward modeling of the magnetic and gravity data. (3) the Singo granite is characterized by relatively high and evenly-distributed equivalent concentration of Uranium (eU) and Thorium (eTh) compared to the surroundings and this is apparent in the Potassium (K)-eTh-eU radiometric ternary image. (4) the granitic body is defined by a gravity low anomaly that persisted to a depth of three km as shown by the Bouguer anomaly image and its five km upward continuation. We used these observations to identify this granitic body as a nested igneous ring complex and we refer to it as the Singo Igneous Ring Complex (SIRC). We further interpreted the eight ring structures as individual igneous ring complexes aligned in an E-W and NE-SW direction and these were developed due to repeated calderas collapse. Additionally, we interpreted the ring-shaped magnetic anomalies as due to hydrothermally-altered margins

  9. Lung function in relation to silicosis and silica exposure in granite workers.

    PubMed

    Ng, T P; Chan, S L

    1992-09-01

    Lung function tests (forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and FEV1/FVC %) were related to silica exposure and the extent of radiological opacities in a study of 206 active and 132 previously employed granite workers from two quarries. The investigations included detailed personal interviews, spirometric testing and radiographic examination of the chest. The chest X-ray films were read randomly and independently by three readers, using International Labour Office (ILO) standard films. Cumulative exposure to respirable silica (mg.m-3-yr) and total granite dust (million particles per cubic foot (mppcf-yr)) were estimated for each subject based on his years of employment at various jobs and historical and current measurements of quarry-, period- and job-specific exposures. The results suggest that chronic simple silicosis, especially for profusion category 2 and 3, was associated with significant lung function loss. As expected, mixed dust fibrosis was associated with little or no functional disturbance. Massive fibrosis was associated with significant obstructive and restrictive impairment. No additional effect of exposure to respirable silica on lung function loss was found after allowing for the presence of "silicosis". However, exposure to total dust (mppcf-yr) appeared to be associated with some lung function loss independent of silicosis. Our results indicate that chronic simple silicosis is not a benign disease; silica exposure is the primary cause, but the lung function loss in silicotics is directly attributable to the fibrotic lung disease. However, exposure to total granite dust beyond the respirable size range may separately produce additional lung function loss.

  10. External gamma-ray dose rate and radon concentration in indoor environments covered with Brazilian granites.

    PubMed

    Anjos, R M; Juri Ayub, J; Cid, A S; Cardoso, R; Lacerda, T

    2011-11-01

    Health hazard from natural radioactivity in Brazilian granites, covering the walls and floor in a typical dwelling room, was assessed by indirect methods to predict external gamma-ray dose rates and radon concentrations. The gamma-ray dose rate was estimated by a Monte Carlo simulation method and validated by in-situ measurements with a NaI spectrometer. Activity concentrations of (232)Th, (226)Ra, and (40)K in an extensive selection of Brazilian commercial granite samples measured by using gamma-ray spectrometry were found to be 4.5-450 Bq kg(-1), 4.9-160 Bq kg(-1) and 190-2029 Bq kg(-1), respectively. The maximum external gamma-ray dose rate from floor and walls covered with the Brazilian granites in the typical dwelling room (5.0 m × 4.0 m area, 2.8 m height) was found to be 120 nGy h(-1), which is comparable with the average worldwide exposure to external terrestrial radiation of 80 nGy h(-1) due to natural sources, proposed by United Nations Scientific Committee on the Effects of Atomic Radiation. Radon concentrations in the room were also estimated by a simple mass balance equation and exhalation rates calculated from the measured values of (226)Ra concentrations and the material properties. The results showed that the radon concentration in the room ventilated adequately (0.5 h(-1)) will be lower than 100 Bq m(-3), value recommended as a reference level by the World Health Organization.

  11. Magnetic Fabrics of the Cabreuva Granite, São Paulo State, SE Brazil: Preliminary Results

    NASA Astrophysics Data System (ADS)

    Abujamra, J. P.; Raposo, M. I. B.

    2015-12-01

    Magnetic fabric and rock magnetism studies were performed on the units of the 570 ± 3 Ma-old isotropic Cabreuva granite (NW of São Paulo State). This intrusion with 160 km2 is roughly elliptical in the oriental and occidental sectors whereas in the south sector it is circular. It is composed of quartz-monzodiorite, granodiorite, quartz-monzonite, monzogranite, diorite, quartz syenite and synogarnite. Magnetic fabrics were determined by applying both anisotropy of low-field magnetic susceptibility (AMS) and anisotropy of anhysteretic remanent magnetization (AARM). The two fabrics are coaxial. The parallelism between AMS and AARM tensors excludes the presence of a single domain (SD) effect on the AMS fabric of the units. Several rock-magnetism experiments performed in one specimen from each sampled unit show that for all units the magnetic susceptibility and magnetic fabrics are carried by magnetite grains. Foliations and lineations in the units were successful determined by applying magnetic methods. Most of the magnetic foliations are horizontal or steeply dipping in all units, and are roughly parallel to the foliation of the rocks which surround the granite. The magnetic lineations present mostly low plunges for the whole pluton. Thin section analysis show that rocks from the Cabreuva granite were not affected by the regional strain during and after emplacement. This evidence allows us to interpret the observed magnetic fabrics as primary in origin (magmatic) acquired when the rocks were solidified as a result of magma flow, in which horizontally plunging magnetic lineation suggests that the feeder zone is far from this area.

  12. Exploring rock fissures: does a specialized root morphology explain endemism on granite outcrops?

    PubMed Central

    Poot, Pieter; Hopper, Stephen D.; van Diggelen, Josepha M.H.

    2012-01-01

    Background and Aims Worldwide, many plant species are confined to open, shallow-soil, rocky habitats. Although several hypotheses have been proposed to explain this habitat specificity, none has been convincing. We suggest that the high level of endemism on shallow soils is related to the edaphic specialization needed to survive in these often extremely drought-prone habitats. Previous research has shown that species endemic to ironstone communities in SW Australia have a specialized root morphology that enhances their chance to access fissures in the underlying rock. Here we test the generality of these findings for species that are confined to a shallow-soil habitat that is of much greater global significance: granite outcrops. Methods We compared temporal and spatial root growth and allocation of three endemic woody perennials of SW Australian granite outcrop communities with those of congeners occurring on nearby deeper soils. Seedlings of all species were grown in 1·2 m long custom-made containers with a transparent bottom that allowed monitoring of root growth over time. Key Results The granite outcrop endemics mostly differed in a predictable way from their congeners from deeper soils. They generally invested a larger portion of their biomass in roots, distributed their roots faster and more evenly over the container and had a lower specific root length. In different species pairs the outcrop endemics achieved their apparent advantage by a different combination of the aforementioned traits. Conclusions Our results are consistent with earlier work, indicating that species restricted to different types of drought-prone shallow-soil communities have undergone similar selection pressures. Although adaptive in their own habitat in terms of obtaining access to fissures in the underlying rock, these root system traits are likely to be maladaptive in deeper soil habitats. Therefore, our results may provide an explanation for the narrow endemism of many shallow

  13. Unusual lithospheric structure beneath the Hyderabad granitic region, eastern Dharwar craton, south India

    NASA Astrophysics Data System (ADS)

    Pandey, O. P.; Agrawal, P. K.; Chetty, T. R. K.

    2002-03-01

    Using multiparametric geological and geophysical data, the evolutionary history of the lithosphere beneath the Late Archean—early Proterozoic Hyderabad granitic region (HGR) of the eastern Dharwar craton of south Indian shield has been attempted. Our study reveals that the entire granitic region and the surroundings (˜200 km×200 km) is being neotectonically uplifted possibly due to a major intrusive body situated at sub-crustal depth, leading to changes in river courses and also erosion of several kilometers (˜10 km) from its upper crustal column. Beneath this region, the Moho is elevated (32-33 km), the reduced heat flow is of the order of 28 mW/m 2 and the asthenosphere is located at shallow depths of about 124 km, i.e. far less than 200-400 km depth found in Precambrian shield areas of the globe. The cratonic mantle lithosphere beneath HGR contains a highly conductive (15 Ωm) hydrous and seismically anisotropic metasomatic zone between depth of 90 and 100 km, where the estimated temperatures could be in the range of 900-1000 °C. The surface granitic layer, containing unusually high radioactivity (5.25 μW/m 3), appears very thin probably a kilometer or so, beneath which the entire crustal column seems to be differentiated and made up of low radioactive granulite facies (?) rocks of acid to intermediate composition. Persistent episodic thermal reactivations during the last 2.6 gega years and continuous uplifting seems to have played a major role towards making its crustal column unusual.

  14. Mineralogy and Geochemistry of Granitic rocks within Lichen Hills, Outback Nunatak, Northern Victoria Land, Antarctica

    NASA Astrophysics Data System (ADS)

    KIM, T.; KIM, Y.; Lee, I.; Lee, J.; Woo, J.

    2015-12-01

    The study areas, Lichen Hills and Outback Nunatak are located in the Northern Victoria Land which is close to Pacific Ocean side of Transantarctic Mountain (TAM), Antarctica. According to the study of Zeller and Dreschoff (1990), the radioactivity values of Lichen hills and Frontier Mt. area in the Victoria Land were very high. To identify the geochemical characteristics of granitic rocks in these areas, 13 samples of Lichen Hills rocks and 4 samples of Outback Nunatak rocks are analyzed. For mineralogical study, samples were observed in macroscale as well as microscale including microscope electron probe analysis. Rock samples of Lichen Hills, Outback Nunatak are mainly leucogranite and granitic pegmatite. These rock samples are composed of quartz, k-feldspar, plagioclase, muscovite, garnet, tourmaline like granite. In SEM-EDS analysis, the observed light colored minerals show relatively high Th, U, Dy, Ce, Nb concentration. This suggests that rock samples may contain minerals such as fergusonite, monazite, thorite, allanite, karnasurtite which are considered to be REE-bearing minerals. Samples of related rocks have been analyzed in terms of major, trace and rare earth element (REE) concentrations using X-ray fluorescence (XRF) spectrometer and Inductively Coupled Plasma Mass Spectrometer (ICP-MS). As concentration of SiO2 increase, Al2O3, TiO2, Fe2O3, MgO, P2O5 concentration decrease and Na2O, K2O, MnO concentration increase. Analyzed trace elements and REE are normalized using CI Chondrite, Primitive mantle. The normalized data show that LREE are enriched compared to HREE. The distinct negative anomalies of Eu, Sr are observed, indicating that rock-forming melts are fairly processed state of fractional crystallization. It means that Th, U, Nb, Ta are much enriched in the melts.

  15. Stream water chemistry in a gabbro/granite watershed, Quabbin reservation, central Massachusetts

    SciTech Connect

    Reid, J.B. Jr.; Gallant, J.; Christensen, C.; Mengason, M. . School of Natural Science)

    1993-03-01

    While monitoring pH-alkalinity relationships in tributaries of the Quabbin Reservoir, the authors have discovered an anomalous brook whose waters become progressively more acidic downstream. The watershed's bedrock is roughly half Prescott hornblende gabbro and half Cooleyville granitic gneiss with the contact crossing the watershed diagonally; gabbroic bedrock dominates the stream's upper reaches. Outcrop density and topography suggest relatively thin till cover (< [approximately]2m). All parts of the stream get some contribution from both bedrock types, through gabbro contribution diminishes smoothly downstream. Springs in gabbro (pH [approximately]7, alk 20--30mg/1, cond [approximately]50[mu]mho) and in granite (pH [approximately]5, alk 2--6 mg/1, cond [approximately]15[mu]mho) retain these characteristics through dry and wet seasons; the stream's response to high rain events is more complex and can be used to estimate where surface water and groundwater each make their greatest contributions. Each point along the brook can be assigned a value of %gabbro characterizing the bedrock proportions in the watershed upstream of it; plots of major cations, alkalinity and conductivity vs. %gabbro show strong positive correlation. Two-week leaching experiments (initial pH = 4) with A, B and C soil horizons from both sides of the contact show greatest rises (to pH = 5.5) in gabbro soils distant from the contact, and progressively smaller increases crossing the contact to granite soils (pH rises to 4.5). The data suggest that bedrock and soil chemistry are primarily responsible for stream chemistry; topography and residence time here play secondary roles.

  16. Overview of granitic rocks in the Bradfield Canal area, southeastern Alaska

    SciTech Connect

    Koch, R.D. )

    1993-04-01

    Granitic rocks in the Bradfield Canal area of southeastern Alaska are part of the Coast plutonic-metamorphic complex and include rocks representing several different periods of magmatic activity. Units belonging to the previously named Admiralty-Revillagigedo, great tonalite sill, Coast Mountains, and Groundhog Basin-Cone Mountain belts are present. The Texas Creek Granodiorite is located in the southeastern part of the area and is probably 212 Ma or somewhat older. It consists mainly of locally deformed and altered calc-alkalic biotite-hornblende granodiorite and is closely associated with important mineral deposits. Distinguishing features include primary epidote, accessory garnet, and locally a distinctive plagioclase-porphyritic texture. Northeast of the Admiralty-Revillagigedo belt lies the northwest-trending great tonalite sill belt. These rocks are 58--55 Ma and consist of calc-alkalic, generally well-foliated and locally lineated biotite-hornblende and hornblende tonalite, quartz diorite, and granodiorite. The Coast Mountains belt granitic rocks are the most extensive in the area. The granite has been explored for U, Th, and REE deposits. The Coast plutonic-metamorphic complex records dynamothermal and regional contact metamorphic events related to the regional plutonism. Most of the lengthy and complicated magmatic and metamorphic history of the complex is related to Late Cretaceous collision of the Alexander and Wrangellia terranes and juxtaposition of the Gravina overlap assemblage to the west (Superterrane II) against the Yukon prong and Stikine terrane to the east (Superterrane I). An exception is the Texas Creek Granodiorite, which is related to a pre-accretionary Jurassic arc in the Stikine terrane.

  17. External gamma-ray dose rate and radon concentration in indoor environments covered with Brazilian granites.

    PubMed

    Anjos, R M; Juri Ayub, J; Cid, A S; Cardoso, R; Lacerda, T

    2011-11-01

    Health hazard from natural radioactivity in Brazilian granites, covering the walls and floor in a typical dwelling room, was assessed by indirect methods to predict external gamma-ray dose rates and radon concentrations. The gamma-ray dose rate was estimated by a Monte Carlo simulation method and validated by in-situ measurements with a NaI spectrometer. Activity concentrations of (232)Th, (226)Ra, and (40)K in an extensive selection of Brazilian commercial granite samples measured by using gamma-ray spectrometry were found to be 4.5-450 Bq kg(-1), 4.9-160 Bq kg(-1) and 190-2029 Bq kg(-1), respectively. The maximum external gamma-ray dose rate from floor and walls covered with the Brazilian granites in the typical dwelling room (5.0 m × 4.0 m area, 2.8 m height) was found to be 120 nGy h(-1), which is comparable with the average worldwide exposure to external terrestrial radiation of 80 nGy h(-1) due to natural sources, proposed by United Nations Scientific Committee on the Effects of Atomic Radiation. Radon concentrations in the room were also estimated by a simple mass balance equation and exhalation rates calculated from the measured values of (226)Ra concentrations and the material properties. The results showed that the radon concentration in the room ventilated adequately (0.5 h(-1)) will be lower than 100 Bq m(-3), value recommended as a reference level by the World Health Organization. PMID:21729819

  18. Smolt Condition and Timing of Arrival at Lower Granite Reservoir, 1984 Annual Report.

    SciTech Connect

    Scully, Richard J.; Buettner, Edwin W.

    1986-02-01

    Hatcheries released 9.3 million chinook salmon and 6.3 million steelhead smolts and presmolts upriver from Lower Granite Reservoir for migration in spring, 1984. Peak passage of yearling chinook salmon occurred the third week in April at both Whitebird and Snake River traps. Passage of steelhead was still increasing when high water stopped trapping in mid-May. Average migration rate between release sites and Snake River (the head of Lower Granite Reservoir) was 13.2 miles/day and from that point on through the reservoir to the dam, 1.9 miles/day. Salmon River discharge, when considered along with other environmental factors, had the greatest effect on migration rate of smolts branded both at hatcheries and at the Whitebird trap and migrating to the head of Lower Granite Reservoir. Migration rate for steelhead released from Dworshak Hatchery and recaptured at the Clearwater trap was 34 miles/day. Survival rates to the Snake River trap of branded chinook salmon smolts released at Hells Canyon Dam, Rapid River, South Fork Salmon and Decker Flat were 52%, 65%, 68% and 35%, respectively. Classical descaling, where at least 40% of the scales are missing from at least two of five areas on the side of a smolt, ranged from 0 to 5.3% at hatcheries for chinook salmon and was less than 1% for steelhead. Scattered descaling, where at least 10% of scales are missing from at least one side of a fish, was always more extensive than was classical descaling, ranging from 2.5 times greater for Clearwater hatchery steelhead to 6.8 times greater for Clearwater wild steelhead. Mean total length of chinook salmon yearlings was the same at all the traps, i.e., 128 mm (117 mm fork length) +- 1 mm.

  19. Environmental isotopes as indicators for ground water recharge to fractured granite.

    PubMed

    Ofterdinger, U S; Balderer, W; Loew, S; Renard, P

    2004-01-01

    To assess the contribution of accumulated winter precipitation and glacial meltwater to the recharge of deep ground water flow systems in fracture crystalline rocks, measurements of environmental isotope ratios, hydrochemical composition, and in situ parameters of ground water were performed in a deep tunnel. The measurements demonstrate the significance of these ground water recharge components for deep ground water flow systems in fractured granites of a high alpine catchment in the Central Alps, Switzerland. Hydrochemical and in situ parameters, as well as delta(18)O in ground water samples collected in the tunnel, show only small temporal variations. The precipitation record of delta(18)O shows seasonal variations of approximately 14% and a decrease of 0.23% +/- 0.03% per 100 m elevation gain. delta(2)H and delta(18)O in precipitation are well correlated and plot close to the meteoric water line, as well as delta(2)H and delta(18)O in ground water samples, reflecting the meteoric origin of the latter. The depletion of 18O in ground water compared to 18O content in precipitation during the ground water recharge period indicates significant contributions from accumulated depleted winter precipitation to ground water recharge. The hydrochemical composition of the encountered ground water, Na-Ca-HCO3-SO4(-F), reflects an evolution of the ground water along the flowpath through the granite body. Observed tritium concentrations in ground water range from 2.6 to 16.6 TU, with the lowest values associated with a local negative temperature anomaly and anomalous depleted 18O in ground water. This demonstrates the effect of local ground water recharge from meltwater of submodern glacial ice. Such localized recharge from glaciated areas occurs along preferential flowpaths within the granite body that are mainly controlled by observed hydraulic active shear fractures and cataclastic faults.

  20. Hand-Hewn Granite Basins at Native American Saltworks, Sierra Nevada, California

    USGS Publications Warehouse

    Moore, James G.; Diggles, Michael F.

    2009-01-01

    This site in the northern Sierra Nevada contains about 369 circular basins carved in fresh, glaciated granodioritic bedrock, with 325 basins crowded together in an area of 2,700 m2 on the main terrace. These terrace basins have a median average diameter of 125 cm (80 percent between 100 and 160 cm) and a median depth of 75-80 cm. They show a strong congruity to similar granitic basins in the southern Sierra Nevada apparently of Native American origin that are generally shallower. The basins are not of natural origin, as indicated by uniformity in size and nonoverlapping character of the basins; their common arrangement in lineaments; details of the shape of the basins; features in common with granite basins in the Southern Sierra Nevada; and, most compelling, the clustering of all the basins adjacent to (within 20 m of) two saline streams fed from a nearby salt spring. Native Americans apparently excavated them for the purpose of collecting saline water to evaporate and make salt for their use, and also as an animal attractant and a trade commodity. The flow of the salty streams delivers about 2.9 metric tons of salt per summer season to the basin area, and evaporation rates and the holding capacity of the basins indicate that about 2.5 tons of salt could be produced per season. This correspondence shows that the Indians made enough basins to exploit the resource. The site is the most impressive prehistoric saltworks yet discovered in North America and represents a unique departure from traditional hunter-gatherer activities to that of manufacturing. The actual grinding of so many basins in granite could not have been done without the labor of a concentrated population. It is believed that the work was accomplished over a long time by many people and with the use of fire to help disaggregate the bedrock.

  1. CIELAB color space values of burnt granitic soils as a tool for estimating fire severity

    NASA Astrophysics Data System (ADS)

    Cancelo-González, Javier; Cachaldora, Carlos; Díaz-Fierros, Francisco; Prieto, Beatriz

    2014-05-01

    Soil colour is often used to characterize and differentiate soils, as the colour is one of the most distinctive morphological features of a soil. As the colour of soil is strongly influenced by the type and amount of organic matter and Fe content, both of which are fire-sensitive components, colour and burn severity should be correlated. In this work we explore the usefulness of the CIELAB color space parameters of burnt soils as a tool for estimating fire severity. For this purpose, samples of forest soils developed on granite were collected from three different sites of NW Spain and subjected to controlled thermal shocks at microcosm scale. The thermal shock was performed in topsoil by the action of infrared lamps, which allowed reproducing similar temperatures to those reached in low, moderate and high severity fires. The maximum temperature and the degree hours (DH) reached during the heating were measured as indicators of fire severity. Three different methods of measuring the colour of the burnt samples were compared in order to determine which was best for the purpose of the study. Changes in the colour of the soil and in the contents of organic matter and iron compounds were also analysed. The results obtained in the present study for granitic soils show that the values of the CIELAB parameters defining the colour of the surface of burnt granitic forest soils increased with the temperature and DH reached. Although the amount of organic matter was significantly correlated with all colour parameters and with temperature and DH reached, the Fe compounds were not significantly correlated with either CIELAB parameters, temperature or DH reached. Statistical analysis of data allowed formulate simple expressions for estimating temperature and DH reached from CIELAB and organic matter values.

  2. Geophysical well log analysis of fractured granitic rocks at Atikokan, Ontario, Canada

    USGS Publications Warehouse

    Paillet, Frederick L.; Hess, A.E.

    1987-01-01

    Two boreholes, drilled to approximate depths of 750 and 1,260 m in a granitic intrusion located near Atikokan, Ontario, were studied by obtaining a full suite of conventional borehole geophysical logs. In addition, selected intervals in these boreholes were logged with a borehole acoustic televiewer that produces a high-resolution image of the borehole wall, an acoustic waveform-logging system using 34-kiloHertz magnetostrictive and 5-kiloHertz sparker sources, and a highly sensitive heat-pulse flowmeter. Emphasis was on identifying and characterizing fracture zones that represent groundwater conduits in deeper portions of the granite, and on characterizing the properties of the largest intervals of unfractured granite. Major fracture zones were indicated by correlating geophysical log anomalies detected on the suite of conventional logs (unpublished data from Atomic Energy of Canada). However, several other anomalies, were identified as mafic intrusions of approximately the same thickness as major fracture zones. Geophysical log anomalies were compared for all major fracture zones that could serve as significant groundwater conduits, and fracture zone permeability is estimated on the basis of acoustic tube-wave attenuation in these intervals. Acoustic televiewer logs obtained at depths below 1,000 m in the deeper well indicate that most of the few fractures identified on core at these depths do not remain open enough under in situ conditions to produce detectable anomalies in acoustic refraction. Flowmeter data indicate that some groundwater circulation occurs in the upper portion of both boreholes. Water in the shallower of the two holes was observed to flow at 2.0 L/min; most of this flow entered the borehole at a depth < 25 m, and no flow occurred below a depth of 100 m. Downflow at rates < 0.5 L/min was determined to enter the deeper borehole within 20 m of the surface, and to exist at various fractures down to a depth of 250 m. (Author 's abstract)

  3. Uranium in granites from the Southwestern United States: actinide parent-daughter systems, sites and mobilization. First year report

    SciTech Connect

    Silver, L T; Williams, I S; Woodhead, J A

    1980-10-01

    Some of the principal findings of the study on the Lawler Peak Granite are: the granite is dated precisely by this work at 1411 +- 3 m.y., confirming its synchroneity with a great regional terrane of granites. Uranium is presently 8-10 times crustal abundance and thorium 2-3 times in this granite. Uranium is found to be enriched in at least eight, possibly ten, primary igneous mineral species over the whole-rock values. Individual mineral species show distinct levels in, and characteristics ranges of, uranium concentration. It appears that in a uraniferous granite such as this, conventional accuracy mineral suites probably cannot account for most of the uranium in the rock, and more rare, high U-concentration phases also are present and are significant uranium hosts. It appears that at least two different geological episodes have contributed to the disturbance of the U-Th-Pb isotope systems. Studies of various sites for transient dispersal of uranium, thorium, and radiogenic lead isotopes indicate a non-uniform dispersal of these components. It appears that the bulk rock has lost at least 24 percent of its original uranium endowment, accepting limited or no radiogenic lead or thorium migration from the sample.

  4. Influence of granite-grit on nutrient digestibility and haematological parameters of broiler chickens fed rice offal based diets.

    PubMed

    Idachaba, C U; Abeke, F O; Olugbemi, T S; Ademu, L A

    2013-10-01

    A total of 270 broiler chickens were used for the study. The birds were fed common diet containing 23% Crude protein and 2864 kcal kg(-1) Metabolizable energy at the starter phase while 20% Crude protein and 2923 kcal kg(-1) Metabolizable energy was fed at the finisher phase. Starter and finisher diets contained 10 and 15% inclusion levels of rice offal respectively. Granite grit was added to the basal diet at 0.0, 2.0, 4.0, 6.0, 8.0 and 10.0 g per bird per month thus making a total of six treatments. Each treatment was replicated three times with 15 birds per replicate in a completely randomized design. Packed cell volume and haemoglobin level were not significantly (p>0.05) affected by dietary grit levels while total protein increased across the graded levels of granite grit. Crude protein, crude fibre and nitrogen free extract significantly (p<0.05) improved with increasing grit levels. These parameters improved up to the highest level of grit addition (10.0 g) granite-grit. It was concluded that 10.0 g granite grit per bird per month is beneficial to broiler chickens as it allows for efficient nutrient utilization. Further study to determine the optimum level of granite grit in broiler diet is encouraged since result obtained showed the optimum level was not attained. PMID:24502172

  5. Comparative evaluation of UV-vis-IR Nd:YAG laser cleaning of beeswax layers on granite substrates

    NASA Astrophysics Data System (ADS)

    Pan, A.; Chiussi, S.; González, P.; Serra, J.; León, B.

    2011-04-01

    The beeswax treatment applied in the sixties to prevent rain water from penetrating the outer stone surface of valuable granitic Galician monuments is contributing to the acceleration of the superficial degradation process of these monuments. At present, the northern sector of the renaissance frieze in the Cloister of the Cathedral of Santiago de Compostela is one of the most representative examples. Conventional wax removal methods (water, chemical and mechanical cleaning) can possibly destruct important details of the relief. Therefore laser removal is considered as a good alternative. In this work, we report systematic investigations of the effect of laser cleaning at different Nd:YAG laser wavelengths (266, 355, 532 and 1064 nm) on representative samples of the real historical surfaces. Laser removal of beeswax on granite at neither of the four wavelengths of the Nd:YAG laser is not a layer by layer removal process. For each irradiance and wavelength there is a maximum thickness that can be completely removed by a single pulse. Above this thickness the waxy material is not removed, although it undergoes thermal modifications; since the fraction of radiation that reaches the granite substrate is not enough to trigger the ejection of material. Our results show that the wax-granite interface plays a fundamental role in granite cleaning, and when the wax is weakened by absorption of radiation at 266 nm, the removal process becomes more efficient.

  6. Appraisal and evolution of hydrochemical processes from proximity basalt and granite areas of Deccan Volcanic Province (DVP) in India

    NASA Astrophysics Data System (ADS)

    Sonkamble, Sahebrao; Sahya, Ashalata; Mondal, N. C.; Harikumar, P.

    2012-05-01

    SummaryThis paper deals with a systematic hydrochemical study carried out at proximity basalt and granite areas of Deccan Volcanic Province (DVP) in India to assess groundwater quality and evaluate the hydrochemical processes. A total of 40 groundwater samples were collected equally from these areas and analyzed. Results showed that the groundwaters rich in alkaline earth in the basalt and alkali rich element in the granite. The dominancy of cations was observed as Ca2+ > Mg2+ > Na+ > K+ in the basalt and Na+ > Mg2+ > K+ > Ca2+ in the granite, whereas anions as HCO3->Cl>SO42- and Cl>HCO3->SO42-, respectively. Hydrochemical processes were identified with the helps of ion exchange, carbonate weathering and dissolution, multiple ionic ratios, and silicate weathering, which shown the predominance of carbonate, dolomite, calcite and silicate (anorthite) weathering in basalt, but in granite, silicate (alkali feldspar) weathering was dominated. Factor analysis also showed that there were multiple processes acting on groundwaters, were separated from the main cluster. Salinity, Sodium Absorption Ratio (SAR), Soluble Sodium Percentage (SSP), Residual Sodium Carbonate (RSC), Kelley's Ratio (KR) and Permeability Index (PI) in well samples showed that groundwater in basalt was more suitable for irrigation purposes. Further, a digital elevation model (DEM) was generated using Global mapper (8.0 version) software, which aided to decipher the thickness of basalt trap, and vertical transition zone of basaltic (trap) and granitic (basement) aquifer at this DVP comprising with the well depths and groundwater chemistry.

  7. Anomalously low strength of serpentinite sheared against granite and implications for creep on the Hayward and Calaveras Faults

    USGS Publications Warehouse

    Moore, Diane E.; Lockner, David A.; Ponce, David A.

    2010-01-01

    Serpentinized ophiolitic rocks are juxtaposed against quartzofeldspathic rocks at depth across considerable portions of the Hayward and Calaveras Faults. The marked compositional contrast between these rock types may contribute to fault creep that has been observed along these faults. To investigate this possibility, we are conducting hydrothermal shearing experiments to look for changes in frictional properties resulting from the shear of ultramafic rock juxtaposed against quartzose rock units. In this paper we report the first results in this effort: shear of bare-rock surfaces of serpentinite and granite, and shear of antigorite-serpentinite gouge between forcing blocks of granitic rock. All experiments were conducted at 250°C. Serpentinite sheared against granite at 50 MPa pore-fluid pressure is weaker than either rock type separately, and the weakening is significantly more pronounced at lower shearing rates. In contrast, serpentinite gouge sheared dry between granite blocks is as strong as the bare granite surface. We propose that the weakening is the result of a solution-transfer process involving the dissolution of serpentine minerals at grain-to-grain contacts. Dissolution of serpentine is enhanced by modifications to pore-fluid chemistry caused by interaction of the fluid with the quartz-bearing rocks. The compositional differences between serpentinized ultramafic rocks of the Coast Range Ophiolite and quartzofeldspathic rock units such as those of the Franciscan Complex may provide the mechanism for aseismic slip (creep) in the shallow crust along the Hayward, Calaveras, and other creeping faults in central and northern California.

  8. Influence of granite-grit on nutrient digestibility and haematological parameters of broiler chickens fed rice offal based diets.

    PubMed

    Idachaba, C U; Abeke, F O; Olugbemi, T S; Ademu, L A

    2013-10-01

    A total of 270 broiler chickens were used for the study. The birds were fed common diet containing 23% Crude protein and 2864 kcal kg(-1) Metabolizable energy at the starter phase while 20% Crude protein and 2923 kcal kg(-1) Metabolizable energy was fed at the finisher phase. Starter and finisher diets contained 10 and 15% inclusion levels of rice offal respectively. Granite grit was added to the basal diet at 0.0, 2.0, 4.0, 6.0, 8.0 and 10.0 g per bird per month thus making a total of six treatments. Each treatment was replicated three times with 15 birds per replicate in a completely randomized design. Packed cell volume and haemoglobin level were not significantly (p>0.05) affected by dietary grit levels while total protein increased across the graded levels of granite grit. Crude protein, crude fibre and nitrogen free extract significantly (p<0.05) improved with increasing grit levels. These parameters improved up to the highest level of grit addition (10.0 g) granite-grit. It was concluded that 10.0 g granite grit per bird per month is beneficial to broiler chickens as it allows for efficient nutrient utilization. Further study to determine the optimum level of granite grit in broiler diet is encouraged since result obtained showed the optimum level was not attained.

  9. Geochemistry of late Cretaceous granitoids from northeastern Washington: implication for genesis of two-mica Cordilleran granites

    SciTech Connect

    Asmerom, Y.; Ikramuddin, M.; Kinart, K.

    1988-05-01

    Mesozoic two-mica granites and I-type granodiorites from northeastern Washington have initial /sup 87/Sr//sup 86/Sr ratios around 0.7100, similar to many other Cordilleran granitoids. Metapelite and calcsilicate country rocks, equivalent to the Belt Supergroup, have measured /sup 87/Sr//sup 86/Sr ratios in the range of 0.91 to 0.98. Unlike many of their Cordilleran counterparts, the northeastern Washington two-mica granites are enriched in U, Rb, and other incompatible elements, and therefore cannot have been derived from depleted lower crust sedimentary sources. Both the two-mica granites and the I-type granodiorites have similar rare-earth-element and trace-element enrichment patterns. Trace-elements modeling shows that it is feasible to derive the two-mica granites by 60% partial melting of a granodiorite-like source. The close association of Cordilleran metamorphic core complexes and older I-type granodiorites with two-mica granites supports this model.

  10. Effects of work exposure, retirement, and smoking on bronchoalveolar lavage measurements of lung dust in Vermont granite workers.

    PubMed

    Christman, J W; Emerson, R J; Hemenway, D R; Graham, W G; Davis, G S

    1991-12-01

    Estimation of the exposure to respirable dust in the workplace is an important aspect of industrial hygiene. We performed bronchoalveolar lavage (BAL) on 42 healthy nonindustrial control subjects and 44 workers in the Barre, Vermont granite industry to determine whether BAL materials reflected occupational exposure. The granite workers held jobs with a range of dust exposure intensities and had employment histories from 1 to 43 yr; 12 workers were retired. None of the workers had radiologic evidence of silicosis. The granite dust content of BAL materials was measured by enumerating the percentage of cells positive for particulates by polarized light microscopy, by analysis for silicon by scanning electron microscopy with energy-dispersive X-ray spectrometry, and by chemical analysis. Minerals were present in greater quantity in the BAL cells from granite workers than from nonindustrial control subjects. Polarized light microscopy was comparable in sensitivity, specificity, and overall accuracy to electron microscopy; chemical analysis was less accurate than either microscopic technique. Tobacco smoking did not interfere with the detection of the occupationally related minerals or influence the quantity of dust present. The mineral in BAL cells was partially related to the intensity of exposure within the granite industry and to the duration of employment, but there was great individual variation among subjects. Retirement led to a decrease in BAL mineral content, but substantial dust remained for many years.

  11. Geochronology and tectonic significance of Middle Proterozoic granitic orthogneiss, North Qaidam HP/UHP terrane, Western China

    USGS Publications Warehouse

    Mattinson, C.G.; Wooden, J.L.; Liou, J.G.; Bird, D.K.; Wu, C.L.

    2006-01-01

    Amphibolite-facies para- and orthogneisses near Dulan, in the southeast part of the North Qaidam terrane, enclose minor ultra-high pressure (UHP) eclogite and peridotite. Field relations and coesite inclusions in zircons from paragneiss suggest that felsic, mafic, and ultramafic rocks all experienced UHP metamorphism and a common amphibolite-facies retrogression. Ion microprobe U-Pb and REE analyses of zircons from two granitic orthogneisses indicate magmatic crystallization at 927 ?? Ma and 921 ?? 7 Ma. Zircon rims in one of these samples yield younger ages (397-618 Ma) compatible with partial zircon recrystallization during in-situ Ordovician-Silurian eclogite-facies metamorphism previously determined from eclogite and paragneiss in this area. The similarity between a 2496 ?? 18 Ma xenocrystic core and 2.4-2.5 Ga zircon cores in the surrounding paragneiss suggests that the granites intruded the sediments or that the granite is a melt of the older basement which supplied detritus to the sediments. The magmatic ages of the granitic orthogneisses are similar to 920-930 Ma ages of (meta)granitoids described further northwest in the North Qaidam terrane and its correlative west of the Altyn Tagh fault, suggesting that these areas formed a coherent block prior to widespread Mid Proterozoic granitic magmatism. ?? Springer-Verlag 2006.

  12. 3,800-Myr granitic gneiss in South-Western Minnesota

    USGS Publications Warehouse

    Goldich, S.S.; Hedge, C.E.

    1974-01-01

    WE have previously arrived at an age of 3,550 Myr for granitic1 gneiss in the vicinities of Morton and Montevideo in the Minnesota River valley, south-western Minnesota. We now report new Rb-Sr analyses (Table 1) and an age of 3,800 Myr for the fine grained foliated phase of the Montevideo Gneiss of Lund2. The rocks have undergone a complex history of metamorphism which remains to be deciphered, but the age determinations reveal that the geological mapping and previous interpretations did not provide a proper basis for sampling. ?? 1974 Nature Publishing Group.

  13. Geochemical Signatures of Neoproterozoic Granites and Granitoid-gneisses from Angavo Belt, Central Madagascar

    NASA Astrophysics Data System (ADS)

    Raharimahefa, T.

    2015-12-01

    The basement rocks of Madagascar record high-grade metamorphism, magmatism, and contractional and extensional structures that accompanied the collision of the eastern and western Gondwana segments of the supercontinent followed by its collapse. In the eastern central Madagascar, granitoids dominate the landscape and occur in a large area near and within the N-S trending highly strained zone known as the Angavo Shear Zone or Angavo belt. The area is a key in understanding the evolution of basement of Madagascar and the reconstruction of the Gondwana supercontinent. These granitoids range from layered to massive and previously published U-Pb zircon dating yielded three distinctive Neoproterozoic magmatisms at 770 Ma to 820 Ma, ca. 660Ma, and ca 550Ma. However, it was unknown whether these ages represent distinct magmatic pulses or reflect a continuous granitoid emplacement. This work contributes to the knowledge of the Malagasy basement rocks and to explore and discuss the origin and petrotectonic evolution of the granites and granitoid-gneisses from this part of the Madagascar. The rock samples are placed into three groups: group A and B for granitoid-gneisses and a third group for the granite layers. Group A and B are metaluminous and slightly peraluminous, respectively. All rocks have typical subduction zone calc-alkaline signatures. Group A is characterized by enrichment in large ion lithophile elements (LILE) but low U, LREE enrichment, depletion in the high field strength elements (HFSE). In contrast, Group B has REE patterns closely similar to Archean sediments. The granite layers show fractionated REE patterns in which HREE patterns show strong correlation with Zr abundances. Trends in major element variation diagrams and the enrichment of incompatible elements could be explained by simple fractional crystallization, while the overall geochemical signatures reflect either (1) melting of ancient crust or (2) crustal contamination of a more evolved magmas that

  14. Uranium isotopic distribution in the mineral phases of granitic fracture fillings by a sequential extraction procedure.

    PubMed

    Crespo, M T; Pérez del Villar, L; Jiménez, A; Pelayo, M; Quejido, A; Sánchez, M

    1996-01-01

    In order to study the recent rock-water interaction processes in the E1 Berrocal site, a sequential leaching method has been applied to granitic fracture fillings to obtain the U isotopic distribution in the mineral phases of these samples. Based on the mineralogical composition of these materials, six dissolution steps have been chosen to extract U as exchangeable cation, from carbonates, amorphous Fe-oxyhydroxides, labile resistates and highly insoluble resistates. In this way, the processes involved in the rock-water interaction phenomena, mainly dissolution, precipitation, coprecipitation and adsorption can be distinguished and even approximately dated.

  15. Geologic map of the Granite 7.5' quadrangle, Lake and Chaffee Counties, Colorado

    USGS Publications Warehouse

    Shroba, Ralph R.; Kellogg, Karl S.; Brandt, Theodore R.

    2014-01-01

    The geologic map of the Granite 7.5' quadrangle, Lake and Chaffee Counties, Colorado, portrays the geology in the upper Arkansas valley and along the lower flanks of the Sawatch Range and Mosquito Range near the town of Granite. The oldest rocks, exposed in the southern and eastern parts of the quadrangle, include gneiss and plutonic rocks of Paleoproterozoic age. These rocks are intruded by younger plutonic rocks of Mesoproterozoic age. Felsic hypabyssal dikes, plugs, and plutons, ranging in age from Late Cretaceous or Paleocene to late Oligocene, locally intruded Proterozoic rocks. A small andesite lava flow of upper Oligocene age overlies Paleoproterozoic rock, just south of the Twin Lakes Reservoir. Gravelly fluvial and fan deposits of the Miocene and lower Pliocene(?) Dry Union Formation are preserved in the post-30 Ma upper Arkansas valley graben, a northern extension of the Rio Grande rift. Mostly north-northwest-trending faults displace deposits of the Dry Union Formation and older rock units. Light detection and ranging (lidar) imagery suggests that two short faults, near the Arkansas River, may displace surficial deposits as young as middle Pleistocene. Surficial deposits of middle Pleistocene to Holocene age are widespread in the Granite quadrangle, particularly in the major valleys and on slopes underlain by the Dry Union Formation. The main deposits are glacial outwash and post-glacial alluvium; mass-movement deposits transported by creep, debris flow, landsliding, and rockfall; till deposited during the Pinedale, Bull Lake, and pre-Bull Lake glaciations; rock-glacier deposits; and placer-tailings deposits formed by hydraulic mining and other mining methods used to concentrate native gold. Hydrologic and geologic processes locally affect use of the land and locally may be of concern regarding the stability of buildings and infrastructure, chiefly in low-lying areas along and near stream channels and locally in areas of moderate to steep slopes. Low

  16. Combined geophysical methods for detecting soil thickness distribution on a weathered granitic hillslope

    NASA Astrophysics Data System (ADS)

    Yamakawa, Yosuke; Kosugi, Ken'ichirou; Masaoka, Naoya; Sumida, Jun; Tani, Makoto; Mizuyama, Takahisa

    2012-04-01

    The usefulness of electrical resistivity imaging (ERI) as a highly accurate method for determining the soil thickness distribution on hillslopes was validated by combining intensive measurements using invasive methods, i.e., cone penetration testing and boreholes, with ERI in three granitic watersheds. Areas of high electrical resistivity (ρ) contrast reflecting soil-bedrock interfaces were found in all three study watersheds. However, ρ values of soil and we