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Sample records for pluton ne turkey

  1. Petrological and geochemical constraints on the origin of mafic dykes intruding the composite Kaçkar Pluton from the eastern Blacksea magmatic arc, NE Turkey

    NASA Astrophysics Data System (ADS)

    Aydin, Faruk; Oguz, Simge; Baser, Rasim; Uysal, Ibrahim; Sen, Cüneyt; Karsli, Orhan; Kandemir, Raif

    2015-04-01

    Geological, petrographical and geochemical data of mafic dykes intruding the composite Kaçkar Pluton from the eastern Blacksea magmatic arc (EBMA), NE Turkey, provide new insights into the nature of the metasomatizing agents in subcontinental lithospheric mantle beneath the region during the late Mesozoic-early Tertiary. Mafic dykes from the Çaykara and Hayrat (Trabzon), and also Ikizdere (Rize) areas from the northern margin of the EBMA consist of basalts, dolerites, lamprophyres (basic member) and lesser basaltic andesites and trachyandesites (evolved member). All dykes have no deformation and metamorphism. The outcrops of these dykes vary, with thickness from 0.2 to 10 m. and visible length from 3 to 20 m. In general, the mafic dykes dip steeply and cut directly across the Kaçkar Pluton, and show NW- and NE-trending, roughly parallel to the orientations of the EBMA main faults. Most of the dyke samples display subaphyric to porphyritic texture with phenocrysts of plagioclase (up to 10%), clinopyroxene (5-20%), amphibole (5-15%), and some contain variable amount of biotite (5-20%), lesser quartz (1-2%), and minor euhedral zircon, apatite and Fe-Ti oxides. The basic members of the mafic dykes have SiO2 of 44.1-51.9%, MgO of 4.5-12.1%, and TiO2 >mostly 0.8% (up to 2.3%) with K2O+Na2O of 1.3-6.6% with mostly subalkaline character. They are relatively high in mg-number (0.45-0.73) and transition metals (V=171-376 ppm, Co=22-45 ppm, Ni=3-148 ppm, and Sc=21-49 ppm). The evolved members of the dykes exhibit relatively higher SiO2 (57.1-60.2%) and K2O+Na2O (5.6-9.0%), and lower MgO (2.2-5.9%) and TiO2 (0.5-0.8%) contents than those from the basic dykes. Also, these samples have slightly low mg-number (0.41-0.65) and transition metals (V=99-172 ppm, Co=9-22 ppm, Ni=1-43 ppm, and Sc=9-20 ppm). In the Harker diagrams, all samples of the mafic dykes form a continuous array, and exhibit similar geochemical characteristics. In general, SiO2 inversely correlates with MgO, Fe

  2. Emplacement of the Solarya Pluton (NW Turkey)

    NASA Astrophysics Data System (ADS)

    Ünal, Alp; Altunkaynak, Şafak

    2017-04-01

    The Solarya pluton is one of the major plutons located in NW Anatolia. It consists of three plutonic rock groups: K-feldspar megacrystalline granodiorite (KFMG), microgranite-granodiorite (MGG) and haplogranite (HG). Also mafic dikes and mafic microgranular enclaves (MME) are common within the plutonic body. The northern and southern parts of the pluton present different textural properties. At the northern part of the pluton, K-feldspar megacrystalline granodiorite with porphyritic texture is dominant while southern part of the pluton is formed from microgranite-granodiorite with microgranular texture. Haplogranite, which is typical with its graphic/granophyric texture, outcrops between KFMG and country rocks as a thin aureole. The emplacement of the Solarya pluton began forcefully at the deeper levels of the epizone and then reached to shallow levels in the crust. The northern and southern part of the pluton displays textural and structural indicators of this different emplacement levels. At the northern part, between KFMG and the country rocks, pluton developed a narrow contact metamorphic zone characterized by the hornblend-hornfels facies. Additively, through the northern and eastern margin, the structural properties of the regional metamorphic rocks have changed depending on the emplacement of pluton indicating a forceful emplacement. The basement rocks at the southern boundary represent a "roof pendant" on the MGG. In some places of southern margin, MGG gradually passes into the subvolcanic rocks (microgranodiorite-quartzdiorite porphyries) which were emplaced into the ring and radial faults connected to pluton emplacement. The amphibole-plagioclase geothermobarometer results of Solarya pluton indicate that, for MGG 0.8-1.0 kb and 626-678 C and for K-feldspar megacrystalline granodiorite 1.8-2.3 kbar and 737-752 C pressure and temperature emplacement conditions are calculated. This data suggest that while the southern part of the pluton were emplaced into

  3. Petrology of the shoshonitic Çambaşı pluton in NE Turkey and implications for the closure of the Neo-Tethys Ocean: Insights from geochemistry, geochronology and Sr-Nd isotopes

    NASA Astrophysics Data System (ADS)

    Özdamar, Şenel; Roden, Michael F.; Billor, Mehmet Z.

    2017-07-01

    The Eastern Pontide Orogenic Belt (EPOB) is one of the well-preserved continental magmatic arcs in the Alpine-Himalayan Belt and consists of Paleozoic to Miocene plutonic bodies. This paper presents new geological, bulk-rock major and trace element analyses, biotite Ar-Ar ages and Sr-Nd isotope data on representative samples from the Çambaşı granitic body exposed in the northwestern part of the EPOB. Although the majority of the plutons in the EPOB show calc-alkaline affinity and I-type character, the Çambaşı pluton has a shoshonitic affinity and an I-type, metaluminous signature. The pluton is composed of mainly monzonite, quartz monzonite and granite bodies including monzo-dioritic mafic microgranular enclaves (MMEs). Excluding the MMEs, these rocks have 57.7-70.2 wt.% SiO2, 13.1-17.5 wt.% Al2O3, 3.06-3.64 wt.% Na2O, 3.66-5.92 wt.% K2O, 0.33-3.3 wt.% MgO and Mg# < 30, indicating intermediate to evolved compositions. They are characterized by light rare earth element (LREE)-enrichment, relatively flat heavy rare earth element (HREE) patterns with small negative Eu anomalies and moderately fractioned REE patterns [average (La/Yb)N = 11.32]. Decreasing Fe2O3T, MgO, CaO, TiO2, Ba, Eu, and Sr with increasing SiO2 contents are consistent with fractional crystallization and can be related to fractionation of plagioclase, clinopyroxene, hornblende, apatite and Fe-Ti oxides. Initial 87Sr/86Sr ratios vary between 0.70470 and 0.70478, while those of 143Nd/144Nd lie between 0.51262 and 0.51263. Major, trace element and initial Sr-Nd homogeneity show that fractional crystallization played a key role in the evolution of the pluton. 40Ar/39Ar dating of four biotite samples from the pluton gave plateau ages of between 44.62 ± 0.1 Ma and 44.10 ± 0.0 Ma, which are interpreted as cooling ages of the plutonic rocks. We suggest that the Çambaşı pluton formed in a post-collisional extensional setting where partial melting of chemically enriched lithospheric mantle was

  4. Petrography and geochemistry of Ilıca-Şamlı Pluton, NW Turkey

    NASA Astrophysics Data System (ADS)

    Aydın, Halil Can; Özdamar, Şenel

    2017-04-01

    The major and trace elements of the plutonic rocks from the Ilıca-Şamlı Pluton, Northwest of Turkey, were studied to understand petrogenesis. The plutonic rocks consist of a variety of rock types ranging from diorite to granodiorite. Diorites and granodiorite contain large, massive alkali feldspar crystals which are porphyritic textures. These plutonic rocks have SiO2=62-65, Al2O3=14,55-15,74, Fe2O3=4,03-5,85, MgO=1,85-2,80, CaO=4,83-5,96, Na2O=3,14-3.58, K2O=3,04-4,16 major oxide percentages. All of the rocks show a calc-alkaline afinity. Chondrite-normalized REE patterns are moderately fractionated and relatively flat. They display small negative Eu anomalies with enrichment of LILE and less amount of depletion of HFSE. The 40Ar/39Ar ages ˜21-22 Ma. These ages are interpreted as crystalliczation ages of the plutonic rocks and also these ages imply collision of the Intra-Pontide Suture and Anatolide-Tauride platform.

  5. Petrogenesis of Post-collisional high Ba-Sr granitoids: the Solarya Pluton, NW Turkey

    NASA Astrophysics Data System (ADS)

    Unal, Alp; Kamaci, Omer; Altunkaynak, Safak

    2015-04-01

    In NW Turkey, the Late Oligocene-Early Miocene phase of post-collisional magmatism is characterized by widespread granitic pluton emplacements straddling the continental collision zone marked by the Izmir-Ankara suture zone (IASZ). This granitic magmatism produced both low Ba-Sr- and high Ba-Sr granitoids with distinct geochemical properties. One of the major plutons emplaced to the north of İzmir-Ankara suture zone, the Solarya pluton is representative of high Ba-Sr granitoids. We present here whole-rock chemical and Sr-Nd-Pb-O isotopic compositions, as well as 40Ar/39Ar ages of the Solarya pluton to evaluate the timing, nature and genesis of potassic, high Ba-Sr granites. The Solarya pluton consists of three coeval granitic members (K-Feldspar megacrystalline granodiorite, fine grained granodiorite and haplogranite) and associated mafic magmatic enclaves/dykes of gabbroic diorite to dioritic in composition. K-feldspar megacrystalline granodiorite, fine grained granodiorite and haplogranite are high K calc-alkaline in character whereas low silica mafic magmatic enclaves and dykes are mildly alkaline and display shoshonitic affinity. Both granitic members and mafic enclaves/dykes are characterized by high Ba (710-2489 ppm), Sr (305-708ppm), low Y and HREE contents and lack of significant negative Eu anomalies. They are metaluminous and display enrichment in LILE and depletion in P, Ta, Nb and Ti. Sr-Nd-Pb and O isotope compositions of mafic enclaves and dykes are similar to their host granitoids. They have initial 87Sr/86Sr values of 0.70702- 0.70805 and 143Nd/144Nd values of 0.51235-0.51250 and their ɛNd values range between -4,9 and -2,05. 206Pb/204Pb and 207Pb/204 Pb isotopic values vary from 18,75 to 18,88 and 15,68 to 15,73, respectivelly. Whole rock and quartz 18O isotopic ratios range between 8 and 10,6. All these isotopic characteristics and major-trace element compositions of Solarya pluton and associated mafic enclaves/dykes suggest a subcontinental

  6. Geochemistry of uranium and thorium and natural radioactivity levels of the western Anatolian plutons, Turkey

    NASA Astrophysics Data System (ADS)

    Papadopoulos, Argyrios; Altunkaynak, Şafak; Koroneos, Antonios; Ünal, Alp; Kamaci, Ömer

    2017-01-01

    Seventy samples from major plutons (mainly granitic) of Western Anatolia (Turkey) have been analyzed by γ-ray spectrometry to determine the specific activities of 238U, 226Ra, 232Th and 40K (Bq/kg). Τhe natural radioactivity ranged up to 264 Bq/kg for 238U, 229.62 Bq/kg for 226Ra, up to 207.32 Bq/kg for 232Th and up to 2541.95 Bq/kg for 40K. Any possible relationship between the specific activities of 226Ra, 238U, 232Th and 40K and some characteristics of the studied samples (age, rock-type, colour, grain size, occurrence, chemical and mineralogical composition) was investigated. Age, major and trace element geochemistry, color, pluton location and mineralogical composition are likely to affect the concentrations of the measured radionuclides. The range of the Th/U ratio was large (0.003-11.374). The latter, along with 226Ra/238U radioactive secular disequilibrium, is also discussed and explained by magmatic processes during differentiation.

  7. 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.

  8. The generation of high Sr/Y plutons following Late Jurassic arc-arc collision, Blue Mountains province, NE Oregon

    NASA Astrophysics Data System (ADS)

    Schwartz, Joshua J.; Johnson, Kenneth; Miranda, Elena A.; Wooden, Joseph L.

    2011-09-01

    High Sr/Y plutons (Sr/Y > 40) occupy large areas in ancient and modern orogenic belts, yet considerable controversy exists regarding mechanisms of their generation, the tectonic settings in which they form, and their relationship to contractional deformation through time. In the Blue Mountains province (NE Oregon), a suite of Late Jurassic (148-145 Ma), high Sr/Y plutons intrude Middle Jurassic (162-157 Ma), low Sr/Y (< 40) arc-related lavas and plutons in the Dixie Butte area immediately after widespread Late Jurassic arc-arc collision (159-154 Ma). Early, pre- to syn-kinematic low Sr/Y lavas and plutons (162-157 Ma) have flat to slightly enriched light rare earth element (REE) abundances, low Sr (< 400 ppm) and Sr/Y values (< 40), and strongly positive initial epsilon Hf values (+ 10.1 to + 12.3: 2σ weighted average). Ce/Y values from basalts and gabbros yield a maximum crustal thickness of ~ 23 km. These geochemical and isotopic features suggest derivation from a depleted-mantle source and/or shallow-level (≪ 40 km) melting of pre-existing island arc crust with little to no evolved crustal input. In contrast, post-kinematic high Sr/Y plutons (148-145 Ma) are more compositionally restricted (tonalite-trondhjemite-granodiorite) and display depleted heavy REE abundances, an absence of Eu anomalies, elevated Sr (> 600 ppm) and Sr/Y values (> 40), and positive initial epsilon Hf values (+ 10.5 to + 7.8: 2σ weighted average). These geochemical and isotopic results are consistent with geochemical models suggesting derivation from partial melting of island arc crust in the presence of a plagioclase-poor to absent, clinopyroxene + hornblende + garnet-bearing source (depths > 35-40 km). We propose that the transition from low Sr/Y to high Sr/Y magmatism resulted from orogenic thickening of island arc crust in the Dixie Butte area during Late Jurassic arc-arc collision between the Olds Ferry and Wallowa island arcs at 159-154 Ma. This fundamental change in crustal

  9. Zircon Lu-Hf isotope systematics and U-Pb geochronology, whole-rock Sr-Nd isotopes and geochemistry of the early Jurassic Gokcedere pluton, Sakarya Zone-NE Turkey: a magmatic response to roll-back of the Paleo-Tethyan oceanic lithosphere

    NASA Astrophysics Data System (ADS)

    Karsli, Orhan; Dokuz, Abdurrahman; Kandemir, Raif

    2017-05-01

    The early Mesozoic was a critical era for the geodynamic evolution of the Sakarya Zone as transition from accretion to collision events in the region. However, its complex evolutionary history is still debated. To address this issue, we present new in situ zircon U-Pb ages and Lu-Hf isotope data, whole-rock Sr-Nd isotopes, and mineral chemistry and geochemistry data of plutonic rocks to better understand the magmatic processes. The Gokcedere pluton is mainly composed of gabbro and gabbroic diorite. LA-ICP-MS zircon U-Pb dating reveals that the pluton was emplaced in the early Jurassic (177 Ma). These gabbros and gabbroic diorites are characterized by relatively low SiO2 content of 47.09 to 57.15 wt% and high Mg# values varying from 46 to 75. The samples belong to the calc-alkaline series and exhibit a metaluminous I-type character. Moreover, they are slightly enriched in large ion lithophile elements (Rb, Ba, Th and K) and light rare earth elements and depleted in high field strength elements (Nb and Ti). Gabbroic rocks of the pluton have a depleted Sr-Nd isotopic composition, including low initial 87Sr/86Sr ranging from 0.705124 to 0.705599, relatively high ɛ Nd ( t) values varying from 0.1 to 3.5 and single-stage Nd model ages ( T DM1 = 0.65-0.95 Ga). In situ zircon analyses show that the rocks have variable and positive ɛ Hf ( t) values (4.6 to 13.5) and single-stage Hf model ages ( T DM1 = 0.30 to 0.65 Ga). Both the geochemical signature and Sr-Nd-Hf isotopic composition of the gabbroic rocks reveal that the magma of the studied rocks was formed by the partial melting of a depleted mantle wedge metasomatized by slab-derived fluids. The influence of slab fluids is mirrored by their trace-element characteristics. Trace-element modeling suggests that the primary magma was generated by a low and variable degree of partial melting ( 5-15%) of a depleted and young lithospheric mantle wedge consisting of phlogopite- and spinel-bearing lherzolite. Heat to melt the

  10. Nature of Phyllosilicates and Magma Types in the Plutonic Complexes of NE Egypt

    NASA Astrophysics Data System (ADS)

    Abdel-Rahman, A.

    2007-05-01

    The Late Proterozoic plutonic complexes of northeastern Egypt belong to a number of magma types of variable tectonic regimes, and exhibit a variety of phyllosilicate minerals. The results show that the phyllosilicates define three compositionally distinct groups. Phyllosilicates in the anorogenic peralkaline granites, which were developed from a hypersolvus felsic melt, are restricted to iron-rich siliceous annites and belong to type A-biotite (referring to biotite in anorogenic alkaline A-type suites). Such Fe-enriched, Al-depleted mica compositions suggest that the substitutions Fe3+ = Al, 3Fe2+ = 2Al, Fe2+ = Mg and (Fe2+ + Si) = 2Al are vital in producing annitic compositions in the peralkaline granites. In sharp contrast, phyllosilicates in the trondhjemitic pluton that crystallized from a peraluminous felsic melt, are siderophyllitic in composition and belong to type P-biotite (referring to biotite in peraluminous, including S-type suites). The substitutions Fe2+ = Mg, along with the Tschermaks substitution (Fe2+, Mg) + Si = 2Al are vital in producing siderophyllitic compositions in the trondhjemite pluton. The substitution 2Al = 3Mg (or Fe2+) also plays a role when referring to a possible solid solution between phlogopite (or annite) end-member and muscovite end-member. This pluton also contains late- to post-magmatic muscovite. Phyllosilicates in the diorite-tonalite and the voluminous granodiorite-adamellite orogenic complexes (crystallized from calcic to calc-alkaline subsolvus magmas), cover a wide range of composition, and belong to type C-biotite (referring to biotite in calcic and calc- alkaline, mostly I-type suites). The nature of micas and the magmatic stages of their development were controlled by the various physiochemical conditions (including the behavior of volatiles) prevailed during the crystallization of these hypersolvus, dry, anorogenic magmas versus subsolvus, wet, orogenic magmatic systems.

  11. Investigation of Plutonic Rocks in Biga Peninsula, NW Turkey, using 3D Normalized Full Gradient of Magnetic Data

    NASA Astrophysics Data System (ADS)

    Ekinci, Y. L.; Yiǧitbaş, E.

    2012-04-01

    Airborne magnetic data of Biga Peninsula were investigated by using 3D Normalized Full Gradient (NFG) technique. The NFG procedure is based on the downward continuation of the potential field data and the NFG amplitude is calculated by dividing the Analytic Signal (AS) of downward continued magnetic data by the average of AS. Application of NFG technique usually enhances the anomalies by computing the anomaly to a level close to the source bodies and points to the boundaries of causative bodies. To that end, a MATLAB based code consisting of a series of linked functions was developed and used for analyses. Study area covers an area of 120 km x 180 km and the data were collected with 1-2 km profile intervals and with about 70 m sampling from 625 m above the ground surface by MTA (General Directorate of Mineral Research and Exploration). 2 km sampling intervals for both north and east directions were used for gridding of the magnetic data. Regional anomalies were approximated by means of element shape functions used in finite element method and then residuals were computed. Prior to the application of 3D NFG, Reduction to the Pole (RTP) transformation was applied to residual data in order to remove the complexity due to the effects of the direction of magnetization and ambient field. RTP transformation process was performed using 55 and 4 degrees for inclination and declination angles, respectively. 3D NFG operation was performed to reduced to pole data for 6 different depth levels (-200, -400, -600, -800, -1000 and -1200 m). Analyzing the resulting anomaly maps of different depth levels together with the geological map (1/500.000) showed that the locations of maximum NFG amplitudes indicate the boundaries of plutonic rocks having high magnetization intensity. Additionally, horizontal and vertical extensions of plutonic rocks were also determined. Keywords: Airborne magnetic data, normalized full gradient, plutonic rocks, Biga Peninsula-Turkey

  12. Geochemistry of the Topuk Pluton associated with the Kozbudaklar W-skarn deposit (Western Anatolia, Turkey): Implication for crystallization conditions

    NASA Astrophysics Data System (ADS)

    Orhan, Ayşe; Demirbilek, Mehmet; Mutlu, Halim

    2017-06-01

    The Kozbudaklar scheelite-bearing skarn deposit in the Tavşanlı Zone, western Turkey, occurs at the contact between Eocene Topuk pluton and Triassic İnönü marble of calcic character. The Topuk pluton is medium-coarse grained, granodiorite in composition and has a hypidiomorphic equigranular texture. The host rock contains mafic microgranular enclaves (MME) of monzodiorite-monzogabbro composition and is interrupted by porphyritic granodiorite and granite-aplite vein rocks. The pluton is calk-alkaline, metaluminous and composed of I-type melt character. δ18O and δD compositions of silicate minerals from granodioritic host rock are 5.9-10.6‰ and -77.0 to -71.4‰ and conformable with the range of unaltered I-type granites. Trace element contents indicate that pluton is crystallized from mantle-derived magma interacted with continental crust in a volcanic arc or subduction related setting. Major and trace element concentrations of Topuk pluton are quite consistent with geochemical patterns of Cu-skarn granitoids. Results of mineral chemistry analysis of the pluton yield that plagioclases are of oligoclase-andesine, amphiboles are of magnesio-hornblende and biotites are of ferro-magnesian composition. Amphiboles and biotites of granodioritic host rock are represented by calc-alkaline, I-type melt composition evolved in a subduction environment. Based on the results of plagioclase-Al in hornblende and amphibole chemistry data from the pluton, two different stages are proposed for the magma crystallization. The first stage was developed in a relatively deeper environment (>15 km) under high pressure (>4 kbar) and low log ƒO2 (>-17.6) conditions which reflect fractional crystallization and magma-mixing depth of basaltic magma and these conditions are not correlated with scheelite mineralization. The second crystallization stage of magma which proceeded at shallow depths (<6 km) was also developed in two separate phases with respect to P-T conditions. The first

  13. The Pombal granite pluton: Magnetic fabric, emplacement and relationships with the Brasiliano strike-slip setting of NE Brazil (Paraiba State)

    NASA Astrophysics Data System (ADS)

    Archanjo, C. J.; Bouchez, J.-L.; Corsini, M.; Vauchez, A.

    1994-03-01

    The Pombal pluton (500 km 2), a suite of diorite, syenite and porphyritic granite bodies, is here used to constrain kinematics of Brasiliano-age tectonic episodes in northeast Brazil. The pluton intrudes high-grade to migmatitic gneiss forming the western basement of the Seridó belt, and is located at the intersection between two sets of continental-scale dextral strike-slip shear zones. The northern set of shear zone strikes NE-SW and branches, southwards, into the E-W Patos mega-shear zone. A detailed microstructural and low-field magnetic susceptibility study was performed to unravel the relationships between solid-state deformation in the country rocks and magma emplacement. Porphyritic granite and syenite have quite high magnetic susceptibilities (10 -3-10 -2 SI units) indicative of magnetite as the principal carrier of susceptibility. The magnetic fabric is remarkably homogeneous in orientation throughout the pluton. It is characterized by a shape-preferred alignment of magnetite, itself parallel to the shape fabric of mainly biotite (±amphibole), i.e. to the magmatic fabric. Even close to the contact with the high-temperature mylonites of the Patos shear zone, south of Pombal, no imprint of the E-W-trending structures is observed in the fabrics of either the granite or the host rocks. Granite emplacement and its internal fabric development is concluded to be independent of the movement of the Patos shear zone. In the southwestern border of the pluton, a low-dip foliation bearing a NE-SW-striking lineation is shared in both the magmatic fabric of the pluton and the solid-state fabric. Farther to the north, approaching the NE-SW strike-slip shear zone, the magmatic fabric is characterized by a steeply dipping NE-striking foliation carrying a subhorizontal lineation. Transition from low to steep dips of the planar fabrics is progressive. Two models are proposed for emplacement of the Pombal pluton. One considers magma injection during an early episode of

  14. Recrystallization and anatexis along the plutonic-volcanic contact of the Turkey Creek caldera, Arizona

    USGS Publications Warehouse

    du Bray, E.A.; Pallister, J.S.

    1999-01-01

    Unusual geologic and geochemical relations are preserved along the contact between intracaldera tuff and a resurgent intrusion within the 26.9 Ma Turkey Creek caldera of southeast Arizona. Thick intracaldera tuff is weakly argillically altered throughout, except in zones within several hundred meters of its contact with the resurgent intrusion, where the groundmass of the tuff has been variably converted to granophyre and unaltered sanidine phenocrysts are present. Dikes of similarly granophyric material originate at the tuff-resurgent intrusion contact and intrude overlying intracaldera megabreccia and tuff. Field relations indicate that the resurgent intrusion is a laccolith and that it caused local partial melting of adjacent intracaldera tuff. Geochemical and petrographic relations indicate that small volumes of partially melted intracaldera tuff assimilated and mixed with dacite of the resurgent intrusion along their contact, resulting in rocks that have petrographic and compositional characteristics transitional between those of tuff and dacite. Some of this variably contaminated, second-generation magma coalesced, was mobilized, and was intruded into overlying intracaldera rocks. Interpretation of the resurgent intrusion in the Turkey Creek and other calderas as intracaldera laccoliths suggests that intrusions of this type may be a common, but often unrecognized, feature of calderas. Development of granophyric and anatectic features such as those described here may be equally common in other calderas. The observations and previously undocumented processes described here can be applied to identification and interpretation of similarly enigmatic relations and rocks in other caldera systems. Integration of large-scale field mapping with detailed petrographic and chemical data has resulted in an understanding of otherwise intractable but petrologically important caldera-related features.

  15. Geochemical and Isotopic Features of Çaykara (Trabzon, NE Turkey) Intrusive Complex

    NASA Astrophysics Data System (ADS)

    Sen, Cuneyt; Aydınçakır, Emre; Aydin, Faruk; Dokuz, Abdurrahman; Karslı, Orhan; Yılmazer, Sinan; Dündar, Buket

    2017-04-01

    peraluminous characteristics. The primitive mantle normalized multi-element variation diagrams of the studied samples show enrichment in LILE relative to HFSE and also negative Nb, Ta, P, Ti and positive Pb anomalies. Chondrite-normalized rare earth element (REE) patterns are [(La/Lu)N=8-10] and display negative Eu anomalies. When obtained initial data is plotted on tectonic discrimination diagram, as expected the tectonic setting of the plutons in subject was observed representing island arc environment. This work was supported by the Scientific and Technological Research Council of Turkey (TUBITAK, grant 114Y219).

  16. Zircon Record of the Plutonic-Volcanic Connection and Protracted Rhyolite Melt Extraction at Turkey Creek Caldera, Arizona

    NASA Astrophysics Data System (ADS)

    Deering, C. D.; Schoene, B.; Keller, C. B.; Bachmann, O.; Beane, R. J.; Ovtcharova, M.

    2014-12-01

    The Turkey Creek caldera of Southeastern Arizona formed as the result of the catastrophic eruption of more than 500 km3 of high-silica rhyolite (Rhyolite Canyon Tuff). This event occurred ~27 Ma and was coincident with the early phases of Basin and Range extension. The emplacement of the ignimbrite was immediately followed by a resurgent intrusion of dacite/monzonite porphyry (DPI), some of which reached the surface as crystal-rich dacite lavas (DPL) along the ring fault. Due to uplift and erosion, the intracaldera and outflow facies of the Rhyolite Canyon Tuff (RCT) and resurgent intrusion are well-exposed, which renders this an ideal laboratory for examining the plutonic-volcanic connection in a mid- to upper-crustal environment. We examined the potential petrogenetic link between the crystal-poor rhyolite and the crystal-rich intermediate intrusion and lavas through zircon CA-TIMS geochronology and ICP-MS trace element analyses. CA-TIMS U-Pb dates indicate that the RCT and DPI/DPL were coeval, forming over a protracted period of time (>300 kyrs.) prior to the catastrophic event. The trace element data (e.g. Lu/Sc, Y/Hf, Dy/Y) for the individual zircons in the dacitic/monzonitic units and erupted rhyolite record a continuous trend that is interpreted to reflect crystal fractionation. The combination of zircon U-Pb dating and trace element analyses also allows us to trace the apparent timing and duration of the rhyolite melt extraction from the intermediate mush, as the trace element ratios for the rhyolite diverge from those of the DPI approx. 100-150 kyrs. before eruption. This protracted timescale for building an intermediate mush large enough to hold 500 km3 of rhyolite is consistent with that observed for other large ignimbrites in arc settings.

  17. Determining the Pollution Parameters of Degirmendere Stream (Trabzon, NE TURKEY)

    NASA Astrophysics Data System (ADS)

    Sunnetci, M. O.; Hatipoglu, E.; Firat Ersoy, A.; Gultekin, F.

    2013-12-01

    The pollution parameters of Degirmendere Stream (Trabzon, TURKEY) are determined in this study. The study area is located between Maçka, 26 km to the south of Trabzon city, and the Black Sea. The area consists of Late Cretaceous volcano-sedimentary rocks, dacite, and basalt, overlain by Eocene volcanic rocks. Quaternary alluvium overlay all geological units following Degirmendere Stream bed. In-situ physical parameter measurements, anion-cation analysis, and heavy and pollutant element analysis on water samples were carried out for four months at four different locations on the stream. The stream's water temperature values were between 4.7 and 9.7oC, pH values were between 6.01 and 7.98, dissolved oxygen (DO) values were between 7.03 and 12.38 mg/l, electrical conductivity (EC) values were between 86 and 254 μS/cm. According to the Piper diagram, the stream water is classified as Ca-HCO3 type water. In the Schoeller diagram, the lines combining mek/l values of the ions in stream water are parallel. Al concentration in the stream water varied from 0.06 to 0.22 mg/l, Mn concentration varied from 0.1 to 0.36 mg/l, and Fe concentration varied from 0.01 to 0.12 mg/l. The stream water is classified as first class in point of temperature, pH, DO, total dissolved solids (TDS), NO3-, P, Pb, Fe, and Al; first and second class in point of NH4+; second class in point of Cu; and third class in point of NO2-, according to the Water Pollution Control Regulation of the Turkish Republic's Criteria for Inland Surface Water Classification. Results indicate waters of the Degirmendere Stream is very good-good for irrigation use according to the Wilcox diagram.

  18. Improvement of stored turkey semen quality as a result of He-Ne laser irradiation.

    PubMed

    Iaffaldano, N; Meluzzi, A; Manchisi, A; Passarella, S

    2005-02-01

    Two experiments were carried out to evaluate the effects of He-Ne laser irradiation at various energy doses on the quality of stored turkey semen. Four semen pools were used in Experiment 1. Each pool was divided into 10 aliquots, nine of which were irradiated with energy doses ranging from 0.144 to 10.8 J/cm2 while the tenth one was not irradiated (control). Each sample was evaluated for motility immediately after irradiation, 24 and 48 h later. Energy doses ranging from 3.24 to 5.4 J/cm2 had higher (P <0.01) sperm motility index (SMI) value compared to the control and samples irradiated with lower and higher laser doses. The energy dose of 3.96 J/cm2 was selected for Experiment 2 to obtain further insight on its effects on turkey sperm preservation for up to 60 h. Each pool of four semen was divided into two aliquots: one represented the control and the other one was irradiated with He-Ne laser at an energy dose of 3.96 J/cm2. Each sample was evaluated for motility and viability immediately after irradiation and then at 12 h intervals up to 60 h. The cell energy charge was also measured by HPLC. Exposure to 3.96 J/cm2 increased the SMI and viability of turkey semen stored for 60 h compared to the control (P <0.05). The cell energy charge of irradiated samples was 200% higher than in the control. Laser irradiation increased the longevity of stored turkey spermatozoa, and might be a useful technique to enhance semen quality in long-term storage.

  19. Dolomitization in Late Jurassic-Early Cretaceous Platform Carbonates (Berdiga Formation), Ayralaksa Yayla (Trabzon), NE Turkey

    NASA Astrophysics Data System (ADS)

    Yıldız, Merve; Ziya Kırmacı, Mehmet; Kandemir, Raif

    2017-04-01

    ABSTRACT Pontides constitute an E-W trending orogenic mountain belt that extends about 1100 km along the northern side of Turkey from the immediate east of Istanbul to the Georgian border at the east. Tectono-stratigraphically, the Pontides are divided into three different parts: Eastern, Central, and Western Pontides. The Eastern Pontides, including the studied area, comprise an area of 500 km in length and 100 km in width, extending along the southeast coast of the Black Sea from the Kizilirmak and Yesilirmak Rivers in the vicinity of Samsun to the Little Caucasus. This area is bordered by the Eastern Black Sea basin to the north and the Ankara-Erzincan Neotethyan suture zone to the south. The Late Jurassic-Early Cretaceous platform carbonates are widely exposed in E-W direction in the Eastern Pontides (NE Turkey). The Platform carbonates shows varying lithofacies changing from supratidal to platform margin reef laterally and vertically, and was buried until the end of Late Cretaceous. The studied Ayralaksa Yayla (Trabzon, NE Turkey) area comprises one of the best typical exposures of formation in northern zone of Eastern Pontides. In this area, the lower parts of the formation are pervasively dolomitized by fabric-destructive and fabric-preserving replacement dolomite which are Ca-rich and nonstoichiometric (Ca56-66Mg34-44). Replacement dolomites (Rd) are represented by D18O values of -19.0 to -4.2 (VPDB), D13C values of 4.4 to 2.1 \\permil (VPDB) and 87Sr/86Sr ratios of 0.70889 to 0.70636. Petrographic and geochemical data indicate that Rd dolomites are formed prior to compaction at shallow-moderate burial depths from Late Jurassic-Early Cretaceous seawater and/or partly modified seawater as a result of water/rock interaction and they were recrystallized at elevated temperatures during subsequent burial. In the subsequent diagenetic process during the Late Cretaceous when the region became a magmatic arc, as a result of interaction with Early Jurassic volcanic

  20. Source of magma for Elet-Ozero pluton (NE Baltic Shield) - subduction or plume-related material?

    NASA Astrophysics Data System (ADS)

    Ryabchikov, Igor; Kogarko, Liya

    2016-04-01

    Eletozero pluton is located in the northeastern part of the Karelian Craton, it covers an area of about 100 km2 and cuts through Archaean granite-gneisses. The complex has a concentric zoned structure, the peripheral part being composed of a layered gabbro series; the central area is occupied by nepheline syenites. Mafic and ultramafic rocks in this intrusion often contain potassium feldspar (olivine monzonites and monzonites). Gabbroids are characterized by rhythmic layering expressed in the alternation of leucocratic layers predominantly composed of plagioclase and melanocratic layers with pyroxenes, olivine, titanomagnetite and ilmenite. The rocks of the pluton are enriched in highly incompatible elements by comparison with moderately incompatible elements: average primitive mantle normalized La/Lu ratio is 18.3. At the same time, all the rocks from Elet-Ozero massif including the most primitive ones (high Mg-numbers and high Ni contents) exhibit distinct positive Ba anomaly: mean chondrite normalized Ba/Th ratio is 15.3 (both elements have similar incompatibility-[1]). Enrichment of parent magma in Ba is also confirmed by the presence of high-Ba feldspars and micas in some samples of gabbroids. The most Ba-rich feldspar contains 75% of celsian component: K0.09Na0.04Ca0.008Sr0.04Ba0.75Al1.73Fe0.14Si2.20O8. Ba is a fluid mobile incompatible lithophile element that is probably the most sensitive indicator of subduction fluid addition to the mantle wedge. Thus, positive Ba anomaly suggests input of subduction related component into the source of Elet-Ozero magma. The presence of subduction related material in the lithosphere of Karelian craton has been proposed on the basis of Os isotope studies of mantle xenoliths from Finnish kimberlites [2]. The age of this subduction event is similar to the age of Elet-Ozero pluton. On the other hand, there are certain arguments in favor of connection of Elet-Ozero intrusive complex with mantle plume activity. In particular it

  1. Meteorological analysis of flash floods in Artvin (NE Turkey) on 24 August 2015

    NASA Astrophysics Data System (ADS)

    Baltaci, Hakki

    2017-07-01

    On 24 August 2015 intense rainfall episodes generated flash floods and landslides on the eastern Black Sea coast of Turkey. As a consequence of the heavy rainstorm activity over Artvin and its surroundings (NE Turkey), 11 people died and economic losses totaled a million dollars. Over the 6 h of the event (from 05:00 to 11:00 UTC), total accumulated rainfall amounts of 136, 64, and 109 mm were measured in the Hopa, Arhavi, and Borçka settlements of Artvin city, respectively. This study comprehensively investigates the meteorological characteristics of those flash floods. In terms of synoptic mechanisms, the cutoff surface low from the summer Asian monsoon settled over the eastern Black Sea. After two days of quasistationary conditions of this cyclone, sea surface temperatures (SSTs) reached 27.5 °C (1.5 °C higher than normal) and low-level moisture convergence developed. In addition, transfer of moisture by warm northerly flows from the Black Sea and relatively cool southerly flows from the land coasts of the Artvin district exacerbated the unstable conditions and thus played a significant role in the development of deep convective cells. Severe rainstorms as well as the slope instability of the region triggered landslides and worsened flood damages in the Artvin area. This study supports conventional weather analysis, satellite images, and forecast model output to alert forecasters to the potential for heavy rainfall.

  2. Magnetic susceptibility and partial anhysteretic remanence anisotropies in the magnetite-bearing granite pluton of Tourão, NE Brazil

    NASA Astrophysics Data System (ADS)

    Trindade, Ricardo I. F.; Raposo, M. Irene B.; Ernesto, Marcia; Siqueira, Roberto

    1999-12-01

    Rock magnetism and magnetic fabric studies were performed in the Tourão granite (western part of Seridó belt, NE Brazil). This pluton (350 km 2) is composed of K-rich calc-alkalic monzogranites and was emplaced between a set of NE- and E-trending dextral strike-slip shear zones. Electronic and optical microscopy, thermomagnetic curves, hysteresis data and coercivity spectra revealed that magnetite (fine- and coarse-grained) is the unique ferromagnetic mineral in these rocks. Anisotropy of low-field magnetic susceptibility (AMS) was measured in 83 sites, and for many sites from central and southern parts of the intrusive body a large scatter was noticed. Anisotropy of partial anhysteretic remanence (pAAR) was determined for 29 sites in the 0-50 mT (pAAR 0-50) and 19 sites in the 50-90 mT (pAAR 50-90) windows to isolate the fabric contribution of the remanence bearing grains (magnetite). In most sites AMS is dominantly carried by magnetite, whereas in some sites the paramagnetic contribution exceeds 60% of the bulk susceptibility. The pAAR 0-50 is assumed to be related to coarse-grained early crystallized magnetites, while the pAAR 50-90 is interpreted as due to fine needle-shaped magnetites hosted in biotites. The combined analysis of these magnetic techniques permits interpretation in terms of fabric formation in the Tourão granite and the inference that at least two successive kinematic events were recorded in this intrusive body devoid of any solid-state deformation overprint. The AMS and pAAR 0-50 fabrics for most of the sites correlate with the early NNE-trending magmatic fabric, whereas pAAR 50-90 reveals a different fabric, probably related to late partitioning of magmatic straining along the E-trending shear zones. In the southern part of the body, a completely different pAAR 0-50 fabric is correlated with the late intrusion of charnockite stocks.

  3. Subduction initiation for the formation of high-Cr chromitites in the Kop ophiolite, NE Turkey

    NASA Astrophysics Data System (ADS)

    Zhang, Peng-Fei; Uysal, Ibrahim; Zhou, Mei-Fu; Su, Ben-Xun; Avcı, Erdi

    2016-09-01

    The Kop ophiolite in NE Turkey is a forearc fragment of Neo-Tethys ocean, consisting mainly of a paleo-Moho transition zone (MTZ) and a harzburgitic upper mantle unit. Locally, the Kop MTZ contains cumulate dunites and high-Cr chromitites (Cr# up to ca. 79), which are cut by pyroxenites. Dunites and chromitites in the MTZ have REE concentrations that are 1-2 orders of magnitude lower than those of chondrite; they are either depleted in LREE or have concave REE shapes. The LREE depleted patterns are interpreted to reflect production of cumulate rocks by magmas derived from a depleted mantle, the concave patterns the modification of these rocks by LREE-enriched fluids. Clinopyroxenes from pyroxenites are diopsidic and characterized by high Mg#s (ca. 92-96) and high CaO contents (ca. 24-25 wt.%); their Al2O3 contents (1.0-3.0 wt.%) fall between those of clinopyroxenes in N-MORB and komatiite/boninite, suggesting that the parental melts originated from more refractory mantle than abyssal lherzolites. However, these clinopyroxenes display LREE depleted patterns consistent with those of clinopyroxenes in abyssal lherzolites, indicating their genetic connection with decompression melting of asthenosphere. The cross-cutting relationship between pyroxenite veins and chromitiferous rocks suggests that depleted mantle remained beneath the proto-forearc after chromitite formation; it had not been significantly modified by slab-derived components and continued interacting with the upwelling asthenosphere until pyroxenite crystallization. This study provides a temporal constraint on the formation of high-Cr chromitites; they possibly began to be produced during the transition between early and late proto-forearc spreading, during which subduction dehydration had not well developed.

  4. Statistical Evaluation of the Geochemical Data from Akoluk Epithermal Gold Area (Ulubey-Ordu), NE Turkey

    NASA Astrophysics Data System (ADS)

    Yaylalı-Abanuz, G.; Tüysüz, N.

    2009-04-01

    There are several economic epithermal gold deposits in the eastern Pontide arc basin in northeast of Turkey. These mineralizations are generally found as veins in NE-SW and NW-SE trending shear fractures. The presence of faults and associated suitable hydrothermal alteration in the study area has been important guide for the gold exploration. Since region is intensely covered with thick soil and rocks are exposed in limited areas, stream sediment and soil geochemistry studies are the most commonly used methods in the exploration of mineral deposits. In this study, the applicability of soil geochemistry surveys in the exploration of mineral deposits in areas of intense overburden is tested using statistical methods. A vein type gold occurence is confined to the fault zones crossing dacitic tuffs of Upper Cretaceous age. Faults appear to be a conjugate set of a shear system, striking N 45-50 E, and N 55-60 W dipping 80-85 SE and 70-80 NW respectively. Mineralization occurs generally as replacement of dacitic tuffs along the fault planes and less of void fillings. Main ore minerals are native gold, stibnite, zinkenite, pyrite, marcasite, realgar, orpiment, sphalerite, galena, chalcopyrite, malachite, and azurite, and the most common gangue mineral is barite. Soil is residual and well developed ranging in thickness from 0.5 m to 1 m. Elements analyzed and interpreted are the ones which are known to have close association with gold. Of these Au, Ag, Sb, As, Zn, Mo, W, and Ba show a single very significant anomaly pattern although several other small isolated anomalies are also recorded. The latter must be related to sampling artifacts. The significant one is circular in shape and has a diameter of approx. 200 m. It is strikingly of interest that anomaly shape does not imitate fracture system. This may be due to the fact that sampling interval is wider than the fault zones. However the circular pattern may suggest a granitic intrusion in subcrop as the main controller of

  5. Kilop Cretaceous Hardground (Kale, Gümüshane, NE Turkey):description and origin

    NASA Astrophysics Data System (ADS)

    Eren, Muhsin; Tasli, Kemal

    2002-06-01

    A hardground surface is well exposed in the Kilop area of Kale (Gümüshane, NE Turkey) which forms part of the Eastern Pontides. Here, the hardground is underlain by shallow water Lower Cretaceous limestones, and overlain by Upper Cretaceous red limestones/marls which contains a planktonic microfauna including Globotruncanidae. In the field, the recognition of the hardground is based on the presence of extensive burrows (especially vertical burrows), the encrusting rudistid bivalve Requienia, neptunian-dykes with infills of pelagic sediments and synsedimentary faults. Skolithos and Thalassinoides-type burrows are present. Some burrow walls show iron hydroxide-staining. The extensive burrowing occurred prior to lithification. On the other hand, the neptunian-dykes and synsedimentary faults, which cut the hard ground, occurred after the lithification. These features indicate the progressive hardening of the substrate. The burrowed limestone consists of an intrabioclastic peloidal grainstone which was deposited in an intertidal to shallow, subtidal, moderate to relatively high energy environment. The peloidal limestone shows little or no evidence of submarine cementation, characterized by only scarce relics of isopachous cement rims of bladed calcite spar. The grainstone cement is composed predominantly of blocky calcite and overgrowth calcite cements on the echinoid-fragments. The origin of this cement is controversial. Biostratigraphic analysis of the limestones demonstrates that there is a marked stratigraphic gap (hiatus), spanning the Aptian to the Santonian, in the Cretaceous of the Kilop area. The formation of the Kilop Hardground is related to the break-up and subsidence of the Eastern Pontides carbonate platform during the formation of the Black Sea backarc basin. Hardground development was initiated in a shallow marine environment of slow sedimentation and with moderate to high energy indicating slow subsidence. Later, the hardground subsided abruptly, as

  6. River terrace development in the NE Mediterranean region (Syria and Turkey): Patterns in relation to crustal type

    NASA Astrophysics Data System (ADS)

    Bridgland, David R.; Demir, Tuncer; Seyrek, Ali; Daoud, Mohamad; Abou Romieh, Mohammad; Westaway, Rob

    2017-06-01

    It is widely recognized that the optimal development of river terraces globally has been in the temperate latitudes, with NW and Central Europe being areas of particular importance for the preservation of such archives of Quaternary environmental change. There is also a growing consensus that the principal drivers of terrace formation have been climatic fluctuation against a background of progressive (but variable) uplift. Nonetheless river terraces are widely preserved in the Mediterranean region, where they have often been attributed to the effects of neotectonic activity, with a continuing debate about the relative significance of fluctuating temperature (glacials-interglacials) and precipitation (pluvials-interpluvials). Research in Syria and southern-central Turkey (specifically in the valleys of the Tigris and Ceyhan in Turkey, the Kebir in Syria and the trans-border rivers Orontes and Euphrates) has underlined the importance of uplift rates in dictating the preservation pattern of fluvial archives and has revealed different patterns that can be related to crustal type. The NE Mediterranean coastal region has experienced unusually rapid uplift in the Late Quaternary. The relation between the Kebir terraces and the staircase of interglacial raised beaches preserved along the Mediterranean coastline of NW Syria reinforces previous conclusions that the emplacement of the fluvial terrace deposits in the Mediterranean has occurred during colder climatic episodes.

  7. Geochronology and geochemistry of the Parashi granitoid, NE Colombia: Tectonic implication of short-lived Early Eocene plutonism along the SE Caribbean margin

    NASA Astrophysics Data System (ADS)

    Cardona, A.; Weber, M.; Valencia, V.; Bustamante, C.; Montes, C.; Cordani, U.; Muñoz, C. M.

    2014-03-01

    The Parashi granitoid of northeasternmost Colombia intrudes the Upper Cretaceous to Lower Paleocene accretionary complex formed by the collision of the Caribbean arc and the continental margin of South America. This granitoid presently separated of the continental margin includes a major quartzdiorite body with andesite to dacite dikes and mafic enclaves. Zircon U-Pb LA-MC-ICP-MS and K-Ar geochronology on the quartzdiorite and the dikes suggest that crystallization extended from ca. 47 to 51 Ma. Major and trace elements are characterized by a medium-K, immature continental arc signature and high Al2O3, Na2O and Ba-Sr contents. Initial 87Sr/86Sr isotopic values range between 0.7050 and 0.7054, with 143Nd/144Nd = 0.51235-0.51253, ɛNd and ɛHf values from -0.81 to -4.40 and -4.4 and -5.2. Major and trace element ratios and isotopic modeling suggest that sedimentary and/or quartzofeldspathic crustal sources were mixed with a mafic melt input. The petrotectonic and geological constraints derived from this granitoid suggest that Parashi plutonism records an immature, oblique subduction-zone setting in which the presence of a high-temperature mantle realm and strong plate coupling associated to upper crust subduction caused the partial fusion of a previously tectonically underplated mafic crust and associated metasediments exposed in the continental margin. The limited temporal expression of this magmatism and the transition to a regional magmatic hiatus are related to a subsequent change to strongly and slow oblique tectonics in the Caribbean-South America plate interactions and the underflow of a relatively thick slab of Caribbean oceanic crust.

  8. The post-thaw irradiation of avian spermatozoa with He-Ne laser differently affects chicken, pheasant and turkey sperm quality.

    PubMed

    Iaffaldano, N; Paventi, G; Pizzuto, R; Passarella, S; Cerolini, S; Zaniboni, L; Marzoni, M; Castillo, A; Rosato, M P

    2013-11-30

    The effects of post-thaw Helium-Neon (He-Ne) laser irradiation on mobility and functional integrity of frozen/thawed chicken, pheasant and turkey spermatozoa were investigated. Cytochrome C oxidase (COX) activity was also determined as a measure of the effect of irradiation on mitochondrial bioenergetics. Semen samples from each species were collected, processed and frozen according to the pellet procedure. After thawing, each semen sample was divided into two subsamples: the first one was the control; the second one was irradiated with a single mode continuous He-Ne laser wave (wavelength 632.8 nm; 6 mW; 3.96 J/cm(2)). Then the samples were assessed for sperm mobility (Accudenz(®) swim-down test), viability (SYBR-14/PI staining), osmotic-resistance (HOS test) and COX activity. The irradiation was effective P<0.05 increasing sperm motility in the turkey semen (0.228 ± 0.01 compared with 0.294 ± 0.02). The irradiation also caused an increase (P<0.05) of the COX activity in pheasant (+135 ± 4%) and turkey (+116 ± 4%) sperm, without affecting viability and osmotic-resistance. The COX was positively correlated (P<0.05) with the viability of chicken sperm, however no significant interactions were found between mobility and COX activity in the three avian species. Due to the difference in energetic metabolism among avian species used in this study, the He-Ne laser irradiation has a differential action on bio-stimulation of turkey, chicken and pheasant spermatozoa. The present results are the first to elucidate the possibility for restoration of motility of cryopreserved avian spermatozoa by bio-stimulation provided via He-Ne laser irradiation. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Iron mineralization and associated skarn development around southern contact of the Eğrigöz pluton (northern Menderes Massif-Turkey)

    NASA Astrophysics Data System (ADS)

    Uǧurcan, Okşan Gökçen; Oyman, Tolga

    2016-11-01

    The Eğrigöz pluton is located in the northern portion of the Menderes Massif, which is the largest known metamorphic core complex that is also characterized by large-scale extension. Kalkan and Karaağıl skarn deposits are located on the southern border of the Eğrigöz Pluton, whereas Katrandağ mineralization developed along the roof pendant. Skarnization in these three areas is associated with the peraluminous, I-type, calc-alkaline, high-K calc-alkaline Eğrigöz Pluton. Geochemical characteristics of the pluton indicate that it was generated in a continental arc setting. Kalkan, Karaağıl, and Katrandağ skarns are hosted in marble bands in two-mica gneiss of the Kalkan Formation, a locally dolomitic and clay-bearing limestone of the Arıkaya Formation and locally dolomitised limestone of the Balıkbaşı Formation, respectively. Skarn development occurred sequentially in two stages, prograde and retrograde. In Kalkan skarn, prograde stage is characterized by clinopyroxene (Di56-73 Hd26-43 Joh1-2), garnet (Adr45-69 Grs30-52 Alm0-1.4 Sps0.7-2.3), amphibole, and magnetite, whereas retrograde stage is dominated by epidote, amphibole, chlorite, quartz, and calcite. In Karaağıl, both calcic and magnesian skarn association occurred as a result of local variations in dolomite content in Arıkaya Formation. The prograde assemblage of magnesian skarn is composed chiefly of spinel, amphibole and olivine. These mineral assemblages were, partially or fully, altered to serpentine, talc, and chlorite during retrograde alteration. Mesh textures of the serpentine indicates that the serpentine was altered from olivine. Olivine was completely destroyed during retrograde alteration without relict grains remaining. Calcic skarn paragenesis include garnet (Grs36-80Adr20-62Alm0-2.2Sps0.2-2.6), clinopyroxene (Di81-92 Hd7-19 Jo0-1), and plagioclase, that belongs to the earlier stage, and amphibole of the retrograde stage. High grossular end member of the garnet probably

  10. Iron isotopic fractionation and origin of chromitites in the paleo-Moho transition zone of the Kop ophiolite, NE Turkey

    NASA Astrophysics Data System (ADS)

    Zhang, Peng-Fei; Zhou, Mei-Fu; Su, Ben-Xun; Uysal, Ibrahim; Robinson, Paul T.; Avcı, Erdi; He, Yong-Sheng

    2017-01-01

    The paleo-Moho transition zone (MTZ) of the Kop ophiolite in NE Turkey is mainly composed of dunites, which are locally interlayered with chromitites and contain minor relics of harzburgites. Large Fe isotopic variations were observed for magnesiochromite (- 0.14 to 0.06‰) and olivine (- 0.12 to 0.14‰) from the MTZ rocks. In individual samples, magnesiochromite has lighter Fe isotopic compositions than olivine, which was probably caused by subsolidus Mg-Fe exchange between them. Both magnesiochromite and olivine display an increasing trend of δ56Fe along a profile from chromitite to dunite. This trend reflects continuous fractional crystallization in a magma chamber, which resulted in heavier Fe isotopes concentrated in the evolved magmas. In each cumulate cycle of chromitite and dunite, dunite was formed from relatively evolved melts after massive precipitation of magnesiochromite. Mixing of more primitive and evolved melts in the magma chamber was a potential mechanism for triggering the crystallization of magnesiochromite, generating chromitite layers in the cumulate pile. Before mixing happened, the primitive melts had reacted with mantle harzburgites during their ascendance; whereas the evolved melts may lie on the olivine-chromite cotectic near the liquidus field of pyroxene. Variable degrees of magma mixing and differentiation are expected to generate melts with different δ56Fe values, accounting for the Fe isotopic variations of the Kop MTZ.

  11. Trace element geochemistry of Jurassic coals from Eastern Black Sea Region, NE-Turkey

    SciTech Connect

    Cebi, F.H.; Korkmaz, S.; Akcay, M.

    2009-07-01

    The majority of coal deposits in the world are of Carboniferous and Tertiary age but Jurassic coals are seldom present. They are also exposed in northern Turkey and occur both at the lower and upper sections of the Liassic-Dogger volcanic- and volcani-clastic series. The coals at the base of the Jurassic units are characterized by higher Ba, Th, Zr, and Cr-Ni and lower S values than those at the top of the units, indicating, in general, laterally consistent trace element contents. The vertical distribution of trace elements in individual coal seams is also rather consistent. The B contents of coals from the Godul and Norsun areas vary from 1.5 to 4.3 ppm whereas those from the Alansa area are in the range of 95 to 138 ppm. This suggests that the coals in the Godul and Norsun areas were deposited in a swamp environment inundated by the sea from time to time, whereas coals of the Alansa were deposited in a saline environment.

  12. Turkey.

    PubMed

    1988-03-01

    Focus in this discussion of Turkey is on the following: geography; the people; history; government and political conditions; the economy; defense; and relations between the US and Turkey. In 1986, Turkey's population was estimated to be 51.8 million with an annual growth rate of 2.5%. The infant mortality rate is 12.3/1000 with a life expectancy of 62.7 years. Turkey is located partly in Europe and partly in Asia. Since 1950, urban areas have experienced tremendous growth, and squatter dwellings are evident around the cities' edges. About half of Turkey's population live in urban areas. Turkish culture is made up of both the modern and traditional, Ottoman and folkloric, elements. The Republic of Turkey was founded by Mustafa Kemal, subsequently named Ataturk, in 1982 after the collapse of the 600-year-old Ottoman empire. The new republic focused on modernizing and Westernizing the empire's Turkish core -- Anatolia and a small part of Thrace. The 1982 constitution preserves a democratic, secular, parliamentary form of government with a strengthened presidence. It provides for an independent judiciary along with the safeguarding of internationally recognized human rights. The legislative functions are carried out by the unicameral, 450-member GNA. The economy is developing structurally, yet the agricultural sector remains significant and produces cotton, tobacco, grains, fruits, and vegetables. Over half of the labor force are farmers, contributing over 1/5 of the gross domestic product. A significant portion of industry also is involved in processing agricultural products. The period from the mid-1960s to the mid-1970s was the longest sustained period of economic growth and development in modern Turkish history, with annual growth rates of nearly 7%. Oil price increases after 1973 and the concomitant European recession slowed Turkish growth and also revealed major structural deficiencies. The economic crisis worsened in 1979 as oil prices doubled again. The Demirel

  13. Volcanological, petrographical and geochemical characteristics of Late Cretaceous volcanic rocks around Borçka-Artvin region (NE Turkey)

    NASA Astrophysics Data System (ADS)

    Baser, Rasim; Aydin, Faruk; Oguz, Simge

    2015-04-01

    This study presents volcanological, petrographical and geochemical data for late Cretaceous volcanic rocks from the Borçka-Artvin region (NE Turkey) in order to investigate their origin and magmatic evolution. Based on the previous ages and recent field studies, the late Cretaceous time in the study area is characterized by two different bimodal volcanic periods. The first bimodal period of the late Cretaceous volcanism is mainly represented by mafic rock series (basaltic-basaltic andesitic pillow lavas and hyaloclastites) in the lower part, and felsic rock series (dacitic lavas, hyaloclastites, and pyrite-bearing tuffs) in the upper part. The second bimodal period of the late Cretaceous volcanism begins with mafic rock suites (basaltic-andesitic lavas and dikes-sills) and grades upward into felsic rock suites (biotite-bearing rhyolitic lavas and hyaloclastites), which are intercalated with hyaloclastites and red pelagic limestones. All volcano-sedimentary units are covered by Late Campanian-Paleocene clayey limestones and biomicrites with lesser calciturbidites. The mafic volcanic series of the study area, which comprise basaltic and andesitic rocks, generally show amygdaloidal and aphyric to porphyritic texture with phenocrysts of calcic to sodic plagioclase and augite in a hyalopilitic matrix of plag+cpx+mag. Zircon and magnetite are sometimes observed as accessory minerals, whereas chlorite, epidote and calcite are typical alteration products. On the other hand, the felsic volcanic series consisting of dacitic and rhyolitic rocks mostly display porphyritic and glomeroporphyritic textures with predominant feldspar, quartz and some biotite phenocrysts. The microgranular to felsophyric groundmass is mainly composed of aphanitic plagioclase, K-feldspar and quartz. Accessory minerals such as zircon, apatite and magnetite are common. Typical alteration products are sericite and clay minerals. Late Cretaceous Artvin-Borçka bimodal rock series generally display a

  14. Geological and geomechanical properties of the carbonate rocks at the eastern Black Sea Region (NE Turkey)

    NASA Astrophysics Data System (ADS)

    Ersoy, Hakan; Yalçinalp, Bülent; Arslan, Mehmet; Babacan, Ali Erden; Çetiner, Gözde

    2016-11-01

    Turkey located in the Alpine-Himalayan Mountain Belt has 35% of the natural stone reserves of the world and has good quality marble, limestone, travertine and onyx reserves especially in the western regions of the country. The eastern Black Sea Region with a 1.4 million meters cubes reserve has a little role on the natural stone production in the country. For this reason, this paper deals with investigation on the potential of carbonate stone in the region and determination of the geological and geo-mechanical properties of these rocks in order to provide economic contribution to the national economy. While the study sites are selected among the all carbonate rock sites, the importance as well as the representative of the sites were carefully considered for the region. After representative samples were analyzed for major oxide and trace element compositions to find out petrochemical variations, the experimental program conducted on rock samples for determination of both physical and strength properties of the carbonate rocks. The results of the tests showed that there are significant variations in the geo-mechanical properties of the studied rock groups. The density values vary from 2.48 to 2.70 gr/cm3, water absorption by weight values range from 0.07 to 1.15% and the apparent porosity of the carbonate rocks are between 0.19 and 3.29%. However, the values of the UCS shows variation from 36 to 80 MPa. Tensile and bending strength values range from 3.2 to 7.5 MPa and 6.0-9.2 MPa respectively. Although the onyx samples have the lowest values of apparent porosity and water absorption by weight, these samples do not have the highest values of UCS values owing to occurrence of the micro-cracks. The UCS values of the rock samples were also found after cycling tests However, the limestone samples have less than 5% deterioration after freezing-thawing and wetting-drying tests, but travertine and onyx samples have more than 15% deterioration. Exception of the apparent

  15. PRECIPITATION OF PLUTONOUS PEROXIDE

    DOEpatents

    Barrick, J.G.; Manion, J.P.

    1961-08-15

    A precipitation process for recovering plutonium values contained in an aqueous solution is described. In the process for precipitating plutonium as plutonous peroxide, hydroxylamine or hydrazine is added to the plutoniumcontaining solution prior to the addition of peroxide to precipitate plutonium. The addition of hydroxylamine or hydrazine increases the amount of plutonium precipitated as plutonous peroxide. (AEC)

  16. Mechanics of Triangle Plutons

    NASA Astrophysics Data System (ADS)

    Parker, G. A.; Yin, A.

    2013-12-01

    Although most plutons around the world display circular or elliptic geometry in map view, some crop out with distinctive triangle geometry. The most prominent examples of the latter types of plutons are those exposed in the White-Inyo Mountains of eastern California. They include the Cretaceous Birch Creek pluton and Jurassic Beer Creek pluton. The triangle plutons are commonly bounded by overturned folds on all three sides, suggesting that the emplacement was mostly accommodated by magmatic expansion. Here, we present a mechanical model to explain the formation of triangle plutons. First, a rising pluton expands in the brittle upper crust, causing its overlain strain to expand uniformly in all directions. Such uniform expansion leads to the formation of a triple-junction like crack system, with three arms oriented at about 120 degrees from one another. Second, the rising and expanding magmatic body intrudes into the three extensional fracture zones and pushes the wall rocks of the cracks laterally as they fill and expand the cracks. Third, the three triangular domains bounded by the triple-junction like extensional cracks become folded as a result of uniform expansion of the magma. Our mechanical models are currently being evaluated against field observations using balanced cross sections around the rims of the Birch Creek pluton, and simulation of the mechanics and kinematic evolution of its country rocks using scaled analogue experiments.

  17. Volcanostratigraphy, petrography and petrochemistry of Late Cretaceous volcanic rocks from the Görele area (Giresun, NE Turkey)

    NASA Astrophysics Data System (ADS)

    Oguz, Simge; Aydin, Faruk; Baser, Rasim

    2015-04-01

    In this study, we have reported for lithological, petrographical and geochemical features of late Cretaceous volcanic rocks from the Çanakçı and the Karabörk areas in the south-eastern part of Görele (Giresun, NE Turkey) in order to investigate their origin and magmatic evolution. Based on the previous ages and recent volcano-stratigraphic studies, the late Cretaceous time in the study area is characterized by an intensive volcanic activity that occurred in two different periods. The first period of the late Cretaceous volcanism (Cenomanian-Santonian; 100-85 My), conformably overlain by Upper Jurassic-Lower Cretaceous massive carbonates (Berdiga Formation), is represented by bimodal units consisting of mainly mafic rock series (basaltic-andesitic lavas and hyaloclastites, dikes and sills) in the lower part (Çatak Formation), and felsic rock series (dacitic lavas and hyaloclastites, crystal- and pyrite-bearing tuffs) in the upper part (Kızılkaya Formation). The second period of the late Cretaceous volcanism (Santonian-Late Campanian; 85-75 Ma) is also represented by bimodal character and again begins with mafic rock suites (basaltic-basaltic andesitic lavas and hyaloclastites) in the lower part (Çağlayan Formation), and grades upward into felsic rock suites (biotite-bearing rhyolitic lavas, ignimbrites and hyaloclastites) through the upper part (Tirebolu Formation). These bimodal units are intercalated with volcanic conglomerates-sandstones, claystones, marl and red pelagic limestones throughout the volcanic sequence, and the felsic rock series have a special important due to hosting of volcanogenic massive sulfide deposits in the region. All volcano-sedimentary units are covered by Tonya Formation (Late Campanian-Paleocene) containing calciturbidites, biomicrites and clayey limestones. The mafic rocks in the two volcanic periods generally include basalt, basaltic andesite and minor andesite, whereas felsic volcanics of the first period mainly consists of

  18. Lithospheric convective removal related post-collisional middle Eocene magmatism along the Izmir-Ankara-Erzincan suture zone (NE Turkey).

    NASA Astrophysics Data System (ADS)

    Göçmengil, Gönenç; Karacık, Zekiye; Genç, Ş. Can

    2017-04-01

    Obliteration of the Mesozoic Neo-Tethyan Ocean and succeeding collision of the micro plates along the northern part of Turkey lead the development of the İzmir-Ankara-Erzincan suture zone (IAESZ). The suturing and collision stages terminate with the amalgamation of the three different crustal blocks (Pontides, Central Anatolian Crystalline Complex and Anatolide-Tauride Block) in the Paleocene-Early Eocene period. After the collisional stage; a new phase of extension and magmatism concomitantly developed at the both sides and as well as along the IAESZ during the Middle Eocene period. However, the origin, mechanism and driving force of the post-collisional magmatism is still enigmatic. To understand and better constrain the syn-to post collisional evolutionary stages, we have carried out volcano-stratigraphy and geochemistry based study on the middle Eocene magmatic associations along a transect ( 100 km) from Pontides to the Central Anatolian Crystalline Complex (CACC) at the NE part of the Turkey. Middle Eocene magmatic activity in the region has been represented by calc-alkaline, alkaline, shoshonitic volcanic and granitic rocks together with scarce gabbroic intrusions. We particularly focused on middle Eocene volcano-sedimentary successions (MEVSS) to constrain the tectono-magmatic evolution of the abovementioned transect. The volcano-sedimentary succsessions are coevally developed and cover the crustal blocks (Pontides and CACC) and the IAESZ with a region wide unconformity. We have differentiated three lava series (V1-V2-V3) and their sub-groups (V1a-V1b; V2a-V2b) in MEVSS. Generally, all lava series have middle-K to shoshonitic composition with distinct subduction characteristics. V1 series is marked by presence of hydrous phenocrysts such as amphibole+biotite. V1a sub-group constitute the first volcanic product and characterized by the high Mg# (42-69); alkaline basaltic andesite, and hawaiites. V1b sub-group is represented by calc-alkaline, low Mg# (24

  19. Mineral chemical compositions of late Cretaceous volcanic rocks in the Giresun area, NE Turkey: Implications for the crystallization conditions

    NASA Astrophysics Data System (ADS)

    Oǧuz, Simge; Aydin, Faruk; Uysal, İbrahim; Şen, Cüneyt

    2016-04-01

    This contribution contains phenocryst assemblages and mineral chemical data of late Cretaceous volcanic (LCV) rocks from the south of Görele and Tirebolu areas (Giresun, NE Turkey) in order to investigate their crystallization conditions. The LCV rocks in the study area occur in two different periods (Coniasiyen-Early Santonian and Early-Middle Campanian), which generally consist of alternation of mafic-intermediate (basaltic to andesitic) and felsic rock series (dacitic and rhyolitic) within each period. The basaltic and andesitic rocks in both periods generally exhibit porphyritic to hyalo-microlitic porphyritic texture, and contain phenocrysts of plagioclase and pyroxene, whereas the dacitic and rhyolitic rocks of the volcanic sequence usually show a vitrophyric texture with predominant plagioclase, K-feldspar, quartz and lesser amphibole-biotite phenocrysts. Zoned plagioclase crystals of the mafic and felsic rocks in different volcanic periods are basically different in composition. The compositions of plagioclase in the first-stage mafic rocks range from An52 to An78 whereas those of plagioclase from the first-stage felsic rocks have lower An content varying from An38 to An50. Rim to core profile for the zoned plagioclase of the first-stage mafic rocks show quite abrupt and notable compositional variations whereas that of the first-stage felsic rocks show slight compositional variation, although some of the grains may display reverse zoning. On the other hand, although no zoned plagioclase phenocryst observed in the second-stage mafic rocks, the compositions of microlitic plagioclase show wide range of compositional variation (An45-80). The compositions of zoned plagioclase in the second-stage felsic rocks are more calcic (An65-81) than those of the first-stage felsic rocks, and their rim to core profile display considerable oscillatory zoning. The compositions of pyroxenes in the first- and second-stage mafic-intermediate rocks vary over a wide range from

  20. Effects of land-use changes on landslides in a landslide-prone area (Ardesen, Rize, NE Turkey).

    PubMed

    Karsli, F; Atasoy, M; Yalcin, A; Reis, S; Demir, O; Gokceoglu, C

    2009-09-01

    Various natural hazards such as landslides, avalanches, floods and debris flows can result in enormous property damages and human casualties in Eastern Black Sea region of Turkey. Mountainous topographic character and high frequency of heavy rain are the main factors for landslide occurrence in Ardesen, Rize. For this reason, the main target of the present study is to evaluate the landslide hazards using a sequence of historical aerial photographs in Ardesen (Rize), Turkey, by Photogrammetry and Geographical Information System (GIS). Landslide locations in the study area were identified by interpretation of aerial photographs dated in 1973 and 2002, and by field surveys. In the study, the selected factors conditioning landslides are lithology, slope gradient, slope aspect, vegetation cover, land class, climate, rainfall and proximity to roads. These factors were considered as effective on the occurrence of landslides. The areas under landslide threat were analyzed and mapped considering the landslide conditioning factors. Some of the conditioning factors were investigated and estimated by employing visual interpretation of aerial photos and topographic data. The results showed that the slope, lithology, terrain roughness, proximity to roads, and the cover type played important roles on landslide occurrence. The results also showed that degree of landslides was affected by the number of houses constructed in the region. As a consequence, the method employed in the study provides important benefits for landslide hazard mitigation efforts, because a combination of both photogrammetric techniques and GIS is presented.

  1. Geotechnical mapping for alluvial fan deposits controlled by active faults: a case study in the Erzurum, NE Turkey

    NASA Astrophysics Data System (ADS)

    Yarbasi, Necmi; Kalkan, Ekrem

    2009-08-01

    Erzurum, the biggest city of Eastern Anatolia Region in the Turkey, is located in Karasu Plain. Karasu Plain, located on the central segment of the Erzurum Fault Zone, is an intermountain sedimentary basin with a Miocene-Quaternary volcanic basement, andesitic-basaltic lava flows and fissure eruptions of basaltic lava. It was filled in the early Quaternary by lacustrine fan-delta deposits. The basin is characterized by NNE-SSW trending sinistral wrench faults on its eastern margin and ENE-WSW trending reverse faults on its southern margin. Both systems of active faults intersect very near to Erzurum, which is considered to be the most likely site for the epicenter of a probable future large earthquake. Historical records of destructive earthquakes, morphotectonic features formed by paleo-seismic events and instrument seismic data of region indicate to a very high regional seismicity. The residential areas of Erzurum are located on thick alluvial fan deposits forming under the control of faults on the central segment of the Erzurum Fault Zone, which is one of the most active fault belts of the East Anatolian Region. Over time, the housing estates of city such as Yenisehir and Yildizkent have been expanded toward to the west and southwest part of Erzurum as a consequence of rapid and massive construction during the last 30 years. Geotechnical investigation has therefore been undertaken the residential areas of city in order to characterize geotechnical properties over the varied lithologies examine the potential for geotechnical mapping and assess the foundation conditions of the present and future settlement areas. The geological field observations and operations have been performed to make the soil sampling and characterize the lateral and vertical changes in thickness of the alluvial deposits in trenches, excavations and deep holes with 6-12 m sections. The soil samples have been subjected to a series of tests under laboratory conditions to obtain physical and

  2. Cordierite-bearing strongly peraluminous Cebre Rhyolite from the eastern Sakarya Zone, NE Turkey: Constraints on the Variscan Orogeny

    NASA Astrophysics Data System (ADS)

    Dokuz, Abdurrahman; Külekçi, Elif; Aydınçakır, Emre; Kandemir, Raif; Cihat Alçiçek, M.; Pecha, Mark E.; Sünnetçi, Kadir

    2017-05-01

    The Cebre Rhyolite with an outcropping area up to 12 km2 is one of the rare extrusions in the Variscan basement of the Sakarya Zone. The unit consists of high-K calc alkaline rhyolites (SiO2 = 74-82 wt.%). Abundant phenocrysts of quartz and K-feldspar are accompanied by subordinate cordierite phenocrysts, rare muscovite microphenocrysts and biotite microcrysts set in a fine-grained groundmass. Three types of rock fragments (xenoliths) have been recognized; (i) porphyritic, (ii) equigranular hypabyssal and (iii) hypocrystalline fragments. Zircon U-Pb dating indicates that the Cebre Rhyolite was extruded at 332.8 ± 4.38 Ma, which post-dates the Variscan low temperature metamorphism and pre-dates the emplacement of I-type granitic intrusions (325-303 Ma).The samples are strongly peraluminous with A/CNK values ranging from 1.48 to 2.95 and A/NK from 1.49 to 2.99. They have very high K2O (3.72-7.42 wt.%) and Al2O3 (10.77-14.11 wt.%) contents, but very low CaO (0.02-0.21 wt.%), Na2O (0.05-0.78 wt.%) and MgO (0.3-0.21 wt.%) contents. The samples show geochemical affinity with the upper continental crust, e.g., enrichment of large ion lithophile elements (LILEs; K, Rb, U, Th, Pb), depletion of high field strength elements (HFSEs; Nb, Ta, Ti), Sr, P and Eu, but ԐNd(t) values (- 3.06 to - 8.75) and isotope ratios of Sr(t)(87Sr/86Sr = 0.70499-0.70915) and Pb(t) (206Pb/204Pb = 16.41-17.570, 207Pb/204Pb = 15.54-15.59, 208Pb/204Pb = 36.20-37.22) are similar to those of the lower crust. Geochemical and isotope data indicate that the Cebre Rhyolite was generated by melting of metapelitic rocks with some addition of intermediate metaigneous derived magma. As a geodynamic model, we propose that the Variscan Orogeny in Turkey was occurred by collision of Gondwana with an arc/terrane separated from the southern margin of Laurussia. This collision was followed shortly after by splitting of oceanic lithosphere into two pieces and sinking down into asthenosphere. Rapid upwelling of

  3. Compositional change of granitoids from Eastern Pontides Orogenic Belt (NE Turkey) at ca. 84 Ma: Response to slab rollback of the Black Sea

    NASA Astrophysics Data System (ADS)

    Liu, Ze; Zhu, Di-Cheng; Eyuboglu, Yener; Wu, Fu-Yuan; Rızaoǧlu, Tamer; Zhao, Zhi-Dan; Xu, Li-Juan

    2016-04-01

    Magma generation and evolution is a natural consequence of mantle dynamics and crust-mantle interaction. As a result, changes of magma compositions in time and space can be used, in turn, to infer these deep processes. In this paper we report new zircon U-Pb age and Hf isotope, whole-rock major and trace element, and Nd isotope data for the granitoids from Kürtün in Eastern Pontides. These data, together with the data in the literature, reveal the occurrence of magma compositional variations at ca. 84 Ma in the region, providing new insights into the mantle dynamics responsible for the generation of the extensive Late Cretaceous felsic magmatism in Eastern Pontides Orogenic Belt (NE Turkey) (Eyuboglu et al., 2015). Group I samples (SiO2 = 77-62 wt.%) were concentrated in 91-86 Ma and are characterized by their low CaO (1.6-1.5 wt.%) and Th (8.2-3.0 ppm) contents and low K2O/Na2O (0.7-0.1) and Th/La (0.4-0.2) ratios. Group II samples (SiO2 = 71-63 wt.%) were concentrated in 82-72 Ma and include high concentrations of CaO (5.2-3.0 wt.%) and Th (29.6-14.3), high K2O/Na2O (1.5-1.1) and varying Th/La (1.0-0.5) ratios. Group I samples have positive zircon eHf(t) (+9.6 to +7.6) and whole-rock eNd(t) (+3.5 to +2.5), significantly differing from those of Group II samples with eHf(t) of +1.9 to -1.5 and whole-rock eNd(t) of -3.6 to -3.8. Modeling results indicate that the Nd-Hf isotopic compositions of Group I and II samples can be interpreted as having derived from partial melting of the low-K amphibolite within the juvenile lower crust beneath the Eastern Pontides Orogenic Belt that incorporated into 15-20% and 70-75% enriched components from the basement rocks represented by the Carboniferous granites exposed in the region, respectively. In combination with the geological observations that indicate the occurrence of regional thermal subsidence (Bektaş et al., 1999) and extensional structure (Bektaş et al., 1999, 2001) during the Campanian (83.6-72.1 Ma), the coeval

  4. Late Silurian plutons in Yucatan

    NASA Astrophysics Data System (ADS)

    Steiner, M. B.; Walker, J. Douglas

    1996-08-01

    U-Pb measurements of zircons from two composite plutons in the Maya Mountains of the Yucatan Block (Belize) give Late Silurian ages. Zircons from one of the five compositional phases of the Mountain Pine Ridge pluton yield an age of 418±3.6 Ma. A second compositional phase gives a minimum age of 404 Ma, and zircons from a third phase, although plagued with high common Pb, yield ages consistent with the other two. Zircons from one compositional phase of the Hummingbird-Mullins River pluton indicate an age of about 410-420 Ma. These data demonstrate that two of the three Maya Mountains plutons residing among the strata of the Late Pennsylvanian through Permian Santa Rosa Group are older than that sedimentation. Although the third pluton was not dated, both the similarity of sedimentary facies patterns adjacent to it to those adjacent to one of the plutons dated as Late Silurian and a published single Rb-Sr age of 428 ± 41 Ma suggest this third pluton also was emergent during Santa Rosa deposition. Thus the new U/Pb dates and other data suggest that all three Maya Mountains plutons pre-date Late Carboniferous sedimentation and that none intrude the Santa Rosa Group. Although very uniform ages of about 230 Ma amongst all plutons, derived from abundant earlier dating by the K-Ar system, led to the conclusion that intrusion mostly had occurred in the Late Triassic, the U-Pb ages (obtained from the same sites as the K-Ar dates) demonstrate that the K-Ar ages do not derive from a Late Triassic intrusive episode. The K-Ar dates probably are a signature of the rifting associated with Pangean breakup and formation of the Gulf of Mexico. In a reconstructed Pangea, the position of the Maya Mountains Late Silurian plutons suggests that the Late Silurian Acadian-Caledonian orogen of eastern North America extended through the region of the future Gulf of Mexico. Finally, the U-Pb ages of the Maya Mountains plutons are the same as those of a group of shocked zircons found in the

  5. Petrological Features of The Post-Collisional Volcanics on the Izmir-Ankara-Erzincan Suture Zone at Around Almus and Yıldızeli Regions, NE Turkey.

    NASA Astrophysics Data System (ADS)

    Göçmengil, G.; Karacik, Z.; Genç, Ş. C.

    2014-12-01

    Following the closure of the northern Neo-Tethyan ocean, post-collisional magmatism developed both on the Izmir-Ankara-Erzincan suture zone (IAESZ) and the northern (Pontides) and southern (Kırşehir block) continents. Cenozoic volcanics (particularly Middle to Upper Eocene) from the Almus and Yıldızeli regions (NE, Turkey) have poorly known and exposed along the northern and southern part of the IAESZ respectively. In this presentation; we present geological, geochemical and isotopic data of these volcanic rocks to characterize the petrological evolution and petrogenesis on the different tectonic blocks. Almus region, have a composite basement of Mesozoic metamorphic and ophiolitic rocks. Volcanic and sedimentary units of the Middle Eocene covering the basement units have a stratigraphic sequence of: a basal conglomerate; fossiliferous sandstone/shale; epiclastic rocks; auto-brecciated lavas with basalt/basaltic andesite lava flows. All these units are cut by trachyte stocks. Besides, basement of Yıldızeli region consisting of Cretaceous Kırşehir block metamorphics with IAESZ melangé and flysch units. Volcanic and sedimentary units covers the basement are trachyte-trachyandesite lavas; fossiliferous limestone; basalt/basaltic andesite lava flows; pyroclastic units with dacitic lavas. Basalt/basaltic andesites from Almus region are sub-alkaline/mildly alkaline and display middle to high-K character. REE data display relative enrichments in LILE (Sr, K, Rb, Ba, Th) together with negative anomalies of Nb, Ta and P. Trachyte stocks are shoshonitic and display LILE enrichment together with negative patters of Nb, Ta, P and Eu. Besides, trachyte-trachyandesite and basalt/basaltic andesite from Yıldızeli region are sub-alkaline/mildly alkaline with middle-K to shoshonitic character. REE patterns show enrichments in LILE and depletion of Nb, Ta, P and Ti for both rock suites. The 87Sr/86Sr and 143Nd/144Nd ratios of volcanic rocks from both regions, range from 0

  6. Geochronological and geochemical constraints on the petrogenesis of late Cretaceous volcanic rock series from the eastern Sakarya zone, NE Anatolia-Turkey

    NASA Astrophysics Data System (ADS)

    Aydin, Faruk; Oǧuz, Simge; Şen, Cüneyt; Uysal, İbrahim; Başer, Rasim

    2016-04-01

    New SHRIMP zircon U-Pb ages and whole-rock geochemical data as well as Sr-Nd-Pb and δ18O isotopes of late Cretaceous volcanic rock series from the Giresun and Artvin areas (NE Anatolia, Turkey) in the northern part of the eastern Sakarya zone (ESZ) provide important evidence for northward subduction of the Neo-Tethyan oceanic lithosphere along the southern border of the ESZ. In particular, tectonic setting and petrogenesis of these subduction-related volcanites play a critical role in determining the nature of the lower continental crust and mantle dynamics during late Mesozoic orogenic processes in this region. The late Cretaceous time in the ESZ is represented by intensive volcanic activities that occurred in two different periods, which generally consist of alternation of mafic-intermediate (basaltic to andesitic) and felsic rock series (dacitic to rhyolitic) within each period. Although there is no geochronological data for the lower mafic-intermediate rock series of the first volcanic period, U-Pb zircon dating from the first cycle of felsic rocks yielded ages ranging from 88.6±1.8 to 85.0±1.3 Ma (i.e. Coniacian-Early Santonian). The first volcanic period in the region is generally overlain by reddish biomicrite-rich sedimentary rocks of Santonian-Early Campanian. U-Pb zircon dating for the second cycle of mafic-intermediate and felsic rocks yielded ages varying from 84.9±1.7 to 80.8±1.5Ma (i.e. Early to Middle Campanian). The studied volcanic rocks have mostly transitional geochemical character changing from tholeiitic to calc-alkaline with typical arc signatures. N-MORB-normalised multi-element and chondrite-normalised rare earth element (REE) patterns show that all rocks are enriched in LILEs (e.g. Rb, Ba, Th) and LREEs (e.g. La, Ce) but depleted in Nb and Ti. In particular, the felsic samples are characterised by distinct negative Eu anomalies. The samples are characterized by a wide range of Sr-Nd-Pb isotopic compositions (initial ɛNd values from -7

  7. Late-stage sinking of plutons

    USGS Publications Warehouse

    Glazner, A.F.; Miller, D.M.

    1997-01-01

    Many granodiorite to diorite plutons in the Great Basin of western North America are surrounded by rim monoclines or anticlines that suggest relative downward movement of the plutons while wall rocks were hot and ductile. We propose that such plutons rise to a level of approximately neutral buoyancy and then founder as their densities increase ??? 40% during crystallization. Late-stage sinking of intermediate to mafic plutons should be common when wall rocks are rich in weak, low-density minerals such as quartz and calcite. Structures related to sinking will overprint those related to initial pluton emplacement and may be mistaken for regional tectonic structures.

  8. Late Cretaceous A- and I-type granite association in the Sakarya Zone, NE Turkey: implications for the origin and slab roll-back of Neotethyan oceanic lithosphere

    NASA Astrophysics Data System (ADS)

    Karsli, Orhan; Aydin, Faruk; Uysal, İbrahim; Dokuz, Abdurrahman; Kandemir, Raif

    2017-04-01

    We present new geochronological, isotopical and geochemical data for the granitoid plutons that crop out within the eastern Sakarya Zone, in order to understand their origin and genetic links between A- and I-type granites. The plutons were divided into two subgroups as A- and I-type granites. LA-ICP-MS zircon U-Pb crystallization ages of 72 and 80 Ma indicate emplacement in latest Cretaceous time in the area. The plutons have almost similar mineral assemblages consisting mainly of quartz, alkali feldspar, plagioclase, amphibole, biotite and pyroxene with accessory minerals such as ilmenite, magnetite, apatite and zircon. They are mostly metaluminous to weakly peraluminous, with ASI (molar Al2O3/[CaO+K2O+Na2O]) values of 0.80 to 1.20 and belongs to shoshonitic and ultra-potassic series for A-types and high-K calc-alkaline for I-types. The samples of all the plutons have almost similar 87Sr/86Sr(i) ratios ranging from 0.704 to 0.707, relatively low ɛNd (t) values varying from -5 to 2 and their young TDM ages (0.70-1.20 Ga). The in situ zircon analyses of the samples show that the rocks have variable negative and positive ɛHf (t) values (-5 to 6) and Hf two-stage model ages (0.7 to 1.5 Ga), which are indicative of minor addition juvenile material. Simple isotope modeling of Sr-Nd data points to mixing of 70-90% of the lower crustal-derived melt with  10-30% of the mantle-derived melt at depths of lower crust. The required heat for partial melting is upwelling of hot asthenosphere triggered by slab roll-back events. All the data suggest that the metaluminous A- and I-type granites were derived from partial melting of the Paleoproterozoic lower continental crust dominated by mafic rocks in amphibolitic composition, with minor input of subcontinental lithospheric mantle-derived magma and followed by subsequent a limited fractional crystallization to generate a variety of rock types. Here, we believe that underplated basaltic magma, which carry alkaline fluids

  9. Possible cryptic tectono-magnetic fabrics in `post-tectonic' granitoid plutons of the Canadian Shield

    NASA Astrophysics Data System (ADS)

    Borradaile, Graham J.; Kehlenbeck, Manfred M.

    1996-01-01

    Two late Archean granitic plutons forcefully intruded and thermally metamorphosed Archean schists. Feldspar magacrysts aligned concentrically with the margins during inflation. Substantial tectonic deformation never affected the plutons. Nevertheless, both plutons show the same, consistently oriented, cryptic magnetic fabric revealed by anisotropy of low field susceptibility (AMS) from 134 samples. They have an NE-SW vertical magnetic foliation and a magnetic lineation trending 060/15. Eigenvalues of the orientation distribution of principal susceptibilities show that the magnetic fabrics have almost identical strengths, orientations and symmetry in both plutons. We propose a post-magmatic reactivation of the earlier regional tectonic shortening. This imparted a 'cryptic tectonic' magnetic fabric on the plutons that overprinted the magmatic AMS fabric in most outcrops. The plutons' AMS fabrics are subparallel to the much older schistosity of the country rocks. Because multidomain magnetite provides > 99% of the low field susceptibility of the rocks, it controls the AMS. However, we see no alignment of the magnetite grains. Thus, magnetic anisotropy may be due to stress alignment of intragranular domain walls and not controlled by grain shape, as usually assumed for magnetite.

  10. The Rhodope Zone as a primary sediment source of the southern Thrace basin (NE Greece and NW Turkey): evidence from detrital heavy minerals and implications for central-eastern Mediterranean palaeogeography

    NASA Astrophysics Data System (ADS)

    Caracciolo, L.; Critelli, S.; Cavazza, W.; Meinhold, G.; von Eynatten, H.; Manetti, P.

    2015-04-01

    Detrital heavy mineral analysis coupled with a regional geological review provide key elements to re-evaluate the distribution of the Rhodope metamorphic zone (SE Europe) in the region and its role in determining the evolution of the Thrace basin. We focus on the Eocene-Oligocene sedimentary successions exposed in the southern Thrace basin margin to determine the dispersal pathways of eroded crustal elements, of both oceanic and continental origins, as well as their different contributions through time. Lithological aspects and tectonic data coupled with geochemistry and geochronology of metamorphic terranes exposed in the area point to a common origin of tectonic units exposed in NW Turkey (Biga Peninsula) with those of NE Greece and SE Bulgaria (Rhodope region). The entire region displays (1) common extensional signatures, consisting of comparable granitoid intrusion ages, and a NE-SW sense of shear (2) matching zircon age populations between the metapelitic and metamafic rocks of the Circum-Rhodope Belt (NE Greece) and those of the Çamlica-Kemer complex and Çetmi mélange exposed in NW Turkey. Detrital heavy mineral abundances from Eocene-Oligocene sandstones of the southern Thrace basin demonstrate the influence of two main sediment sources mostly of ultramafic/ophiolitic and low- to medium-grade metamorphic lithologies, plus a third, volcanic source limited to the late Eocene-Oligocene. Detrital Cr-spinel chemistry is used to understand the origin of the ultramafic material and to discriminate the numerous ultramafic sources exposed in the region. Compositional and stratigraphic data indicate a major influence of the metapelitic source in the eastern part (Gallipoli Peninsula) during the initial stages of sedimentation with increasing contributions from metamafic sources through time. On the other hand, the western and more external part of the southern Thrace margin (Gökçeada, Samothraki and Limnos) displays compositional signatures according to a mixed

  11. Chemical and mineralogical changes of waste and tailings from the Murgul Cu deposit (Artvin, NE Turkey): implications for occurrence of acid mine drainage.

    PubMed

    Sağlam, Emine Selva; Akçay, Miğraç

    2016-04-01

    Being one of the largest copper-producing resources in Turkey, the Murgul deposit has been a source of environmental pollution for very long time. Operated through four open pits with an annual production of about 3 million tons of ore at an average grade of about 0.5% Cu, the deposit to date has produced an enormous pile of waste (exceeding 100 million tons) with tailings composed of 36 % SiO2, 39% Fe2O3 and 32% S, mainly in the form of pyrite and quartz. Waters in the vicinity of the deposit vary from high acid-acid (2.71-3.85) and high-extremely metal rich (34.48-348.12 mg/l in total) in the open pits to near neutral (6.51-7.83) and low metal (14.39-973.52 μg/l in total) in downstream environments. Despite low metal contents and near neutral pH levels of the latter, their suspended particle loads are extremely high and composed mainly of quartz and clay minerals with highly elevated levels of Fe (3.5 to 24.5% Fe2O3; 11% on average) and S (0.5 to 20.6% S; 7% on average), showing that Fe is mainly in the form of pyrite and lesser hematite. They also contain high concentrations of As, Au, Ba, Cu, Pb, and Zn. Waters collected along the course of polluted drainages are supersaturated with respect to Fe phases such as goethite, hematite, maghemite, magnetite, schwertmannite and ferrihydrite. Secondary phases such as Fe-sulphates are only found near the pits, but not along the streams due to neutral pH conditions, where pebbles are covered and cemented by Fe-oxides and hydroxides indicating that oxidation of pyrite has taken place especially at times of low water load. It follows, then, that the pyrite-rich sediment load of streams fed by the waste of the Murgul deposit is currently a big threat to the aquatic life and environment and will continue to be so even after the closure of the deposit. In fact, the oxidation will be enhanced and acidity increased due to natural conditions, which necessitates strong remedial actions to be taken.

  12. Organic Geochemical Characteristics and Depositional Environment of Aǧaçbaşi Plateau Peat, Köprübaşi/Trabzon, NE Turkey

    NASA Astrophysics Data System (ADS)

    Hoş Çebi, Fatma; Korkmaz, Sadettin

    2013-04-01

    Young peat deposits crop out in the southern part of the Aǧaçbaşı region of Trabzon city, Northern Turkey. In this study, chemical, organic geochemical, petrographic and palynological features of the peat occurrences are investigated and results obtained evaluated. According to palynological investigations, it is determined that peats were occured in terrestrial or lacustrine environments, which is containing average of 80% woody, 15% herbaceous and 5% amorphous organic matter. Age of peats has been determined as Miocene or younger, by the palynological age determinations. It is understood from the obtained SCI (Sport Color Index) analysis results that constituting organic material of peat is immature. Total organic carbon content of the peat is average 41.69% by pyrolysis analysis. HI values were calculated as average 315.46 mgHC/gTOC, which is very high for the coal occurrences. The high OI values (avg. 134 mgCO2/gTOC) show that the environments of peat deposits were oxic or suboxic. TAR (Terrigenous/Aquatic Ratio) and CPI (Carbon Preference Index) index value, is found to be 2.4 and 3.4 respectively. These values that resulted from dominance of high-numbered n-alkanes, indicate terrestrial organic matter input. According to the m/z 191 and m/z 217 mass peaks of GC chromatogram data which is obtained by biomarker analysis, sterane/hopane ratio suggests algal organic matter. Moreover, the lack of C34 and C35 homohopans show that organic matter deposited under oxic or suboxic conditions. Moretane/hopane, Tm/Ts and Tm/C30 hopane ratios were calculated in order of 0.15, 3.25 and 0.33, respectively. These values imply acidic and oxic conditions during the formation of peat. Due to the absence of 17α(H)-28.30-bisnorhopan in the m/z 191 chromatograms, it is concluded that Aǧaçbaşı plateau peat might be deposited in a terrestrial or lacustrine environments under oxic or suboxic conditions. Dominant sterane content of C29 suggests terrestrial organic matter input

  13. 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.

  14. Geochemistry and petrology of Late Cretaceous subvolcanic rocks (Macka-Trabzon) in the north of the eastern Black Sea region, NE-Turkey

    NASA Astrophysics Data System (ADS)

    Aydin, Faruk

    2013-04-01

    In this study, geochronological, geochemical and isotopical data for the early Campanian subvolcanic rocks (Macka-Trabzon) in the north of the eastern Blacksea region, northeastern Turkey, have initially been presented with the aim of determining its magma source and geodynamic evolution. The subvolcanic rocks cutting the subduction-related Late Cretaceous volcano-sedimantary rocks in the region are characterized by several sills and dykes with columnar structures and they consist of amphibole-rich quartz-diorite and quartz-tonalite porphyries, with some dioritic mafic microgranular enclaves. The host rocks have a microgranular porphyritic texture, and they contain 15-25% phenocryst of plagioclase and amphibole and have a matrix that is composed primarily of fine-grained quartz, orthoclase, and plagioclase. Accessory apatite, zircon and Fe-Ti oxides are present in all of the rocks. Secondary minerals such as epidote, calcite, sericite and clays are sometimes observed in the matrix or as hydothermal alteration products of some amphibole and plagioclase phenocrysts. When compared to the host rocks, the magmatic enclaves without quartz are fine-grained, and they contain higher ferromagnesian phases and lower feldspar minerals. Ar-Ar geochronology studies on the amphibole separates reveal that the porphyries have a crystallization ages of 81±0.5 Ma. All samples show a high-K calc-alkaline differentiation trend and I-type features with metaluminous character. The rocks and magmatic enclaves are characterized by enrichment of LILE and depletion of HFSE with negative Nb, Ti, Zr and P anomalies. The chondrite-normalized REE patterns are not fractionated [(La/Yb)N = 9-11] and do not display Eu anomalies (Eu/Eu* = 0.7-0.9). The porphyritic rocks and their enclaves are almost isotopically similar. Sr-Nd isotopic data for all of the samples display initial Sr = 0.7085-0.7087, epsilon Nd (81 Ma) = -6.0 to -6.9, with TDM = 1.38-1.63 Ga. The lead isotopic ratios are (206Pb/204Pb

  15. Crystal mush flow in a small concentrically expanded pluton (Castle Crags pluton; Klamath Mountains, CA, USA)

    NASA Astrophysics Data System (ADS)

    Machek, Matej; Závada, Prokop; Petrovský, Eduard; Roxerová, Zuzana; Špičák, Aleš

    2017-04-01

    By means of an example of small concentrically-zoned Castle Crags pluton in the Klamath Mountains (USA), we decipher origin of granite rock fabrics, emplacement mode, and evolution of internal architecture of the pluton, which have been mostly in the crystal mush state during fabric development and solidification. Through the detailed microstructural and magnetic study we discuss the pluton fabric formation and emplacement. The study combines the field-based structural measurements, anisotropy of magnetic susceptibility analyses, and rock magnetic properties with detailed quantitative and qualitative microstructural analysis. The pluton structure with the marginal strain gradient is interpreted as a result of compaction, melt segregation and cumulate formation in the granodiorite caused by the intrusion of the throndhjemite magma to the core of the already emplaced granodiorite. The lateral flow of the magma from the central region formed lobe, the existence of which aphiliates the Castle Crags pluton to concentrically expanded plutons, which grew in at least two increments. The AMS results put forward the presence of anomalously high intensive magnetic fabric, (high P values, P > 1.2) and evolution of the T parameter through the pluton. We interpret the high P values as a result of variable microstructural position and crystal plastic deformation of a part of the magnetite crystals due to magma flow in submagmatic state. The AMS ellipsoid shape evolution is explained by fabric intensification in earlier magma pulses due to the intrusion of the throndhjemite magma to the core of the evolving pluton.

  16. Petrology and radiogeology of the Stripa pluton

    SciTech Connect

    Wollenberg, H.; Flexser, S.; Andersson, L.

    1980-12-01

    Both the quartz monzonite and the metavolcanic leptite which it intruded are strongly fractured. Two stages of fracture filling are evident; an earlier stage encompassing quartz, sericite, feldspar, epidote, and chlorite, and a later stage dominated by carbonate minerals. The Stripa quartz monozite is chemically and mineralogically distinct from other plutons in the region. Muscovite is the predominant mica in the quartz monzonite; biotite has been altered to chlorite, hornblende is absent, and accessory minerals are scarce. In contrast, in other plutons in the Stripa region, biotite and hornblende are prominent mafic minerals and accessory minerals are abundant. The Stripa quartz monzonite is also considerably more radioactive than the the leptite and other plutons in the region. Uranium and thorium abundances are both approx. 30 ppM, considerably higher than in normal granitic rocks where the thorium-to-uranium ratio generally exceeds 2. Potassium-argon dating of muscovite from the Stripa quartz monzonite indicates that this rock may be older, at 1691 million years than granitic rock of the neighboring Gusselby and Kloten massifs, whose ages, based on K-Ar dating of biotite, are respectively 1604 and 1640 m.y. Heat flow and heat productivity considerations show that although Stripa quartz monzonite contains high abundances of radioelements, the pluton has little efect on the regional heat flow. If it occurs in a layered plutonic setting, it is not more than 1.5 km thick; otherwise it may comprise a stock, dike, or border phase that is relatively small compared with the large granitic plutons exposed in the region.

  17. Bullialdus - Strengthening the case for lunar plutons

    NASA Astrophysics Data System (ADS)

    Pieters, Carle M.

    1991-11-01

    Although many craters expose materials of a composition different from that of the local surroundings, Bullialdus has excavated material representing three distinct stratigraphic zones that occur in the upper 6 km of crust, the top two of which are gabbroic and the deepest of which is noritic. This three-component stratigraphy at Bullialdus provides strong evidence that the lunar crust includes pockets of compositionally layered material reminiscent of mafic layered plutons. When combined with previous information on the compositional diversity at other large craters, these remote analyses obtained in a geologic context substantially strengthen the hypothesis suggested from lunar samples that plutons play an integral role in lunar crustal evolution.

  18. Microstructures and magnetic fabrics of the Ngaoundéré granite pluton (Cameroon): Implications to the late-Pan-African evolution of Central Cameroon Shear Zone

    NASA Astrophysics Data System (ADS)

    Dawaï, Daouda; Tchameni, Rigobert; Bascou, Jérome; Awe Wangmene, Salomon; Fosso Tchunte, Périclex Martial; Bouchez, Jean-Luc

    2017-05-01

    The Ngaoundéré granite pluton, in Central-North Cameroon, located near the Central Cameroon Shear zone (CCSZ), and previously studied for its petrography and geochemistry, is characterized by the absence of macroscopic markers of deformation. In this study, we report microstructures and magnetic fabrics (AMS) of this pluton and discuss the relationship with the Pan-African evolution of the CCSZ. The pluton consists of a porphyritic Hbl-Bt-monzogranite at its rim and a porphyritic biotite-granite at its core, a petrographic distribution denoting a normal zoning pattern, i.e. more silicic toward the centre. As expected, magnetic susceptibilities values also exhibit a zoning pattern in agreement with petrographic zonation. Thermomagnetic data indicate that this pluton is dominantly ferromagnetic in behaviour. As indicated by its microstructures, the pluton has suffered a continuum of deformation from the magmatic state to the high temperature solid-state during magma crystallization and solidification. The magnetic foliations dominantly strike NE-SW and dip moderately to steeply and the lineations mostly plunge shallowly to the NE or SW, roughly parallel to NE-to ENE-trending Central Cameroun Shear Zone (CCSZ). The foliation poles define a girdle pattern with a zone axis (52°/11°) rather close to the best line of the lineations (44°/21°). These fabrics correlate with the structures of the country rocks ascribed by several workers to a regional transpression. Toward the margins of the pluton, particularly the northern one, the lineations tend to rotate from NE to N in azimuth. This change is interpreted as due to strain partitioning, simple shearing with NE-SW extension being relayed by compression toward the northern pluton border. This new magnetic fabric study suggests that the Ngaoundéré pluton (poorly dated at c. 575 Ma) was emplaced during the late stages of the CCSZ dextral transpressive movement. It also provides some more constraints on the correlation

  19. Asymmetric textural and structural patterns of a granitic body emplaced at shallow levels: The La Chinchilla pluton, northwestern Argentina

    NASA Astrophysics Data System (ADS)

    Macchioli Grande, M.; Alasino, P. H.; Rocher, S.; Larrovere, M. A.; Dahlquist, J. A.

    2015-12-01

    New mapping and a detailed structural study of the La Chinchilla stock, Sierra de Velasco, NW Argentina, suggest an asymmetrical shape of the pluton and provide strong evidence for its shallow emplacement depth. The pluton is a Lower Carboniferous monzogranite composed of K-feldspar, quartz, plagioclase and biotite. It exhibits an internal asymmetric textural zoning, defined by porphyritic granite in the southeastern region to equigranular granite in the northwestern region. The presence of subhorizontal dikes in the northwestern area, where the contacts dip shallowly, and subvertical dikes intruding the host rock nearby steep-dipping intrusive contacts in the southeastern region are compatible with an overall asymmetrical shape and internal structure of this pluton. Considering published crystallization ages, a dominant strain field occurring at around 12 Ma is inferred based on magmatic fabrics in the pluton and its host rock (the Huaco pluton), with a principal shortening direction oriented SW-NE, consistent with the general NW-SE strike of the body. Field evidence supports brittle fracturing and block displacement as the dominant emplacement mechanism, suggesting that magmatic stoping dominated during the late stage of the evolution of the magma chamber.

  20. 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.

  1. Multiphase groundwater flow near cooling plutons

    USGS Publications Warehouse

    Hayba, D.O.; Ingebritsen, S.E.

    1997-01-01

    We investigate groundwater flow near cooling plutons with a computer program that can model multiphase flow, temperatures up to 1200??C, thermal pressurization, and temperature-dependent rock properties. A series of experiments examines the effects of host-rock permeability, size and depth of pluton emplacement, single versus multiple intrusions, the influence of a caprock, and the impact of topographically driven groundwater flow. We also reproduce and evaluate some of the pioneering numerical experiments on flow around plutons. Host-rock permeability is the principal factor influencing fluid circulation and heat transfer in hydrothermal systems. The hottest and most steam-rich systems develop where permeability is of the order of 10-15 m2. Temperatures and life spans of systems decrease with increasing permeability. Conduction-dominated systems, in which permeabilities are ???10-16m2, persist longer but exhibit relatively modest increases in near-surface temperatures relative to ambient conditions. Pluton size, emplacement depth, and initial thermal conditions have less influence on hydrothermal circulation patterns but affect the extent of boiling and duration of hydrothermal systems. Topographically driven groundwater flow can significantly alter hydrothermal circulation; however, a low-permeability caprock effectively decouples the topographically and density-driven systems and stabilizes the mixing interface between them thereby defining a likely ore-forming environment.

  2. Petrology and radiogeology of the Stripa pluton

    SciTech Connect

    Wollenberg, Harold; Flexser, Steve; Andersson, Lennart

    1980-12-01

    To better define the character of the rock encompassing the thermomechanical and hydrological experiments at the Stripa mine in central Sweden, and to help determine the size of the Stripa pluton, detailed studies were conducted of the petrology and radiogeology of the quartz monzonite and adjacent rocks. Petrologic studies emphasized optical petrography, with supplementary X-ray diffraction, X-ray fluorescence and microprobe analyses. Radiogeologic investigations were based primarily on surface and underground gamma-ray spectrometric measurements of uranium, thorium and potassium, supplemented by laboratory gamma spectrometric analyses and fission-track radiographic determinations of the locations and abundance of uranium in the rock matrix. Both the quartz monzonite and the metavolcanic leptite which it intruded are strongly fractured. Two stages of fracture filling are evident; an earlier stage encompassing quartz, sericite, feldspar, epidote, and chlorite, and a later stage dominated by carbonate minerals. The Stripa quartz monzonite is chemically and mineralogically distinct from other plutons in the region. Muscovite is the predominant mica in the quartz monzonite; biotite has been altered to chlorite, hornblende is absent, and accessory minerals are scarce. In contrast, in other plutons in the Stripa region biotite and hornblende are prominent mafic minerals and accessory minerals are abundant. The Stripa quartz monzonite is also considerably more radioactive than the leptite and other plutons in the region. Uranium and thorium abundances are both- 30 ppm, considerably higher than in "normal" granitic rocks where the thorium-to-uranium ratio generally exceeds 2. Potassium-argon dating of muscovite from the Stripa quartz monzonite indicates that this rock may be older, at 1691 million years than granitic rock of the neighboring Gusselby and Kloten massifs, whose ages, based on K-Ar dating of biotite, are respectively 1604 and 1640 m.y. Heat flow and heat

  3. Mafic sill/dykes intruding into late Maastrichtian-early Paleocene calciclastic units, NE-Turkey: Petrographical and geochemical features of latest magmatic activity before collision in the eastern Sakarya zone

    NASA Astrophysics Data System (ADS)

    Aydin, Faruk; Oǧuz, Simge; Karsli, Orhan; Kandemir, Raif; Şen, Cüneyt; Uysal, İbrahim

    2017-04-01

    We present here new petrographical, mineralogical and whole-rock geochemical data for mafic sill/dykes intruding into late Maastrichtian-early Paleocene calciclastic units in the Düzköy (Trabzon) and Cankurtaran (Artvin) areas (NE Turkey) of the eastern Sakarya zone (ESZ) in order to decipher the latest magmatic activity in the final stage of subduction-related magmatism of the ESZ. U-Pb zircon dating for the mafic sill/dykes in the region yielded ages varying from 83.6 to 78.5Ma (i.e. Early Campanian). Mafic sill/dykes consist of mostly basalts and lesser basaltic-andesites with komatiitic basalts. Most of the dyke samples display aphyric to porphyritic texture with phenocrysts of plagioclase (mostly replaced by calcite), clinopyroxene (partly uralized), olivine (almost serpentinized), and amphibole (partly chloritized). Based on the MgO, Nb and Zr contents with Nb/Y ratio, the mafic dykes from Düzköy area are mainly classified as two subgroups (basalts and basaltic andesites) while those of Cankurtaran can be divided into three different groups (low- and high-Nb normal basalts and komatitic basalts). Düzköy basaltic dykes have higher MgO (3.8-7.8%) and lower Nb (3-4ppm) and Zr (53-62ppm) contents with Nb/Y ratio (˜0.2) than those of Düzköy basaltic-andesitic dykes (MgO: ˜1.8%, Nb: 6-15ppm, Zr: 106-145ppm, Nb/Y: 0.3-0.6). On the other hand, Cankurtaran mafic sill/dykes have relatively high MgO contents (˜4-20%). These sill/dykes with 15-20% of MgO and <1% TiO2 contents are called as komatiitic basalt which has relatively low K2O (<1%), Nb (˜1ppm), Zr (23-26ppm) and Y (8ppm) contents with Nb/Y ratio (˜0.1-0.2). However, normal basalts from Cankurtaran have quite lower MgO contents (˜4-9%) than that of the komatiitic basalt. Also, they can be divided into two subgroups in terms of MgO (5.7-8.7% for group 1 and 4.0-4.4% for group 2), Nb (3-14ppm for group 1 and 19-21ppm for group 2), Zr (94-111ppm for group 1 and 125-140ppm for group 2) contents, and Nb

  4. The Port Mouton Shear Zone: intersection of a regional fault with a crystallizing granitoid pluton

    NASA Astrophysics Data System (ADS)

    Clarke, D. Barrie; McCuish, Krista L.; Vernon, Ron H.; Maksaev, Victor; Miller, Brent V.

    2002-04-01

    The peraluminous tonalite-monzogranite Port Mouton Pluton is a petrological, geochemical, structural, and geochronological anomaly among the many Late Devonian granitoid intrusions of the Meguma Lithotectonic Zone of southern Nova Scotia. The most remarkable structural feature of this pluton is a 4-km-wide zone of strongly foliated (040/subvertical) monzogranites culminating in a narrow (10-30 m), straight, zone of compositionally banded rocks that extends for at least 3 km along strike. The banded monzogranites consist of alternating melanocratic and leucocratic compositions that are complementary to the overall composition of that part of the pluton, suggesting an origin by mineral-melt and mineral-mineral sorting. Biotite and feldspar are strongly foliated in the plane of the compositional bands. These compositional variations and foliations originated by a process of segregation flow during shearing of the main magma with a crystallinity of 55-75%. Subsequent minor brittle fracturing of feldspars, twinning of microcline, development of blocky sub-grains in quartz, and kinking of micas demonstrate overprinting by a high-temperature deformation straddling the monzogranite solidus. Small folds and late sigmoidal dykes indicate dextral movement on the shear zone. This Port Mouton Shear Zone (PMSZ) is approximately co-linear with the only outcrops of Late Devonian mafic intrusions in the area, two of which are syn-plutonic with well-developed mingling textures in the marginal tonalite of the Port Mouton Pluton. Also closely co-linear with the mafic intrusions are a granitoid dyke that extends well beyond the outer contact of the Port Mouton Pluton, a swarm of large aligned angular xenolithic slabs, a zone of thin wispy schlieren banding, a large Be-bearing pegmatite, and a breccia pipe with abundant garnetiferous metapelitic xenoliths. In various ways, the shear zone may control all of these features. The Port Mouton Shear Zone is parallel to many other NE

  5. Thermal maturation of incrementally assembled plutons

    NASA Astrophysics Data System (ADS)

    Davis, J.; Coleman, D. S.; Heizler, M. T.

    2009-12-01

    The Cretaceous zoned intrusive suites of the Sierra Nevada batholith (SNB) were each assembled over 8-11 million years through incremental amalgamation of sheeted intrusions. Emplacement as small sheet-like increments inhibits development of a voluminous zone of melt bearing rock; instead the active magma body represents only a small portion of the total volume intruded. Plutons formed incrementally will have a protracted thermal history (T-t) that can be elucidated using thermochronologic techniques yielding insights into the thermal evolution of the lithosphere at magma chamber-pluton scales. Thermal histories are derived for plutons from the dike-like John Muir Intrusive Suite (JMIS) and the laccolithic Mount Whitney Intrusive Suite (MWIS), both located in the eastern-central SNB, by correlating estimated zircon saturation and argon closure temperatures with U-Pb zircon and titanite, 40Ar/39Ar amphibole, biotite, and K-feldspar ages. Close agreement among zircon and hornblende ages indicate rapid cooling following intrusion. However, hornblende and biotite ages are separated by 6-9 million years indicating slow protracted cooling. We interpret these data to reflect the thermal maturation of an incrementally assembled magma system in which temperatures cycled between ~500-300°C for millions of years. Hornblende ages were not reset by younger intrusions, therefore maximum reheating temperatures did not exceed ~500°C for geologically significant durations. T-t cooling curves from the intrusive suites are used to calibrate finite difference numerical simulations of pluton assembly. Intrusion geometries are modeled (HEAT 3D, Wohletz, 2007) by stacking horizontal increments from the top-down and bottom-up and vertical increments are emplaced syntaxially and antitaxially and are designed to generate plutons of the approximate dimensions, depth of emplacement, and age range of the Sierran suites. Numerical simulations yield the following general observations: 1) an

  6. Inhomogeneous Shearing Around Major Shear Zone: Evidence From the Magnetic Fabric of Late-Panafrican Plutons in the Tuareg Shield (Algeria)

    NASA Astrophysics Data System (ADS)

    Henry, B.; Derder, M. E.; Bayou, B.; Guemache, M.; Nouar, O.; Ouabadi, A.; Djellit, H.; Amenna, M.; Hemmi, A.

    2007-05-01

    Teg Orak and Tihaliouine are Late-Panafrican granitic intrusions situated in the Tuareg shield, northwest of Tamanrasset. Both plutons are located close to the 4°50 accident, one of the N-S major shear zone cutting the Hoggar. They are constituted of several granitic facies, indicating differentiation and multiphase intrusion. They show only very locally preferred visible orientation of their minerals. Anisotropy of Magnetic Susceptibility (AMS) was determined on samples collected along cross-sections in the Teg Orak (349 samples for 43 sites) and Tihaliouine (160 samples for 21 sites) plutons. At Tihaliouine, the AMS presents relatively scattered directions, with magnetic foliation having often strike similar to that of the plutons border. At Teg Orak, samples collected in the north-western part of the pluton present also AMS rather in relation with orientation of the pluton border. For all the other samples, including those from an aplitic dyke crossing the granite and whatever the facies of the granite, the fabric is very coherent. Magnetic lineation is subhorizontal, striking NW-SE. Magnetic foliation plunges to the NE on the north-eastern part of the plutons, has a weak dip in the central part and plunges to the SW in the south-western part. This disposition indicates deformation of the eastern part of the granite during late magmatic stages in relation with dextral strike-slip movement along the shear zone. Tihaliouine and western Teg Orak (mainly with fabric related with magma flow) intruded within older granite while eastern part of Teg Orak (with fabric related to deformation) is located within diorites and metamorphic rocks. In the Teg Orak - Tihaliouine area, granitic host-rocks acted therefore as a rigid block, protecting the studied plutons from the effect of regional deformation, while metamorphic and more basic plutonic rocks had a more deformable behavior and allowed intrusion strain.

  7. Wild turkey

    Treesearch

    William F. Moore; John C. Kilgo; William D. Carlisle; Michael B. Caudell

    2005-01-01

    Wild turkeys (Meleagris gallopavo) were once abundant throughout the southeast, but unregulated hunting and habitat destruction greatly reduced populations to a few thousand birds by 1930 (Hust and Dickson 1992). Though intensive restocking efforts beginning in the 1950s, protection from hunting, and reforestation, southeastern turkey populations...

  8. Timing of Proterozoic deformation, plutonism, and metamorphism in the Los Pinos Mountains, Central New Mexico

    SciTech Connect

    Shastri, L.L. . Dept. of Geology); Bowring, S.A. )

    1992-01-01

    Geochronologic, structural, and metamorphic studies within the Los Pinos Mountains (LPM), central NM provide new insights into the Proterozoic geologic history of this area. The LPM consist of a NE-trending, NW-dipping sequence of complexly deformed amphibolites and felsic schists. These have been intruded by a pervasively deformed granitic pluton. Two predominant deformational fabrics exist in the LPM. S1 is an early northwest-trending foliation, commonly parallel to compositional layering, which is folded about S2. S2 is axial planar foliation to tight to isoclinal folds and is the regional NE-trending fabric. Other fabrics and complex fold interference patterns may be related to localized strain partitioning around granitic bodies. A network of granitic dikes associated with the pluton crosscuts S2 but contains a weak foliation parallel to S2, suggesting synkinematic intrusion of the dikes. Regional metamorphism in the LPM took place at upper greenschist to lower amphibolite facies. Electron microprobe traverses of garnets show compositional variation indicative of growth zoning. No abrupt changes in composition representative of multiple metamorphic events are observed. Garnet-biotite geothermometry yields average rim temperatures of 454 [+-] 50 C. U-Pb geochronology of zircons from amphibolite, granite, and a granite dike indicates essentially the same age for all three units (1.66 Ga). The amphibolite contains abundant zircons which have complex morphologies typical of metamorphic growth; however, an igneous origin cannot yet be precluded. Spheres from the same amphibolite yield a near concordant age of 1.62 Ga. Thus, deformation, plutonism, and possibly the peak of metamorphism, were coeval at ca. 1.66 Ga, with metamorphism cooling through the blocking temperature of sphene at 1.62 Ga. The LPM are similar to other mountain ranges in south-central New Mexico where 1.66 Ga ages have been reported.

  9. Geochemistry and Geochronology of Eocene Plutons in Northeastern Washington: A Test of Farallon Slab Rollback as a Cause of the Challis Event

    NASA Astrophysics Data System (ADS)

    Caulfield, L.; Tepper, J. H.

    2015-12-01

    The causes of widespread magmatism and extension that affected the Pacific Northwest during the Eocene "Challis Event" are poorly understood. Two models that have been advanced to explain this activity are passage of a slab window (e.g., Haeussler et al., 2011) and rollback of the subducting Farallon slab following accretion of Siletzia (Schmandt and Humphreys, 2011). Both scenarios would have resulted in widespread magmatism but with different temporal patterns. Based on reconstructed plate motion vectors magmatism related to a slab window should produce a younging-to-the-NW pattern whereas magmatism associated with slab rollback should young to the S or SW. Existing dates on Eocene igneous units in NE Washington appear to show an overall younging to the SW, consistent with the slab rollback model. However, many of these dates (mainly K-Ar) have large uncertainties so we are conducting a U-Pb dating and geochemical survey of Eocene plutons across the region. An initial set of zircon U-Pb ages (by LA-MC-ICP-MS) from five intrusions in east-central WA range from 50.7 - 46.7 Ma and young to the SW, a trend similar to that observed among Eocene rocks in the Idaho Batholith (Gaschnig et al., 2013). To further investigate this pattern we are dating an additional ten plutonic units that define a ~100 km SW-NE transect through NE WA. From NE to SW the units in this transect are (with dates from WA DNR mapping) as follows: Sheppard granite (undated), Herron Creek intrusion (51.4 +/- 1.9 Ma), Mt. Bonaparte pluton (52.8 +/- 2.6 Ma), Daisy Trail granite (49.9 +/- 0.3 Ma), Swimptkin Creek pluton (48.2 +/- 1.2 Ma), Moses pluton (48.6 +/- 1.2 Ma), Keller Butte granite (52.9 +/- 0.4 Ma), Johnny George plutonic complex (49.9 +/- 0.45 Ma), Manilla Creek (undated), and Swawilla Basin pluton (58.8 +/- 2.2 Ma). Results of this study should lead to a better understanding of the cause(s) of Challis magmatism and specifically its relationship to the ~50-48 Ma accretion of Siletzia.

  10. A Structural-Thermal Model of the Karkonosze Pluton (Sudetes Mountains, SW Poland) for Hot Dry Rock (HDR) Geothermal Use

    NASA Astrophysics Data System (ADS)

    Bujakowski, Wiesław; Barbacki, Antoni; Miecznik, Maciej; Pająk, Leszek; Skrzypczak, Robert

    2016-12-01

    The main objective of this study was to develop a spatial temperature distribution of the Karkonosze Pluton to indicate optimum locations for HDR systems at drillable depth. HDR geothermal technology makes it possible to extract heat from the Earth in areas where no hydro-geothermal resources are present. To produce electricity in a binary cycle, system temperatures of > 100°C are usually required. In this paper, the authors have analysed the potential opportunities for applying HDR technology in the area of the Karkonosze Pluton, which is regarded as an optimum location for the application of the HDR concept (due to the potential for stimulation offered by the mechanical properties of the granites, radiogenic heat production, modern tectonic activity, and the thickness of the pluton). The model used in the analysis, which takes into account a hypothetical assessment of the manner and paths of fluid migration within the pluton, provides an insight into the spatial distribution of subsurface temperatures. It thus allows the location of relatively shallow high-temperature zones, which are optimal for the efficient application of HDR technology, to be identified. With respect to this technology, the Szklarska Poręba area and the NE part of the pluton seem to be better targets than the Cieplice central area, where the model indicated much lower temperatures (e.g. at a depth of 5,000 m, estimated temperatures in the vicinity of Szklarska Poręba were about 185°C and in the vicinity of Cieplice they were about 140°C).

  11. Petrology of Aztec Wash pluton, Eldorado Mountains, southern Nevada

    SciTech Connect

    Falkner, C.M.; Miller, C.F. ); Wooden, J.L. )

    1993-04-01

    Aztec Wash pluton, a 50 km[sup 2] intrusive complex in the northern Eldorado Mountains, was emplaced ca. 16 Ma (Faulds et al., 1990) during extension within the Colorado River Corridor. The pluton displays extreme compositional variability, ranging from olivine gabbro (ca. 50 wt% SiO[sub 2]) to highly evolved aplite (76% SiO[sub 2]). Most of the intrusion is medium grained, homogeneous granite (ca. 72% SiO[sub 2]), but 1/3 is highly heterogeneous and dominated by mafic to intermediate rocks; a 6 [times] 3km, N-S mafic zone almost bisects the pluton. Well-displayed magma mingling and late mafic and felsic dikes verify the coexistence of mafic and felsic melts. Hornblende barometry indicates that the entire exposed portion of Aztec Wash pluton was emplaced at very shallow depth (pluton has undergone little tilting. Mafic dikes that preceded emplacement of the pluton are variably dipping and in some cases sub horizontal, possibly suggesting a more complex pre-pluton deformational history. The authors propose the following emplacement history for Aztec Wash pluton: felsic magma intruded shallow levels of crust; the base of the magma chamber was intruded by basalt; after the upper portion of the initial magma was largely crystallized, basalt ascended into, perhaps remobilized, and mingled with felsic magma; this ascent may have been facilitated by E-W extension of the crystallizing pluton; more discrete syn- to post-pluton, mafic to felsic dikes mark additional intrusive pulses triggered by basalt intrusion and extensional fracturing. Field relations suggest that the mingling led to mixing in both the main units and the late dikes, but geochemical data indicate that mixing, if it occurred, was not a simple 2-end member process.

  12. Death Valley turtlebacks: Mesozoic contractional structures overprinted by Cenozoic extension and metamorphism beneath syn-extensional plutons

    NASA Astrophysics Data System (ADS)

    Pavlis, T. L.; Miller, M.; Serpa, L.

    2008-07-01

    -thrust belts. Our work to the east of Death Valley suggests these thrusts were part of a NW trending thrust system that overprinted an older NE trending fold-thrust system that tracks into the Death Valley region from Nevada. These NW trending thrusts probably underlie all of the southern Black Mountains (south of the turtlebacks) and we suggest that pre-extensional structural relief along these basement thrusts placed basement at shallow crustal levels throughout what is now the Black Mountains; a conclusion consistent with the absence of rocks younger than Cambrian beneath Tertiary unconformities throughout the southern Death Valley region. In Late Miocene time, a major detachment system formed and the turtlebacks represent a mid-crustal shear zone developed during that time period, but this system is older, and structurally beneath younger detachments systems that comprise the Amargosa fault system. During motion on the detachment, an ~2km thick plutonic sheet was emplaced along the shear zone forming the Miocene plutonic assemblages of the Black Mountains, and produced upper amphibolite facies metamorphic assemblages along the floor of the pluton in what are now the Copper Canyon and Mormon Point turtlebacks, but the Badwater Turtleback escaped this metamorphism due to a different structural position. Motion continued along the floor of the pluton but syn-extensional folding produced structural relief along folds with axes parallel to the extension direction. Ultimately a new detachment system cut obliquely across the older extensional system, removing the roof of the pluton, but cutting down to its floor in the turtlebacks. This fault system formed a complex detachment system updip in the famous 'Amargosa Chaos', and removing the entire cover sequence from the Black Mountains (~10-12km of crustal section). The turtlebacks are therefore a composite structure in which extension contemporaneous with folding, presumably as a result of distributed transcurrent motion during

  13. Thermal Modeling of Large Composite Plutons

    NASA Astrophysics Data System (ADS)

    Bartley, J. M.; Wohletz, K.; Coleman, D. S.; Glazner, A. F.

    2004-12-01

    Field and geochronologic evidence indicate that large plutons commonly amalgamate from many small intrusive increments [e.g., Glazner et al., 2004, GSA Today; Coleman et al., 2004, Geology]. To investigate the thermal consequences of this process, we model the growth of composite intrusions using the program HEAT. HEAT uses a finite-difference scheme to track transport and storage of heat, and resulting temperature variations, in a 2-D or 3-D intrusion and its wall rocks. Heat advected by wall-rock displacement is conserved kinematically by distributing the heat of intruded rock into adjacent mesh locations following a system determined by the aspect ratio of each intrusive increment. Modeling to date focuses on laccolithic plutons formed by stacking of sills. In a typical model, an 1100°C sill of intermediate-composition magma with a solidus of 750°C, 100-m-thick and 10-km-wide, is emplaced every 10 ka (10 mm/yr vertical inflation rate) for 600 ka to form a tabular pluton 6 km thick. Model runs to date have yielded at least three intriguing results. 1) Stacking of sills from bottom to top produces higher sustained temperatures than stacking from top to bottom. Over the first half of a 600 ka emplacement time, a bottom-up intrusion completely solidifies between increments but, during the latter half, a partial-melt zone becomes a steady-state feature. Dimensions of the partial melt zone vary through a 10 ka intrusive cycle, but the thickness reaches nearly 2 km by the time the last sill is emplaced. An otherwise identical top-down intrusion solidifies completely after each intrusive increment until the last 35 ka, when a small zone of partial melt persists between increments. The large composite complexes of the Sierra Nevada such as the Tuolumne and Whitney intrusive suites appear to have grown from their tops down, but bottom-up plutons also have been widely reported. 2) The partial-melt zone in a bottom-up intrusion mainly forms below each new intrusive

  14. Cooling history of nested plutons from the Variscan Tichka plutonic complex (Morocco)

    NASA Astrophysics Data System (ADS)

    Lécuyer, Christophe; Gasquet, Dominique; Allemand, Pascal; Martineau, François; Martinez, Isabelle

    2017-03-01

    Four imbricated mafic to felsic plutons of Variscan age from Morocco have been investigated for their cooling history and geochemical interactions with surrounding continental rocks. Oxygen isotope compositions of whole rocks and minerals have been used to model the cooling rates of these kilometer-sized intrusions. By combining both the knowledge of oxygen-self diffusion data of rock-forming minerals and the determination by IR-spectroscopy of the water content of quartz, the cooling times are estimated ranging from 105 to 5 × 105 years in agreement with the shallow emplacement (4-6 km depth) of these intrusions into the continental crust. Such fast cooling rates could explain why after assimilation of the various country rocks, heterogeneities of both neodymium and strontium isotope ratios were still preserved. A progressive δ18O increase from the mafic to felsic terms of the plutonic suite, which does not excess 1 to 1.5‰, could be explained by the assimilation of metamorphosed pelitic and volcanic rocks that constitute the basement of the Tichka plutonic complex.

  15. Relationship of voluminous ignimbrites to continental arc plutons: Petrology of Jurassic ignimbrites and contemporaneous plutons in southern California

    USGS Publications Warehouse

    Fohey-Breting, N. K.; Barth, A.P.; Wooden, J.L.; Mazdab, F.K.; Carter, C.A.; Schermer, E.R.

    2010-01-01

    Volcanism was broadly associated in both space and time with Mesozoic plutonism in the Cordillera continental margin arc, but the precise petrogenetic relationships between volcanic rocks and adjacent zoned plutons are not known. Igneous rocks in a tilted crustal section in California include four laterally extensive Jurassic ash flow tuffs from 550 to >1100 m thick underlain at deeper structural levels by Jurassic plutons. Zircon geochronology confirms previous correlations of individual tuffs, suggesting ignimbrites with eruptive volumes up to 800 km3 were deposited both during the apparent Early Jurassic plutonic lull as well as contemporaneous with solidification of regionally widespread Middle and Late Jurassic plutons. The tuffs are weakly to strongly porphyritic (5 to 55% phenocrysts) monotonous intermediate porphyritic dacite to low-silica rhyolite and show strong bulk rock chemical affinity to contemporaneous plutons. Trace element compositions of zircons from the tuffs and contemporaneous plutonic rocks record large and consistent differences in Hf/Zr and REE over similar ranges in Ti abundances, supporting bulk compositional similarities and illuminating similarities and variations in thermal histories despite the effects of hydrothermal alteration. ?? 2009 Elsevier B.V. All rights reserved.

  16. From steep feeders to tabular plutons - Emplacement controls of syntectonic granitoid plutons in the Damara Belt, Namibia

    NASA Astrophysics Data System (ADS)

    Hall, Duncan; Kisters, Alexander

    2016-01-01

    Granitoid plutons in the deeply eroded south Central Zone of the Damara Belt in Namibia commonly show tabular geometries and pronounced stratigraphic controls on their emplacement. Subhorizontal, sheet-like pluton geometries record emplacement during regional subhorizontal shortening, but the intrusion of spatially and temporally closely-related granitoid plutons at different structural levels and in distinct structural settings suggests independent controls on their levels of emplacement. We describe and evaluate the controls on the loci of the dyke-to-sill transition that initiated the emplacement of three syntectonic (560-530 Ma) plutons in the basement-cover stratigraphy of the Erongo region. Intrusive relationships highlight the significance of (1) rigidity anisotropies associated with competent sedimentary packages or pre-existing subhorizontal granite sheets and (2) rheological anisotropies associated with the presence of thick ductile marble horizons. These mechanical anisotropies may lead to the initial deflection of steep feeder conduits as well as subsequent pluton assembly by the repeated underaccretion of later magma batches. The upward displacement of regional isotherms due to the heat advection associated with granite emplacement is likely to have a profound effect on the mechanical stratification of the upper crust and, consequently, on the level at which granitoid pluton emplacement is initiated. In this way, pluton emplacement at progressively shallower crustal depths may have resulted in the unusually high apparent geothermal gradients recorded in the upper crustal levels of the Damara Belt during its later evolution.

  17. Fabric and microstructural analysis of the Loch Borralan pluton, Northwest Highlands, Scotland

    NASA Astrophysics Data System (ADS)

    Calhoun, Justin

    The Loch Borralan pluton was emplaced within the Assynt Region of the Moine Thrust zone during the Scandian event (ca. 435-425 Ma) of the Caledonian Orogeny (478-425 Ma). It consists of two major magma suites, the syenitic early suite (431.1 +/- 1.2 Ma), and the quartz syenitic later suite (429.2 +/- 0.5 Ma). The region is characterized by a series of in-sequence thrust faults that strike NE-SW and dip approximately 20° to the SE, including (from lower to upper): the Sole Thrust, the Borralan Thrust (hypothesized, but not exposed), the Ben More Thrust, and the Moine Thrust. A series of imbricate thrusts between the Sole and Borralan Thrusts juxtapose repeated Cambrian and Ordovician strata. The Loch Borralan pluton intruded between the Sole and Ben More thrust faults, and may be bounded below by a hypothesized Borralan Thrust fault. Based on the overlap in pluton crystallization age and orogenic activity, the combination of macroscopic field lineation and foliation measurements, anisotropy of magnetic susceptibility (AMS) lineation and foliations measurements, mineral shape preferred orientation (SPO) analysis, and petrographic deformation microstructure analysis will be used to determine if the pluton expresses deformation features and fabrics corresponding to thrust fault tectonics. The dominant magnetic mineralogy as determined by thermomagnetic data and hysteresis plots was determined to be magnetite and titanomagnetite. Some paramagnetic components were seen in the early suite, and can be attributed to biotite. Both minerals contributed to the AMS signal that was used to interpret pluton fabrics. The pluton contains S>L (foliation stronger than lineation) fabrics throughout, defined by alignment of alkali feldspar grains. The foliation strike of both the early and late suites are subparallel to the thrust faults, providing evidence that the fabrics are related to deformation. The early suite is only well exposed in the southeast at the top of the Borralan

  18. Paleocene plutonism and its tectonic implications, North Cascades, Washington

    SciTech Connect

    Miller, R.B. ); Bowring, S.A. ); Hoppe, W.J. )

    1989-09-01

    U-Pb zircon geochronology has identified a northwest-trending belt of Paleocene (68-59 Ma) plutons within the crystalline core of the North Cascades. Most of these plutons show amphibolite facies assemblages and solid-state foiliation. They document extensive Paleogene dynamothermal metamorphism in the core, and combined with other recent studies, demonstrate ongoing metamorphism from mid-Cretaceous to mid-Eocene time. The Paleocene plutons were emplaced during an interval that marked a magmatic lull throughout much of the northern Cordillera. The distribution of latest Cretaceous and Paleocene plutons suggests that magmatism in the North Cascades core records the same eastward retreat that occurred farther north in the Cordillera.

  19. LA ICP MS and Ion Probe U-Pb dating of igneous and metasedimentary units in the NE Pontides, NE Turkey: evidence of Peri-Gondwanan terrane accretion, Late Palaeozoic magmatism/metamorphism and Early Mesozoic extension along the S Eurasian margin

    NASA Astrophysics Data System (ADS)

    Ustaömer, Timur; Robertson, Alastair H. F.; Gerdes, Axel; Ayda Ustaömer, P.

    2010-05-01

    The Artvin area is critical to an understanding of the tectonic development of the S margin of Eurasia and Tethys to the south. We have supplemented recent MTA mapping with 1/25,000-scale mapping of a critical area, combined with integrated stratigraphical, sedimentary, geochemical and geochronological studies. Here, we focus on U-Pb zircon dating of igneous and detrital zircons derived from basement units of the Pontide Autocthon and from overlying slice complexes, carried out by LA ICP MS at Frankfurt University and by Ion Probe at Edinburgh University. The Eastern Pontide Autocthon is overlain by north-vergent thrust sheets, mostly of continental margin origin, whereas Mesozoic (Neotethyan) ophiolites form the uppermost thrust sheet. The Autochton basement (Çamlıkaya pluton) is mainly tonalite, cut by granitic dykes. Both intrusions are of within-plate type, without a chemically identifiable subduction influence. The pluton yielded a concordant age of 330.4 ± 4.2 Ma (Visean), while crosscutting dykes gave an age of 156.3 ± 2.0 Ma (Oxfordian). The overlying lower slice complex (Slice 1) begins with a low-grade meta-clastic basement unit, intruded by coarse-grained granite. Detrital zircons from the meta-clastics yielded late Neoproterozoic (579-700), early Neoproterozoic (0.9 Ga) and Kibaran/Grenvillian (1.1-1.3 Ga) zircon populations. The oldest known zircon has an age of 2719 Ma. Slice 2 above this (Demirkent Intrusive Complex) is represented by foliated amphibolites, cut by granitic veins and, together, cut by swarms of basic-silicic dykes that postdate regional metamorphism and related deformation. A granitic vein yielded a concordia age of 325.4 ± 2.8 Ma (Visean-Serpukhovian). Slice 2 was intruded by two small tonalitic bodies, one of which yielded a concordant age of 179.8 ± 1 Ma (Toarcian). Slice 3 above this begins with granulite-facies gneiss and schist (Karadağ Metamorphics). A representative 1 m-wide meta-granitic stock within paragneiss

  20. Petrogenesis of the reversely-zoned Turtle pluton, southeastern California

    SciTech Connect

    Allen, C.M.

    1989-01-01

    Few plutons with a reversed geometry of a felsic rim and mafic core have been described in the geologic literature. The Turtle pluton of S.E. California is an intrusion composed of a granitic rim and granodioritic core and common microgranitoid enclaves. Field observations, mineral textures and chemistries, major and trace element geochemistry, and isotopic variability support a petrogenetic model of in situ, concomitant, magma mixing and fractional crystallization of rhyolitic magma progressively mixed with an increasing volume of andesitic magma, all without chemical contribution from entrained basaltic enclaves. Hornblende geobarometry indicates the Turtle pluton crystallized at about 3.5 kb. A crystallization sequence of biotite before hornblende (and lack of pyroxenes) suggests the initial granitic magma contained less than 4 wt% H{sub 2}O at temperatures less than 780C. U-Pb, Pb-Pb, Rb-Sr and oxygen isotope studies indicate the terrane intruded by the Turtle pluton is 1.8 Ga, that the Turtle pluton crystallized at 130 Ma, that the Target Granite and garnet aplites are about 100 Ma, and that these intrusions were derived from different sources. Models based on isotopic data suggest the rhyolitic end member magma of the Turtle pluton was derived from mafic igneous rocks, and was not derived from sampled Proterozoic country rocks. Similarity of common Sr and Pb isotopic ratios of these rocks to other Mesozoic intrusions in the Colorado River Region suggest the Turtle pluton and Target Granite have affinities like rocks to the east, including the Whipple Mountains and plutons of western Arizona. P-T-t history of the southern Turtle Mountains implies uplift well into the upper crust by Late Cretaceous time so that the heating and deformation events of the Late Cretaceous and Tertiary observed in flanking ranges did not affect the study area.

  1. Geophysical modeling and structure of Ushuaia Pluton, Fuegian Andes, Argentina

    NASA Astrophysics Data System (ADS)

    Peroni, Javier Ignacio; Tassone, Alejandro Alberto; Menichetti, Marco; Cerredo, María Elena

    2009-10-01

    Within the area of Ushuaia Bay (Tierra del Fuego, southernmost South America) the deformed Lower Cretaceous sedimentary rocks of Yahgán Formation host the Ushuaia Pluton. The intrusive body is oval in map view; it is compositionally varied with rocks ranging from the ultrabasic to the mesosiliceous realm. The emplacement time is constrained within the Albian-Cenomanian span by new amphibole K/Ar data. Meso- and microstructures of Ushuaia Pluton and its host indicate a synkinematic emplacement with a dominant extensional component. A set of transcurrent and normal faults related to the sinistral strike-slip Beagle Channel Fault System affects the pluton and its host. On the basis of aeromagnetic data combined with field information, a new model is presented for the Ushuaia Pluton. Modeling results fit well with a laccolithic body with an estimated volume of around 111 km 3. The model pluton cross-section displays a central zone with an average thickness of 2000 m which progressively thins toward the margins (˜ 500 m) and a southern root which reaches 5000 m deep. The combined structural and geophysical model supports a transtensive scenario for the Ushuaia Pluton emplacement at Early-Late Cretaceous boundary.

  2. Geochemistry and geochronology of late Mesozoic volcanic rocks in the northern part of the Eastern Pontide Orogenic Belt (NE Turkey): Implications for the closure of the Neo-Tethys Ocean

    NASA Astrophysics Data System (ADS)

    Özdamar, Şenel

    2016-04-01

    This paper presents 40Ar/39Ar and U-Pb age data, Sr-Nd isotopes, whole-rock and mineral compositions of Upper Cretaceous volcanic rocks from the Ordu area of the Eastern Pontide Orogenic Belt (EPOB) in northeastern Turkey. The volcanic rocks exhibit a wide compositional range: basalt, basaltic-andesites, andesites and a rhyodacite suite; they are characterized by subparallel light rare earth element (LREE)-enrichment, relatively flat heavy rare earth element (HREE) patterns with Eu anomalies and moderate fractionation [average (La/Yb)N = 8.55]. The geochemical results show that the volcanic rocks have calc-alkaline affinity consistent with arc volcanic rocks erupted in an active continental margin. Initial 87Sr/86Sr values vary between 0.70569 and 0.70606, while initial 143Nd/144Nd values lie between 0.51244 and 0.51249. Crustal contamination affected the mantle-originated primary magma, as indicated by increased 87Sr/86Sr and decreased 143Nd/144Nd ratios with increasing SiO2. New precise laser ablation inductively coupled plasma mass spectrometer (LA-ICP-MS) 206Pb-238U age analyses of zircon and 40Ar/39Ar age data of plagioclase from the volcanics enable a more precise reconstruction of the EBOP. The ages provide insight into the timing of arc formation in this region, constrain the volcanic activity between 86 My (Coniacian) and 75 My (Campanian) and constrain the timing of closure of the Neo-Tethys.

  3. Turkey`s nuclear power effort

    SciTech Connect

    Aybers, N.

    1995-12-01

    This paper discusses the expected role of nuclear energy in the production of electric power to serve the growing needs of Turkey, examining past activities and recent developments. The paper also reviews Turkey`s plans with respect to nuclear energy and the challenges that the country faces along the way.

  4. Petrology of the Plutonic Rocks of west-central Alaska

    USGS Publications Warehouse

    Miller, Thomas P.

    1970-01-01

    A series of plutons in west-central Alaska defines the Hogatza plutonic belt which extends for about 200 miles in an east-west direction from the northeastern Seward Peninsula to the Koyukuk River. The plutonic rocks have an aggregate area of about 1,200 square miles and their composition, distribution, and possible petrogenesis are discussed for the first time in this report. Field, petrographic and chemical data supported by K/Ar age dating indicate the plutonic rocks are divisible into two suites differing in age, location, and composition. The western plutons are mid-Cretaceous (~100 m.y.) in age and consist of a heterogeneous assemblage of monzonite, syenite, quartz monzonite. Associated with these granitic rocks is a group of alkaline sub-silicic rocks that forma belt of intrusive complexes extending for a distance of at least 180 miles from west-central Alaska to the Bering Sea. The complex at Granite Mountain shows a rare example of zoning from an alkaline rim to a quartz-bearing core. The occurrence of a similar complex at Cape Dezhnev on the easternmost tip of Siberia suggests the alkaline province may extend into Siberia. The easternmost plutons are Late Cretaceous (180 m.y.) in age and composed primarily of granodiorite and quartz monzonite similar to calc-alkaline plutons found throughout the North America Cordillera. The plutons are epizonal and intrude deformed but unmetamorphosed Lower Cretaceous andesitic volcanics and volcanic graywacke which constitute the highly mobile Yukon-Koyukuk volcanogenic province of west-central Alaska. No older rocks have been found within the confines of this vast tract; the occurrence of a bounding ophiolite sequence has lead to the suggestion that the province was formed by large-scale rifting and is underlain by oceanic crust. The possibility of no juvenile sialic crust over much of the area suggests that the potassium-rich magma now represented by the alkaline rocks originated in the mantle. The distribution of the

  5. Early Paleozoic alkalic and calc-alkalic plutonism and associated contact metamorphism, central Virginia Piedmont

    USGS Publications Warehouse

    Pavlides, Louis; Arth, Joseph G.; Sutter, J.F.; Stern, T.W.; Cortesini, Henry

    1994-01-01

    Early Paleozoic plutonism in the central Virginia Piedmont consists of the igneous Lahore Complex and Ellisville Pluton. The Lahore Complex consists of a small altered mafic pluton intruded by the shoshonitic, alkalic monzonites of the Lahore Pluton (-450 Ma) that, in turn, is intruded by the calc-alkaline, granodioritic Ellisville Pluton (-440 Ma). These plutons were emplaced at about 760aC at a depth of 12 to 18 km within greenschist-facies rocks and are enclosed by contact-metamorphosed rocks.

  6. Anatomy of the Cretaceous Hobenzan pluton, SW Japan: Internal structure of a small zoned pluton, and its genesis

    NASA Astrophysics Data System (ADS)

    Imaoka, Teruyoshi; Nakashima, Kazuo; Kamei, Atsushi; Hayasaka, Yasutaka; Ogita, Yasuo; Ikawa, Toshiyuki; Itaya, Tetsumaru; Takahashi, Yoshio; Kagami, Hiroo

    2014-11-01

    Field, petrographic, geochemical, and K-Ar and U-Pb age data were used to elucidate the internal structure of the Cretaceous Hobenzan pluton, SW Japan, and the processes which generated that structure. The pluton is elongated E-W with dimensions of about 6.5 × 2.0 km (13 km2), and was emplaced at ~ 95 Ma as a pluton in accretionary complexes. The pluton contains an early tonalite, but most of the body consists of later granitoids that show a continuous differentiation series from biotite-hornblende granodiorite (GD) to hornblende-biotite granite (HBG) and biotite granite (BG). The contacts between the GD and HBG are gradational. The pluton provides an exceptional cross-sectional view of a simple cooling magma body. The GD shows no vertical variations in modal and chemical compositions, whereas the HBG displays differentiation from the lowermost exposure to the top of the pluton. Initial Sr isotope ratios (SrI) in the HBG increase from the lower part to the top of the pluton. The granitoids show continuous compositional variations from 65 to 79 wt.% SiO2 (anhydrous basis), and magmatic differentiation was dominantly controlled by crystal fractionation of hornblende and plagioclase. Field, elemental and Sr-Nd isotope data are consistent with limited operation of assimilation with pelitic rocks and fractional crystallization (AFC), in which assimilation increased with higher degrees of differentiation. The Hobenzan pluton retains a history of granitoid magma evolution in a subvolcanic magma reservoir. The GD formed as a rigid sponge, and melt fraction increases inwards from the walls, forming the HBG mush by fractional crystallization, coupled with small degrees of assimilation of adjacent schists. A more evolved and enriched low-density melt segregated from the mushy cumulate of the HBG by incomplete crystal-melt separation, and moved upwards with the assistance of gas-driven filter pressing, as indicated by the presence of miarolitic cavities, thus forming the BG

  7. Survey of lunar plutonic and granulitic lithic fragments

    NASA Technical Reports Server (NTRS)

    Bickel, C. E.; Warner, J. L.

    1978-01-01

    A catalog of lunar plutonic rocks and granulitic impactites belonging to the ANT suite has been compiled. The coarser-grained, plutonic rocks in the compilation are probably pristine; they belong to two groups, Mg-rich plutonic rocks and anorthosites, with a preponderance of the latter type. The granulitic impactites, however, have bulk and mineral compositions that fall between the two groups defined by the pristine nonmare samples of Warren and Wasson (1977). Thus the granulitic impactites may have originated by metamorphism of mixed impactites in early breccia sheets. The catalog, representative of the lunar crust before the end of heavy bombardment, suggests a crust with over 78 vol. % plagioclase and about equal proportions of material with noritic and troctolitic affinity.

  8. An AMS study of the Takidani pluton (Japan)

    NASA Astrophysics Data System (ADS)

    Hartung, Eva; Caricchi, Luca; Floess, David; Wallis, Simon; Harayama, Satoru

    2016-04-01

    Large plutonic bodies are typically constructed incrementally often by under-accretion of distinct successive magma pulses. Petrography and geochemistry of the Takidani Pluton (1.54 Ma ± 0.23 Ma) in the Northern Japanese Alps show that the chemical and textural variability observed at the roof of this intrusion is best explained by the segregation of residual melt from a crystallising magma body. We carried out a magnetic susceptibility survey (bulk susceptibility and anisotropy of magnetic susceptibility) to identify the structures associated with the emplacement and extraction of residual melts from a magmatic mush. Additionally, we determined shape preferred orientations (SPO) of amphibole at several locations within the Takidani pluton. From bottom to top of the intrusion, the bulk susceptibility is about constant in the main granodioritic part, decreases roofwards within the porphyritic unit, before increasing again within the marginal granodiorite close to the contact with the overlaying Hotaka Andesite. Such variability mimics the major and trace elements compositional variability measured in the whole rock samples. Magnetic foliations are observed at the western tectonic contact of the pluton potentially indicating overprint, while most other magnetic fabrics across the pluton are characterised by triaxial ellipsoids of magnetic susceptibility or magnetic lineations. Our preliminary data and the lack of internal contacts indicate that Takidani Pluton was likely emplaced as a series of successive magma pulses finally merging to produce a large connected magma body. While amphibole foliations may likely be the results of super-solidus tectonic overprint, anisotropy of magnetic susceptibility data may be related to post-emplacement melt segregation.

  9. Paleomagnetism and magnetic fabric of Miocene plutons of the Tonalá shearz zone, Chiapas, Mexico: evidence of rotation of the remanence vector

    NASA Astrophysics Data System (ADS)

    Molina-Garza, Roberto S.; Geissman, John W.

    2016-04-01

    The Late Miocene plutons of coastal Chiapas are elongated parallel to the Tonalá mylonite belt, and some plutons show asymmetric outcrop patterns with sheared tails that trail behind the intrusions. Plutons were emplaced within a transpressional sinistral shear zone. Magnetic fabrics in the plutons are well-developed, and are subparallel to the structural trend of the Tonalá mylonitic belt, but locally magmatic fabrics are preserved. Magnetic fabrics in undeformed granites with igneous textures are also subparallel to the shear zone axis. Strongly deformed plutons have Ṕvalues as high as 1.7. Fabric ellipsoids are predominantly oblate, but they are triaxial in sites with igneous textures. Characteristic magnetizations reside in a cubic phase, such as low-Ti magnetite, but abundant particles in the MD range prevent isolating a stable magnetization in many of the sites. Site means are NW to NE directed, and of moderate positive inclination (or its antipodal), but locally they are very discordant in declination. The overall mean, discarding highly discordant sites is of D= 359.5 and I=41.9 (k=14.2, alpha95=8.1), which is nearly concordant with the NA reference direction indicating gentle northward tilt of less than about 10°. We explain the highly discordant directions as caused by continuing, progressive, deformation in the transpressive shear zone of a thermochemical remanence acquired during deformation. Deformation resulted in rotations, both in a clockwise and an anticlockwise sense. These results are interpreted as paleomagnetic vectors affected by distortional strain, which based on AMS exceed 40% shortening and accommodate shape and volume change in the rock.

  10. Early abyssal- and late SSZ-type vestiges of the Rheic oceanic mantle in the Variscan basement of the Sakarya Zone, NE Turkey: Implications for the sense of subduction and opening of the Paleotethys

    NASA Astrophysics Data System (ADS)

    Dokuz, Abdurrahman; Uysal, İbrahim; Kaliwoda, Melanie; Karsli, Orhan; Ottley, Chris J.; Kandemir, Raif

    2011-11-01

    The boundary between the Gondwana and Laurussia, or a terrane separated from it, is traced by a suture recording the closure of the Rheic ocean in the Pulur, Beyçam and Kurtoğlu areas of the eastern Sakarya Zone of Turkey. Pulur lherzolite has a lower Cr# [100Cr/(Cr + Al) = 5-37] of the spinel and slightly enriched flat medium-heavy rare earth element (M-HREE) whole-rock pattern typical for those of the fertile abyssal-type lherzolite. By contrast, the Beyçam harzburgite displays the mineralogical and geochemical features of a moderately depleted residue at a supra subduction zone (SSZ). Some of spinels from the Beyçam peridotites show TiO2 contents (0.15-0.48 wt.%) identical to a later interaction with a melt of island-arc tholeiite (IAT) composition. Meta-basalt from the Beyçam area is the representative of such a melt and displays the whole-rock M-HREE pattern of a complementary product of the Beyçam harzburgite. Data presented in this study support the primarily northward directed closure of the Rheic ocean, but suggest that the Variscan basement in the eastern part of the Sakarya Zone consists of mantle peridotites formed in a south-vergent SSZ. This dual polarity of subduction in the Rheic ocean, at least in the second half of its closure, is also favored by the geological structure and lithological diversity of the Variscan rocks. These are: (1) spatial distribution of the peridotites, e.g., SSZ-type harzburgites to the north and abyssal-type lherzolites to the south, (2) lack of high-pressure metamorphic rocks, (3) decrease in the degree of Variscan metamorphism toward the north, and (4) emplacement of Variscan syn-collisional magmatism into the low grade metamorphic rocks to the north. Paleotethys was the other ocean of the region created in the Late Paleozoic. Northward subduction of the Rheic ocean from Early Devonian to Early Carboniferous appears to be the most plausible mechanism responsible for the opening of Paleotethys. In this scenario the

  11. Late Jurassic plutonism in the southwest U.S. Cordillera

    USGS Publications Warehouse

    Barth, A.P.; Wooden, J.L.; Howard, K.A.; Richards, J.L.

    2008-01-01

    Although plate reconstructions suggest that subduction was an approximately steady-state process from the mid-Mesozoic through the early Tertiary, recent precise geochronologic studies suggest highly episodic emplacement of voluminous continental-margin batholiths in the U.S. Cordillera. In central and southern California and western Arizona, major episodes of batholithic magmatism are known to have occurred in Permian-Triassic, Middle Jurassic, and late Early to Late Cretaceous time. However, recent studies of forearc-basin and continental-interior sediments suggest that Late Jurassic time was probably also a period of significant magmatism, although few dated plutons of this age have been recognized. We describe a belt of Late Jurassic plutonic and hypabyssal rocks at least 200 km in length that extends from the northwestern Mojave Desert through the Transverse Ranges. The belt lies outboard of both the voluminous Middle Jurassic arc and the ca. 148 Ma Independence dike swarm at these latitudes. The plutons include two intrusive suites emplaced between 157 and 149 Ma: a calc-alkaline suite compositionally unlike Permian-Triassic and Middle Jurassic mon-zonitic suites but similar to Late Cretaceous arc plutons emplaced across this region, and a contemporaneous but not comagmatic alkaline suite. The Late Jurassic was thus a time of both tectonic and magmatic transitions in the southern Cordillera. ?? 2008 The Geological Society of America.

  12. Whole-Rock Geochemistry and Zircon U-Pb Isotopes of the Late Cretaceous Granitoids of the Eastern Taurus (turkey): Implications for Petrogenesis and Geodynamic Setting

    NASA Astrophysics Data System (ADS)

    Beyarslan, Melahat; Lin, Yu-Chin; Chung, Sun-Lin; Feyzi Bingol, Ahmet; Yildirim, Esra

    2015-04-01

    The granitoid plutons out crop largely in the Eastern Taurus, in Turkey. New data, including a combination of field relation, U-Pb zircon geochronology and rock geochemistry on the granitoids in the Eastern Taurus of the Tethyan orogen in Turkey, come from four plutons ( Pertek, Baskil, Göksun and Şifrin). Pertek, Baskil and Göksun plutons consist mainly of diorite, quartz-diorites, tonalite, granodiorites and granites of I-type, with minor monzonite, the Şifrin pluton consists of syenogranite, syenite, monzogranite, monzonite. U-Pb zircon geochronology of four samples of diorite and granite from Pertek and Baskil plutons indicate ages of 86±2 - 79 ± 1Ma. U-Pb zircon geochronology of four samples from the Şifrin granitoid yield ages 77±1-72±1 Ma. Considering these ages, emplacement of the plutons took place during Late Cretaceous (Santonian-Campanian), from 86 to 72 Ma. Although the SiO2 of rocks forming granitoids varies in wide range ( 46.792- 74.092 wt%), they show arc and syn-collision geochemical affinity, with enrichment of LILE (K, Rb, Sr and Ba) and depletion of HFSE (Nb, Ta and Ti) and P. Geochemical data indice that the diorite, tonalite and granodiorite are low-K tholeiite, monzodiorite, monzogranite, granite and K-granite are calc-alkaline and high-K calc-alkaline and monzonite, syenomonzonite and syenite of Şifrin pluton and some samples of the Pertek pluton are shoshonitic. The Eastern Taurus granitoids would be formed by partial melting of possible juvenile arc-derived rocks during subduction of the South Branch of the Neo-Tethyan oceanic crust and subsequent arc-continent collision.

  13. Istanbul, Turkey

    NASA Image and Video Library

    2001-07-21

    This June 16, 2000 image of Istanbul, Turkey show a full 60 by 60 km ASTER scene in the visible and infrared channels. Vegetation appears red, and urban areas blue-green. Bustling Istanbul, with its magnificent historical heritage, has spanned the divide between Europe and Asia for more than 2,500 years. Originally called Byzantium, the city was founded in the 7th century BC on the Golden Horn, an arm of the narrow Bosporus (also spelled Bosphorus) Strait, which connects the Sea of Marmara to the south, with the Black Sea to the north. Constantine I made it his capital of the Eastern Roman Empire in AD 330. As Constantinople, the strategically located city arose as the preeminent cultural, religious, and political center of the Western world. It reached the height of its wealth and glory in the early 5th century. After centuries of decline, the city entered another period of tremendous growth and prosperity when, as Istanbul, it became the capital of the Turkish Ottoman Empire in 1457. Although Turkey moved its capital to Ankara in 1923, Istanbul remains the nation's largest city with a population of over 8 million, its commercial center, and a major port. Two bridges spanning the Bosporus, and ships in the busy channel can be seen on the enlargement. On the image, the water areas have been replaced with a thermal image: colder waters are displayed in dark blue, warmer areas in light blue. Note the dark lines showing boat wakes, and the cold water entering the Sea of Marmara from deeper waters of the Bosporus. http://photojournal.jpl.nasa.gov/catalog/PIA02665

  14. Emplacement and fabric-forming conditions of plutons from structural and magnetic fabric analysis: A case study of the Plana pluton (Central Bulgaria)

    NASA Astrophysics Data System (ADS)

    Georgiev, Neven; Henry, Bernard; Jordanova, Neli; Jordanova, Diana; Naydenov, Kalin

    2014-08-01

    The relationship between intensity parameters, such as the corrected anisotropy degree P‧ and mean susceptibility Km for plutons with similar magnetic mineralogy, yields a criterion to determine the origin of their magnetic fabric: for a same mineralogy, the higher the P‧ values for the same mean susceptibility Km (irrespective of its absolute value) the higher tectonic effect was possible. Using this criterion, comparison of the magnetic fabric of the Upper Cretaceous mid- to shallow crustal level Plana pluton with that of other small Upper Cretaceous plutonic bodies in Sredna Gora Zone (Central and Southeast Bulgaria) highlights the structural evolution of the Plana pluton. The central part of Plana pluton and its southwest, west and east margins have preserved their emplacement fabric. Along its northern contact the pluton is affected by the last movements within the Okol Shear Zone where high-temperature S/L mylonites developed. The fabric of the pluton at its southeastern border was disturbed during the intrusion of the neighboring Gutsal pluton. The similarity in the orientation of magmatic and magnetic structures preserved in the central and southern parts of the Plana pluton and the transition from magmatic to high-temperature superimposed foliations and lineations at its north contact point to a composite superimposed shear-induced and emplacement-related magmatic magnetic fabric. Nearly vertical orientation of magnetic and magmatic foliations and lineations from the undeformed parts of the pluton shows a process of vertical magma rising and emplacement. The sub-vertical high-temperature solid-state mylonitic foliation and dip-parallel stretching lineation in the pluton along its northern contact reveals the transpression nature of the deformation in the vicinity of Okol Shear Zone with a strong pure shear component. The smooth transition between the deformed and undeformed parts of Plana pluton reveals the syn-kinematic character of the emplacement.

  15. The San Blas Pluton: An example of Carboniferous plutonism in the Sierras Pampeanas, Argentina

    NASA Astrophysics Data System (ADS)

    Dahlquist, J. A.; Pankhurst, R. J.; Rapela, C. W.; Casquet, C.; Fanning, C. M.; Alasino, P.; Baez, M.

    2006-03-01

    New geochronological and geochemical data are reported for the San Blas Pluton (SBP), in the northwestern Sierra de Velasco, Sierras Pampeanas, which intrudes Ordovician granitoids developed during the Famatinian orogeny. A precise Carboniferous age of 340±3 Ma is established by U-Pb dating of zircon using a sensitive high-resolution ion microprobe (SHRIMP). The SBP illustrates several petrological and geochemical characteristics of previously reported Carboniferous granitoids in the Sierras Pampeanas. Their generation is consistent with a regional reheating of the crust at approximately 342 Ma, which resulted in the formation of relatively large amounts of granitic melts that were emplaced in higher crustal levels along master fractures (older master shear zones of Lower Paleozoic age). The SBP can be chemically defined as a typical A-type granitoid related to postcollisonal or postorogenic magmatism. Its high REE content and extraordinarily high U and Th concentrations may have economic significance. Many previously published Devonian and Carboniferous K-Ar dates are reset Ordovician ages, but the existence of other Carboniferous bodies in the Sierra de Velasco cannot be discounted until detailed mapping of the whole Sierra is completed.

  16. Miscellaneous investigations series: Bedrock geologic map of the Lone Mountain pluton area, Esmeralda County, Nevada

    SciTech Connect

    Maldonado, F.

    1984-12-31

    The joint attitudes were measured in the field and plotted on aerial photos at a scale of 1:24,000. The pluton is intensely jointed, primarily as a result of cooling and movement of the magma within a northwest-trending stress field. Foliation, in general, is poorly developed, and quality varies from area to area, but it is best developed close to the contacts with the metasedimentary rocks. A prominent northwest foliation direction was observed that parallels the northwest elongation of the exposed pluton. Faults in the pluton are difficult to identify because of the homogeneity of the rock. Several faults were mapped in the northern part of the area where they have a northeast trend and intersect the northwest-trending lamprophyre dikes with little apparent displacement. A major fault that bounds the northern part of the pluton is downthrown to the north and strikes northeast. This fault offsets the alluvium, the metasedimentary rocks, and the pluton and forms fault scraps as high as 10 m. Aeromagnetic data (US Geological Survey, 1979) suggest the following: (1) the local magnetic highs in the central part of the Lone Mountain pluton are probably related to topographic highs (peaks) where the flight lines are closer to the pluton; (2) a magnetic low in the northeastern part of Lone Mountain coincides with the pluton-country rock contact, which may be very steep; (3) the contours for the southwestern part of the mapped area indicate that the pluton-country rock contact is not as steep as that in the northeastern part and that the pluton probably coalesces at depth with the Weepah pluton, a pluton exposed south of the mapped area; and (4) the contours for the area of the Lone Mountain pluton express a northwest-trending gradient that parallels the northwest elongation of the Lone Mountain pluton and the northwest-trending stress field. 10 refs.

  17. Magma flow recorded by magmatic and magnetic fabrics in a shallow granitic pluton: La Gloria Pluton, central Chile

    NASA Astrophysics Data System (ADS)

    Payacán, I. J.; Gutiérrez, F. J.; Gelman, S. E.; Bachmann, O.; Parada, M. A.

    2013-12-01

    To better understand the dynamics of a small, shallow, silicic magma reservoir, magmatic and magnetic (AMS) fabrics are compared in samples obtained from La Gloria Pluton (LGP), a 10 Ma granitic intrusion located in southern Andes. The magnetic fabric of LGP, mainly given by magnetite, is characterized by oblate shapes. Magnetic lineations have a NW trend with subhorizontal dip, following the main pluton elongation, while magnetic foliation planes have dips varying gradually from vertical at the walls to subhorizontal toward the center and the roof of the pluton. On the basis of numerical simulations, magnetic fabric was interpreted to represent the shear record induced by magmatic convection along solidification fronts as the reservoir reached its rheological locking point. Magmatic fabric (mineral orientation) was determined on 12 samples along the pluton. Three mutually orthogonal thin sections were produced for each sample, perpendicular to the AMS tensor axes. Size and orientation of individual crystals were obtained by image analysis. A 2-D tensor for two mineral groups (plagioclase and amphibole+biotitie) was defined in each mineral plane projecting the crystal lengths on the main crystal orientation (given by Bingham statistics). A 3-D magmatic fabric tensor was obtained. In order to compare the magmatic and magnetic fabrics, magmatic anisotropy parameters were defined similar to the AMS tensors. Magmatic fabric and anisotropy parameter values vary depending on the location inside the pluton: (1) Samples located at the borders exhibit vertical foliations and lineations with a NW trend, similar to the magnetic fabric tensors and higher anisotropy values for plagioclase than amphibole+biotite,; (2) samples located at the center of the LGP commonly present subvertical foliations/lineations, which differ from the magnetic fabric, and higher magmatic anisotropy degree values for amphibole+biotite than plagioclase. Based on numerical simulations of the fluid

  18. Fracture controls on valley persistence: the Cairngorm Granite pluton, Scotland

    NASA Astrophysics Data System (ADS)

    Hall, A. M.; Gillespie, M. R.

    2017-09-01

    Valleys are remarkably persistent features in many different tectonic settings, but the reasons for this persistence are rarely explored. Here, we examine the structural controls on valleys in the Cairngorms Mountains, Scotland, part of the passive margin of the eastern North Atlantic. We consider valleys at three scales: straths, glens and headwater valleys. The structural controls on valleys in and around the Cairngorm Granite pluton were examined on satellite and aerial photographs and by field survey. Topographic lineaments, including valleys, show no consistent orientation with joint sets or with sheets of microgranite and pegmatitic granite. In this granite landscape, jointing is not a first-order control on valley development. Instead, glens and headwater valleys align closely to quartz veins and linear alteration zones (LAZs). LAZs are zones of weakness in the granite pluton in which late-stage hydrothermal alteration and hydro-fracturing have greatly reduced rock mass strength and increased permeability. LAZs, which can be kilometres long and >700 m deep, are the dominant controls on the orientation of valleys in the Cairngorms. LAZs formed in the roof zone of the granite intrusion. Although the Cairngorm pluton was unroofed soon after emplacement, the presence of Old Red Sandstone (ORS) outliers in the terrain to the north and east indicates that the lower relief of the sub-ORS basement surface has been lowered by <500 m. Hence, the valley patterns in and around the Cairngorms have persisted through >1 km of vertical erosion and for 400 Myr. This valley persistence is a combined product of regionally low rates of basement exhumation and of the existence of LAZs in the Cairngorm pluton and sub-parallel Caledonide fractures in the surrounding terrain with depths that exceed 1 km.

  19. Fracture controls on valley persistence: the Cairngorm Granite pluton, Scotland

    NASA Astrophysics Data System (ADS)

    Hall, A. M.; Gillespie, M. R.

    2016-12-01

    Valleys are remarkably persistent features in many different tectonic settings, but the reasons for this persistence are rarely explored. Here, we examine the structural controls on valleys in the Cairngorms Mountains, Scotland, part of the passive margin of the eastern North Atlantic. We consider valleys at three scales: straths, glens and headwater valleys. The structural controls on valleys in and around the Cairngorm Granite pluton were examined on satellite and aerial photographs and by field survey. Topographic lineaments, including valleys, show no consistent orientation with joint sets or with sheets of microgranite and pegmatitic granite. In this granite landscape, jointing is not a first-order control on valley development. Instead, glens and headwater valleys align closely to quartz veins and linear alteration zones (LAZs). LAZs are zones of weakness in the granite pluton in which late-stage hydrothermal alteration and hydro-fracturing have greatly reduced rock mass strength and increased permeability. LAZs, which can be kilometres long and >700 m deep, are the dominant controls on the orientation of valleys in the Cairngorms. LAZs formed in the roof zone of the granite intrusion. Although the Cairngorm pluton was unroofed soon after emplacement, the presence of Old Red Sandstone (ORS) outliers in the terrain to the north and east indicates that the lower relief of the sub-ORS basement surface has been lowered by <500 m. Hence, the valley patterns in and around the Cairngorms have persisted through >1 km of vertical erosion and for 400 Myr. This valley persistence is a combined product of regionally low rates of basement exhumation and of the existence of LAZs in the Cairngorm pluton and sub-parallel Caledonide fractures in the surrounding terrain with depths that exceed 1 km.

  20. Magmatic tempo of Earth's youngest exposed plutons as revealed by detrital zircon U-Pb geochronology.

    PubMed

    Ito, Hisatoshi; Spencer, Christopher J; Danišík, Martin; Hoiland, Carl W

    2017-09-29

    Plutons are formed by protracted crystallization of magma bodies several kilometers deep within the crust. The temporal frequency (i.e. episodicity or 'tempo') of pluton formation is often poorly constrained as timescales of pluton formation are largely variable and may be difficult to resolve by traditional dating methods. The Hida Mountain Range of central Japan hosts the youngest exposed plutons on Earth and provides a unique opportunity to assess the temporal and spatial characteristics of pluton emplacement at high temporal resolution. Here we apply U-Pb geochronology to zircon from the Quaternary Kurobegawa Granite and Takidani Granodiorite in the Hida Mountain Range, and from modern river sediments whose fluvial catchments include these plutons in order to reconstruct their formation. The U-Pb data demonstrate that the Kurobegawa pluton experienced two magmatic pulses at ~2.3 Ma and ~0.9 Ma; whereas, to the south, the Takidani pluton experienced only one magmatic pulse at ~1.6 Ma. These data imply that each of these magmatic systems were both spatially and temporally distinct. The apparent ~0.7 Myr age gap between each of the three magmatic pulses potentially constrains the recharge duration of a single pluton within a larger arc plutonic complex.

  1. Istanbul, Turkey

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This June 16, 2000 image of Istanbul, Turkey show a full 60 by 60 km ASTER scene in the visible and infrared channels. Vegetation appears red, and urban areas blue-green. Bustling Istanbul, with its magnificent historical heritage, has spanned the divide between Europe and Asia for more than 2,500 years. Originally called Byzantium, the city was founded in the 7th century BC on the Golden Horn, an arm of the narrow Bosporus (also spelled Bosphorus) Strait, which connects the Sea of Marmara to the south, with the Black Sea to the north. Constantine I made it his capital of the Eastern Roman Empire in AD 330. As Constantinople, the strategically located city arose as the preeminent cultural, religious, and political center of the Western world. It reached the height of its wealth and glory in the early 5th century. After centuries of decline, the city entered another period of tremendous growth and prosperity when, as Istanbul, it became the capital of the Turkish Ottoman Empire in 1457. Although Turkey moved its capital to Ankara in 1923, Istanbul remains the nation's largest city with a population of over 8 million, its commercial center, and a major port. Two bridges spanning the Bosporus, and ships in the busy channel can be seen on the enlargement. On the image, the water areas have been replaced with a thermal image: colder waters are displayed in dark blue, warmer areas in light blue. Note the dark lines showing boat wakes, and the cold water entering the Sea of Marmara from deeper waters of the Bosporus.

    Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, Calif., is the U

  2. Istanbul, Turkey

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This June 16, 2000 image of Istanbul, Turkey show a full 60 by 60 km ASTER scene in the visible and infrared channels. Vegetation appears red, and urban areas blue-green. Bustling Istanbul, with its magnificent historical heritage, has spanned the divide between Europe and Asia for more than 2,500 years. Originally called Byzantium, the city was founded in the 7th century BC on the Golden Horn, an arm of the narrow Bosporus (also spelled Bosphorus) Strait, which connects the Sea of Marmara to the south, with the Black Sea to the north. Constantine I made it his capital of the Eastern Roman Empire in AD 330. As Constantinople, the strategically located city arose as the preeminent cultural, religious, and political center of the Western world. It reached the height of its wealth and glory in the early 5th century. After centuries of decline, the city entered another period of tremendous growth and prosperity when, as Istanbul, it became the capital of the Turkish Ottoman Empire in 1457. Although Turkey moved its capital to Ankara in 1923, Istanbul remains the nation's largest city with a population of over 8 million, its commercial center, and a major port. Two bridges spanning the Bosporus, and ships in the busy channel can be seen on the enlargement. On the image, the water areas have been replaced with a thermal image: colder waters are displayed in dark blue, warmer areas in light blue. Note the dark lines showing boat wakes, and the cold water entering the Sea of Marmara from deeper waters of the Bosporus.

    Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, Calif., is the U

  3. Interplay of plutonism and regional deformation in an obliquely convergent arc, southern Coast Belt, British Columbia

    NASA Astrophysics Data System (ADS)

    Brown, E. H.; Talbot, J. L.; McClelland, W. C.; Feltman, J. A.; Lapen, T. J.; Bennett, J. D.; Hettinga, M. A.; Troost, M. L.; Alvarez, K. M.; Calvert, A. T.

    2000-06-01

    The Coast Plutonic Complex is an extensive zone of continental growth that formed along the Mesozoic convergent margin of northwestern North America. The orogeny creating this belt involved terrane accretion and assembly, massive upward transfer and emplacement of sial in the form of batholiths constituting a magmatic arc, and transformation of broad tracts of sedimentary and volcanic rocks into crystalline continental crust, all operating in more or less the same space and time. The mechanisms and interplay of these orogenic processes are well displayed in the Harrison Lake area of the southern Coast Belt, British Columbia. Great structural relief across the area exhibits a present-day architecture defined by thin, thrust-stacked terrane sheets and early concordant pluton sheets folded on a macroscopic scale, all truncated by oblique dextral-reverse faults and overlain by later floored plutons. Construction of this complex began with terrane assembly on orogen-normal thrusts during a lull in plutonism in the Early Cretaceous. Low-grade metamorphism during this event indicates only modest crustal thickening. Subsequent plutons intruded into the assembled terranes appear to be composites of sheets. Early pluton sheets are now steeply dipping due to folding but were likely intruded as horizontal bodies. Large ovoid post folding plutons are mostly subhorizontal floored bodies, at least in part sheeted. These plutons are underlain by Barrovian mineralogic aureoles that indicate downward vertical displacement of 10 km or more during plutonism, suggesting pluton emplacement by vertical inflation. Magmatic fabrics in these bodies, and the discordant relation of plutons to regional structures, preclude emplacement in active fault zones. Penetrative strain aureoles flanking plutons are mostly limited to zones a few hundred meters wide, and regional tectonic structures are widely preserved. Tectonic deformation of the arc is characterized by contraction and strike-slip, not

  4. Structural characterization of the Misajé granitic pluton (NW Cameroon): constraints from magnetic and field observations

    NASA Astrophysics Data System (ADS)

    Fozing, Eric Martial; Njanko, Théophile; Naba, Séta; Kwékam, Maurice; Njonfang, Emmanuel; Rochette, Pierre

    2016-11-01

    The Misajé granitic pluton, emplaced between 569 and 560 Ma in an amphibolitic and gneissic host rock, comprises four petrographic units namely biotite-hornblende granite (BHG), granodiorite (Gd), biotite granite (BG), and leucocratic granite (LG). Four major tectonic events have been described in the studied area: a D1-early tectonic event, responsible of the E-W flat foliation which has been progressively transposed by a D2 tectonic event. A D2 event has developed heterogeneous simple shear in a dextral transpressive context with moderate to strong dipping NE-SW striking foliation; a D3 tectonic event has lead to a sinistral N-S ductile shear characterized by N- to ENE-striking foliation and E-W strike-slip shear corridors and a D4 tectonic event that developed N-S dextral ductile strike-slip deformation. The magnetic study of the pluton, based on the AMS parameters, reveals the coexistence of both paramagnetic (dominated by iron-bearing silicates; 54 % of sites) and ferromagnetic (due to the occurrence of PSD and MD grains of magnetite or other ferromagnetic minerals; 46 % of sites) behaviors. Magnetic foliation shows best poles at 55/82 for the whole pluton, 95/32 in BHG, and 273/83 in BG, and the magnetic lineation trends are mostly NNE-SSW with best lines at 210/8, 198/19, and 36/3, respectively. The trend of the magnetic lineation in BG indicates an S-shape trajectory, suggesting a sinistral sense of shear motion along discrete E-W corridors situated at the northern and southern ends. Kinematic indicators in BG point to a sinistral sense of shear, suggesting its emplacement during the D3 event. The close relationship between K 1 and K 3 points to a syn-kinematic emplacement and crystallization of the Misajé granitic pluton during the Pan-African event, and the tectonic evolution of the study area is considered to be coeval with the tectonic evolution of the trans-Saharan Pan-African belt of eastern Nigeria.

  5. Emplacement mechanism of the Middle-Late Jurassic Qitianling pluton and its implications on the Mesozoic tectonics of South China Block

    NASA Astrophysics Data System (ADS)

    Liu, Hongsheng; Chen, Yan; Faure, Michel; Scaillet, Bruno; Wang, Bo; Martelet, Guillaume; Huang, Fangfang; Zhu, Jinchu; Wang, Rucheng; Erdmann, Saskia

    2016-04-01

    The widespread Mesozoic magmatism that extends about 1500km along the NE-SW strike and 800km wide in the southeastern part of the South China Block is a remarkable feature that has attracted the attention of geoscientists since 1940's. Numerous studies have been carried out, and consequently, several geodynamic models related to the emplacement mechanism have been proposed, based essentially on petrology, geochronology, and (isotopic) geochemistry. Recently, a general consensus is apparently achieved within the geosciences community on the tectonic contexts of the South China Block during the Triassic (compressive) and Cretaceous (extensive) periods, however the tectonic setting of the Jurassic is still in debate, moreover the Jurassic magmatism is closely related to abundant mineralization of rare metal elements. Due to the similarities in age, rock type and major geochemical feature of Jurassic granite, the Qitianling granitic pluton, situated in the Nanling area and dated at ca. 157 Ma, was chosen as the target of this study among 41 visited plutons. Previous studies divide the Qitianling pluton into three petrographic facies, namely: i) Bt + Qtz + Fsd + Amp, ii) Bt + Qtz + Fsd + (Amp) , iii) Bt + Qtz + Fsd. Zircon U-Pb dating indicate the age peak of these different facies at 161Ma, 157-156Ma and 149Ma, respectively. The field observation shows that: 1) the granite is isotropic without visible preferred mineral orientation or deformation; 2) the contact between the granite and country rocks is sharp, with a 1-10m narrow thermal aureole, but without any visible deformation. The microscopic observation on the thin sections of wall rocks and granite doesn't show any mineral preferred orientation consisting to the field observation. Therefore, a total of 53 sampling sites and 318 oriented cores were collected from the Qitianling pluton for an Anisotropy of Magnetic Susceptibility (AMS) study. The investigation on rock magnetism shows the pseudo

  6. SHRIMP U-Pb dating and geochemistry of the Cretaceous plutonic rocks in the Korean Peninsula: A new tectonic model of the Cretaceous Korean Peninsula

    NASA Astrophysics Data System (ADS)

    Kim, Sung Won; Kwon, Sanghoon; Park, Seung-Ik; Lee, Changyeol; Cho, Deung-Lyong; Lee, Hong-Jin; Ko, Kyoungtae; Kim, Sook Ju

    2016-10-01

    The Cretaceous tectonomagmatism of the Korean Peninsula was examined based on geochemical and geochronological data of the Cretaceous plutonic rocks, along with distribution of volcano-sedimentary nonmarine N- to NE-trending fault bounded sedimentary basins. We conducted sensitive high-resolution ion microprobe (SHRIMP) zircon U-Pb ages and whole-rock geochemical compositions of 21 Cretaceous plutonic rocks, together with previously published data, from the central to southern Korean Peninsula. Four age groups of plutonic rocks were identified: Group I (ca. 119-106 Ma) in the northern to central area, Group II (ca. 99-87 Ma) in the central southern area, Group III (ca. 85-82 Ma) in the central to southern area, and Group IV (ca. 76-67 Ma) in the southernmost area. These results indicate a sporadic trenchward-younging trend of the Cretaceous magmatism in the Korean Peninsula. The Group I, II, and III rocks are dominated by high-K calc-alkaline I-type rocks with rift-related A-type granitoids. In contrast, the Group IV rocks are high-K calc-alkaline I-type plutonic rocks with no A-type rocks. The geochemical signatures of the entire groups indicated LREEs (light rare earth elements) enrichments and negative Nb, Ta, and Ti anomalies, indicating normal arc magmatism. A new tectonic model of the Cretaceous Korean Peninsula was proposed based on temporal and spatial distribution of the Cretaceous plutons represented by four age groups; 1) magmatic quiescence throughout the Korean Peninsula from ca. 160 to 120 Ma, 2) intrusions of the I- and A-type granitoids in the northern and central Korean Peninsula (Group I plutonic rocks from ca. 120 to 100 Ma) resulted from the partial melting of the lower continental crust due to the rollback of the Izanagi plate expressed as the conversion from flat-lying subduction to normal subduction. The Gyeongsang nonmarine sedimentary rift basin in the Korean Peninsula and adakite magmatism preserved in the present-day Japanese Islands

  7. Reconnaissance study of the Taylor Mountains pluton, southwestern Alaska

    USGS Publications Warehouse

    Hudson, Travis L.; Miller, Marti L.; Klimasauskas, Edward P.; Layer, Paul W.

    2010-01-01

    The Taylor Mountains pluton is a Late Cretaceous to early Tertiary (median age 65 + or ? 2 Ma) epizonal, composite biotite granite stock located about 235 km (145 mi) northeast of Dillingham in southwestern Alaska. This 30 km2 (12 mi2) pluton has sharp and discordant contacts with hornfels that developed in Upper Cretaceous clastic sedimentary rocks of the Kuskokwim Group. The three intrusive phases in the Taylor Mountains pluton, in order of emplacement, are (1) porphyritic granite containing large K-feldspar phenocrysts in a coarse-grained groundmass, (2) porphyritic granite containing large K-feldspar and smaller, but still coarse, plagioclase, quartz, and biotite phenocrysts in a fine-grained groundmass, and (3) fine-grained, leucocratic, equigranular granite. The porphyritic granites have different emplacement histories, but similar compositions; averages are 69.43 percent SiO2, 1.62 percent CaO, 5.23 percent FeO+MgO, 3.11 percent Na2O, and 4.50 percent K2O. The fine-grained, equigranular granite is distinctly felsic compared to porphyritic granite; it averages 75.3 percent SiO2, 0.49 percent CaO, 1.52 percent FeO+MgO, 3.31 percent Na2O, and 4.87 percent K2O. Many trace elements including Ni, Cr, Sc, V, Ba, Sr, Zr, Y, Nb, La, Ce, Th, and Nd are strongly depleted in fine-grained equigranular granite. Trace elements are not highly enriched in any of the granites. Known hydrothermal alteration is limited to one tourmaline-quartz replacement zone in porphyritic granite. Mineral deposits in the Taylor Mountains area are primarily placer gold (plus wolframite, cassiterite, and cinnabar); sources for these likely include scattered veins in hornfels peripheral to the Taylor Mountain pluton. The granite magmas that formed the Taylor Mountains pluton are thought to represent melted continental crust that possibly formed in response to high heat flow in the waning stage of Late Cretaceous subduction beneath interior Alaska.

  8. MiniBooNE

    SciTech Connect

    Mahn, Kendall Brianna Mcconnel; /Columbia U.

    2007-03-01

    MiniBooNE is a short baseline neutrino experiment designed to confirm or refute the LSND observed excess of electron anti neutrinos in a muon anti neutrino beam. The experimental setup, data samples, and oscillation fit method are discussed. Although the result was not public at the time of the talk, MiniBooNE has since published results, which are discussed briefly as well.

  9. Geology of the Redcap Mountain area, Coast Plutonic Complex, British Columbia

    SciTech Connect

    Hill, M.L.

    1985-01-01

    The Redcap Mountain area lies within the Coast Plutonic Complex about 60 km northeast of Prince Rupert, British Columbia. Detailed geologic investigations in this area provide information on the protolith of the Central Gneiss Complex, the conditions and timing of metamorphism and deformation, and the timing of plutonism. These results have significant implications for the tectonic history of this part of the Coast Plutonic Complex.

  10. Origin and evolution of calcalkaline plutons in the Northeast Kingdom batholith, Vermont

    SciTech Connect

    Ayuso, R.A.; Arth, J.G.

    1985-01-01

    Geochemical and petrographic study of five calcalkaline Devonian plutons in the Northeast Kingdom batholith suggests that they were generated from similar sources but evolved differently. The modally homogeneous Willoughby granite (WG) and the Derby granodiorite (DG) are the most aluminous plutons and contain muscovite and biotite (+/- garnet). The West Charleston diorite (WCD) and the Nulhegan granodiorite (NG) are relatively mafic plutons containing pyroxene, hornblende, and biotite. The Echo Pond (EP) has a granodioritic core but is dioritic along its southern margin. Regular variations of major and trace elements are found in NG and in the relatively sodic DG. More erratic chemical variations are found for WG. The more mafic plutons have higher Sr and lower Rb, Nb and Ta compared to the more felsic WG and DG. Rare-earth patterns for all plutons show higher light than heavy rare-earths. However, the more mafic plutons are comparatively less enriched, have smaller Eu anomalies, and tend to have higher contents of heavy rare earths than the WG and DG. The felsic Willoughby pluton is the best candidate for an upper crustal minimum melt. A deeper origin for the more mafic plutons is likely. Significant differences in the rare earths and ferromagnesian elements indicate that the WG, DG, and EP cannot be related by a simple fractionation scheme to the more mafic plutons.

  11. NATO and Turkey.

    DTIC Science & Technology

    1987-03-23

    Turkey, it is useful to relate to Turkey’s history and give some information about the Anatolian Peninsula. According to remains from the Neolithic period ...NO.- RECIPIENT’S CATALOG NUMBER 4. TITLE (and Subtitle) -. TYPE OF REPORT & PERIOD COVERED NATO and Turkey Individual Study Project 6. PERFORMING ORG...the integrity and security of NATO area. Since the establishment of NATO, the world has experienced a cold war period of many crises. However, the

  12. Turkey Country Analysis Brief

    EIA Publications

    2017-01-01

    Turkey is well placed to serve as a hub for oil and natural gas supply headed to Europe and other Atlantic markets from Russia, the Caspian region, and the Middle East. Turkey has been a major transit point for oil and is becoming more important as a transit point for natural gas. Growing volumes of Caspian oil are being sent to Black Sea ports such as Novorossisyk, Russia and Supsa, Georgia and then to Western markets by tanker via the Turkish Straits (Bosporus and Dardanelles waterways). Caspian oil and oil from northern Iraq also cross Turkey by pipeline, through the Ceyhan oil terminal on Turkey's Mediterranean coast.

  13. Origin of adakite-like plutons in southern Korea

    NASA Astrophysics Data System (ADS)

    Oh, Jeong-Im; Choi, Sung Hi; Yi, Keewook

    2016-10-01

    We present Sr-Nd-Pb isotopic compositions for two adakite-like intrusions in southern Korea (Jindong and Bongnae), including major and trace element concentrations, and the sensitive high-resolution ion microprobe (SHRIMP) zircon U-Pb age. Our aim is to constrain the origin and tectonomagmatic processes that gave rise to the plutons. A SHRIMP U-Pb zircon age of 88.7 ± 0.7 Ma was obtained from a Jindong granodiorite sample. The Jindong plutons belong to the medium-K calc-alkaline series, and have an overall enrichment in large ion lithophile elements (LILE), such as K, Rb, Ba, and Pb, and a relative depletion in high field strength elements, such as Nb, Ta, and Ti, compared with the neighboring elements in the primitive mantle-normalized multi-trace element variation diagram. It was found that (87Sr/86Sr)i = 0.70475-0.70596, (143Nd/144Nd)i = 0.512547-0.512604, [(εNd)i = + 0.4 to 2.2], and (206Pb/204Pb)i = 18.19-18.37, which fall within the field of the arc-type Cretaceous to Tertiary Bulguksa intrusive rocks in the Sr-Nd and Pb-Pb isotopic correlation diagrams. The elevated Sr/Y (17-40), but low La/Yb (3.7-8.8) ratios of the Jindong plutons, together with their coherent geochemical trends and U-shaped rare earth element (REE) patterns, indicate that they were not formed by slab melting, but by amphibole-dominated fractional crystallization of the Bulguksa-like arc magma. A SHRIMP U-Pb zircon age of 226.5 ± 2.5 Ma was obtained from a Bongnae tonalite sample. The Bongnae plutons belong to the shoshonitic series. Their trace element patterns resemble the Jindong samples, but are characterized by significantly negative U anomalies in mafic rocks. They also have elevated MgO, Ni, Co, Cr, Rb, Ba, Sr, and low Al2O3 and Na2O contents at a given SiO2 concentration compared with the Jindong plutons, and are typified by highly radiogenic Sr and unradiogenic Nd and Pb isotopic compositions: [(87Sr/86Sr)i = 0.71096-0.71290, (143Nd/144Nd)i = 0.511641-0.511681, (εNd)i = - 13

  14. The Geochronology and Geochemistry of Caldera-related Plutons in the Southern Rocky Mountain Volcanic Field: Insight into the Volcanic-plutonic Connection

    NASA Astrophysics Data System (ADS)

    Zimmerer, M. J.; Mills, R. D.; Tappa, M. J.; McIntosh, W. C.; Coleman, D. S.

    2009-12-01

    Preliminary Ar-Ar and U-Pb results from the Questa (NM) and Mt. Aetna (CO) caldera systems indicate that their caldera-related plutons are not cumulates or residual material from which caldera-collapse ignimbrites differentiated. Rio Grande rift-related faulting and erosion at both locations provide exposures of intracaldera volcanic rocks and subcaldera intrusions, allowing for the comparison of cogenetic volcanic and plutonic rocks. Resurgent plutons at both locations are indistinguishable in age to the associated ignimbrite, however the majority of plutons are either younger or older than the caldera-forming event. The geochemistry of the resurgent plutons and corresponding ignimbrite is similar. These results challenge the common interpretation that melt for ignimbrite eruptions is derived from crystal-mushes, which are then preserved as plutons. The Questa caldera, northern New Mexico, formed during the 25.4 Ma eruption of the peralkaline Amalia Tuff. Peralkaline phases of two resurgent plutons, Virgin Canyon and Canada Pinabete, are geochemically similar to the Amalia Tuff, but these phases have yet to be successfully dated. The metaluminous phase of the Canada Pinabete pluton is indistinguishable in age to the Amalia Tuff, suggesting that the peralkaline phase is also contemporaneous. The remaining seven plutons associated with the Questa caldera were emplaced between 25.2 and 19.4 Ma. Postcaldera plutonism was coeval with volcanism, though these plutons have not been geochemically linked to any postcaldera volcanic rocks. The Mt. Aetna complex consists of the Mt. Princeton batholith and the nested Mt. Aetna caldera. The Mt. Princeton batholith has been inferred to be the less-evolved source of the 37.2 Ma Wall Mountain Tuff. During the eruption of the 34.0 Ma Badger Creek Tuff, the fully crystallized Mt. Princeton batholith was involved in the Mt. Aetna caldera collapse. New Ar-Ar and U-Pb ages indicate the Mt. Princeton batholith is too young to be the

  15. Why are plutons dry? Outgassing mechanisms of crustal magmatic bodies

    NASA Astrophysics Data System (ADS)

    parmigiani, andrea; Huber, Christian; Bachmann, Olivier; Leclaire, Sébastien

    2016-04-01

    Magma bodies crystallizing to completion within the crust (i.e., forming plutons) typically undergo significant amounts of second boiling (i.e. cooling and crystallization of dominantly anhydrous minerals lead to volatile saturation and bubble nucleation/growth). The low water content (< 1 wt % H2O) and vanishing residual porosity of most plutons, despite the high volatile concentrations of their magma sources (commonly > 6 wt % H2O for evolved compositions in subduction zones), testify that outgassing from crystalline mushy reservoirs must be an efficient and widespread process. Understanding this outgassing mechanism is key to understand how volatiles are transferred from mantle depths to the surface. From the hydrodynamics point of view, the mass balance of exsolved volatiles in these plutonic bodies is controlled by the difference between the rate of degassing (formation of bubbles by 2nd boiling) and outgassing (transport of gas out of the magma body). In this study, we use pore-scale multiphase modeling to constrain these rates as function of the crystal and volatile contents in the magma. Because second boiling is a slow process, one can consider equilibrium degassing as a valid assumption. Outgassing, on the other end, is controlled by the competition between buoyancy, capillary and viscous forces. Our numerical simulations are used to determine the most efficient setting for gas to escape its magmatic trap. The high viscosity of interstitial melts and capillary forces (due to the non-wetting nature of the gas phase with most of the mineral phases in magmatic systems) strongly limits gas transport until vertically extensive gas channels are generated. We show that channels can readily form in volatile-rich coarse-grained mush zones in the upper crust, and allow efficient outgassing at crystallinities around 50-75 vol%, when millimetric bubbles can still win capillary resistive forces.

  16. Emplacement mode of a composite post-collisonal pluton in the Klamath Mountains (California, USA)

    NASA Astrophysics Data System (ADS)

    Machek, M.; Zavada, P.; Spicak, A.

    2011-12-01

    The Klamath Mountains represent an accreationary complex on the northwest California and southwestern Oregon. It consists of four arcuate belts representing terranes of former island archipelago environments that span in age from Paleozoic to Jurrasic and are divided by eastward dipping thrust faults (Snoke and Barnes, 2006). During and after the accretion, the entire thrust sheet was penetrated by numerous plutonic bodies. The Castle Crags pluton was selected for detailed internal fabrics to understand the emplacement mode of post-collisional plutons. Castle Crags pluton that intruded the Eastern Klamath terrane and in particular ultramafic Trinity Complex subterrane is an elliptical NW-SE elongated pluton with 12 km and 7 km in its long and short dimension, respectively. It is a well exposed composite plutonic body with about 1 km vertical crossfall. The pluton is affected by prominent NW-SE trending vertical joints and another less well developed vertical set perpendicular to the first one. The pluton is zoned and consists of three following igneous varieties: 1) marginal fine-grained granodioritic facies with abundant subsolidus shear zones, 2) coarse-grained granodiorite and 3) central, circular in plan-form and about 2 km in diameter, domain of trondhjemite. Numerous miarolitic cavities with macroscopically measurable trends mark the transition between the central trondhjemite and surrounding granodiorite (Vennum, 1980 a,b). Macroscopic foliations, jointing and sampling on the Castle Crags was carried out along the main crest of the pluton and numerous sideway crests and valleys gaining about 70 samples. The internal magmatic foliations and magnetic foliations show a concentric pattern of margin-parallel vertical foliations. The magnetic lineations reveal plunge trends parallel to the margins of the pluton and continuously increasing plunge angles from the margin to the core of the pluton. The zonality and fabric pattern of the pluton can reflect either

  17. Comparison of the triple-point temperatures of 20Ne, 22Ne and normal Ne

    NASA Astrophysics Data System (ADS)

    Nakano, T.; Tamura, O.; Nagao, K.

    2013-09-01

    At the National Metrology Institute of Japan (NMIJ), the triple points of 20Ne and 22Ne were realized using modular sealed cells, Ec3Ne20 and Ec8Ne22, made by the Istituto Nazionale di Ricerca Metrologica (INRiM) in Italy. The difference of the triple-point temperatures of 20Ne and 22Ne was estimated by using the sub-range of standard platinum resistance thermometers (SPRTs) calibrated by NMIJ on the International Temperature Scale of 1990 (ITS-90). The melting curves obtained with the Ec3Ne20 and Ec8Ne22 cells show narrow widths (0.1 mK) over a wide range of the inverse of the melted fraction (1/F) from 1/F=1 to 1/F=10. The liquidus point Ttp estimated by the melting curves from F˜0.5 to F˜0.85 using the Ec8Ne22 is 0.146 29 (4) K higher than that using the Ec3Ne20 cell, which is in good agreement with that observed by INRiM using the same cells. After correction of the effect of impurities and other isotopes for Ec3Ne20 and Ec8Ne22 cells, the difference of Ttp between pure 20Ne and pure 22Ne is estimated to be 0.146 61 (4) K, which is consistent with the recent results reported elsewhere. The sub-ranges of SPRTs computed by using the triple point of 20Ne or 22Ne realized by the Ec3Ne20 cell or the Ec8Ne22 cell in place of the triple point of Ne for the defining fixed point of the ITS-90 are in good agreement with those realized on the basis of the ITS-90 at NMIJ within 0.03 mK, which is much smaller than the non-uniqueness and the sub-range inconsistency of SPRTs.

  18. Turkey: Thwarted Ambition

    DTIC Science & Technology

    1997-01-01

    policy makers were dramatic, challenging, and worrying. At a stroke, the strategic center of gravity moved from Germany to Turkey, but the extinction of...with Arab neighbors, and the Sevres- phobia of an assault on Turkey’s territorial integrity were all accusations thrown at the government as these

  19. Adult Education in Turkey

    ERIC Educational Resources Information Center

    Miser, Rifat; Ural, Ozana; Ünlühisarýklý, Özlem

    2013-01-01

    This study investigates the situation and practices of adult education in Turkey in terms of (a) participants, (b) providers, and (c) program areas. The data were derived from published statistical data and one-to-one interaction with adult education providers when such data are unavailable. Turkey has a long tradition of adult education with…

  20. Distance Education in Turkey

    ERIC Educational Resources Information Center

    Ruzgar, Nursel Selver

    2004-01-01

    Many countries of the world are using distance education with various ways, by INTERNET, by post and by TV. In this work, development of distance education in Turkey has been presented from the beginning. After discussing types and applications for different levels of distance education in Turkey, the distance education was given in the cultural…

  1. Modern Turkey Revisited.

    ERIC Educational Resources Information Center

    Lewis, Bernard

    1990-01-01

    Traces the history of Turkey from the Cold War to the present and focuses on Turkey's adoption of a capitalist democratic pro-Western state. Delineates the tensions between pro-Western factions and more traditionally minded Turks. Examines Turkish relations with other Islamic countries, the Arab world, and the Third World. (RW)

  2. Educational Reform in Turkey

    ERIC Educational Resources Information Center

    Lindquist, Cynthia

    2017-01-01

    As a country seeking admission to the European Union, this paper explores educational reforms in Turkey that enhance its possible entry into the European Union and changes still needed for it to be an equal partner. An overview of the school system in Turkey is provided including information on teacher training and preparation, special education…

  3. Glomerophyric plagioclase in epizonal plutons: synneusis or peritectic reaction relationship

    SciTech Connect

    Hogan, J.P.

    1985-01-01

    Glomerophyric plagioclase, a common texture in epizonal granites often attributed to synneusis, may record the peritectic liquidus relationship in the ternary feldspar system. This texture represents a crystallization process rather than a coincidental union of phenocrysts in the melt. Petrologic studies of the Northport monzogranite, Maine, yield P-T conditions of 1.5-1.0 Kb, 703/sup 0/C. Plagioclase crystallized early in the Northport pluton with dendritic, discontinuously zoned cores (An/sub 40/) and normal oscillatory zoned margins (An/sub 35/ to An/sub 10/). Magmatic resorption of the plagioclase resulted in embayment of the margins and dendritic cores. Textural evidence suggests plagioclase and alkali feldspar did not coprecipitate. Alkali feldspar crystallization was initiated concurrent with resorption of plagioclase along the peritectic portion of the liquidus boundary. A model for the formation of glomerophyric plagioclase clusters, derived from the study of the Northport pluton, suggests that a narrow halo of plagioclase like component in the surrounding melt, produced during resorption, envelops individual plagioclase phenocrysts. Overlap of these enrichment halos shifts the bulk composition of the intervening melt off the boundary line into the plagioclase field, resulting in crystallization of a thin layer of plagioclase which bonds the resorbed phenocrysts together.

  4. Guidelines to classification and nomenclature of Arabian felsic plutonic rocks

    USGS Publications Warehouse

    Ramsay, C.R.; Stoeser, D.B.; Drysdall, A.R.

    1986-01-01

    Well-defined procedures for classifying the felsic plutonic rocks of the Arabian Shield on the basis of petrographic, chemical and lithostratigraphic criteria and mineral-resource potential have been adopted and developed in the Saudi Arabian Deputy Ministry for Mineral Resources over the past decade. A number of problems with conventional classification schemes have been identified and resolved; others, notably those arising from difficulties in identifying precise mineral compositions, continue to present difficulties. The petrographic nomenclature used is essentially that recommended by the International Union of Geological Sciences. Problems that have arisen include the definition of: (1) rocks with sodic, zoned or perthitic feldspar, (2) trondhjemites, and (3) alkali granites. Chemical classification has been largely based on relative molar amounts of alumina, lime and alkalis, and the use of conventional variation diagrams, but pilot studies utilizing univariate and multivariate statistical techniques have been made. The classification used in Saudi Arabia for stratigraphic purposes is a hierarchy of formation-rank units, suites and super-suites as defined in the Saudi Arabian stratigraphic code. For genetic and petrological studies, a grouping as 'associations' of similar and genetically related lithologies is commonly used. In order to indicate mineral-resource potential, the felsic plutons are classed as common, precursor, specialized or mineralized, in order of increasing exploration significance. ?? 1986.

  5. Guidelines to classification and nomenclature of Arabian felsic plutonic rocks

    NASA Astrophysics Data System (ADS)

    Ramsay, C. R.; Stoeser, D. B.; Drysdall, A. R.

    Well-defined procedures for classifying the felsic plutonic rocks of the Arabian Shield on the basis of petrographic, chemical and lithostratigraphic criteria and mineral-resource potential have been adopted and developed in the Saudi Arabian Deputy Ministry for Mineral Resources over the past decade. A number of problems with conventional classification schemes have been identified and resolved; others, notably those arising from difficulties in identifying precise mineral compositions, continue to present difficulties. The petrographic nomenclature used is essentially that recommended by the International Union of Geological Sciences. Problems that have arisen include the definition of: (1) rocks with sodic, zoned or perthitic feldspar, (2) trondhjemites, and (3) alkali granites. Chemical classification has been largely based on relative molar amounts of alumina, lime and alkalis, and the use of conventional variation diagrams, but pilot studies utilizing univariate and multivariate statistical techniques have been made. The classification used in Saudi Arabia for stratigraphic purposes is a hierarchy of formation-rank units, suites and super-suites as defined in the Saudi Arabian stratigraphic code. For genetic and petrological studies, a grouping as 'associations' of similar and genetically related lithologies is commonly used. In order to indicate mineral-resource potential, the felsic plutons are classed as common, precursor, specialized or mineralized, in order of increasing exploration significance.

  6. Emplacement, rapid burial, and exhumation of 90-Ma plutons in southeastern Alaska

    USGS Publications Warehouse

    Himmelberg, G.R.; Haeussler, P.J.; Brew, D.A.

    2004-01-01

    In southeastern Alaska, granodiorite-tonalite plutons of the Admiralty-Revillagigedo belt intruded the Jurassic-Cretaceous Gravina belt along the eastern side of the Alexander terrane around 90 Ma. These plutons postdate some deformation related to a major contractional event between the previously amalgamated Wrangellia and Alexander terranes and the previously accreted terranes of the North American margin. We studied the aureole mineral assemblages of these plutons near Petersburg, Alaska, determined pressure and temperature of equilibration, and examined structures that developed within and adjacent to these plutons. Parallelism of magmatic and submagmatic fabrics with fabrics in the country rock indicates synchroneity of pluton emplacement with regional deformation and suggests that magma transport to higher crustal levels was assisted by regional deformation. Replacement of andalusite by kyanite or sillimanite indicates crustal thickening soon after pluton emplacement. Regional structural analysis indicates the crustal thickening was accomplished by thrust burial. Thermobarometric analyses indicate the aureoles reached near-peak temperatures of 525 to 635 ??C at pressures of 570 to 630 MPa. Consideration of the rate of thermal decay of the aureoles suggests that burial was rapid and occurred at rates around 5 to 8 mm/year. Structural observations indicate there was contractional deformation before, during, and after emplacement of the 90-Ma plutons. Initial exhumation of the Admiralty-Revillagedo belt in the Petersburg area may have occurred along a thrust west of the pluton belt within the Gravina belt. ?? 2004 NRC Canada.

  7. Plutons and accretionary episodes of the Klamath Mountains, California and Oregon

    USGS Publications Warehouse

    Irwin, William P.; Wooden, Joseph L.

    1999-01-01

    The Klamath Mountains consist of various accreted terranes and include many plutons that range in composition from gabbro to granodiorite. Some of the plutons (preaccretionary plutons) were parts of terranes before the terranes accreted; others (accretionary plutons) intruded during or after the accretion of their host terrane(s). This report attempts to (1) graphically illustrate how the Klamath Mountains grew by the accretion of allochthonous oceanic terranes during early Paleozoic to Cretaceous times, (2) identify the plutons as either preaccretionary or accretionary, and (3) genetically relate the plutonic intrusions to specific accretionary episodes. The eight accretionary episodes portrayed in this report are similar to those shown by Irwin and Mankinen (1998) who briefly described the basis for the timing of the episodes and who illustrated the ~110 degrees of clockwise rotation of the Klamath Mountains since Early Devonian time. Each episode is named for the accreting terrane. In all episodes (Figs. 1-8), the heavy black line represents a fault that separates the accreting oceanic rocks on the left from earlier accreted terranes on the right. The preaccretionary plutons are shown within the accreting oceanic crustal rocks to the left of the heavy black line, and the accretionary plutons in most instances are shown intruding previously accreted terranes to the right. Episodes earlier than the Central Metamorphic episode (Fig. 1), and that may have been important in the formation of the early Paleozoic nucleous of the province (the Eastern Klamath terrane), are not known. The 'Present Time' distribution of the accreted terranes and plutons is shown at a large scale in Figure 9. The schematic vertical section (Fig. 10) depicts the terranes as a stack of horizontal slabs that include or are intruded by vertical plutons. Note that at their base the ~170 Ma preaccretionary plutons of the Western Hayfork subterrane are truncated by the ~164 Ma Salt Creek

  8. Context view from NE ridge of Daybreak Canyon running NE ...

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

    Context view from NE ridge of Daybreak Canyon running NE from lookout tower shows fire line on right and NE side of lookout tower in the far distance. Tree in foreground is Pondaross Pine that survived fires of 1991 and 1994. Camera is pointed SW with wide-angle lens. - Chelan Butte Lookout, Summit of Chelan Butte, Chelan, Chelan County, WA

  9. A PCR Detection Method for Rapid Identification of Melissococcus pluton in Honeybee Larvae

    PubMed Central

    Govan, V. A.; Brözel, V.; Allsopp, M. H.; Davison, S.

    1998-01-01

    Melissococcus pluton is the causative agent of European foulbrood, a disease of honeybee larvae. This bacterium is particularly difficult to isolate because of its stringent growth requirements and competition from other bacteria. PCR was used selectively to amplify specific rRNA gene sequences of M. pluton from pure culture, from crude cell lysates, and directly from infected bee larvae. The PCR primers were designed from M. pluton 16S rRNA sequence data. The PCR products were visualized by agarose gel electrophoresis and confirmed as originating from M. pluton by sequencing in both directions. Detection was highly specific, and the probes did not hybridize with DNA from other bacterial species tested. This method enabled the rapid and specific detection and identification of M. pluton from pure cultures and infected bee larvae. PMID:9572987

  10. Age and intrusive relations of the Lamarck granodiorite and associated mafic plutons, Sierra Nevada, California

    SciTech Connect

    Joye, J.L.; Bachl, C.A.; Miller, J.S.; Glazner, A.F. . Dept. of Geology); Frost, T.P. ); Coleman, D.S. . Dept. of Earth, Atmospheric and Planetary Sciences)

    1993-04-01

    The compositionally zoned Late Cretaceous Lamarck granodiorite, west of Bishop, hosts numerous mafic intrusions ranging from hornblende gabbro to mafic granodiorite. Frost and Mahood (1987) suggested from field relations that the Lamarck and the associated mafic plutons were co-intrusive. Contact relations between the Lamarck host and the mafic intrusions are variable (sharp to diffuse) and in places suggest commingling. In order to constrain the intrusive relationships between the Lamarck and its associated mafic plutons, the authors have analyzed feldspars from the Mt. Gilbert pluton and the Lamarck granodiorite to see if feldspar compositions in the Mt. Gilbert overlap those in the Lamarck host and determined U-Pb zircon ages for the Mt. Gilbert and Lake Sabrina plutons to see if they have the same age as the Lamarck granodiorite. Feldspars from the Lamarck granodiorite are normally zoned and range compositionally from An[sub 38--32]; those in the Mt. Gilbert diorite are also normally zoned but range compositionally from An[sub 49--41] and do not overlap the Lamarck host. Four to five zircon fractions from each pluton were handpicked and dated using U-Pb methods. The Mt. Gilbert mafic diorite has a concordant age of 92.5 Ma and the Lake Sabrina diorite has a concordant age of 91.5 Ma. Ages for the two plutons overlap within error, but multiple fractions from each suggest that the Lake Sabrina pluton is slightly younger than the Mt. Gilbert pluton. These data and field relationships indicate: (1) plagioclase phenocrysts in the Mt. Gilbert pluton were not derived from the Lamarck granodiorite despite their textural similarity; but (2) the Lamarck granodiorite and its associated mafic plutons are co-intrusive as supported by the close agreement of the ages with the crystallization age obtained by Stern and others for the Lamarck granodiorite.

  11. Registration of NE Trailblazer C-1, NE Trailblazer C0, NE Trailblazer C2, NE Trailblazer C3, NE Trailblazer C4, and NE Trailblazer C5 Switchgrass Germplasms

    USDA-ARS?s Scientific Manuscript database

    NE Trailblazer C-1 (GP-101, PI 672015), NE Trailblazer C0 (GP-100, PI 672014), NE Trailblazer C2 (GP-102, PI 672016), NE Trailblazer C3 (GP-103, PI 672017), NE Trailblazer C4 (GP-104, PI 672018), and NE Trailblazer C5 (GP-105, PI 672019) switchgrass (Panicum virgatum L.) germplasms were released by ...

  12. Localized ductile deformation in the Rieserferner Pluton (Eastern Alps)

    NASA Astrophysics Data System (ADS)

    Ceccato, Alberto; Pennacchioni, Giorgio

    2017-04-01

    In the Rieserferner Pluton (Eastern Alps, 32±0.2 Ma, Romer et al., 2003) the post-magmatic cooling and exhumation stages were accompanied by a series of solid-state deformations including jointing, quartz veining, dyke emplacement, localized (cm-dm) ductile shearing and brittle-ductile faulting. The earliest stage of post-magmatic deformation includes the formation of pervasive steeply-dipping joints mainly arranged in two "conjugate" sets striking respectively E-W and NW-SE. These joints were extensively intruded by synkinematic aplite-pegmatite dykes and by quartz veins. Joints, veins and (locally) dikes were exploited as strike-slip ductile shear zones consistently with a WNW-ESE shortening. The mylonitized quartz veins are relatively coarse grained (mm-grain size) and show dominant dynamic recrystallization by grain boundary migration. A later set of joints is shallowly dipping E and is also commonly filled with quartz (and local epidote) veins. Ductile shearing of these vein-filled joints resulted in localized tonalite mylonites and quartz mylonites with a top-to-east kinematics. The quartz mylonites are fine grained (10-20 μm grain size) and resulted from dominant subgrain rotation recrystallization. The foliation of associated tonalite mylonites is marked by biotite+plagioclase+white mica+epidote±sphene±garnet. The "high-temperature" mylonites are crosscut by swarms of steeply-dipping fractures and faults striking N-S and showing a characteristic anastomosing-irregular pattern. These fractures are clustered in zones as large as 10 m and are associated with veins filled with calcite+white mica and with basic dykes (dated at 26 Ma: Steenken et al., 2000). Fluid-rock interactions along these fractures induced weakening and development of local low-temperature mylonites, where deformation mechanisms included pressure-solution and low-temperature plasticity of quartz. The orientation and kinematics of E-dipping mylonites and later low-temperature mylonites

  13. Melt segregation evidence from a young pluton, Takidani Granodiorite (Japan)

    NASA Astrophysics Data System (ADS)

    Hartung, Eva; Caricchi, Luca; Floess, David; Wallis, Simon; Harayama, Satoru; Chiaradia, Massimo; Kouzmanov, Kalin

    2016-04-01

    We are presenting new petrological data from one of the youngest exposed plutons in the world, the Takidani Granodiorite (Japan), which has been suggested as a source for large volume ignimbrites (> 300km3). Takidani Granodiorite (1.54 Ma ± 0.23 Ma) is located within the active Norikura Volcanic Chain in the Northen Japan Alps and has been previously linked to large andesitic (1.76 Ma ± 0.17 Ma) and rhyolitic eruptions (1.75 Ma ± 0.17 Ma). The pluton is vertically zoned and consists of granites (67 to 68 wt.% SiO2) in the lower section, granodiorites (65 to 66 wt.% SiO2) in the middle section, a chemically more evolved fine-grained porphyritic unit (67 to 71 wt.% SiO2) near the roof and a marginal granodiorite at the roof (67 to 68 wt.% SiO2). The porphyritic texture of the more evolved unit near the roof indicates rapid crystallisation, which could be the result of the late intrusion of this unit at the roof of the magmatic system. However, no sharp contact is found between the underlying granodiorite and the porphyritic unit. Instead, a gradual change in rock fabric, whole-rock chemistry and mineralogy is observed suggesting that melt was extracted from the granodiorite. Electron microprobe analyses of plagioclases show three main crystal populations (Type I, II and III) with distinct anorthite and Fe contents. Type I plagioclase (An30-40) occurs dominantly within the marginal granodiorite at the roof. Type II plagioclase (An40-45) are common in the granodiorite and porphyritic unit. Type III plagioclase (An45-50) is predominantly present in the granite. All plagioclase populations share a common sodic rim (An22) across the different units. Takidani Granodiorite rocks are compared to crystallisation experiments from similar magmatic suites. Emplacement conditions of the Takidani Granodiorite are obtained from the latter as well as barometry, thermometry and hygrometry indicating that magmas were ultimately emplaced at around 200 MPa, 850° C to 875° C and

  14. Mineralization related to Alvand pluton in the Hamadan, western Iran

    NASA Astrophysics Data System (ADS)

    Salehi, M. H.; Doosti, E. A.; Ahadnejad, V.

    2009-04-01

    The Alvand (Hamadan) plutonic batholith is one of the largest plutonic bodies in the Sanandaj-Sirjan metamorphic belt. This complex is consist of mafic part (gabbro-diorite-tonalite), intermediate (granite-granodiorite porphyroids), and hololeucocratic granitoids. Previous studies have shown that S-type granite-granodiorites are mostly peraluminous and calc-alkaline; the gabbro-diorite-tonalite suite is mostly metaluminous and tholeiitic to calc-alkaline (Sepahi, 2008). High initial 87Sr-86Sr ratios (0.7081 to 0.7115), low epsilon Nd values (-1.0 to -3.3), and peraluminous character reflects a different origin for the granites, possibly crustal sources (Ghalamghash et al, 2007). Aplite-pegmatite dikes are intruded in granitoide rocks, metamorphic rocks and the contact of Alvand granite with metamorphic rocks. The contact of Alvand granite with metamorphic rocks is sharp. By using heavy mineral studies on the alluvium of Alvand complex, it is recognized 28 minerals amongst Scheelite, Cassiterite, Ilmenite, Zircon and Garnet. Different geostatistical studies such as variant, bivariant and multivariant studies have been done on rough data of heavy minerals. They showed normal concentration of gold in studied rocks and low enrichment of tin and tungsten. The index of the ore elements average, frequeney distribution criteria of elements, the ratio of elements index and multielements show that Alvand granite is barren. Mineralography studies did not recognized any tin and tungsten minerals. The grains of gold was recognized in some of the microscopic thin sections. Calcopyrotite is the most important ore mineral that is accompanied with oxides and iron carbonates. The contacts of aplite-pegmatite dikes with granitoide rocks mostly are not prolific. For recognizing Scheelite, some samples of rocks studied by ultraviolet and few Scheelite is recognized in the samples. Some alteration zone observed in this area but they are not accompany with main mineralization. Although

  15. Petrological imaging of an active pluton beneath Cerro Uturuncu, Bolivia

    NASA Astrophysics Data System (ADS)

    Muir, Duncan D.; Blundy, Jon D.; Hutchinson, Michael C.; Rust, Alison C.

    2014-03-01

    Uturuncu is a dormant volcano in the Altiplano of SW Bolivia. A present day ~70 km diameter interferometric synthetic aperture radar (InSAR) anomaly roughly centred on Uturuncu's edifice is believed to be a result of magma intrusion into an active crustal pluton. Past activity at the volcano, spanning 0.89 to 0.27 Ma, is exclusively effusive and almost all lavas and domes are dacitic with phenocrysts of plagioclase, orthopyroxene, biotite, ilmenite and Ti-magnetite plus or minus quartz, and microlites of plagioclase and orthopyroxene set in rhyolitic groundmass glass. Plagioclase-hosted melt inclusions (MI) are rhyolitic with major element compositions that are similar to groundmass glasses. H2O concentrations plotted versus incompatible elements for individual samples describe a trend typical of near-isobaric, volatile-saturated crystallisation. At 870 °C, the average magma temperature calculated from Fe-Ti oxides, the average H2O of 3.2 ± 0.7 wt% and CO2 typically <160 ppm equate to MI trapping pressures of 50-120 MPa, approximately 2-4.5 km below surface. Such shallow storage precludes the role of dacite magma emplacement into pre-eruptive storage regions as being the cause of the observed InSAR anomaly. Storage pressures, whole-rock (WR) chemistry and phase assemblage are remarkably consistent across the eruptive history of the volcano, although magmatic temperatures calculated from Fe-Ti oxide geothermometry, zircon saturation thermometry using MI and orthopyroxene-melt thermometry range from 760 to 925 °C at NNO ± 1 log. This large temperature range is similar to that of saturation temperatures of observed phases in experimental data on Uturuncu dacites. The variation in calculated temperatures is attributed to piecemeal construction of the active pluton by successive inputs of new magma into a growing volume of plutonic mush. Fluctuating temperatures within the mush can account for sieve-textured cores and complex zoning in plagioclase phenocrysts

  16. Granite fabrics and regional-scale strain partitioning in the Seridó belt (Borborema Province, NE Brazil)

    NASA Astrophysics Data System (ADS)

    Archanjo, Carlos J.; Trindade, Ricardo I. F.; Bouchez, Jean Luc; Ernesto, Marcia

    2002-01-01

    Fabrics of the Brasiliano-age granitoid plutons of the Seridó belt (northeastern Brazil) were organized following the partitioned regional strain field which shaped larger areas of the basement and its metapelitic cover. Nine plutons located at the central and western portions of the belt have been investigated by means of anisotropy of magnetic susceptibility. These plutons, emplaced between 580 and 575 Ma, are mainly potassic calk-alcalic magnetite-bearing monzogranites. The presence of primary coarse-grained magnetite as the main magnetic mineral is indicated by optical and electronic microscopy, magnetic susceptibilities, hysteresis ratios, and thermomagnetic curves. The plutons show a strong internal coherence of magnetic fabric, with foliation poles distributed around a zone axis parallel to the gently plunging mean lineation. The magnetic fabric was used to trace the strain partitioning along the belt. In the central transpressive shear belt the magnetic lineations are parallel to north trending regional stretching. On the other hand, in the western basement block a voluminous granitic magmatism was emplaced as a consequence of a transtensional/extensional deformation. Lineations in these granites trend in a NE direction, which is parallel to the transport, inferred from kinematic indicators along the shear zones. A crustal-scale east trending dextral shear zone connects both the transtensional and transpressional domains.

  17. Segregation of immiscible liquids: From droplet size to plutonic scale

    NASA Astrophysics Data System (ADS)

    Zhang, Z.; Wu, B.; Wang, T.; Hui, H.

    2016-12-01

    Silicate liquid immiscibility has been evidenced as discrete glassy droplets in volcanic rocks microscopically. Furthermore, this process has been proposed to have resulted in mafic and felsic fractions on outcrop scale in plutons. However, it is unclear how tiny discrete immiscible liquid droplets could be segregated from a continuous melt (medium) and lead to magmatic differentiation on a chamber scale. The settling of immiscible liquid droplets depends on their sinking (or floating) velocities, which could be described using the Stokes' law. The discrete liquid droplets during settling could collide and coalesce with each other, resulting in larger droplets, which is different from the collision of crystals in the magma. The coalescence can significantly increase the droplet velocities, which are proportional to the square of the droplet radii according to the Stokes' law. In a slow-cooling magma chamber, the exsolution and settling of the discrete liquid droplets may reach "equilibrium", which here we call the steady state. Numerical analyses using population dynamics equations have been carried out to study how physical properties of melts affect the segregation of immiscible liquids at the steady state. Our preliminary results indicate that the residence time (average time it takes for discrete droplets to settle) of discrete melt with viscosity higher than that of the medium could be longer than that of discrete melt with viscosity lower than that of the medium, by even more than one order of magnitude. Furthermore, the residence time is approximately proportional to the square root of the medium viscosity, inversely proportional to the square root of the density difference and inversely proportional to the exsolution rate if the discrete melt is exsolved as initially small droplets ( 10 µm in radius). This study could shed light on understanding the feasibility of formation of plutons through liquid immiscibility in dynamics.

  18. Cretaceous plutonic rocks in the Donner Lake-Cisco Grove area, northern Sierra Nevada, California

    USGS Publications Warehouse

    Kulow, Matthew J.; Hanson, Richard E.; Girty, Gary H.; Girty, Melissa S.; Harwood, David S.

    1998-01-01

    The northernmost occurrences of extensive, glaciated exposures of the Sierra Nevada batholith occur in the Donner Lake-Cisco Grove area of the northern Sierra Nevada. The plutonic rocks in this area, which are termed here the Castle Valley plutonic assemblage, crop out over an area of 225 km2 and for the most part are shown as a single undifferentiated mass on previously published geological maps. In the present work, the plutonic assemblage is divided into eight separate intrusive units or lithodemes, two of which each consist of two separate plutons. Compositions are dominantly granodiorite and tonalite, but diorite and granite form small plutons in places. Spectacular examples of comb layering and orbicular texture occur in the diorites. U-Pb zircon ages have been obtained for all but one of the main units and range from ~120 to 114 Ma, indicating that the entire assemblage was emplaced in a narrow time frame in the Early Cretaceous. This is consistent with abundant field evidence that many of the individual phases were intruded penecontemporaneously. The timing of emplacement correlates with onset of major Cretaceous plutonism in the main part of the Sierra Nevada batholith farther south. The emplacement ages also are similar to isotopic ages for gold-quartz mineralization in the Sierran foothills west of the study area, suggesting a direct genetic relationship between the voluminous Early Cretaceous plutonism and hydrothermal gold mineralization.

  19. Late Proterozoic and Silurian alkaline plutons within the southeastern New England Avalon zone

    SciTech Connect

    Hermes, O.D. ); Zartman, R.E. )

    1992-07-01

    Distinct pulses of quartz-bearing, alkaline plutonism and volcanism are known to have occurred in the Avalon zone of southeastern New England during the Late Ordovician, Early Silurian, Devonian, and Carboniferous. Zircon separates from the Franklin and Dartmouth plutons demonstrate that two additional, previously unrecognized periods of alkaline magmatism occurred. The Franklin pluton yields an age of 417 {plus minus} 6 Ma (Late Silurian), whereas the Dartmouth pluton is Late Proterozoic (595 {plus minus} 5 Ma) and markedly older than the other plutons of alkaline affinity. The new ages further emphasize the episodic nature and long-term duration of such alkaline igneous events within the southeastern New England Avalon zone. The Dartmouth pluton may represent a post-collisional alkaline granite emplaced in the Late Proterozoic, almost immediately after a major period of calcalkaline igneous activity that accompanied plate convergence and continental accretion. The abrupt change from orogenic calcalkaline igneous activity to post-collisional alkaline granite, followed by younger episodes of anorogenic emplacement, is remarkably similar to igneous events reported from pan-African mobile belts widespread throughout Africa. In addition, parts of the Dartmouth pluton exhibit features indicative of mixing and commingling of felsic and mafic melts that are associated with coevally formed mylonitic fabrics. Because these fabrics are conformable to those in adjacent gneisses, but discordant with Alleghanian fabrics in the nearby Carboniferous Narragansett basin, they represent some of the best candidates for pre-Alleghanian structures thus far identified in the southeastern New England Avalon zone.

  20. Plutonism, oblique subduction, and continental growth: An example from the Mesozoic of California

    SciTech Connect

    Glazner, A.F. )

    1991-08-01

    Major episodes of Mesozoic plutonism in California correlate with periods of oblique subduction and trench-parallel transport of western California along intrabatholithic faults. Major episodes of plutonism occurred in the Late Jurassic, during left-oblique convergence, and in the mid-Cretaceous, during right-oblique convergence. In contrast, a conspicuous lull in plutonism (but continuation of volcanism) in the earliest Cretaceous coincides with a time when the North America-Farallon convergence vector, although large in magnitude, was oriented perpendicular to the trench. This correlation suggests that plutonism is facilitated by strike-slip faulting within the batholithic belt; one explanation, which helps to solve the plutonic room problem, is that plutons are passively emplaced at releasing bends in the strike-slip faults, and volume is conserved by thrusting at the trench. If this correlation is generally applicable, then it implies that mid-crustal plutonism is limited beneath areas in which the convergence vector is subperpendicular to the trench. Continental growth in such areas may occur dominantly by volcanism.

  1. Structure of the Castillo granite, Southwest Spain: Variscan deformation of a late Cadomian pluton

    NASA Astrophysics Data System (ADS)

    EguíLuz, L.; Apraiz, A.; ÁBalos, B.

    1999-12-01

    A geometrical reconstruction of the 500 Ma old Castillo granite pluton (SW Iberia) is completed on the basis of structural and geophysical (rock magnetism) techniques. The pluton is intrusive into latest Proterozoic-earliest Cambrian metasediments and conforms a tabular intrusion 6 km in diameter and 1.7 km thick that was emplaced at a depth of 10 km. Its magnetic fabric reveals that the strike of moderately to steeply dipping magmatic flow planes forms a high angle to the regional tectonic trends. Magnetic foliations and associated moderately to gently plunging magnetic lineations represent magmatic flow planes and directions. The internal anisotropy of the granite together with the structure shown by the country rocks attest the lateral propagation of the pluton and its latter inflation. The pluton's root zone would correspond to a likely thin, subvertical feeder structure initiated near the orientation of regional σ1 at the time of emplacement. During the Variscan orogeny the pluton was tilted and underwent localized brittle-ductile strain in relation to shear zone deformation in the footwall of a major ductile thrust. Tilting permits the observation and study of a vertical profile of the intrusion. Localized deformation caused superposition of tectonic zonations on the magmatic ones, a reactivation of the basal contact of the pluton, and dismemberment from its root. This and other granitoid plutons of similar age emplaced at a similar depth constrained the creation of crustal mechanical heterogeneity and anisotropy. This controlled the site of pluton emplacement, the nucleation of a major ductile thrust, and localization of deformation and tectonic displacements along the pluton margins during later orogenic reactivation.

  2. Influence of low-angle normal faulting on radial fracture pattern associated to pluton emplacement in Tuscany, Italy

    NASA Astrophysics Data System (ADS)

    Balsamo, F.; Rossetti, F.; Salvini, F.

    2003-04-01

    Fault-related fracture distribution significantly influences fluid flow in the sub-surface. Fault zone can act either as barriers or conduits to fluid migration, or as mixed conduit/barrier systems, depending on several factors that include the enviromental condition of deformation (pore fluid pressure, regional stress fields, overburden etc.), the kinematics of the fault and its geometry, and the rock type. The aim of this study is to estimate the boundary conditions of deformation along the Boccheggiano Fault, in the central Appennines. Seismic and deep well data are avaible for the Boccheggiano area, where a fossil geothermal system is exposed. The dominant structural feature of the studied area is a NW-SE trending low-angle detachment fault (Boccheggiano fault, active since the upper Miocene times), separating non-metamorphic sedimentary sequences of the Tuscan meso-cenozoic pelagiac succession and oceanic-derived Ligurids in the hangingwall, from green-schists facies metamorphic rocks of Paleozoic age in the footwall. Gouge-bearing mineralized damage zone (about 100 m thick) is present along the fault. The deep geometry of the Boccheggiano Fault is well imaged in the seismic profiles. The fault is shallow-dipping toward NE and flattens at the top of a magmatic intrusion, which lies at about 1000 m below the ground-level. Geometrical relationships indicate syn-tectonic pluton emplacement at the footwall of the Boccheggiano fault. Statistical analysis of fracture distribution pointed out a strong control of both azimuth and frequency by their position with respect to the Boccheggiano Fault: (i) a NW-SE trending fracture set within the fault zone, (ii) a radial pattern associated away from fault zone. Interpretation of structural and seismic data suggest an interplay between the near-field deformation associated with the rising intrusion during its emplacement (radial fracturing) and the NE-SW far-field extensional tectonic regime (NW-SE fractures) recognized in

  3. Informatics in Turkey

    NASA Technical Reports Server (NTRS)

    Cakir, Serhat

    1994-01-01

    In the last twenty years the rapid change in the informatics sector has had economic and social impact on private and government activities. The Supreme Council for Science and Technology of Turkey assigned highest priority to the informatics in its meeting in February 1993. With this advice TUBITAK (The Scientific and Technical Research Council of Turkey) intends to give a strong impulse to development of a research policy in this field.

  4. Energy Security and Turkey

    DTIC Science & Technology

    2008-12-01

    Russia - Ukraine Gas Crisis,” Center for Eurasian Strategis Studies ( ASAM ), Ankara, Turkey, April 21, 2008, www.asam.org.tr/temp/temp111.doc...Necdet Pamir. “Energy in Security and the Most Recent Lesson: The Russia - Ukraine Gas Crisis,” Center for Eurasian Strategis Studies ( ASAM ), Ankara...Crisis,” Center for Eurasian Strategis Studies ( ASAM ), Ankara, Turkey, April 21, 2008, www.asam.org.tr/temp/temp111.doc (accessed May 21, 2008). 53

  5. Pediatric oncology in Turkey.

    PubMed

    Kebudi, Rejin

    2012-03-01

    The survival of children with cancer has increased dramatically in the last decades, as a result of advances in diagnosis, treatment and supportive care. Each year in Turkey, 2500-3000 new childhood cancer cases are expected. According to the Turkish Pediatric Oncology Group and Turkish Pediatric Hematology Societies Registry, about 2000 new pediatric cancer cases are reported each year. The population in Turkey is relatively young. One fourth of the population is younger than 15 years of age. According to childhood mortality, cancer is the fourth cause of death (7.2%) after infections, cardiac deaths and accidents. The major cancers in children in Turkey are leukemia (31%), lymphoma (19%), central nervous system (CNS) neoplasms (13%), neuroblastomas (7%), bone tumors (6.1%), soft tissue sarcomas (6%), followed by renal tumors, germ cell tumors, retinoblastoma, carcinomas-epithelial neoplasms, hepatic tumors and others. Lymphomas rank second in frequency as in many developing countries in contrast to West Europe or USA, where CNS neoplasms rank second in frequency. The seven-year survival rate in children with malignancies in Turkey is 65.8%. The history of modern Pediatric Oncology in Turkey dates back to the 1970's. Pediatric Oncology has been accepted as a subspecialty in Turkey since 1983. Pediatric Oncologists are all well trained and dedicated. All costs for the diagnosis and treatment of children with cancer is covered by the government. Education and infrastructure for palliative care needs improvement.

  6. Cryptosporidiosis and turkey viral hepatitis in turkeys.

    PubMed

    Wages, D P; Ficken, M D

    1989-01-01

    Cryptosporidiosis and turkey viral hepatitis were diagnosed in 25-day-old turkeys with increased mortality, enteritis, and stunting. Necropsy lesions included foul-smelling, tan-colored, loose feces in the terminal small intestines and ceca. The small intestines and ceca were congested. Multiple white to gray foci were present in the liver and pancreas. Mortality attributed to these conditions was estimated at 4.9%. Microscopic lesions included necrosis with accumulations of macrophages in the liver and pancreas. Bile-duct hyperplasia was present in the livers. Microscopic intestinal lesions consisted of mild to moderate atrophy of the villi of the distal small intestine (ileo-cecal junction) with infiltration of the lamina propria by mononuclear cells. Cryptosporidia were identified and appeared to be attached to villous epithelial cells of the terminal small intestines. Cryptosporidium sp. oocysts were also confirmed by fluorescent microscopic examination of feces stained auramine O. Reovirus was isolated on chicken embryo liver cells from affected livers.

  7. Iron variation within a granitic pluton as determined by near-infrared reflectance

    NASA Technical Reports Server (NTRS)

    Baird, A. K.

    1984-01-01

    One-hundred fifty-one previously chemically analyzed samples of tonalite from the Lakeview Mountains pluton, southern California batholith, were analyzed for their iron content using near-infrared spectrophotometry. Compared to the earlier analyses of the same sample set by X-ray fluorescence spectrography, the infrared data have higher analytical variance but clearly define patterns of compositional zonation in the pluton which are closely similar to those patterns obtained from X-ray data; petrogenetic interpretations for the pluton would be the same from either data set. Infrared spectral data can be obtained directly in the field with relatively simple instruments and field measurements can be made to average local heterogeneities that often mask significant plutonic variations.

  8. Volcanic-plutonic parity and the differentiation of the continental crust.

    PubMed

    Keller, C Brenhin; Schoene, Blair; Barboni, Melanie; Samperton, Kyle M; Husson, Jon M

    2015-07-16

    The continental crust is central to the biological and geological history of Earth. However, crustal heterogeneity has prevented a thorough geochemical comparison of its primary igneous building blocks-volcanic and plutonic rocks-and the processes by which they differentiate to felsic compositions. Our analysis of a comprehensive global data set of volcanic and plutonic whole-rock geochemistry shows that differentiation trends from primitive basaltic to felsic compositions for volcanic versus plutonic samples are generally indistinguishable in subduction-zone settings, but are divergent in continental rifts. Offsets in major- and trace-element differentiation patterns in rift settings suggest higher water content in plutonic magmas and reduced eruptibility of hydrous silicate magmas relative to dry rift volcanics. In both tectonic settings, our results indicate that fractional crystallization, rather than crustal melting, is predominantly responsible for the production of intermediate and felsic magmas, emphasizing the role of mafic cumulates as a residue of crustal differentiation.

  9. Typochemistry of rinkite and products of its alteration in the Khibiny Alkaline pluton, Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Konopleva, N. G.; Ivanyuk, G. Yu.; Pakhomovsky, Ya. A.; Yakovenchuk, V. N.; Mikhailova, Yu. A.; Selivanova, E. A.

    2015-12-01

    The occurrence, morphology, and composition of rinkite are considered against the background of zoning in the Khibiny pluton. Accessory rinkite is mostly characteristic of foyaite in the outer part of pluton, occurs somewhat less frequently in foyaite and rischorrite in the central part of pluton, even more sparsely in foidolites and apatite-nepheline rocks, and sporadically in fenitized xenoliths of the Lovozero Formation. The largest, up to economic, accumulations of rinkite are related to the pegmatite and hydrothermal veins, which occur in nepheline syenite on both sides of the Main foidolite ring. The composition of rinkite varies throughout the pluton. The Ca, Na, and F contents in accessory rinkite and amorphous products of its alteration progressively increase from foyaite and fenitized basalt of the Lovozero Formation to foidolite, rischorrite, apatite-nepheline rocks, and pegmatite-hydrothermal veins.

  10. Iron variation within a granitic pluton as determined by near-infrared reflectance

    NASA Technical Reports Server (NTRS)

    Baird, A. K.

    1984-01-01

    One-hundred fifty-one previously chemically analyzed samples of tonalite from the Lakeview Mountains pluton, southern California batholith, were analyzed for their iron content using near-infrared spectrophotometry. Compared to the earlier analyses of the same sample set by X-ray fluorescence spectrography, the infrared data have higher analytical variance but clearly define patterns of compositional zonation in the pluton which are closely similar to those patterns obtained from X-ray data; petrogenetic interpretations for the pluton would be the same from either data set. Infrared spectral data can be obtained directly in the field with relatively simple instruments and field measurements can be made to average local heterogeneities that often mask significant plutonic variations.

  11. Pluton emplacement in a releasing bend in a transpressive regime: the arrozal granite in the Paraíba do Sul shear belt, Rio de Janeiro.

    PubMed

    Nummer, Alexis R; Machado, Rômulo; Dehler, Nolan M

    2007-06-01

    The Arrozal Granite, situated in the southwestern region of the State of Rio de Janeiro, has a granitic to granodioritic composition. It contains a strong mylonitic foliation along its border, passing gradually to a well-developed magmatic foliation towards its center. Structural analysis indicates that the Arrozal Granite was emplaced along the Além-Paraíba Shear Zone in a dextral transpressive tectonic regime. A regional shift of the trend along this shear zone from NE-SW to E-W, observed in the area, is interpreted to be casually related to the creation of space for the emplacement of the granite. Our data indicate that releasing bends may have played an important role for space generation during the emplacement of the Arrozal Granite and other plutons.

  12. A comparative study of two rear-arc plutons and implications for the Fuegian Andes tectonic evolution: Mount Kranck Pluton and Jeu-Jepén Monzonite, Argentina

    NASA Astrophysics Data System (ADS)

    González-Guillot, M.; Prezzi, C.; Acevedo, R. D.; Escayola, M.

    2012-10-01

    A petrologic, geochemical and geophysical study of two Late Cretaceous plutons of the Fuegian Andes is carried out: the Jeu-Jepén Monzonite (JJM) and the Mt. Kranck Pluton (MKP). The plutons show a wide lithological spectrum from ultramafic lithologies (clinopyroxenites and hornblendites), gabbros, diorites to late stage K-feldspar syenite veins. They represent the top of magmatic chambers exposed at or close to the roof level. Mode and chemistry indicate a monzonitic-mildly alkaline trend with high K2O content, equivalent to shoshonitic series. Trace element composition is typical of arc magmas. These features plus their high LILE content (Ba 320-1600 ppm, Sr 475-1560 ppm), high LILE/HFSE ratio (Rb/Zr 0.6-1.6) and age confirm they belong to a rear-arc, monzonitic to mildly alkaline suite (the Fuegian Potassic Magmatism). Therefore, they represent the farthest-from-the-trench plutons in the suite. The petrographical and chemical characteristics of the plutons suggest the lithological spectrum is the result of magmatic differentiation. The process involved crystal accumulation and magma mingling at the early stages, favored either by injections of fresh magma from deeper reservoirs and/or the action of convective currents within the chamber. Country rock assimilation also took part simultaneously with crystallization. The JJM and MKP lie along the trace of a Cenozoic left-lateral strike-slip fault (Magallanes-Fagnano fault system), on opposite blocks. However, lithological, chemical and geophysical subtle differences between these two plutons suggest they evolved in individual magmatic chambers and therefore the distance between them cannot be used as an estimation of total offset along the fault, as was indicated in previous studies.

  13. Geochemical and temporal relationships between plutonic and volcanic rocks from the Aleutian arc: a pilot study

    NASA Astrophysics Data System (ADS)

    Cai, Y.; Rioux, M. E.; Kelemen, P. B.; Goldstein, S. L.

    2013-12-01

    Aleutian arc volcanics are predominantly basaltic while known plutonic rocks are systematically more felsic and have compositions that overlap estimates for the bulk composition of the continental crust. The Aleutian arc is unique among active intra-oceanic arcs in its widespread exposure of Paleogene and Neogene mid-crustal plutonic rocks, as well as the lavas and sediments that these plutons intruded. Thus, understanding the genesis of Aleutian plutonic rocks is a key to understanding continental genesis and evolution via arc magmatism. We have measured major, trace element contents and Sr-Nd-Hf-Pb isotope compositions of 26 mafic to intermediate plutonic rocks, ranging in age from ~32-9 Ma, across the Aleutian arc and compared them with spatially associated Quaternary volcanic rocks. The samples cover a large range of Mg# (73 to 35). Most samples do not show substantial Eu anomalies, and they represent primary magmas rather than differentiated cumulates. Compared to associated volcanics, the plutonic rocks show similar to slightly higher SiO2 and K2O contents at a given Mg#. For many trace elements, the plutonic and volcanic rocks are similar (e.g., elemental concentrations and La/Sm, Th/Nd, Lu/Hf, Dy/Yb ratios). However, the plutonic rocks show on average higher Nd and Hf isotope ratios and lower Pb isotope ratios than volcanic rocks from the same island. The difference in isotope compositions between the plutonic rocks and their volcanic neighbors indicates differences in the mantle sources. This could reflect temporal variation of mantle composition under the Aleutians. Based on U-Pb zircon geochronology of representative samples, the data may indicate decreasing Nd (-Hf) isotope ratios of the sub-Aleutians mantle through time in some regions. However, more data is necessary from plutonic rocks to determine if this will hold up. Alternatively, the compositional differences (e.g. higher Si and K) between the plutonics and the volcanics could reflect different

  14. Fluorine in Olivines from Plutonic, Extrusive, and Hypabyssal Suites

    NASA Astrophysics Data System (ADS)

    Guggino, S. N.; Hervig, R. L.; Bell, D. R.

    2007-12-01

    Fluorine contents in a wide range of naturally-occurring olivine grains were determined by secondary ion mass spectrometry (SIMS) using a Cs+ primary beam, detection of negative secondary ions and an auxiliary electron gun for charge neutralization. A range of minerals and glasses containing 3 to 1300 ppm F were used to calibrate the secondary ion signal. Matrix effects appear to be small, and because fluorine has a high electron affinity, sensitivity is high (sub-ppm). Olivines from the study by Simkin and Smith (J. Geol., 1970) were analyzed for their F contents and span a range of suites that include upper mantle xenoliths and kimberlites, plutonic intrusives, ophiolites, shallow hypabyssal picrites and teschenites, and extrusive alkaline and tholeiitic basalts. Overall, the olivines in this study show a range of F concentrations from 0.5 to 32 ppm. Olivines from high- pressure environments show the highest individual and average F values, however large variations are also observed in this suite. Mantle xenoliths from this sample collection show a maximum and average F value of 14 and 4.1 ppm, respectively, and one olivine from kimberlite contains 32 ppm F. Earlier analyses from our laboratory (Hervig and Bell, 2005 Fall AGU) show a larger range in F from mantle-derived olivines. Plutonic intrusives and ophiolites, including layered intrusives and cumulates, show a range of F contents from 0.5 to 15 ppm, with an average value of 4 ppm. Olivines from the Kiglapait layered intrusion, Labrador show F content increasing with degree of fractional crystallization until the P2O5 content of the rock begins to increase. At this point, F in olivine decreases, presumably indicating partitioning of F into apatite. In the Hawaiian suites studied, F in olivine was high (8-12 ppm) in evolved andesites and lower (1-8 ppm) in more primitive basalts. Hypabyssal suites include a peridotite dike from Skye, (F < 1 ppm), a chilled olivine dolerite from Bornaskitaig (F = 2 ppm), a

  15. The fate of turkey #88

    Treesearch

    Mark A. Rumble; Todd Mills

    1993-01-01

    On January 9, 1990, 32 turkeys were captured in the Black Hills of South Dakota using the drug alpha-chloralose. One of these turkeys had a unique tag attached to it's wing that indicated it had been trapped previously Let's look back in time and see what made the events in the life of this turkey deviate slightly from "The Events in the Turkey Year...

  16. Petrology and Geochemistry of Neoproterozoic Arc Plutons Beneath the Atlantic Coastal Plain, SRS, SC

    SciTech Connect

    Maryak, M.

    1998-10-21

    In this report is presented first a brief review of the regional geologic setting of the Savannah River Site, descriptions of the plutonic rock units sampled here, whole rock geochemical data on the plutonic igneous rocks, and finally, a discussion of how the crystalline basement rocks of the Savannah River Site formed and how they may correlate with other terranes exposed in the Piedmont of the Carolinas, Georgia, and Virginia.

  17. Tertiary epizonal plutonic rocks of the Selway-Bitterroot Wilderness, Idaho County, Idaho

    SciTech Connect

    Motzer, W.E.

    1996-01-01

    Geologic mapping in the Selway-Bitterroot Wilderness identified approximately 731 kmS of epizonal plutonic granitic rocks within the Bitterroot lobe of the Idaho batholith. From north to south, the intrusions are the Rock Lake Creek stock and the Whistling Pig, Running Creek, Bad Luck and Painted Rocks plutons. The stock and plutons consist of medium- to coarse-grained biotite and hornblende-biotite syenorgranite to monzogranite and quartz syenite capped by fine-grained biotite leucogranite. These rocks are intruded by late-synplutonic leucogranite dikes and post plutonic porphyritic rhyolite to rhyodacite and basalt dikes. The medium-grained granitic rocks are high in SiO2, K2O, Na2O, Ga, Th, U, W and Zr, but low in Al7O3, CaO, MgO, Cr, Ni, Co and V. Most of the granites are peraluminous. Rare-earth element (REE) plots (rock sample/chondrite) show enrichment in light REE over heavy REE with strong EU depletions. K-Ar biotite radiometric age determinations for medium-grained granites in all of the plutons range from approximately 51 Ma (Whistling Pig pluton) to 43.7 Ma (Painted Rocks pluton). Petrogenetic studies suggest that the plutons were rapidly emplaced to within 3.0 km of the paleosurface. The types, textures and color of the rocks result from devolatilization of the crystallizing melt and very low-grade hydrothermal alteration. The fluorine-rich melts are the fractionated with accumulate residue; they are considered to be anorogenic (A-type) granites intruded into the center of a metamorphic core complex.

  18. The Future of Secular Turkey

    DTIC Science & Technology

    1997-03-01

    AND SUBTITLE The Future of Secular Turkey 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e...government in Turkey between the Islamist Refah Party and secular True Path Party has focused Western concern on the future of secular Turkey. The

  19. Uranium-Lead Zircon Ages and Sr, Nd, and Pb Isotope Geochemistry of Selected Plutonic Rocks from Western Idaho

    USGS Publications Warehouse

    Unruh, Daniel M.; Lund, Karen; Kuntz, Mel A.; Snee, Lawrence W.

    2008-01-01

    Across the Salmon River suture in western Idaho, where allochthonous Permian to Cretaceous oceanic rocks are juxtaposed against Proterozoic North American rocks, a wide variety of plutonic rocks are exposed. Available data indicate much variation in composition, source, and structural state of these plutons. The plutonic rocks were long described as the western border zone of the Cretaceous Idaho batholith but limited pre-existing age data indicate more complicated origins. Because the affinity and age of the plutonic rocks cannot be reliably determined from field relations, TIMS U-Pb dating in conjunction with Sr, Nd, and Pb isotopic studies of selected plutons across the suture in western Idaho were undertaken. The data indicate three general groups of plutons including (1) those that intruded the island arc terranes during the Triassic and Jurassic, those that intruded near the western edge of oceanic rocks along the suture in the Early Cretaceous, and the plutons of the Idaho batholith that intruded Proterozoic North American rocks in the Late Cretaceous. Plutons that intruded Proterozoic North American rocks commonly include xenocrystic zircons and in several cases, ages could not be determined. The least radiogenic Sr and most radiogenic Nd are found among the Blue Mountains superterrane island arc samples. Suture-zone plutons have isotopic characteristics that span the range between Idaho batholith and island arc samples but mostly follow island arc signatures. Plutons of the Idaho batholith have the most radiogenic initial Pb and Sr ratios and the least radiogenic Nd of the samples analyzed.

  20. Origin of mineralogical zoning in an intermediate subvolcanic pluton by crystal settling and conductive cooling

    SciTech Connect

    Hildebrand, R.S.

    1985-01-01

    The Rainy Lake Intrusive Complex is one of nine sheet-like intermediate plutons that are compositionally, temporally, and spatially linked to andesitic stratovolcanoes in the western Great Bear Magmatic Zone, an early Proterozoic continental magmatic arc. The pluton, exposed in oblique cross section, has a flat roof and is 1.5 km thick by 12 km long. The observed distribution of plagioclase phenocrysts in the body closely resembles the sinusoidal olivine distribution patterns found in lava lakes and some mafic sills. The shape of the curve indicates that the volume fraction plagioclase phenocrysts in the pluton at the time of intrusion ranged for 10% near the roof to 50% near the base. Calculations indicate that the plagioclase phenocrysts were denser than the surrounding melt. The effects of different crystal concentrations on the viscosity, and hence settling velocities, were computed as a function of height in the pluton; settling velocities ranged, at the time of intrusion, from 160 meters per year near the top to less than 1 meter per year near the base. The observed sinusoidal distribution curve for plagioclase can be explained by the interplay between crystal settling and the solidification of the pluton from the top downwards and the bottom upwards. This suggests that whole body convection did not play a major role in the cooling of the pluton.

  1. Assessment of gamma radiation exposure and distribution of natural radioactivity in beach sands associated with plutonic rocks of Greece

    NASA Astrophysics Data System (ADS)

    Papadopoulos, Argyrios; Koroneos, Antonios; Christofides, Georgios; Stoulos, Stylianos

    2016-04-01

    This study aims to evaluate the activity concentrations of 238U, 226Ra, 232Th, 228Th and 40K along beaches of Greece associated with plutonic rocks. They range from 6-940, 1-2292, 5-10143, 5-9953 and 27-1319 Bq/kg respectively, with some of them representing the highest values of natural radioactivity measured in sediments in Greece. The investigated beaches include Sithonia peninsula (Chalkidiki, N. Greece), some islands of the Aegean Sea (Mykonos, Paros, Naxos, Serifos, Ikaria), the area of Kavala (N. Greece), Samothraki island, NE Chalkidiki and Maronia (NE Greece). Several of these places are associated with high touristic activity such as Mykonos, Naxos, Paros, Serifos, Ikaria, Sithonia and Kavala. The (% wt.) heavy magnetic fraction (HM) (allanite, amphibole, mica, clinopyroxene, magnetite and hematite), the heavy non-magnetic fraction (HNM) (monazite, zircon, titanite and apatite) and the total heavy fraction (TH), were correlated with the concentrations of the measured radionuclides in the bulk samples. The heavy fractions seem to control the activity concentrations of 238U and 232Th of all the samples, showing some local differences in the main 238U and 232Th mineral carrier. The measured radionuclides in the beach sands were normalized to the respective values measured in the granitic rocks, which are their most probable parental rocks, so as to provide data upon their enrichment or depletion. The highest values of the equivalent dose have been reported in Mykonos, Naxos, Kavala and Sithonia. The annual equivalent dose which should be limited to at least 1 mSv y-1, varies between 0.003 and 0.759 mSv y-1 for tourists and from 0.012 to 3.164 mSv y-1 for local people working on the beach.

  2. Transplantation in Turkey.

    PubMed

    Haberal, Mehmet

    2013-01-01

    The cornerstone events of transplantation history in Turkey are summarized herein. In 1975, we performed the first living-related renal transplant in Turkey. We followed this in 1978 with the first deceased donor kidney transplantation, using an organ supplied by Eurotransplant. In 1979, the law on harvesting, storage, grafting, and transplantation of organs and tissues was enacted; later that year, the first local deceased donor kidney transplantation was performed by our team. In 1988, another groundbreaking event in Turkey was successfully achieved: the first cadaveric liver transplantation. In 1990, the first pediatric living-related segmental liver transplantation in Turkey, the region, and Europe was performed by our team. One month later, an adult-to-adult living-related liver transplantation was successfully performed. In May 1992, we performed the first combined liver-kidney transplantation from a living-related donor, which was the first operation of its kind. To date, we have performed 2,084 kidney and, since 1988, 439 liver transplantations. During 29 years of solid organ transplantation history in Turkey, 20,794 kidney transplants have been performed nationwide in 62 different centers, as well as 6,565 liver, 621 heart, and 168 pancreas transplants. In 2001, the Ministry of Health established the National Coordination Center as an umbrella organization to promote transplantation activities, especially for deceased donor organ procurement. Transplantation activities are accelerating daily throughout the country, but deceased donors are still far below the desired rates.

  3. Isotopic constraints on the petrogenesis of jurassic plutons, Southeastern California

    USGS Publications Warehouse

    Mayo, D.P.; Anderson, J.L.; Wooden, J.L.

    1998-01-01

    The 165 Ma Eagle Mountain intrusion is a heterogeneous, enclave-bearing, metaluminous remnant of the Cordilleran Jurassic arc that cuts regionally metamorphosed pre-Mesozoic rocks in the southeastern Mojave Desert of California. The main phase of the intrusion consists of granodiorite to tonalite host facies, diorite mixed facies, and homogeneous monzogranite facies. The host facies contains microdiorite enclaves interpreted as intermingled masses of mafic magma. Late-phase leucogranite stocks cut the main phase. Mineral equilibria indicate emplacement at ???6.5 km depth, with solidus temperatures ranging from 760??C for diorite to 700??C for felsic granodiorite. Although uniform radiogenic-isotope compositions (Sri = 0.7085, ???Ndi = -9.4) suggest derivation from a single source, no known source has the composition required. A hybrid source is proposed, consisting of various proportions of juvenile mantle and recycled lower crust. Calculations indicate that the source of the Eagle Mountain intrusion comprised >60% juvenile mantle and <40% recycled crust. On the basis of their isotopic compositions, other mafic Jurassic plutons in the region were derived from sources containing different proportions of mantle and crustal components.

  4. KM3NeT

    SciTech Connect

    Jong, M. de; Collaboration: KM3NeT Collaboration

    2015-07-15

    KM3NeT is a large research infrastructure, that will consist of a network of deep-sea neutrino telescopes in the Mediterranean Sea. The main objective of KM3NeT is the discovery and subsequent observation of high-energy neutrino sources in the Universe. A further physics perspective is the measurement of the mass hierarchy of neutrinos. A corresponding study, ORCA, is ongoing within KM3NeT. A cost effective technology for (very) large water Cherenkov detectors has been developed based on a new generation of low price 3-inch photo-multiplier tubes. Following the successful deployment and operation of two prototypes, the construction of the KM3NeT research infrastructure has started. The prospects of the different phases of the implementation of KM3NeT are summarised.

  5. Constraints on the depth of generation and emplacement of a magmatic epidote-bearing quartz diorite pluton in the Coast Plutonic Complex, British Columbia

    USGS Publications Warehouse

    Chang, J.M.; Andronicos, C.L.

    2009-01-01

    Petrology and P-T estimates indicate that a magmatic epidote-bearing quartz diorite pluton from Mt. Gamsby, Coast Plutonic Complex, British Columbia, was sourced at pressures below ???1.4 GPa and cooled nearly isobarically at ???0.9 GPa. The P-T path indicates that the magma was within the stability field of magmatic epidote early and remained there upon final crystallization. The pluton formed and crystallized at depths greater than ???30 km. REE data indicate that garnet was absent in the melting region and did not fractionate during crystallization. This suggests that the crust was less than or equal to ???55 km thick at 188 Ma during the early phases of magmatism in the Coast Plutonic Complex. Late Cretaceous contractional deformation and early Tertiary extension exhumed the rocks to upper crustal levels. Textures of magmatic epidote and other magmatic phases, combined with REE data, can be important for constraining the P-T path followed by magmas. ?? 2009 Blackwell Publishing Ltd.

  6. Is there a geochemical link between volcanic and plutonic rocks in the Organ Mountains caldera?

    NASA Astrophysics Data System (ADS)

    Memeti, V.; Davidson, J.

    2013-12-01

    Results from separate volcanic and plutonic studies have led to inconsistent conclusions regarding the origins and thus links between volcanic and plutonic systems in continental arcs and the magmatic processes and time scales responsible for their compositional variations. Some have suggested that there is a geochemical and geochronological disconnect between volcanic and plutonic rocks and hence have questioned the existence of magma mush columns beneath active volcanoes. Investigating contemporary volcanic and plutonic rocks that are spatially connected is thus critical in exploring these issues. The ca. 36 Ma Organ Mountains caldera in New Mexico, USA, represents such a system exposing contemporaneous volcanic and plutonic rocks juxtaposed at the surface due to tilting during extensional tectonics along the Rio Grande Rift. Detailed geologic and structural mapping [1] and 40Ar/39Ar ages of both volcanics and plutons [2] demonstrate the spatial and temporal connection of both rock types with active magmatism over >2.5 myr. Three caldera-forming ignimbrites erupted within 600 kyr [2] from this system with a total erupted volume of 500-1,000 km3 as well as less voluminous pre- and post-caldera trachyte and andesite lavas. The ignimbrite sequence ranges from a crystal-poor, high-SiO2 rhyolite at the base to a more crystal-rich, low-SiO2 rhyolite at the top. Compositional zoning with quartz-monzonite at the base grading to syenite and alaskite at the top is also found in the Organ Needle pluton, the main intrusion, which is interpreted to be the source for the ignimbrites [1]. Other contemporaneous and slightly younger plutons have dioritic to leucogranitic compositions. We examined both volcanic and plutonic rocks with petrography and their textural variations with color cathodoluminescence, and used whole rock element and Sr, Nd and Pb isotope geochemistry to constrain magma compositions and origins. Electron microprobe analyses on feldspars have been completed to

  7. Mineral potential of selected felsic plutons in the eastern and southeastern Arabian Shield, Kingdom of Saudi Arabia

    USGS Publications Warehouse

    du Bray, Edward A.

    1983-01-01

    Most of the plutons studied are similar to metallogenically specialized granites described elsewhere in the world and found associated with deposits of tin, tungsten, or molybdenum and other rare metals. Only four of the plutons, the Sitarah, Tarban, and Gaharra monzogranites and the Bwana granite, contained highly anomalous amounts of tin, tungsten, or molybdenum and altered zones- and (or) numerous quartz veins and otherwise appeared to have noteworthy mineral potential. Additional work on at least these four plutons is suggested.

  8. Melt segregation and assembly of the youngest exposed magma chamber in the world: Takidani Pluton (Japan)

    NASA Astrophysics Data System (ADS)

    Hartung, E.; Caricchi, L.; Floess, D.; Wallis, S.; Harayama, S.

    2014-12-01

    Segregation of residual melt from partially crystallized magmas is a process of paramount importance for the chemical evolution of magmas and the construction of reservoirs of potentially eruptible magma. In this study we investigate the Takidani pluton, one of the youngest exposed plutons on Earth (˜1Ma). This chemically zoned magmatic body is located within the active Norikura Volcanic Chain in the Northern Japan Alps and associated with large dacitic to rhyolitic deposits (Nyukawa Pyroclastic Flow Deposit and Ebisutoge-Fukuda tephra). Our study focuses on the physical processes responsible for the extraction of residual melt from a crystallizing magma and the construction of the subvolcanic reservoirs that fed large silicic eruptions. Detailed structural mapping and sampling along four transects from the base to the top of the pluton were carried out along with a magnetic susceptibility survey. Our preliminary results indicate that the pluton was assembled by multiple intrusions. The pluton can be broadly separated into three distinct lithological units: 1) fine grained granite; 2) equigranular granodiorite that locally grades into either porphyritic granodiorite or granite towards the roof of the intrusion; and 3) mafic granodiorite. Units 1) and 2) form the core of the intrusion and together represent about 70% of the total volume of the pluton. Our results show that the equigranular granodiorite is internally inhomogeneous with felsic lenses of lower magnetic susceptibility. The magnetic susceptibility decreases gradually towards the roof of the pluton reaching its lowest value within leucrocratic porphyritic units. Higher magnetic susceptibility values at the contact with the roof correspond to a slightly more mafic porphyritic unit. Melt segregation and evolution of the Takidani Granodiorite are being further investigated using bulk rock and mineral chemistry (EMPA and LA-ICP-MS) together with anisotropy of magnetic susceptibility.

  9. Record of Hybridization Preserved in Zircon, Aztec Wash Pluton, NV

    NASA Astrophysics Data System (ADS)

    Bromley, S. A.; Miller, C. F.; Claiborne, L. L.; Wooden, J. L.; Mazdab, F. K.

    2007-12-01

    The mid-Miocene Aztec Wash pluton comprises a smaller granite zone and a larger, highly heterogeneous zone in which evidence for interaction between basaltic and granitic magmas is ubiquitous. Granitic rocks in both zones show textural and compositional evidence for crystal accumulation and melt fractionation. In the heterogeneous zone, basalts have chilled, crenulate margins against granitic rocks, and there is widespread evidence for mechanical contamination of each lithology (coarse resorbed alkali feldspar in fine-grained mafic rock; mafic enclaves in granite). "Grey rocks" of intermediate composition are exposed on dm to 100's of m-scale as enclaves, pods, and initially subhorizontal sheets. They are variable texturally, but most are dominantly fine- grained and equigranular. Textures of grey rocks are consistent with rapid solidification from melt-rich magma, and, in combination with isotopic compositions intermediate between felsic and mafic rocks of the pluton, suggest an origin by near-complete homogenization of a hybrid melt (Bleick et al. 2005; Ericksen 2005). The elemental chemistry of zircon preserves information about the evolving magmatic environment in which it was hosted (Claiborne et al., 2006). Owing to its slow dissolution rate, it has the potential to survive periods of undersaturation with only partial resorption. Thus, it may record drastic shifts in T and melt chemistry that would accompany mafic-felsic hybridization. We are investigating zircon zoning patterns by cathodoluminescence (CL) and elemental compositions by SHRIMP-RG to evaluate the record of processes that they preserve. Temperatures of zircon growth are estimated using Ti-in-zircon thermometry (Watson et al. 2006), assuming a(TiO2) of ca. 0.7 (sphene +/-ilmenite are ubiquitous). Zircons from the granite zone yield estimated T's of 700-860 C, whereas those from grey rocks range from 710- 910 C. While both granite and grey zircon populations show dramatic T variations among and

  10. Educational Institutions: Terminology. Turkey.

    ERIC Educational Resources Information Center

    Council for Cultural Cooperation, Strasbourg (France).

    Prepared from interviews with personnel of the Turkish Ministry of National Education, and other educational administrators in that country, this publication provides a guide to the terminology used to name the types of public educational institutions found in Turkey. Private educational institutions, military schools, higher schools attached to…

  11. Cloning Creationism in Turkey.

    ERIC Educational Resources Information Center

    Edis, Taner

    1999-01-01

    Defines how political balances and changes in Turkey effect creation-evolution relation. Describes the influences of Bilim Arastirma Vakfi (BAV) on these changes, which are directly targeted to public education, and discusses the content of creationism. Questions why Islamic creationism is a copy of that of the Institute for Creation Research…

  12. Educational Reform in Turkey

    ERIC Educational Resources Information Center

    Aksit, Necmi

    2007-01-01

    There are a number of reform initiatives underway in Turkey but some of these, which are concerned with curricular and structural changes, have encountered serious difficulties. This paper begins with a brief summary of school effectiveness and school improvement research guiding many educational reforms. It then gives some information about…

  13. Osteomyelitis in turkeys

    USDA-ARS?s Scientific Manuscript database

    Turkey osteomyelitis complex (TOC) is a condition in which apparently healthy, usually male birds have infections that are hidden in their bones, joints, and muscles. Some of these birds have a green liver, which provides a method for detecting these carcasses in the processing plant. Our research h...

  14. Wind energy and Turkey.

    PubMed

    Coskun, Aynur Aydin; Türker, Yavuz Özhan

    2012-03-01

    The global energy requirement for sustaining economic activities, meeting social needs and social development is increasing daily. Environmentally friendly, renewable energy resources are an alternative to the primary non-renewable energy resources, which devastate ecosystems in order to meet increasing demand. Among renewable energy sources such as hydropower, biopower, geothermal power and solar power, wind power offers distinct advantages to Turkey. There is an increasing tendency toward wind globally and the European Union adjusted its legal regulations in this regard. As a potential EU Member state, Turkey is going through a similar process. The number of institutional and legal regulations concerning wind power has increased in recent years; technical infrastructure studies were completed, and some important steps were taken in this regard. This study examines the way in which Turkey has developed support for wind power, presents a SWOT analysis of the wind power sector in Turkey and a projection was made for the concrete success expected to be accomplished in the future.

  15. Educational Institutions: Terminology. Turkey.

    ERIC Educational Resources Information Center

    Council for Cultural Cooperation, Strasbourg (France).

    Prepared from interviews with personnel of the Turkish Ministry of National Education, and other educational administrators in that country, this publication provides a guide to the terminology used to name the types of public educational institutions found in Turkey. Private educational institutions, military schools, higher schools attached to…

  16. Axiom turkey genotyping array

    USDA-ARS?s Scientific Manuscript database

    The Axiom®Turkey Genotyping Array interrogates 643,845 probesets on the array, covering 643,845 SNPs. The array development was led by Dr. Julie Long of the USDA-ARS Beltsville Agricultural Research Center under a public-private partnership with Hendrix Genetics, Aviagen, and Affymetrix. The Turk...

  17. On Turkey Identification.

    ERIC Educational Resources Information Center

    Libbee, Kristin Sheridan; Libbee, Michael

    1979-01-01

    Human relations skills are more widely taught and used, and inevitably misused. This aritcle is intended as a brief self-defense course identifying those who undergo this usually temporary, metamorphosis into "turkeys." It provides a rough categorization of subspecies with their identifying characteristics and a proposal for return to personhood.…

  18. On Turkey Identification.

    ERIC Educational Resources Information Center

    Libbee, Kristin Sheridan; Libbee, Michael

    1979-01-01

    Human relations skills are more widely taught and used, and inevitably misused. This aritcle is intended as a brief self-defense course identifying those who undergo this usually temporary, metamorphosis into "turkeys." It provides a rough categorization of subspecies with their identifying characteristics and a proposal for return to personhood.…

  19. Cloning Creationism in Turkey.

    ERIC Educational Resources Information Center

    Edis, Taner

    1999-01-01

    Defines how political balances and changes in Turkey effect creation-evolution relation. Describes the influences of Bilim Arastirma Vakfi (BAV) on these changes, which are directly targeted to public education, and discusses the content of creationism. Questions why Islamic creationism is a copy of that of the Institute for Creation Research…

  20. Special Education in Turkey

    ERIC Educational Resources Information Center

    Eres, Figen

    2010-01-01

    The quality and the prevalence of education are the major indicators of the development of a society. It is a kind of human right to every person living in the society to be educated in a sufficient way. The education of the disabled people, a social reality in Turkey, is not sufficiently carried out. This paper aims at the education of the…

  1. Granitoid pluton formation by spreading of continental crust: the Wiley Glacier complex, northwest Palmer Land, Antarctica

    NASA Astrophysics Data System (ADS)

    Vaughan, Alan P. M.; Wareham, Christopher D.; Millar, Ian L.

    1997-12-01

    The emplacement mechanism, geometry, and isotope geochemistry of plutons of the Wiley Glacier complex suggest that new continental crust grew by multiple injection of tonalitic dykes during dextral transtension in the Antarctic Peninsula magmatic arc in Early Cretaceous times. The suggested mechanism is analogous to basalt dyke injection during sea-floor spreading. During normal-dextral shear, the Burns Bluff pluton, a sheeted, moderately east-dipping, syn-magmatically sheared tonalite-granodiorite intruded syn-magmatically sheared quartz diorite of the Creswick Gap pluton and 140 ± 5 Ma hornblende gabbro. UPb dating of zircon and ArAr dating of hornblende and biotite suggest that both granite s.l. plutons were emplaced between 145 and 140 Ma, but that extensional shearing was active from the time of emplacement until ca. 127 Ma. The Burns Bluff pluton is chilled at its margin, and grades through mylonitised, porphyritic tonalite-granodiorite sheets and tonalite-granodiorite sheets with minor chilling, to a kilometre-scale body of coarse-grained, hypidiomorphic tonalite-granodiorite. Co-magmatic microdiorite forms dykes and abundant synplutonic mafic enclaves. These dykes opened as echelon veins during episodic dextral shear and were deformed to trains of enclaves during continued normal-dextral shear. Pluton-marginal porphyritic and hypidiomorphic tonalite-granodiorite forms large, fault-hosted sheets emplaced progressively under extension with minor dextral shear. Kinematic indicators from pluton-marginal granite s.l. dykes suggest that early in pluton accretion, intrusive sheets cooled rapidly, with simple shear prior to full crystallisation changing to ductile simple shear during cooling. Kinematic indicators towards the pluton core suggest that as the pluton grew, and cooled more slowly, emplacement switched from sheeting to in situ inflation with simple shear distributed across a broad zone prior to full crystallisation of magma. Cross

  2. Strontium and oxygen isotopic variations in Mesozoic and Tertiary plutons of central Idaho

    USGS Publications Warehouse

    Fleck, R.J.; Criss, R.E.

    1985-01-01

    Regional variations in initial 87Sr/86Sr ratios (ri) of Mesozoic plutons in central Idaho locate the edge of Precambrian continental crust at the boundary between the late Paleozoic-Mesozoic accreted terranes and Precambrian sialic crust in western Idaho. The ri values increase abruptly but continuously from less than 0.704 in the accreted terranes to greater than 0.708 across a narrow, 5 to 15 km zone, characterized by elongate, lens-shaped, highly deformed plutons and schistose metasedimentary and metavolcanic units. The chemical and petrologic character of the plutons changes concomitantly from ocean-arc-type, diorite-tonalite-trondhjemite units to a weakly peraluminous, calcic to calcalkalic tonalite-granodiorite-granite suite (the Idaho batholith). Plutons in both suites yield Late Cretaceous ages, but Permian through Early Cretaceous bodies are confined to the accreted terranes and early Tertiary intrusions are restricted to areas underlain by Precambrian crust. The two major terranes were juxtaposed between 75 and 130 m.y. ago, probably between 80 and 95 m.y. Oxygen and strontium isotopic ratios and Rb and Sr concentrations of the plutonic rocks document a significant upper-crustal contribution to the magmas that intrude Precambrian crust. Magmas intruding the arc terranes were derived from the upper mantle/subducted oceanic lithosphere and may have been modified by anatexis of earlier island-arc volcanic and sedimentary units. Plutons near the edge of Precambrian sialic crust represent simple mixtures of the Precambrian wall-rocks with melts derived from the upper mantle or subducted oceanic lithosphere with ri of 0.7035. Rb/Sr varies linearly with ri, producing "pseudoisochrons" with apparent "ages" close to the age of the wall rocks. Measured ??18O values of the wall rocks are less than those required for the assimilated end-member by Sr-O covariation in the plutons, however, indicating that wall-rock ??18O was reduced significantly by exchange with

  3. Thermochronology of the Cornubian batholith in southwest England: Implications for pluton emplacement and protracted hydrothermal mineralization

    USGS Publications Warehouse

    Chesley, J.T.; Halliday, A.N.; Snee, L.W.; Mezger, K.; Shepherd, T.J.; Scrivener, R.C.

    1993-01-01

    The metalliferous ore deposits of southwest England are associated with biotite-muscovite granites that intruded upper Paleozoic sediments and volcanic rocks at the end of the Hercynian Orogeny. The hydrothermal mineralization can be subdivided into four stages: 1. (1) exoskarns 2. (2) high-temperature tin and tungsten oxide-bearing sheeted greisen bordered veins and Sn-bearing tourmaline veins and breccias 3. (3) polymetallic quartz-tourmaline-chlorite-sulfide-fluorite-bearing fissure veins, which represent the main episode of economic mineralization 4. (4) late-stage, low-temperature polymetallic fluorite veins. U-Pb dating of monazite and xenotime and 40Ar 39Ar dating of muscovite were used to determine emplacement ages and cooling times for individual plutons within the Cornubian batholith, as well as separate intrusive phases within the plutons. In addition, 40Ar 39Ar ages from hornblende and secondary muscovite and Sm-Nd isochron ages from fluorite were employed to determine the relationship between pluton emplacement and different stages of mineralization. The U-Pb ages indicate that granite magmatism was protracted from ~300 Ma down to ~275 Ma with no evidence of a major hiatus. There is no systematic relation between the age of a pluton and its location within the batholith. The U-Pb ages for separate granite phases within a single pluton are resolvable and indicate that magma emplacement within individual plutons occurred over periods of as much as 4.5 myrs. Felsic porphyry dike emplacement was coeval with plutonism, but continued to ~270 Ma. The geochronologic data suggest that the Cornubian batholith originated from repeated melting events over 30 myrs and was formed by a series of small coalescing granitic bodies. Cooling rates of the main plutons are unrelated to emplacement age, but decrease from the southwest to the northeast from ~210??C myr-1 to ~60??C myr-1 with a mean of 100??C myr-1. These slow cooling rates appear to reflect the addition of

  4. Reconnaissance geochemical exploration of plutons of syenite and shonkinite, southern Asir, Kingdom of Saudi Arabia

    SciTech Connect

    Overstreet, W.C.; Assegaff, A.B.; Hussain, M.A.; Naqvi, M.I.; Selner, G.I.; Matzko, J.J.

    1985-01-01

    Reconnaissance geochemical exploration for rare metals in plutons of syenite and shonkinite disclosed generally less than 20 ppM Nb in rocks, wadi sediments, and concentrates. The sparsity of Nb is accompanied by low values for La, Sn, W, Y, and Zr and relatively high but insignificant values for Be and Mo. Base and precious metals are either below their respective limits of determination in the various sample media or are present at background levels commensurate with average crustal abundances in felsic rocks. Pegmatite dikes associated with the syenite plutons are rare and lack vermiculite. The present investigation disclosed no possible ore deposits in the plutons covered by the field work. Known kyanite-topaz-natroalunite rocks in the vicinity of the surveyed areas should be examined for possible deposits of Cu, Mo, or Au associated with high-alumina hydrothermal deposits. 27 refs., 7 figs., 21 tabs.

  5. Tectonic significance of early Oligocene plutonism on Adak Island, central Aleutian Islands, Alaska

    NASA Astrophysics Data System (ADS)

    Citron, G. P.; Kay, R. W.; Mahlburg Kay, S.; Snee, L. W.; Sutter, J. F.

    1980-08-01

    Six biotite and two hornblende separates from the Hidden Bay pluton, Adak Island, yielded K-Ar dates that cluster about an average of 33.13 ± 0.41 m.y. B.P. This average is interpreted as the time of intrusion of the pluton and provides the first documentation of an early Oligocene magmatic event in the central Aleutian island arc. Biotite and hornblende from the nearby Kagalaska pluton on Adak Island yielded nearly concordant K-Ar dates that have an average of 13.15 ± 0.55 m.y. B.P., in good agreement with published dates of about 13 to 14 m.y. B.P. *Present address: Amoco Production Company, P.O. Box 3092, Houston, Texas 77001

  6. Use of olivine and plagioclase saturation surfaces for the petrogenetic modeling of recrystallized basic plutonic systems

    NASA Technical Reports Server (NTRS)

    Hanson, G. N.

    1983-01-01

    During petrogenetic studies of basic plutonic rocks, there are at least three major questions to be considered: (1) what were the relative proportions of cumulate crystals and intercumulus melt in a given sample? (2) what is the composition and variation in composition of the melts within the pluton? and (3) what is the original composition of the liquids, their source and evolution prior to the time of emplacement? Use of both saturation surfaces can place strong limits on the compositions of potential cumulate phases and intercumulus melts. Consideration of appropriate trace elements can indicate whether a sample is an orthocumulate, adcumulate or mesocumulate. Thus, when trace element and petrographic data are considered together with the saturation surfaces, it should be possible to begin to answer the three major questions given above, even for strongly recrystallized basic plutons.

  7. Late Cretaceous ductile deformation, metamorphism and plutonism in the Piute Mountains, eastern Mojave Desert

    SciTech Connect

    Fletcher, J.M.; Karlstrom, K.E. )

    1990-01-10

    Late Cretaceous deformation in the Piute Mountains involved ductile thrusting on a network of anastomosing northeast and southwest directed shear zones. The shear zones often separate Proterozoic lithologies with strong competency contrasts, suggesting that Proterozoic crustal anisotropies were important in controlling the geometry of the shear zone network. Shear zones now divide the crust into wedge- and lozenge-shaped blocks. The Piute Mountains can be separated into two kinematic domains, each characterized by a dominant sense of shear. Thrusting in the southwest directed kinematic domain ended at 85 {plus minus} 7 Ma, the age of the late synkinematic East Piute pluton. Thrusting in the northeast directed kinematic domain could have lasted until 74 {plus minus} 3 Ma, the age of the Lazy Daisy pluton. Postthrusting northwest-southeast shortening produced a second generation of upright open folds with a northeast striking subvertical crenulation cleavage. F{sub 2} strain increases toward the south and is concentrated around the margins of the Lazy Daisy pluton. This deformation was synchronous with pluton emplacement. Lake Cretaceous peak metamorphism outlasted all ductile deformation. Peak metamorphic grade increases from upper greenschist facies in the north to upper amphibolite facies as the Lazy Daisy pluton is approached. Temperature and pressure of approximately 450 C and 2.5-4.0 kbar were achieved during ductile thrusting. Temperatures of 500-540 C existed at the onset of upright open folding, and peak temperatures as high as 620 C near the Lazy Daisy pluton occurred after F{sub 2} upright folding. All penetrative deformation ended before 72-71 Ma, by which time the area had cooled to below 300 C.

  8. Family practice in Turkey.

    PubMed

    Ozsahin, Akatli Kursad

    2014-03-01

    The national project 'Transformation in Health' was started in 2005 to provide expert primary care by family physicians, and decrease expenses in Turkey. The number of family physicians was far below the need, so public physicians were promoted to family physician status after a 10-day intensive course. The government declared some satisfactory results, but privately paid family physicians were not accepted into the system. Furthermore, the government stopped paying for their services from private settings. Some family physicians became unemployed as the major payer for all forms of medical care in Turkey denied their services. The process showed it's value in time. Nevertheless, family physicians should be the core of this transformation as family medicine is an academic and a scientific discipline and a primary care-oriented specialty with its own specific educational content, research and base of evidence, which cannot be achieved through standard medical education.

  9. Comparing magnetic and magmatic fabrics to constrain the magma flow record in La Gloria pluton, central Chile

    NASA Astrophysics Data System (ADS)

    Payacán, Italo; Gutiérrez, Francisco; Gelman, Sarah E.; Bachmann, Olivier; Parada, Miguel Ángel

    2014-12-01

    This contribution illustrates a case study of a pluton (La Gloria pluton; LGP) where magnetic and magmatic fabrics are locally decoupled. We compare the magmatic fabric with the available magnetic fabric data to explore their abilities and elucidate the magma flow record of LGP. Results indicate that magnetic (controlled by multi-domain magnetite) and magmatic fabrics are generally consistent throughout LGP. Foliations define an axisymmetric pattern that gradually changes from vertical near lateral margins to less steep in the pluton interior, whereas lineations are subhorizontal following the elongation direction of the pluton. However, samples at the pluton center show marked differences between both fabrics: magnetic fabrics indicate subhorizontal magnetic lineations and foliations, and magmatic fabrics indicate subvertical lineations and foliations. Both magnetic and magmatic fabrics are interpreted to record strain caused by magma flow during thermal convection and lateral magma propagation at the transition between low and high crystallinity stages. We suggest that fabrics acquisition and consistency were determined by shear conditions (pure/simple shear rates ratio) and the orientation of the magma flow direction with respect to a rigid boundary (critical crystalline region) of the pluton. Magmatic fabric differs at the center of the pluton because pure shear is dominant and ascendant flows are orthogonal to the horizontal rigid boundary. LGP represents a whole-scale partly molten magma reservoir, where both thermal convection and lateral propagation of the magma are recorded simultaneously. This study highlights the importance of characterizing both fabrics to properly interpret magma flow recorded in plutons.

  10. Terrorism in Turkey.

    PubMed

    Rodoplu, Ulkumen; Arnold, Jeffrey; Ersoy, Gurkan

    2003-01-01

    Over the past two decades, terrorism has exacted an enormous toll on the Republic of Turkey, a secular democracy with a 99.8% Muslim population. From 1984 to 2000, an estimated 30,000 to 35,000 Turkish citizens were killed by a nearly continuous stream of terrorism-related events. During this period, the Partiya Karekerren Kurdistan (PKK), a Kurdish separatist group (re-named KADEK in 2002), was responsible for the vast majority of terrorism-related events (and casualties), which disproportionately affected the eastern and southeastern regions of Turkey, in which the PKK has focused its activities. Most terrorist attacks over the past two decades have been bombings or shootings that produced < 10 casualties per event. From 1984 to 2003, 15 terrorist attacks produced > or = 30 casualties (eight shootings, five bombings, and two arsons). The maximum number of casualties produced by any of these events was 93 in the Hotel Madimak arson attack by the Turkish Islamic Movement in 1993. This pattern suggests that terrorist attacks in Turkey rarely required more than local systems of emergency medical response, except in rural areas where Emergency Medical Services (EMS) are routinely provided by regional military resources. The last decade has seen the development of several key systems of local emergency response in Turkey, including the establishment of the medical specialty of Emergency Medicine, the establishment of training programs for EMS providers, the spread of a generic, Turkish hospital emergency plan based on the Hospital Emergency Incident Command System, and the spread of advanced training in trauma care modeled after Advanced Trauma Life Support.

  11. Authoritarianism in Turkey

    DTIC Science & Technology

    2014-09-01

    stage that the AKP has brought Turkey to is Levitsky and Way’s theory of competitive authoritarianism.7 General background literature on the...suffice to express the political situation. However, it can be generalized that the “center-right” section of the market is crowded by many parties...this are pre- existing. The General Staff and Foreign Ministry traditionally coordinate to determine Turkish foreign policy.92 The actual codification

  12. Nursing in Turkey.

    PubMed

    Baumann, Steven L

    2006-10-01

    The current discussion on the nursing shortage needs to focus as much on nursing job satisfaction and retention as on nursing recruitment and education. Selected aspects of the motivational psychology of Abraham Maslow, Mihaly Csikszentmihalyi, and Frederick Hertzberg are here discussed in light of the challenges-opportunities of nursing in Turkey and elsewhere. Also discussed is an innovative program to support the application of nursing theory and professional development in Toronto, Canada.

  13. Greece and Turkey

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Summer is in full swing in this stunning true-color image of the southeastern European countries and Turkey captured by MODIS on June 29, 2002. Clockwise from left, the mountains of Greece, Albania, Macedonia, Yugoslavia, Bulgaria, and Turkey are swathed in brilliant greens and shades of golden brown; meanwhile (counterclockwise from left) the Ionian, Mediterranean, Aegean, and Black Seas are beautifully blue and green.Running diagonally across the image from the bottom middle to the top right is a gray streak that is caused by the angle of reflection of the sun on the water (called sun glint). The darker areas within this gray swath denote calmer water, and make visible currents that would not otherwise be noticeable.Surprisingly few fires were burning hot enough to be detectable by MODIS when this image was acquired during the height of the summer dry season. A single fire is visible burning in mainland Greece, six are visible in northwestern Turkey, and one burns on the western coast (marked with red outlines). Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  14. [Stranger in Turkey].

    PubMed

    Dorhout Mees, E J

    1997-12-20

    The author, a professor of nephrology, reports some impressions of his 7-year stay in Turkey. He worked at the Ege University in Izmir, traditionally one of the most 'western' cities. He and his wife, who gave unpaid assistance to dialysis patients, attempted to integrate into Turkish society as fully as possible. They traversed the country in weekends and holidays and introduced as many Dutch guests as they could to the unique archeological treasures, the magnificent nature and the extremely friendly population. Work at the university focused increasingly on cultivating a critical attitude with regard to the self, society and the trends and commercialization of medicine in Turkey and in the rest of the world. Self-reliance, also, had to be strengthened. Although this contravened the authority-based Turkish educational system, the efforts were clearly appreciated and even stirred enthusiasm in many of the younger people. There is no doubt that a foreign worker is regarded much more favourable in Turkey than in the Netherlands.

  15. Late Cretaceous and early Tertiary plutonism and deformation in the Skagit Gneiss Complex, north Cascade Range, Washington and British Columbia

    USGS Publications Warehouse

    Haugerud, R.A.; Van Der Heyden, P.; Tabor, R.W.; Stacey, J.S.; Zartman, R.E.

    1991-01-01

    The Skagit Gneiss Complex forms a more-or-less continuous terrane within the North Cascade Range. The complex comprises abundant plutons intruded at mid-crustal depths into a variety of metamorphosed supracrustal rocks of both oceanic and volcanic-arc origin. U-Pb zircon ages from gneissis plutons within and near the Skagit Gneiss Complex indicate magmatic crystallziations between 75 and 60 Ma. Deformation, recrystallization, and migmatization in part postdate intrusion of the 75-60 Ma plutons. This latest Cretaceous and earliest Tertiary plutonism and migmatization may reflect thermal relaxation following early Late Cretaceous orogeny. The complex was ductilely extended northwest-southeast shortly after intrusion of granite dikes at ~45 Ma, but before emplacement of the earliest (~34 Ma) plutons of the Cascade arc. -from Authors

  16. Paleoproterozoic layered PGE-bearing Monchetundra pluton, Kola Peninsula: Sm-Nd age of metamorphic alteration of mafic rocks

    NASA Astrophysics Data System (ADS)

    Kunakkuzin, E. L.; Serov, P. A.; Bayanova, T. B.; Nerovich, L. I.; Borisenko, E. S.

    2015-09-01

    The aim of this work is Sm-Nd study of metamorphic alteration of massive gabbronorites from the Monchetundra pluton. The mafic rocks of the pluton are unevenly metamorphosed up to amphibolite facies with the formation of garnet, hornblende, and other minerals. The presence of garnet is a distinctive feature of this pluton in comparison with other Paleoproterozoic PGE-bearing plutons of the eastern part of the Baltic shield: Mt. General'skaya, Fedorovo-Pana, Imandra lopolith, and Monchepluton [9]. The degree of metamorphic alteration of rocks increases near the faults, the largest of which is Monchetundra fault separating the studied pluton from the Monchepluton. This fault was formed about 1.9-2.0 Ga ago according to Sm-Nd and Rb-Sr mineral isochrons for minerals from metagabbro-anorthosites of the M1 well.

  17. Construction of the Devonian bimodal Gouldsboro pluton via multiple intrusion, coastal Maine, USA

    NASA Astrophysics Data System (ADS)

    Koteas, C.

    2006-12-01

    The Gouldsboro pluton (377 ± 19 ma) (Metzger et al., 1982) of the eastern coastal Maine magmatic province preserves abundant evidence of mechanical interaction between mafic and felsic magmas, as well as the stoping and doming of country rock. Coastal Maine is a unique location where subequal volumes of felsic and mafic material have interacted and are preserved in both plutonic and volcanic complexes. The effects of generation and mobilization of large volumes of magma in the shallow crust are well-preserved. The Gouldsboro pluton provides an excellent perspective from the highest to lowest sections (southwest to northeast) of a hybrid magmatic system. The Gouldsboro magmatic complex is hosted by undated greenstone to the north that is overlain by the 477 ± 18 ma (Metzger, 1977) meta-volcanic/meta-sedimentary Bar Harbor formation. Blocks of both units are discernable as 10 cm to 2 m-diameter blocks within the pluton. The Gouldsboro granite is dominantly a fine to medium grained feldspar- rich leucocratic hornblende granite, although biotite is sometimes present. Miarolitic cavities are common in the highest exposure of the system, especially in the south where the finest grained, most leucocratic granite occurs. Other units include, from lowest to highest in the system, hybrid diorite-gabbro, hybrid granite-granodiorite, granite hosting 30 cm to 3 m-diameter globular basaltic pillows, and a previously unrecognized pyroclastic unit, very similar to the lowermost member of the Cranberry Isle series, a volcanic breccia (Seaman et al., 1999). The pyroclastic unit is intruded by medium grained granite hosting angular fragments of volcanic, mafic plutonic, and country rock. While the contact between gabbro near the base of the pluton and granite in the middle of the pluton is commonly gradational, there are complex intrusive breccias in some areas where fine to coarse, angular diorite to gabbro xenoliths are hosted by granodiorite and granite. Enclave-rich zones

  18. Granodiorite Pluton Formation at the Mid-Cenozoic Never Summer Igneous Complex, North-Central Colorado

    NASA Astrophysics Data System (ADS)

    Jacob, K. H.; Farmer, G.

    2012-12-01

    Field observations, major- and trace-element geochemistry, and Sr and Nd isotopic data were used to assess the petrogenesis of epizonal intrusive rocks and related volcanic rocks from the ~28 Ma Never Summer igneous complex in north-central Colorado. Intrusive igneous rocks at this igneous center consist of an older granodiorite pluton (the Mt Richthofen stock, MRS) that is intruded by the granitic Mt. Cumulus stock. The latter has a uniform bulk composition equivalent to that of high silica rhyolite (~77 wt % SiO2, ɛNd(T) ~ -6). Whole rock studies of the MRS reveal that it is compositionally zoned (55-67 wt % SiO2,ɛNd(T) -0.5 to -5.7, 87Sr/86Sr(T) 0.7049 to 0.7119), with the lowest wt % SiO2 and highest ɛNd(T) occurring along the western margin of the pluton. Field observations, combined with the observed compositional variations, suggest that the pluton was originally a shallowly intruded (< 2 km), ~1 km thick sill that was vertically zoned from a mafic base to more felsic roof. The entire pluton has been tilted ~25 degrees to the west after emplacement. Given the lack of obvious wall-rock assimilation at the level of pluton emplacement, the isotopic variations in the pluton most likely reflect differences in the isotopic compositions of melts from which the pluton was assembled. Obvious field evidence exists for underplating of the developing pluton by mafic, high ɛNd (T) (>-2) melts and illustrates that mafic magmas were present in the uppermost crust and likely participated in pluton formation. The higher wt % SiO2 and lower ɛNd(T) portions of the MRS, however, could not have been derived directly from the mafic magmas in any closed system process. One option is that the MRS ultimately represents the product of mixing of >70 wt % SiO2 melts (+ crystals), analogous to the melts from which the Mt. Cumulus stock crystallized, and underplating mafic magma. This model implies that two primary magmas types, high silica rhyolite and basalt/basaltic andesite

  19. Refugee movements and Turkey.

    PubMed

    Kirisci, K

    1991-12-01

    There has been a long tradition in the Ottoman Empire and the Turkish Republic of receiving refugees. There were Jewish refugees from the Spanish Inquisition, Hungarians and Poles fleeing revolts in 1848-9, and those of Turkish descent and usually from the Balkans. Concurrent with this trend is the history of refugees and immigrants leaving Turkey, such as many Armenians, Greeks and Jews leaving at the turn of the century, and after 1923 and the Treaty of Lausanne. Little is currently published on the topic. This article defines a refugee; provides an overview of the refugee problems of the 1980's due to Bulgarian, Kurdish, and Turkish refugees; and the legal and political aspects. As a country of origin, there is discussion of the political and economic aspects of Turkish asylum seekers in Europe. The potential refugee flows to and from Turkey are also examined. I) For this study, refugees are victims of political violence and are persecuted for political or religious beliefs, ethnic or racial background, or war. In Turkey, there are national refugees, international refugees outside the Convention, and UNHCR Convention refugees. During the 1980's all 3 groups were arriving: from eastern Europe, Iranian Kurds, Iraqis, and ethnic Turks from Bulgaria and Afghanistan. The Turkish restricted acceptance of the 1951 Convention on Refugees creates serious humanitarian and security consequences for refugees other than those from eastern Europe and of Turkish ethnicity. Political considerations play an important role in treatment where security threats outweigh humanitarian need. The case is given for Kurdish refugees. II) Asylum seekers from Turkey in Western Europe was determined between 1986-90 to be 185,000 from applications. These figures have risen steadily due to the political instability and military activity of areas bordering Iraq and Syria, the Emergency Region. In addition there are economic and employment problems, and there has been a suspension of human

  20. Map showing the distribution and characteristics of plutonic rocks in the Tonopah 1 degree by 2 degrees Quadrangle, central Nevada

    USGS Publications Warehouse

    John, D.A.

    1987-01-01

    The accompanying table includes the name (if any) of the pluton and its location, the age of the pluton (either a radiometric age or an age inferred from field relations), modal composition, texture, mineralogy, hydrothermal alteration and mineralization related to the pluton, the source of mapping shown on this map, and published references on the pluton. Radiometric ages are either published K-Ar and fission track ages or new whole-rock Rb-Sr ages determined by A. C. Robinson on samples collected either for this study or as part of regional Sr-isotope studies by R.W. Kistler and A.C. Robinson. K-Ar ages published prior to 1977 are corrected using the new I.U.C.S. constants (Steiger and Jager, 1977). Muscovite alteration ages are reported for several plutons and represent minimum ages for emplacement of these plutons. Compositional classification follows the T. J. G.S. system (“Streckeisen, 1976) and is based either on modal analyses of slabs or estimates from hand specimens. All modes, unless otherwise noted, were measured in this study. The number of modes determined is shown in parentheses, and the range in volume percent of major minerals is given. Where no modal data are available, the color index (percentage of mafic minerals) and major mafic minerals are given for most plutons. Data tabulated on hydrothermal alteration and mineralization related to plutons are based on observations made during field studies for this project. Clear genetic relation between granitic plutonism and several mineral deposits previously attributed to granitic plutonism were not substantiated, and these inconsistencies are noted in the table.

  1. Geochemical Constraints on Collision-related Intrusive Rocks in Central, Northwestern and Western Anatolia (Turkey)

    NASA Astrophysics Data System (ADS)

    Ilbeyli, Nurdane

    2010-05-01

    The intrusive rocks in Anatolia occupy a broad petrological range from I- to A- type granitoids. Thus, Turkey is a natural laboratory to study collision-related magmatism, its geochemical characteristic, source region and also tectono-magmatic evolution. The central, northwestern and western Anatolian magmatic provinces are defined by a large number of Late Mesozoic to Late Cenozoic collision-related granitoids (Ilbeyli and Kibici 2009). Calc-alkaline, subalkaline and alkaline intrusive rocks in central Anatolia are mainly metaluminous, high-K and I- to A-types. They cover a petrological range from monzodiorite through quartz monzonite to granite/syenite. All these intrusive rocks are enriched in LILE and are also radiogenic in terms of Sr, and unradiogenic in terms of Nd, isotope ratios. Their geochemical characteristics show that the intrusive rocks originated from a mantle source containing large subduction components, and have experienced crustal assimilation and fractional crystallization. Delamination of a thermal boundary layer, and/or slab breakoff is the likely mechanisms for the initiation of the diverse magmatism in the complex (Ilbeyli et al. 2009). Calc-alkaline plutonic rocks in northwestern Anatolia are mainly metaluminous, medium- to high-K and I-types. They are monzonite to granite, and all are enriched in LILE and depleted in HFSE, showing features of arc-related intrusive rocks. Geochemical data reveal that these plutons were derived from partial melting of mafic lower crustal sources. These rocks are related to subduction of the northern branch of the Neo-Tethyan ocean beneath the Sakarya microcontinent during Cretaceous-Paleocene times (Kibici et al. 2008). Calc-alkaline intrusive rocks in western Anatolia are metaluminous, high-K and I-types. They have a compositional range from granodiorite to granite, and are enriched in LILE and depleted in HFSE. Geochemical characteristics of these intrusive rocks indicate that they could have originated

  2. English Language Teaching Profile: Turkey.

    ERIC Educational Resources Information Center

    British Council, London (England). English Language and Literature Div.

    The role of English in Turkey is discussed, with attention directed to: (1) education within the educational system, (2) English teachers, (3) teaching materials, (4) English outside the educational system, and (5) British and American support for the teaching of English. Although English is not used as a means of social communication in Turkey,…

  3. ‘Diffuse faulting’ in the Machu Picchu granitoid pluton, Eastern Cordillera, Peru

    NASA Astrophysics Data System (ADS)

    Mazzoli, Stefano; Vitale, Stefano; Delmonaco, Giuseppe; Guerriero, Vincenzo; Margottini, Claudio; Spizzichino, Daniele

    2009-11-01

    A series of batholiths, forming part of the 'roots' of a Permo-Liassic rift system, are exposed in the high Eastern Cordillera of central Peru as a result of tectonic inversion. Shortening of the Machu Picchu granitoid pluton was accommodated by widespread shear reactivation of primary joints, by a process termed here 'diffuse faulting'. Fault-like reactivation of precursor joint surfaces, marked by chlorite, epidote and quartz shear fibres, is locally evidenced by few centimetres offsets within apparently undeformed granite. Analysis of fault slip data indicates that shear reactivation of different joint sets was kinematically consistent with ENE oriented shortening. Less frequent mylonitic shear zones appear to have evolved from the common brittle precursors. Apart from rare phyllonitic shear zones, fluid-rock interaction along the brittle precursors was generally limited, and pluton deformation appears to be mainly controlled by the geometry and distribution of primary joints. Three main sets of reactivated joints can be recognized, characterized by oblique-slip kinematics with variable reverse and strike-slip components of motion. Theoretical modelling based on quantitative fracture analysis (scan-line data) and different displacement-length relationships applied to the main reactivated joint sets yield first-order estimates of pluton finite strain. The results suggest that bulk finite strain is oblate and essentially coaxial, and is characterized by horizontal shortening not exceeding 10%. Relatively small finite strains, integrated over the size of the pluton, still result in a few kilometres of crustal shortening.

  4. Field Guide to Plutonic and Metamorphic Rocks. Earth Science Curriculum Project Pamphlet Series PS-5.

    ERIC Educational Resources Information Center

    Romey, William D.

    Suggested are methods for the collection of field evidence about processes that form plutonic and metamorphic rock. Description and discussion of these types of rocks are provided. The planning and execution of a successful field trip is discussed. Advanced field projects are also discussed. Included are five appendices, references, and a…

  5. Chaotic Flow Patterns from a Deep Plutonic Environment: a Case Study on Natural Magma Mixing

    NASA Astrophysics Data System (ADS)

    De Campos, Cristina P.

    2015-07-01

    This work focuses on the mixing between basalt and granite in a deep plutonic environment. The description of mixing patterns and measurements of fractal dimensions, and the evaluation of geochemical data from a Cambro-Ordovician granitic pluton are summarized and discussed. Different morphologic domains within the pluton reveal concentric fragmented and/or folded layers of granite in a gabbro/granite mixed matrix. This stands in contrast to two predominantly regular gabbroic regions. These regular regions are separated by tightly stretched filament areas, in which mixing is enhanced. Sharp and gradational contacts between granitic and gabbroic domains depict the interplay among frozen flows (mingling) and convection-enhanced diffusion processes (mixing). Measurements of fractal dimensions at different scales and analysis of normalized concentration variance for major elements point towards magma mixing: the compositional variability and flow patterns of the studied pluton have been greatly controlled by a natural chaotic mixing process between a granitic and a basaltic end-member. During the mixing process, coeval fractional crystallization no doubt contributed to increasing the complexity of the system. However, since flow, and therefore mixing, stops with temperature decrease, flow patterns must have retained the predominant morphology and composition of the moment at which both contrasting magmas came together and froze. Flow patterns have been preserved. With further temperature decrease, fractional crystallization took over and hybrid rocks were generated from the fractionation of magmas previously mixed in different proportions.

  6. Rock-Forming feldspars of the Khibiny alkaline pluton, Kola Peninsula, Russia

    NASA Astrophysics Data System (ADS)

    Ivanyuk, G. Yu.; Pakhomovsky, Ya. A.; Konopleva, N. G.; Kalashnikov, A. O.; Korchak, Yu. A.; Selivanova, E. A.; Yakovenchuk, V. N.

    2010-12-01

    This paper describes the structural-compositional zoning of the well-known Khibiny pluton in regard to rock-forming feldspars. The content of K-Na-feldspars increases inward and outward from the Main foidolite ring. The degree of coorientation of tabular K-Na-feldspar crystals sharply increases in the Main ring zone, and microcline-dominant foyaite turns into orthoclase-dominant foyaite. The composition of K-Na-feldspars in the center of the pluton and the Main ring zone is characterized by an enrichment in Al. This shift is compensated by a substitution of some K and Na with Ba (the Main ring zone) or by an addition of K and Na cations to the initially cation-deficient microcline (the central part of the pluton). Feldspars of volcanosedimentary rocks occurring as xenoliths in foyaite primarily corresponded to plagioclase An15-40, but high-temperature fenitization and formation of hornfels in the Main ring zone gave rise to the crystallization of anorthoclase subsequently transformed into orthoclase and albite due to cooling and further fenitization. Such a zoning is the result of filling the Main ring fault zone within the homogeneous foyaite pluton with a foidolite melt, which provided the heating and potassium metasomatism of foyaite and xenoliths of volcanosedimentary rocks therein. The process eventually led to the transformation of foyaite into rischorrite-lyavochorrite, while xenoliths were transformed into aluminum hornfels with anorthoclase, annite, andalusite, topaz, and sekaninaite.

  7. Turkey's energy demand and supply

    SciTech Connect

    Balat, M.

    2009-07-01

    The aim of the present article is to investigate Turkey's energy demand and the contribution of domestic energy sources to energy consumption. Turkey, the 17th largest economy in the world, is an emerging country with a buoyant economy challenged by a growing demand for energy. Turkey's energy consumption has grown and will continue to grow along with its economy. Turkey's energy consumption is high, but its domestic primary energy sources are oil and natural gas reserves and their production is low. Total primary energy production met about 27% of the total primary energy demand in 2005. Oil has the biggest share in total primary energy consumption. Lignite has the biggest share in Turkey's primary energy production at 45%. Domestic production should be to be nearly doubled by 2010, mainly in coal (lignite), which, at present, accounts for almost half of the total energy production. The hydropower should also increase two-fold over the same period.

  8. A new species of Centaurea sect. Pseudoseridia (Asteraceae) from north-eastern Turkey

    PubMed Central

    Yüzbaşıoğlu, İbrahim Sırrı; Bona, Mehmet; Genç, İlker

    2015-01-01

    Abstract Centaurea ziganensis Yüzb., M. Bona & İ. Genç, a new species is described and illustrated from Gümüşhane province, NE Turkey. The new species grows in rocky places on the south face of Zigana Mountains, and is closely related to Centaurea drabifolioides, from which it differs mainly in stem, achene and phyllary appendage characters. Micromorphological structures of achenes and karyological features of Centaurea ziganensis and Centaurea drabifolioides were examined in this study. PMID:26312039

  9. Ne-20/Ne-22 in the Martian Atmosphere: New Evidence from Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Park, J.; Nyquist, L. E.; Herzog, G. F.; Nagao, K.; Mikouchi, T.; Kusakabe, M.

    2017-01-01

    Analyses of Ne trapped in "pods" of impact melt in the Elephant Moraine 79001 (EET 79001) Martian meteorite led to suggest (Ne-20/Ne-22) approx.10 in the Martian atmosphere (MA). In contrast, obtained trapped (Ne-20/Ne-22)Tr approx.7 from an impact melt vein in Yamato 793605 (Y-793605) and concluded that the isotopic composition of Martian Ne remained poorly defined. A "pyroxene-rich" separate from Dhofar 378 (Dho 378) analyzed gave a comparatively high trapped Ne concentration and (Ne-20/Ne-22) = 7.3+/-0.2 in agreement with the Y-793605 value. We explore the hypothesis that Martian Ne was trapped in the Dho 378 meteorite in a manner similar to entrapment of terrestrial Ne in tektites strengthening the "Martian atmosphere" interpretation. We also report new data for Northwest Africa 7034 (NWA 7034) that are consistent with the Ne data for Dho 378.

  10. Latest Mesozoic-Early Cenozoic Continental Extension and Related Alkaline Magmatism in Central Anatolia, Turkey

    NASA Astrophysics Data System (ADS)

    Kadioglu, Y. K.

    2009-04-01

    The Central Anatolian crystalline complex (CACC) in Turkey includes a suite of latest Mesozoic-early Cenozoic plutonic rocks intruding the metamorphic and ophiolitic basement rocks. The intrusive rocks consist of three groups of granitoid, syenitoid, and gabbroids plutons. The granitoid units occur around the periphery of the CACC as large plutonic bodies, whereas the syenitoid assemblages crop out in the inner part of the CACC as small plutons. All the felsic plutons are crosscut by the gabbroid rocks in the region. The alkaline rocks of the CACC change in composition from nordmarkite through pulaskite to lusitanite, and are made of silica-saturated and silica-undersaturated magmas. The silica under-saturated alkaline rocks have gradual contacts with the silica-saturated alkaline rocks and constitute the main component of the alkaline rocks in the CACC. Nepheline, pseudoleucite, cancrinite, nosean, melanite and arfvedsonite are the main typical mineral compositions of the silica-undersaturated alkaline rocks. The leucite- and pseudoleucite-bearing rocks have porphyritic textures intruding the other main subunits of the alkaline rocks at high topographic elevations in the region. They are mostly composed of foid syenite, monzosyenite, monzodiorite and include rare amount of monzogabbro and foidolite. Each subunit has a transitional contact with the others and is crosscut by alkali feldspar foid syenite veins. Felsic dykes intrude the alkaline rock units and fluorite-bearing hydrothermal veins, which manifest themselves as alteration zones. The alkaline rocks have an abundance of xenolithic enclaves but lack any magma mixing-mingling produced enclaves. Normalized elemental patterns of the analyzed alkaline rocks show a slight enrichment in large ion lithophile elements (LILE) and light rare earth elements relatively to high field strength elements (HFSE) and heavy rare earth elements (HREE). The less fluid mobile, LILE and LREE concentration in the alkaline rocks

  11. Formation of the Yandangshan volcanic-plutonic complex (SE China) by melt extraction and crystal accumulation

    NASA Astrophysics Data System (ADS)

    Yan, Li-Li; He, Zhen-Yu; Jahn, Bor-ming; Zhao, Zhi-Dan

    2016-12-01

    The association of volcanic and shallow plutonic rocks in caldera may provide important clues to the geochemical evolution of silicic magma systems. The Yandangshan caldera is a typical example of late Mesozoic volcanic-plutonic complex in SE China. It is composed of a series of rhyolitic extrusives and subvolcanic intrusions of porphyritic quartz syenites. In this work, we conducted petrological and geochemical studies, as well as zircon dating, on the coexisting volcanic and plutonic rocks from the Yandangshan caldera. The results of SHRIMP and LA-ICP-MS zircon U-Pb dating revealed that the crystallization of the rhyolitic extrusives and subvolcanic intrusions was contemporaneous within analytical errors and in a short period (104-98 Ma). Geochemically, the volcanic rocks are characterized by high Rb/Sr and Rb/Ba ratios and depletion in Ba, Sr, P, Eu and Ti, while the shallow plutons show high K, Ba, Al, Fe and low Rb/Sr and Rb/Ba ratios with insignificant negative Eu anomalies. The volcanic and plutonic rocks have a similar range of zircon Hf isotopic compositions (εHf(t) = - 10.0 to + 1.5) and TDM2 model ages of 2.10-1.23 Ga. They also have comparable whole-rock Sr and Nd isotopic compositions ((87Sr/86Sr)i = 0.7084-0.7090; εNd(t) = - 7.8 to - 6.5) and zircon oxygen isotopic compositions (δ18O mainly = 4.5 to 6.0‰). We argue that the volcanic-plutonic complex of the Yandangshan caldera was formed by reworking of Paleoproterozoic lower crusts in the eastern Cathaysia block, and that the complex could be linked by fractional crystallization and crystal accumulation in a shallow magma chamber. The volcanic rocks represent the highly fractionated end-member, whereas the subvolcanic intrusions of porphyritic quartz syenites could be the residual crystal mushes. This case study could have a general implication for the genetic relationship between volcanic and shallow plutonic rocks in calderas.

  12. Insights Into the Formation of Rhyolite From the Searchlight Pluton: Evidence from Oriented Quartz Clusters

    NASA Astrophysics Data System (ADS)

    Froemming, N.; Deering, C. D.; Beane, R. J.; Bachmann, O.

    2012-12-01

    The Miocene Searchlight pluton (SLP) in the Colorado River extensional corridor of southern Nevada, is well-exposed and tilted near-vertical for exceptional cross-sectional study of magma reservoir dynamics and crystal fractionation of a mid- to upper-crustal pluton (3 to 13 km depth). The upper quartz monzonite section is dominated by minerals in apparent random orientation with a medium- to fine-grained texture due to direct contact with the cold host rock. The middle granitic section is dominated by coarse-grained quartz and feldspar, and interpreted to be a zone of extracted liquid from an intermediate magma. The lower monzonite section is composed of coarse-grained plagioclase and potassium feldspar. We used the crystallographic orientations of quartz clusters, as determined by Electron Backscatter Diffraction (EBSD), to test for crystal accumulation in the SLP. Clusters of quartz crystals with matched dipyramidal faces (parallel or Esterel twin orientation) may indicate a period of crystal accumulation. By analyzing representative samples from each section of the pluton, we found that the lower section (intermediate cumulate) and upper section (crystallization front) do not have quartz clusters with matched dipyramidal faces. Although plagioclase grains are aligned in the lower section, the late crystallization of quartz appears to have prevented aligned or preferred growth orientations. In contrast, the middle section has a high percentage of quartz clusters with matched dipyramidal faces - similar to that found in granite porphyry of the Vinalhaven pluton, Maine. The aligned grains may have formed by fractional crystallization, compaction and synneusis of the early forming quartz in this granitic section. We interpret the middle section of the Searchlight pluton as being similar to shallow, upper crustal plutons (3-8 km depth) such as Vinalhaven pluton. The deep vertical exposure of the SLP, shows that the middle section was formed from periodic episodes of

  13. Dichotomy of The Messada Pluton, Serbo-Macedonian Massif, Greece: From Rifting to Subduction

    NASA Astrophysics Data System (ADS)

    Vasilatos, Charalampos

    2016-10-01

    The Messada pluton is a mafic intrusion that is located about 12 km SW of Serres town, (Macedonia Greece) that intrudes the two mica, biotite and the augen gneisses of the Vertiskos formation (Serbo-Macedonian massif). The aim of this study is to investigate, define and evaluate the geochemical characteristics of the pluton in order to determine the geotectonic environment in which the parental magma has been formed. The Mesada pluton is a mid to coarse grained intrusion presenting petrographic variety from diorite and quartz diorite to tonalite and granodiorite. The variety in petrography reflects its chemical inhomogeneity in major and trace elements. It is suggested that parts of pluton have been formed by distinctly different types of magmas originated in diverse geotectonic settings. Those parts of quartz diorite and tonalite composition, present similar geochemical characteristics, LILE/HFSE ratios and negative Nb, but no Ti anomalies in their primitive mantle normalized trace elements spider grams. They exhibit higher HFS values than those of granodioritic composition. Moreover, their ORG normalized spider grams not only suggest that they have been evolved by a common parental magma, but also present the typical characteristics of a “crust dominated” within plate pluton that may have been formed in an early stage during rifting, prior to a subsequent subduction episode. This interpretation may be in accordance with the suggestion for the Gondwanian origin of the more silicic Triassic rift related meta-granites (e.g. Arnea plutonic complex) of the Serbo-Macedonian massif. In contrary; the parts of Mesada pluton of granodioritic composition, exhibit a calc-alkaline to high K calc-alkaline magmatic suite and present higher LILE/HFSE and LREE/HREE ratios, related to a higher crustal component contribution for the magma genesis. Furthermore, their primitive mantle normalized spider grams’ present negative anomalies at Nb and Ti. These characteristics

  14. Igneous banding, schlieren and mafic enclaves in calc-alkaline granites: The Budduso pluton (Sardinia)

    NASA Astrophysics Data System (ADS)

    Barbey, P.; Gasquet, D.; Pin, C.; Bourgeix, A. L.

    2008-08-01

    This study deals with the origin of igneous layering in plutons, and, especially, the extent layering is related to mafic-silicic magma interactions. The Budduso pluton (Sardinia) shows three main scales of organization. (i) Large scale lithological variations correspond to three main magmatic units, with differentiation increasing from the Outer (hornblende-bearing biotite granodiorite/monzogranite) to the Middle (biotite monzogranite) and the Inner (leucomonzogranite) units. The striking homogeneity of 87Sr/ 86Sr initial ratios (0.7090 ± 4) and ɛNd(t) values (- 5.6 ± 0.1) strongly suggests that magma isotopic equilibration was achieved prior to emplacement, whereas mixing/mingling structures observed within the pluton reflect second-stage processes involving broadly cogenetic components. (ii) Metre to decametre-scale igneous layering may be isomodal or modally-graded, locally with cross-layering. Biotite and plagioclase compositions are similar in both biotite-rich and quartzofeldspathic layers, as are the trace-element patterns which differ only by relative abundances. This precludes an origin by fractional crystallization. A penetrative submagmatic fabric superimposed on the layering and corresponding mainly to flattening can be ascribed to interference between pluton growth and regional deformation. (iii) Composite layering and schlieren are commonly associated to mafic microgranular enclaves, locally within synmagmatic shear zones or disrupted synplutonic dykes. In that case, there is a progressive shift in biotite XFe values from the core of enclave (˜ 0.65) to the host monzogranite (˜ 0.72): schlieren in the monzogranite show biotite XFe values similar to that of the host rock, whereas schlieren close to mafic enclaves show lower XFe values (˜ 0.69) towards those of enclave rims. These features can be ascribed to three main processes: (i) assembly of differentiated (± mixed/mingled) magmatic pulses; (ii) local hydrodynamic sorting related to density

  15. The Petrogenesis of the Late Cretaceous Mamba Pluton from the Eastern Gangdese: Constraints from Mineralogy

    NASA Astrophysics Data System (ADS)

    Li, X.

    2011-12-01

    Occurred as stock,the late Cretaceous Mamba pluton, located at the southeast part of the Gangdese terrane, was one of the granitoid intrusions in the Mesozoic-Cenozoic Gangdese gaint magmatic belt, which is composed of Southern Gangdese, Gangdese back-arc fault uplift belt, Middle Gangdes, The Shiquanhe-Laguo Tso-Yongzhu-Nam Tso-Jiali Ophiolitic Méange Zone, and northern Gangdese from south to north, bounded by Indus-Yarlung Zangbo suture zone to the south, and Bangong Tso-Nujiang suture zone to the north(Zhu et al., 2008a), and the Mamba Pluton intruded pre-Ordovician Sumdo Group and early formed intrusions(T3, J1, J3), was unconformably overlied by Eocene Pana Formation. The modal mineralogy of selected samples from Mamba Pluton are calculated via Matlab: quartz(25%), plagioclase(40%), K-feldspar(18%), biotite(9%) and hornblende(5%), with subordinate primary epidote(<1%), and the accessory mineral phases include magnetite(1%), apatite(<1%),sphene(<1%), etc, corresponding to mega-porphyritic hornblende-biotite granodiorite. Hornblende and Biotite are the most common ferromagnesian phases in Mamba Pluton, which are chemically and structurally sensitive to prevailing physico-chemical conditions of host magmas(Czamanske and Wones, 1973; Czamanske et al., 1977; Jiang and An, 1984; Kumar and Pathak, 2010; Speer, 1987a, b; Wones and Eugster, 1965; Zhou, 1986). Specifically, Hornblende occurs as euhedral(rhombic) to subhedral crystal, composing c.a. 5% of the specimens, and depending on the samples, partially replaced by epidote, and some show simple twinnings. Biotite is euhedral to subhedral, and some of them occurs intergranular, moreover, Goethite occurs as weathering products in some biotite. Besides, the texture relationship indicates that its predated hornblende, i.e. hornblende encompasses biotite. Essentially, the K-feldspar is microcline in terms of classification. The X-ray powder diffraction analyses of K-feldspar megacrysts from Mamba Pluton provide degrees

  16. 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

  17. Pluton pinning of an active Miocene detachment fault system, eastern Mojave Desert, California

    NASA Astrophysics Data System (ADS)

    Davis, Gregory A.; Fowler, T. Kenneth; Bishop, Kim M.; Brudos, Thomas C.; Julio Friedmann, S.; Burbank, Douglas W.; Parke, Mary A.; Burchfiel, B. C.

    1993-07-01

    The Miocene Kingston Range-Halloran Hills detachment fault system of the eastern Mojave Desert, California, delineates part of the eastern breakaway zone for a profoundly extended area between the Sierra Nevada and the Spring Mountains structural blocks. The shallow-dipping, west-rooting detachment fault cuts discordantly across Paleozoic and Precambrian units in the Mesozoic foreland fold-and-thrust belt, exhibits west- to southwest-trending corrugations with structural relief of up to 1.5 km, and underlies the terrestrial Shadow Valley basin. Middle Miocene fault displacement and syntectonic sedimentation in the northern basin were terminated at ˜12.4 Ma by intrusion of the large (˜130 km2), shallow-level (≥4 km depth) Kingston Peak pluton across the detachment fault soon after faulting began. Basin sedimentation and fault displacement southeast of the pluton were not, however, disrupted by its emplacement and continued to evolve. Northern "pluton-pinned" and southern "pluton-free" domains were separated by the Blacksmith Hills fault, a northeast-striking, right-slip lateral ramp that accommodated more than 3 km of postpluton differential extension between pinned and nonpinned domains. In more western regions, late phases of detachment-fault-related extension beneath formerly pinned areas (including western and central parts of the pluton itself) are believed to have led to the development of two generations of east-striking left-slip faults. Collectively, these dextral and sinistral transfer faults illustrate the complex patterns of differential extension and accommodation that can characterize detachment-fault systems as adjacent areal domains of extension are generated and die.

  18. Bioethics regulations in Turkey.

    PubMed

    Aydin, E

    1999-10-01

    Although modern technical and scientific developments in medicine are followed closely in Turkey, it cannot be claimed that the same is true in the field of bioethics. Yet, more and more attention is now being paid to bioethics and ethics training in health sciences. In addition, there are also legal regulations in bioethics, some of which are not so new. The objective of these regulations is to provide technical and administrative control. Ethical concerns are rather few. What attracts our attention most in these regulations is the presence of the idea of "consent".

  19. Terrorism Effects on Turkey

    DTIC Science & Technology

    1991-03-05

    1980’ s many changes took place among these countries; however, there are many indications that the IsB still controls these countries’ intelligence ...for opm Zblkadom vote TERRORISM EFFECTS ON TURKEY BY COLONEL TURAN OLCAY Turkish Army ~Is~RI~~tO S EMHT A’: A~pproved for publ~c 03. RMYWARCOLLG...Distribution is unlimited. 4. PERFORMING ORGANIZATION REPORT NUMBER( S ) S . MONITORING ORGANIZATION REPORT NUMBER( S ) Ga. NAME OF PERFORMING ORGANIZATION 6b

  20. Structural interplay between plutons during the construction of a batholith (Cerro Aspero batholith, Sierras de Córdoba, Argentina)

    NASA Astrophysics Data System (ADS)

    Pinotti, Lucio; Tubía, José M.; D'Eramo, Fernando; Vegas, Néstor; Sato, Ana M.; Coniglio, Jorge; Aranguren, Aitor

    2006-05-01

    Magnetic fabric patterns and microstructures of granitic rocks provide evidence of structural modifications as a result of the coalescence of two plutons, Alpa Corral and Talita, during the construction of a large granitic batholith, Cerro Aspero, in the Sierras Pampeanas of Córdoba (Argentina). The Alpa Corral granite is a small and nearly circular pluton, while the larger Talita pluton displays a marked N-S elongation. The NW quadrangle of the Alpa Corral pluton underwent a deformation resulting in foliation trajectories that outline a crescent moon pattern whose inner arc is concordant with the Alpa Corral/Talita contact. The highest values for the magnetic susceptibility and its anisotropy are concentrated in the coalescence zone between both plutons. The magmatic and sub-magmatic nature of the microstructures demonstrates that such a deformation was caused by the southward overriding of the largest Talita pluton while the Alpa Corral pluton was not yet fully crystallized. Rb-Sr geochronology indicates that this process took place 369±9 Ma ago, long after the Famatinian (Ordovician to Early Devonian) deformation of the country rocks, which confirms a synmagmatic, rather than a regional, deformational event.

  1. U-Pb dating and emplacement history of granitoid plutons in the northern Sanandaj-Sirjan Zone, Iran

    NASA Astrophysics Data System (ADS)

    Mahmoudi, Shahryar; Corfu, Fernando; Masoudi, Fariborz; Mehrabi, Behzad; Mohajjel, Mohammad

    2011-05-01

    The Sanandaj-Sirjan Zone (SSZ), which runs parallel to the Zagros fold and thrust belt of Iran, underwent a multistage evolution starting with Neotethys initiation, its subsequent subduction below the Iranian continental crust, and eventual closure during convergence of Arabia towards central Iran. Plutonic complexes are well developed in the northern part of the SSZ and we have dated a number of them by ID-TIMS U-Pb on zircon. The new data record the following events: a Mid Jurassic period that formed the Boroujerd Plutonic Complex (169 Ma), the Astaneh Pluton (168 Ma) and the Alvand Pluton (165 Ma); Late Jurassic emplacement of the Gorveh Pluton (157-149 Ma); Mid Cretaceous (109 Ma) formation of a I-type phase in the Hasan Salary Pluton near Saqqez, followed by Early Paleocene (60 Ma) intrusion of A-type granite in the same pluton; and the youngest intrusive event recorded so far in the SSZ with the intrusion of granite in the Gosheh-Tavandasht Complex near Boroujerd at 34.9 Ma. These different events reflect specific stages of subduction-related magmatism prior to the eventual Miocene collision between the two continental blocks.

  2. 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.

  3. 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.

  4. Numerical modeling of forceful pluton emplacement and associated deformation at different crustal levels - instantaneous, continuous or episodic intrusion?

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Nabelek, P. I.

    2015-12-01

    The Papoose Flat pluton in the White-Inyo Range, California, is one of the best examples of forceful magma emplacement at mid-crustal levels that is revealed by a highly strained aureole. A thermo-rheological 2-D model of the pluton and its aureole is proposed. We explored how the frequency of magma input, from instantaneous to continuous to the bottom of the laccolith, affects the ductile width of the aureole and the crystallinity of the pluton, which has implications for eruption of magma. We modeled these aspects at mid- and upper-crustal levels. The pluton was assumed to be 5 km thick in the middle and 13 km wide. Except for instantaneous growth, pluton was assumed to grow over 5 m.y. The aureole was assumed to have power-law rheology of quartz with dependence on H2O fugacity, which was calculated using the CORK equation (Holland & Powell, 1991) Our result shows that the bottom of the Papoose Flat pluton was emplaced at the brittle-ductile transition zone of the crust. The crustal rheology profile assisted the softening of rocks around the pluton. The simulated temperature and strength profiles confirm that ductile deformation was related to thermal weakening (Saint-Blanquat et al., 2001). Results of incremental growth calculations show that the pluton remains hot and only partially crystalline for millions of years when it grows by frequent input of small batches of liquid. At the mid-crustal level, the ductile region around the pluton is much wider and exists longer than at the shallow crustal level. Brittle rheology is dominant during the late stage growth at the shallow depth. When the pluton grows instantly or by only few episodes of large batches of input, the mobile part of the pluton is thin and the ductile aureole is narrower. High-frequency incremental growth by smaller magma batches produces a large volume of mobile magma that has the potential to induce internal magmatic layering that may be reflected in aligned acquired magnetic susceptibility (AMS

  5. Structural evolution of the La Paya pluton (Sierra de Cachi, NW Argentina): insights from the study of its magnetic fabric

    NASA Astrophysics Data System (ADS)

    Aranguren, Aitor; Hongn, Fernando; María Tubía, José; Vegas, Néstor

    2017-04-01

    The La Paya granite is a pluton elongated in a northerly direction that spreads over 10 km2 in the Sierra de Cachi (Eastern Cordillera of Salta, Andean belt, NW Argentina). This pluton intrudes into high-temperature and low-pressure migmatites and schists. The metamorphic evolution of the country rocks and the emplacement of the La Paya pluton took place in an extensional tectonic setting during Ordovician times (Hongn et al., 2014). Subsequently, a compressional tectonic event led to the formation of large E-verging folds with a penetrative axial planar foliation. Due to the folding event, the current metamorphic zonation is inverted and the metamorphic degree rises towards the west. The granite is concordant with the metamorphic zonation and with the country rocks foliation. Schists with biotite and andalucite (low to medium metamorphic grade) crop out in the eastern border of the pluton and schists with cordierite (high grade) in the western border. The pluton is characterized by the coexistence of magmatic and solid-state structures. The deformation is localized in shear bands concentrated in the pluton roof. Wide sectors of the pluton core preserve medium- to coarse-grained equigranular textures of magmatic origin on which we have collected samples from 28 sites in order to perform an AMS study. Susceptibility values are very low, with k ranging between 19 and 67 x 10-6 SI. The obtained anisotropy values are in agreement with the magmatic character of the analysed samples (Pj between 1,03-1,07). The magnetic foliations are concordant with the contacts of the pluton. They show northwards trends and dips to the west that are steeper close to the eastern pluton border. Magnetic lineations are concentrated in two main maxima that define a great circle parallel to the pluton elongation. The parallelism between the magnetic fabrics from areas with magmatic structures and the structures observed in domains with solid-state deformation points to a syn

  6. [Nuclear families in Turkey].

    PubMed

    Unalan, T

    1988-01-01

    This study examines the household or family types in Turkey in 1983, especially nuclear families. Nuclear families constitute 61.6% of all households in Turkey, and the majority of them are in the West and the Central regions. The highest % of nuclear families was found in the Mediterranean regions, and the lowest in the Black Sea region. Among all nuclear families, 87% of them consist of husband, wife and children, whereas 13% of them have only husband and wife. Nuclear families without children are common in urban areas and in the West while nuclear families with children are mostly found in rural areas and in the East and the Black Sea regions. Nuclear families with 3 or more children constitute 32% of all nuclear households in the West. On the other hand, the corresponding % is 73 for the Eastern region. As a result, it is concluded that nuclear families have significant regional and residential differentiations and households with the same formation in a developed and a less developed region should have different social, economic, and cultural characteristics.

  7. Petrogenesis of Mesoproterozoic granitic plutons, eastern Llano Uplift, central Texas, USA

    NASA Astrophysics Data System (ADS)

    Smith, R. K.; Gray, Walt; Gibbs, Tyson; Gallegos, M. A.

    2010-08-01

    The Llano Uplift of central Texas is a gentle structural dome exposing ˜ 1370 to 1230 Ma metaigneous and metasedimentary rocks of Grenville affinity along the southern margin of Laurentia. The metamorphic rocks were subsequently intruded by ˜ 1119 to 1070 Ma late syn- to post-tectonic granites collectively known as the Town Mountain Granite (TMG). The eastern most of the TMG, the Marble Falls (MF), Kingsland (KL), and Lone Grove (LG) plutons, are metaluminous to marginally peraluminous, high-K, calc-alkaline, ferroan, biotite-calcic amphibole granites [Fe/(Fe + Mg) = 0.71-0.92 and 0.78-0.91 for biotite and calcic amphibole, respectively] displaying distinct variation trends with increasing silica content. They are chemically and texturally zoned and have mineralogical and chemical characteristics similar to A-type granites; i.e., 1) Fe-rich biotites, calcic amphiboles, accessory fluorite, and sporadic rapakivi texture, 2) high K 2O (> 4 wt.%), 3) low Al 2O 3 (< 16 wt.%) and CaO (< 3 wt.%), 4) high Fe/(Fe + Mg), 5) enrichments in Zr, Nb, REE, Ga/Al, and 6) depleted Eu. However, in contrast to typical A-type granites (having low Sr and Ba) the MF, KL,and LG plutons are enriched in Sr and Ba; i.e., up to 229 ppm and 1090 ppm, respectively. On granite discrimination diagrams [(K 2O + Na 2O)/CaO vs. Zr + Nb + Ce + Y (ppm) and Zr (ppm) vs. Ga/Al*10,000] the KL and MF plutons plot within the A-type field, whereas the LG pluton compositions are divided between A-type and fractionated granite fields (I-, S- and M-types). On tectonic discrimination diagrams (Y vs. Nb ) the MF and KL granites plot in the "within-plate" granite field, but the LG pluton plots across several fields including "within-plate" and "volcanic arc plus syn-collisional" fields. Consequently the tectonic classification on a geochemical basis for the LG pluton is unclear. Based on thermal metamorphic mineral assemblages, normative Q-Ab-Or plots, and Q-Ab-Or-H 2O experimental data (Johannes and Holtz

  8. Apatite trace element and halogen compositions as petrogenetic-metallogenic indicators: Examples from four granite plutons in the Sanjiang region, SW China

    NASA Astrophysics Data System (ADS)

    Pan, Li-Chuan; Hu, Rui-Zhong; Wang, Xin-Song; Bi, Xian-Wu; Zhu, Jing-Jing; Li, Chusi

    2016-06-01

    The abundances of trace elements including Sr, Ga and rare earth elements (REE) and halogens in apatite crystals from four intermediate-felsic plutons in the Zhongdian terrane in the Sanjiang region have been determined using electron microprobe and laser ablation inductively coupled plasma mass spectrometry to evaluate the potential of apatite as a petrogenic-metallogenic indicator. The selected plutons include one that is not mineralized (the Triassic Xiuwacu pluton, or the TXWC pluton), one that hosts a porphyry-type Cu deposit (the Pulang pluton, or the PL pluton), one that hosts a porphyry-type Mo deposit (the Tongchanggou pluton, or the TCG pluton), and one that hosts a vein-type Mo deposit (the Cretaceous Xiuwacu pluton, or the CXWC pluton). Except for the CXWC pluton, the other three plutons have adakite-like trace element signatures in whole rocks. The results from this study show that REE, Sr and halogens in apatite can be used to track magma compositions, oxidation states and crystallization history. Apatite crystals from the adakite-like plutons are characterized by much higher Sr/Y and δEu than the non-adakite-type pluton. This means that apatite, which is not susceptible to alteration, is a useful tool for identifying the adakite-like plutons that no longer preserve the initial Sr/Y ratios in whole rocks due to weathering and hydrothermal alteration. Based on apatite Ga contents and δEu values, it is inferred that the parental magmas for the two adakite-like plutons containing porphyry-type Cu and Mo mineralization are more oxidized than that for the non-adakite-type pluton containing vein-type Mo mineralization. Apatite crystals from the vein-type Mo deposit have much lower Cl/F ratios than those from the porphyry-type Cu and Mo deposits. Apatite crystals from the adakite-like pluton without Cu or Mo mineralization is characterized by much lower Cl/F ratios than those from the adakite-like plutons that host the porphyry-type Cu and Mo deposits. The

  9. Amphibole Thermometry and a Comparison of Results from Plutonic and Volcanic Systems

    NASA Astrophysics Data System (ADS)

    Sherman, T. M.; Putirka, K. D.; De Los Reyes, A. M. A.; Ratschbacher, B. C.

    2015-12-01

    Recent work (Ridolfi and Renzulli 2014) shows that amphiboles can be used to infer magmatic temperatures, even without knowledge of co-existing liquids. Here, we apply this approach, using new calibrations, to investigate felsic-mafic magma interactions, in a volcanic (Lassen Volcanic Center, a Cascade volcano) and plutonic (the Jurassic Guadalupe Igneous Complex) system. Preliminary data suggest that volcanic processes, as might be expected, preserve higher temperatures than plutonic materials (on average, volcanic amphiboles recorded 907±57.3°C while plutonic amphiboles recorded 764±59.7°C). We also find that the average T of a given mineral grain decreases with increased mineral size such that those crystallized below 800°C sometimes reach sizes beyond ~1mm, while those near 900°C appear truncated to ~0.3mm. It is not clear if T is the only control on amphibole crystal growth; however, our results would imply that larger grains not only require more time to grow but require continued undercooling. Significant cooling or heating is also recorded in many volcanically- and plutonically-grown grains, which may reflect transitioning between magmas of different T and composition. Core-to-rim cooling trends (with a common T of drop of 80oC) likely represent mafic-to-felsic magma transitions, whereas core-to-rim heating of similar magnitudes indicate a felsic-mafic transition. Some grains, though, exhibit a constant T (in the range 700-900°C) from core to rim, which perhaps indicates some shielding from magma mixing processes. Amphiboles might thus provide a reliable record of the intensity of magma mingling and mixing experienced by any particular enclave. Interestingly, volcanically-derived amphiboles appear to mostly record cooling towards the rims, while their plutonic counterparts tend to experience heating. It would thus appear that at Lassen, amphiboles are unaffected by later mafic magma recharge, but at the GIC, the plutonic amphiboles are more likely to

  10. Volcanic-Plutonic Connection in the Tilzapotla Caldera Ignimbrites in Southern Mexico

    NASA Astrophysics Data System (ADS)

    Martiny, B. M.; Moran Zenteno, D. J.; Roberge, J.; Zuñiga-Lagunes, L.; Flores-Huerta, D.; Solari, L.; Lopez-Martinez, M.

    2011-12-01

    Age and compositional similarities in broad exposures of volcanic and plutonic rocks in the central sector of the late Eocene-early Oligocene silicic volcanic province in southern Mexico provide an excellent opportunity for studying the genetic connection between the volcanic and plutonic realms. The Taxco-Tilzapotla sector is of particular interest given the presence of a NW-SE oriented elliptical dome structure (50 x 35 km) that encloses the Tilzapotla caldera, three medium-grained plutons one of which contains mafic magmatic enclaves, hypabyssal intrusive bodies, rhyolitic domes, and voluminous ignimbrites. North-south trending Laramide folds in Cretaceous marine sedimentary rocks were disrupted when late Eocene magmas intruded into the upper crust, forming the dome and producing opposite plunges in pre-dome fold axes north and south of the elliptical structure. We have obtained LA-ICPMS zircon U-Pb and Ar-Ar mineral ages as well as electron microscope analyses of different magmatic facies in order to: better understand the chronology of magmatic evolution in the area; examine the possible genetic relationship between the plutonic rocks and the principal ignimbritic units, in particular the crystal-rich units; and determine possible compositional differences that might suggest the injection of different batches of magma. U-Pb crystallization ages of 37-36 Ma were determined on zircons from different facies of the Coxcatlan granodiorite. Slightly younger zircon U-Pb crystallization ages were obtained for ignimbrites from the Tilzapotla caldera (36-35 Ma) and for the more mafic Chiautle pluton (34.6 Ma) that is exposed near the southern boundary of the dome structure. Earlier work by our group established caldera collapse and extrusion of the Tilzapotla ignimbrite at 34.3 Ma. Ar-Ar dating gives cooling ages of 33 Ma in sanidine for an intracaldera ignimbrite and some late stage silicic and intermediate magmas yielded mainly between 33-32 Ma. The new and previous

  11. Genesis and evolution of water in a two-mica pluton: A hydrogen isotope study

    USGS Publications Warehouse

    Brigham, R.H.; O'Neil, J.R.

    1985-01-01

    Measurements were made of the hydrogen isotope composition of 74 samples of muscovite, biotite, vein quartz and whole rocks from the Papoose Flat pluton, eastern California, U.S.A., and adjacent metamorphic and sedimentary rocks in order to elucidate the genesis and evolution of water and hydrous minerals in a two-mica granodiorite. Electron microprobe analyses were made of all micas so that the Suzuoki-Epstein equation could be used in evaluating the data. Based on experimental, theoretical and textural evidence of mica paragenesis, a model of hydrogen isotope fractionation between an aqueous vapor and a magma during crystallization has been constructed. This model accounts for the observed hydrogen isotope relations and implies that primary hydrogen isotope compositions have been preserved in a large portion of the pluton. The ?? D-values of biotites vary widely over the range -103 to -66% with most values lying between -90 and -70??? Muscovites, on the other hand, are isotopically more uniform and have ?? D-values of -61 to -41??? with most values lying between -50 and -46??? These data are consistent with the interpretation that biotite formed over a long period of crystallization whereas muscovite formed in a narrow interval, presumably during the final stages of crystallization when alumina and water contents were at their highest. Only 8 of the 21 muscovite-biotite pairs analyzed are in hydrogen isotope equilibrium as calculated from the Suzuoki-Epstein equation. Biotites in the western half of the pluton have relatively low ?? D-values of around -85???, whereas those in the eastern half have higher values of up to -66??? This pattern is a consequence of a loss of permeability associated with the syn-intrusive deformation of the western margin of the pluton. This loss of permeability enhanced the preservation of primary hydrogen isotope relations there by diverting water evolved from the magma out through the eastern half of the pluton where some deuteric

  12. Skarn-type ilmenite mineralization of the Tuzbaşi-Tunceli region, eastern Turkey

    NASA Astrophysics Data System (ADS)

    Altunbey, Mehmet; Sagiroglu, Ahmet

    2003-02-01

    In the Tuzbaşi-Tunceli region of eastern Turkey, skarn-type ilmenite mineralizations occur within the skarn zones along the contact between marbles of the Keban Metamorphic Formation (Permo-Triassic) and gabbros and diorites of the Elazig Magmatic Complex (Coniacian-Campanian). The Elazig Magmatic Complex has characteristics typical of arc magmatism and is composed of plutonic, volcanic, subvolcanic and pyroclastic rocks. Both formations are overlain by sediments of the Alibonca Formation (Lower Miocene) and continental andesitic lava flows of the Karabakır Formation (Upper Miocene-Pliocene). Ilmenite and skarn formation developed as a consequence of plutons (granite-gabbro-diorite) of the Elazig Magmatic Complex intruding into marbles of the Keban Metamorphic Formation. This event also resulted in different types of magnetite mineralization and skarn formation, with different mineral assemblages, in neighbouring areas. Ilmenite concentrations occur as lensoid bodies in garnet-pyroxene calcic exoskarns along (gabbro-diorite)-marble contacts. Ilmenite bodies form syngenetically with skarns, and their TiO 2 contents reach up to 15.83 wt%. The predominant ore mineral is ilmenite, which is often altered to leucoxene and hematite, and occurs disseminated within skarn minerals (predominantly almandine garnet and pyroxene). The titanium of ilmenites apparently originated from the diorites and gabbros, which are otherwise Ti and Al-rich and Si-poor. The intruded marbles supplied the necessary O 2 for ilmenite mineralization.

  13. Turkey's foreign dependence on energy

    SciTech Connect

    Uslu, T.

    2008-07-01

    Turkey becomes more dependent on the external countries in energy production every year. As an average of the period 1994-2002 the total primary energy production has been 27.9 Mtoe, and consumption has been 73.06 Mtoe, so Turkey is dependent on external countries in petroleum, natural gas, and hard coal consumption. The external dependency rate of these fuels has been at levels of 89.3%, 96.6%, and 82%, respectively. In the projections of Turkey for 2020, the primary energy consumption is estimated to be 298 Mtoe, production is estimated to be 70 Mtoe, the ratio of production to consumption will be reduced to 23.5%, and this situation will cause serious risks for sustainable development. In other words, Turkey will have to import 76.5% of the energy that it consumes in the 2020s.

  14. Crystallization processes in the Rocky Hill granodiorite Pluton, California: An interpretation based on compositional zoning of plagioclase

    NASA Astrophysics Data System (ADS)

    Loomis, Timothy P.; Welber, Paul W.

    1982-12-01

    The Rocky Hill Pluton was chosen for study of plagioclase zoning because it has an apparently simple geometry and one-stage emplacement history, documented by Putman and Alfors (1969). The pluton is divided texturally into a hypidiomorphic granular rim fades and porphyritic core facies, both comprising zoned plagioclase phenocrysts averaging 2 4 mm in diameter. Major features of compositional zoning profiles of plagioclase were found to be consistent within a sample, showing resorbed core regions followed by a sharp drop of ca. 10% An to a plateau region, and ending with normal zoning. The width of the plateau region is narrow in samples near the pluton rim but increases systematically toward the pluton core, and the outer part of the plateau develops reverse zoning in the core facies. A review of the effects of pressure, water content of the melt, and temperature on equilibrium and disequilibrium crystallization processes concludes that only variations of temperature and water content during disequilibrium crystallization of plagioclase phenocrysts can produce the observed zoning patterns. Experimental data suggest that the trend toward finer grain size toward the interior of the pluton may be due to increasing water content rather than due to increasing cooling rate. The compositional zoning of plagioclase and textural variations in the pluton can be explained by a model in which the pluton crystallized by migration of a partly crystalline “mush zone” inward from the edge of the plutonic chamber while convection within the residual magma: (1) redistributed water excluded from the mush zone and (2) slowed the cooling rate of the mush zone. The reverse zoning of plagioclase growing in the convecting magma changed to normal zoning after capture in the mush zone because the cooling rate increased and water was removed. Comparison of the results from our study of Rocky Hill with published descriptions of plutons and experimental and theoretical studies of

  15. Hiding the Evidence: Growth of plutons by incremental emplacement of sheets in crystal mush

    NASA Astrophysics Data System (ADS)

    Miller, C. F.; Furbish, D. J.; Claiborne, L. L.; Walker, B. A.; Bleick, H. A.; Steinwinder, T. R.; Koteas, G. C.

    2006-12-01

    Growing evidence supports the notion that plutons are constructed incrementally, commonly over long periods of time, yet field evidence for the multiple injections that seem to be required is commonly sparse or absent (e.g. Glazner et al. 2004). Timescales of up to several million years, among other arguments, indicate that the dominant volume does not remain largely molten, yet if growing plutons are constructed from rapidly solidifying increments it is unlikely that intrusive contacts would escape notice. A model wherein magma increments are emplaced into crystal mush rather than either solid or crystal-poor material provides a plausible explanation for this apparent conundrum. A partially solidified intrusion undoubtedly comprises zones with contrasting melt fraction and therefore strength. The emplacement of dikes that intrude such a strength-zoned intrusion will be guided by the contrasts in the same way that dikes intruding solid media: magma spreads rather than continuing to propagate upward where it encounters a zone of higher rigidity (e.g. experiments by Kavanagh et al. 2006). We propose that ascending magma is in essence trapped by low-strength zones in plutonic mushes that are relatively melt-rich. In many cases, such zones may be subhorizontal and thus sill-like in geometry, but shapes and orientations could be highly variable, depending on the prior history of the composite intrusion. Contacts will commonly be obscure from the start because the contrast between intruding material (crystal-poorer magma) and host (crystal-richer mush) is subtle, and it may be obscured even further by subsequent destabilization of the mush. Field evidence and zircon zoning stratigraphy in plutons of the Colorado River region of southern Nevada support the hypothesis that emplacement of magma replenishments into a mush host is important in pluton construction. Except for highly fractionated dikes and sills, the dominant granite unit of the Spirit Mountain batholith

  16. Timing and nature of tertiary plutonism and extension in the Grouse Creek Mountains, Utah

    USGS Publications Warehouse

    Egger, A.E.; Dumitru, T.A.; Miller, E.L.; Savage, C.F.I.; Wooden, J.L.

    2003-01-01

    The Grouse Creek-Albion-Raft River metamorphic core complex in northwestern Utah and southern Idaho is characterized by several Tertiary plutons with a range of ages and crosscutting relations that help constrain the timing of extensional deformation. In the Grouse Creek Mountains, at least three distinct, superimposed, extension-related Tertiary deformational events are bracketed by intrusive rocks, followed by a fourth event: motion on range-bounding faults. The Emigrant Pass plutonic complex was emplaced at depths of less than 10 km into Permianage rocks. SHRIMP U-Pb zircon analysis indicates a three-stage intrusion of the complex at 41.3 ?? 0.3 Ma, 36.1 ?? 0.2 Ma, and 34.3 ?? 0.3 Ma. The two youngest phases represent distinctly younger intrusive event(s) than the oldest phase, separated by more than 5 m.y. The oldest phase cuts several metamorphosed and deformed younger-on-older faults, providing a pre-41 Ma age bracket for oldest extension-related deformation in the region. The youngest phase(s) are interpreted to have been intruded during delelopment of a map-scale. N-S-trending recumbent fold, the Bovine Mountain fold, formed during vertical shortening of roof rocks during intrusion. This second event folded older normal faults that are likely pre-41 Ma. Zircons from the youngest part of the pluton show inheritance from Archean basement (???2.5 Ga) and from its Proterozoic sedimentary cover (???1.65 Ga). The Red Butte pluton, emplaced at 15-20 km depth, intruded highly metamorphosed Archean orthogneiss at 25.3 ?? 0.5 Ma; cores of some zircons yield latest Archean ages of 2.55 Ga. The pluton is interpreted to have been intruded during a third deformational and metamorphic event that resulted in vertical flattening fabrics formed during NW to EW stretching, ultimately leading to thinning of cover and top-to-the west motion on the Ingham Pass fault. The Ingham Pass fault represents an important structure in the Grouse Creek Mountains, as it juxtaposes two parts

  17. An underground characterization program for a nuclear fuel waste disposal vault in plutonic rock

    SciTech Connect

    Thompson, P.M.; Everitt, R.A.

    1993-12-31

    The Canadian Nuclear Fuel Waste Management Program (CNFWMP) is developing a concept for disposing of nuclear fuel waste that involves placing and sealing it in a disposal vault excavated 500 to 1,000 m deep in the stable plutonic rock of the Canadian Shield. In this concept, engineered and natural barriers serve to isolate the waste from the biosphere. Since 1983, underground characterization and testing in support of the CNFWMP has been ongoing at the Underground Research Laboratory (URL) in southeastern Manitoba. This paper draws on experience gained at the URL to recommend an approach to underground characterization that would provide the necessary information to make design decisions for a disposal vault in plutonic rock.

  18. Isotopic studies of the late Archean plutonic rocks of the Wind River Range, Wyoming.

    USGS Publications Warehouse

    Stuckless, J.S.; Hedge, C.E.; Worl, R.G.; Simmons, K.R.; Nkomo, I.T.; Wenner, D.B.

    1985-01-01

    Two late Archaean intrusive events were documented in the Wind River Range by isotopic studies of the Rb-Sr and U-Th-Pb systems in whole-rock samples and the U-Pb systematics for zircon. An age of approx 2630(20) m.y. for the Louis Lake batholith and apparent ages of 2504(40) to 2575(50) m.y. for the Bear Ears pluton were obtained. Post-magmatic hydrothermal events approximately Tertiary in age, lowered delta 18O values and disturbed parent-daughter relationships in most of the isotopic systems investigated. The two intrusive units apparently were derived from different protoliths. Initial isotopic ratios and petrochemistry for the Louis Lake batholith are consistent with an early Archaean trondhjemitic to tonalitic source. The protolith for the Bear Ears pluton must have been subjected to high-grade metamorphism that caused loss of Rb and U prior to magma generation. -L.C.H.

  19. Petrology and U-Pb geochronology of buried Avalonian plutonic rocks on southeastern Cape Cod

    USGS Publications Warehouse

    Leo, G.W.; Mortensen, J.K.; Barreiro, B.; Phillips, J.D.

    1993-01-01

    Plutonic rocks have been intersected by two separate drill holes on souteastern Cape Cod. Hole CC2 is located about 7 km south of the Nauset anomaly, an east-northeast-trending magnetic lineament that was considered to separate the distinct plutonic zones of Avalon terrane. This drill hole intersected weakly foliated, fairly homogeneous biotite granite. Zircons from this granite give a U-Pb age of 584+9/-8 Ma. Hole CC1 is located about 12 km north of the Nauset anomaly. The drill core intersected foliated, sheared, biotite granodiorite and biotite-hornblende-clinopyroxene-quartz gabbro, metamorphosed to greenschist facies. The deformed and altered state of these rocks, as well as their geochemistry, suggest that their origin and possibly their ages are distinct from the granite in hole CC2. No datable zircons were obtained from rocks in CC1. -from Authors

  20. Pennsylvanian pluton stitching of Wrangellia and the Alexander terrane, Wrangell Mountains, Alaska

    SciTech Connect

    Gardner, M.C.; Bergman, S.C.; Cushing, G.W. ); Plafker, G. ); Campbell, R.B.; Dodds, C.J. ); McClelland, W.C. ); Mueller, P.A. ); MacKevett, E.M. Jr.

    1988-11-01

    A quartz monzonite-syenite-alkali granite plutonic complex in eastern Alaska crosscuts the contact of the Alexander terrane and Wrangellia and intrudes the basement rocks of both terranes. Zircon U-Pb data indicate an intrusion age of 309 {plus minus} 5 Ma (Middle Pennsylvanian) for the pluton, and {sup 40}K-{sup 40}Ar age for hornblende separates indicate cooling to about 450 C during Middle Pennsylvanian-Early Permian time. The new field relations and age data demonstrate the Wrangellia and the Alexander terrane were contiguous during the Middle Pennsylvanian. This conclusion provides an important new constraint on paleogeographic reconstructions of the northwest Cordillera, and necessitates reassessment of stratigraphic and paleomagnetic data that were cited as evidence that the terranes evolved separately until the late Mesozoic.

  1. Paleomagnetic results from seven middle Paleozoic plutons in the Appalachian Piedmont of North and South Carolina

    USGS Publications Warehouse

    Hagstrum, J.T.

    1983-01-01

    Seven isotopically dated plutons of similar middle Paleozoic age (approx. 400 Ma) were sampled for paleomagnetic study. The results from 12 sites (152 samples) within these plutons show two types of remanence behavior that appear fairly consistent with rock composition. The more leucocratic rocks (9 sites) tend to yield single-component magnetizations, of generally lower coercivities and blocking temperatures relative to the other units, that are considered to represent a recent viscous overprint, The mesocratic to melanocratic rocks show both single- and multicomponent magnetizations, the latter giving characteristic directions isolated through remagnetization-plane analysis. Three sites are considered reliable and yield paleomagnetic poles, of inferred Early Devonian age, that may reflect a 30? southward displacement from stable North America. One large site (25 samples) gives a remagnetized pole position of inferred Carboniferous age consistent with poles from North America, perhaps indicating that the Piedmont may have become part of the North American plate by this time.

  2. River Valley pluton, Ontario - A late-Archean/early-Proterozoic anorthositic intrusion in the Grenville Province

    NASA Technical Reports Server (NTRS)

    Ashwal, Lewis D.; Wooden, Joseph L.

    1989-01-01

    This paper presents Nd, Sr, and Pb isotopic data indicating a late-Archean/early-Proterozoic age for the River Valley anorthositic pluton of the southwestern Grenville Province of Sudbury, Ontario. Pb-Pb isotopic data on 10 whole-rock samples ranging in composition from anorthosite to gabbro yield an age of 2560 + or - 155 Ma. The River Valley pluton is thus the oldest anorthositic intrusive yet recognized within the Grenville Province. The Sm-Nd isotopic system records an age of 2377 + or - 68 Ma. High Pb-208/Pb-204 of deformed samples relative to igneous-textured rocks implies Th introduction and/or U loss during metamorphism in the River Valley area. Rb-Sr data from igneous-textured and deformed samples and from mineral separates give an age of 2185 + or - 105 Ma, indicating substantial disturbance of the Rb-Sr isotopic system.

  3. Geochemical study of Palong Pluton at Negeri Sembilan-Pahang border

    NASA Astrophysics Data System (ADS)

    Selamat Din, Khairil Izam Bin; Umor, Mohd Rozi

    2013-11-01

    The geochemical studies are carried out for igneous rocks from Palong Pluton at the border area of Negeri Sembilan and Pahang. The study area is about 250 km2, covering the area of Kemayan, Pasoh and Serting. The purposes of the geochemical study are to classify and determine the chemical characteristic of the granitic rocks, to correlate and interpret the crystallization history of igneous rocks, to determine the rock genesis and to determine the origin of magma. The Palong Pluton is divided into three groups, namely the Kemayan Granite, Serting Granite and Lui Granite. The geochemical data are presented by TAS and Harker Diagrams. The geochemical results show that Kemayan Granite, Serting Granite and Lui Granite are naturally originated from a single magma source. The magma evolution started from Kemayan Granite to Lui Granite and Serting Granite by differentiation proceses.

  4. Felsic plutonic rocks of the Midyan region, Kingdom of Saudi Arabia—I. Distribution, classification and resource potential

    NASA Astrophysics Data System (ADS)

    Ramsay, Colin R.; Drysdall, Alan R.; Clark, Malcolm D.

    About 80 large felsic plutons were emplaced in the Midyan region of the northwestern Arabian Shield between 725 and 570 Ma ago. Polymetallic mineralization, including Mo, Nb, REE, Sn, Ta, U, W and Zr, is associated with particular varieties. Five intrusive suites of regional extent and five other plutons have been identified. The oldest extensive unit is the Muwaylih suite, consisting of trondhjemite, tonalite, diorite and gabbro, with generally trondhjemitic compositional affinities and no known mineral potential. The most voluminous is the Ifal suite, a heterogeneous assemblage of biotite—hornblende monzogranite, granodiorite and quartz monzodiorite in large, oval to irregular plutons characterized by numerous intraplutonic dikes, but with no known mineral potential. The Ifal suite is intruded by plutons of the Atiyah monzogranite, with a variable number of dikes. The Muwaylih, Ifal and Atiyah suites are chemically metaluminous, but the Midyan suite consists of alkali granite to alkali-feldspar granite which is metaluminous to peralkaline. Large, irregular plutons of the Haql suite are composed of perthite leucogranite which is metaluminous to marginally peraluminous or peralkaline. Plutonic rock units of local significance include the Lawz complex, consisting of commonly granophyric syenogranite to monzogranite, the Mowasse quartz syenite and the Sawda (nepheline syenite) complex. Polymetallic Nb sbnd Zr deposits, such as those at Jabal Tawlah and Ghurayyah, are the most important known mineral resources and are related to alkali granite of the Midyan suite. Plumasitic specialized plutons, such as the Ratamah granite, have weak Sn sbnd W sbnd Ta sbnd Nb mineralization, and are related to the Haql suite. Apical and contact zones of plutons of these suites are favorable exploration target areas.

  5. Equine glanders in Turkey.

    PubMed

    Arun, S; Neubauer, H; Gürel, A; Ayyildiz, G; Kusçu, B; Yesildere, T; Meyer, H; Hermanns, W

    1999-03-06

    In the course of an epidemiological study of glanders on a number of Turkish islands in the Sea of Marmara, 1128 horses were examined by using the intracutaneous mallein test. Thirty-five (3-1 per cent) developed an increase in rectal temperature and a swelling at the point of injection. Ten of these horses were killed and glanders was confirmed in five cases by the presence of lesions and by the immunohistological demonstration of the causative agent, Burkholderia mallei. Clinical and pathological findings indicated that in all cases the infection was restricted to the mucous membrane of the nasal cavity with its parasinus, the nostrils and the upper lips. It was confirmed that equine glanders is endemic in Turkey.

  6. Comparison of the triple-point temperatures of {sup 20}Ne, {sup 22}Ne and normal Ne

    SciTech Connect

    Nakano, T.; Tamura, O.; Nagao, K.

    2013-09-11

    At the National Metrology Institute of Japan (NMIJ), the triple points of {sup 20}Ne and {sup 22}Ne were realized using modular sealed cells, Ec3Ne20 and Ec8Ne22, made by the Istituto Nazionale di Ricerca Metrologica (INRiM) in Italy. The difference of the triple-point temperatures of {sup 20}Ne and {sup 22}Ne was estimated by using the sub-range of standard platinum resistance thermometers (SPRTs) calibrated by NMIJ on the International Temperature Scale of 1990 (ITS-90). The melting curves obtained with the Ec3Ne20 and Ec8Ne22 cells show narrow widths (0.1 mK) over a wide range of the inverse of the melted fraction (1/F) from 1/F=1 to 1/F=10. The liquidus point T{sub tp} estimated by the melting curves from F∼0.5 to F∼0.85 using the Ec8Ne22 is 0.146 29 (4) K higher than that using the Ec3Ne20 cell, which is in good agreement with that observed by INRiM using the same cells. After correction of the effect of impurities and other isotopes for Ec3Ne20 and Ec8Ne22 cells, the difference of T{sub tp} between pure {sup 20}Ne and pure {sup 22}Ne is estimated to be 0.146 61 (4) K, which is consistent with the recent results reported elsewhere. The sub-ranges of SPRTs computed by using the triple point of {sup 20}Ne or {sup 22}Ne realized by the Ec3Ne20 cell or the Ec8Ne22 cell in place of the triple point of Ne for the defining fixed point of the ITS-90 are in good agreement with those realized on the basis of the ITS-90 at NMIJ within 0.03 mK, which is much smaller than the non-uniqueness and the sub-range inconsistency of SPRTs.

  7. [Cutaneous leishmaniasis in Turkey].

    PubMed

    Gürel, Mehmet Salih; Yeşilova, Yavuz; Olgen, M Kirami; Ozbel, Yusuf

    2012-01-01

    Cutaneous leishmaniasis (CL) caused by Leishmania protozoon parasites is a disease which is characterized by long-term nodulo-ulcerative lesions healing spontaneously with scarring. The disease has been well-known in Anatolia for centuries and has different names such as; Urfa boil, Antep boil, year boil, Halep boil, oriental sore and beauty scar. The causative agents are Leishmania tropica and Leishmania tropica/Leishmania infantum in Southeastern Anatolia and East Mediterranean, respectively. CL is a notifiable disease in Turkey and, according to the Ministry of Health official records, 46.003 new cases were reported between 1990 and 2010. Among those cases, 96% of them were reported from the Şanlıurfa, Adana, Osmaniye, Hatay, Diyarbakır, İçel and Kahramanmaraş provinces. Although 45% of cases were notified from Şanlıurfa in the past 20 years, its ratio is currently decreasing while other regions' ratios have been showing an increasing trend. Easier transportation between cities, increased travel migration of the population from rural areas to the peripheral suburbs with inadequate infrastructure and unhealthy housing are thought to be the main factors for spreading the disease from Southeastern Anatolia to other regions of Turkey. Lack of treatment of patients as reservoir hosts because of different reasons and ineffective and inadequate use of insecticides against vector sand flies have also played an important role in spreading the disease. Neglect of this disease by patients and health institutions can also be considered as other factors for the spreading. We believe that, after the strategic plan for leishmaniasis prepared by the Turkish Ministry of Health with the contribution of scientists in 2011 is put into practice, the control of the disease will be more effective.

  8. Petrologic evidence for a plutonic igneous origin of anorthositic norite clasts in 67955 and 77017

    NASA Technical Reports Server (NTRS)

    Ashwal, L. D.

    1975-01-01

    Clasts of anorthositic norite in 67955 and 77017, and several other samples, are suggested to represent material which crystallized from a silicate magma in a plutonic environment. Although no statement can be made regarding the ultimate origin of the parent melt, its composition was relatively felsic, starting within the primary field of crystallization of either plagioclase or spinel. The sequence of crystallization was: plagioclase (and/or spinel) olivine - low-Ca pyroxene - high-Ca pyroxene.

  9. 1.1 Ga K-rich alkaline plutonism in the SW Grenville Province

    NASA Astrophysics Data System (ADS)

    Corriveau, Louise; Heaman, Larry M.; Marcantonio, Franco; van Breemen, Otto

    1990-09-01

    U-Pb zircon and baddeleyite dating of six syenitic stocks establishes that the ultrapotassic, potassic alkaline and shoshonitic magmatism with island-arc affinities in the Central Metasedimentary Belt (CMB) of the southwestern Grenville Province, Canada took place between 1089 and 1076 Ma, along a 400-km-long, northeast-trending plutonic belt. These ages indicate that ultrapotassic rocks with arc affinities are not unique to the Phanerozoic. West to east emplacement ages along a northern and southern cross-section of this belt range from 1083±2 Ma (Kensington), through 1081±2 Ma (Lac Rouge) to 1076{-1/+3}Ma (Loranger) in the north, and from 1089{-3/+4}Ma (loon Lake) and 1088±2 Ma (Calabogie), to 1076±2 Ma (Westport) in the south. Although closely spaced in time, in detail these ages suggest a slight younging of this magmatic activity to the southeast. Integration of the geochronological data with the spatial extent and potassic character of the plutons shows that the K-rich alkaline suite is distinct from the nepheline-syenite belt of the Bancroft terrane and from the syenite-monzonite suite of the Frontenac terrane of the CMB, and it is considered to be a magmatic episode unique to the Elzevir terrane and its Gatineau segment. The timing and the postmetamorphic emplacement of these plutons indicate that the regional greenschist to granulite-facies metamorphism of the country rock (precise age unknown) is older than 1089 Ma throughout the entire Elzevir terrane. The potassic magmatism is interpreted as the initiation of the 1090 1050 Ma Ottawan Orogeny in the Elzevir terrane; thus, the regional metamorphism in this terrane, previously assigned to the Ottawan Orogeny, is an earlier event. The contemporaneous emplacement of this postmetamorphic plutonic belt with Keweenawan volcanism is at variance with current tectonic models which consider the Keweenawan rift to be formed at the same time as regional metamorphism in the CMB.

  10. Structure and LA-ICP-MS zircon U-Pb dating of syntectonic plutons emplaced in the Pan-African Banyo-Tcholliré shear zone (central north Cameroon)

    NASA Astrophysics Data System (ADS)

    Nomo, Emmanuel Negue; Tchameni, Rigobert; Vanderhaeghe, Olivier; Sun, Fenguye; Barbey, Pierre; Tekoum, Léontine; Tchunte, Periclex Martial Fosso; Eglinger, Aurélien; Fouotsa, Nicaise Alliance Saha

    2017-07-01

    The Tcholliré massif, in central north Cameroon, consists of elongated granite plutons that crop out along the Pan-African Tcholliré-Banyo shear zone (TBSZ), a potential suture zone within the Central Africa Orogenic Belt. New structural and geochronological data on these granites constrain the tectonic regime and timing of the TBSZ. The plutons consist of syntectonic granites and granodiorite containing dioritic mafic enclaves. They show an S2 sub-vertical foliation, that trends NE-SW to ENE-WSW. The related L2 lineation is subhorizontal to shallowly plunging to the SW or NE. Kinematic indicators such as asymmetric folds, sigmoidal-shape boudins, shear bands, imbricated feldspar phenocrysts along antithetic fractures point to a sinistral sense of shear. Microstructural analysis shows that structures are acquired from the submagmatic to the low temperature solid state suggesting progressive deformation of the magma during its emplacement, crystallization and cooling. U-Pb zircon dating on this massif yields emplacement ages of 719 ± 12 Ma for the biotite-amphibole granite and muscovite granite, 652.2 ± 5.4 Ma for the biotite-granite and 632 ± 13 Ma for the leucogranite. These geochronological data show in addition, Palaeoproterozoic inherited ages of 1631 ± 30 Ma on the leucogranites of this massif, and point to a Palaeoproterozoic contribution in their genesis. The range of ages (ca. 87 Ma) points to the timing of syntectonic emplacement of felsic magmas coeval with sinistral transpression along the TBSZ during the Pan-African orogeny. These results show that the TBSZ has recorded prolonged deformation associated with crustal magmatism between the Palaeoproterozoic Adamawa-Yadé domain to the southeast and the Sinassi-Mayo Kebbi Neoproterozoic magmatic arc to the Northwest.

  11. Structure, age and mode of emplacement of the Hercynian Bordères-Louron pluton (Central Pyrenees, France)

    NASA Astrophysics Data System (ADS)

    Gleizes, Gérard; Crevon, Gérard; Asrat, Asfawossen; Barbey, Pierre

    2006-11-01

    The Hercynian Bordères-Louron pluton (20 km2) in the Central Pyrenees intrudes Devonian and Carboniferous metasediments. It shows a concentric zoning and consists of a significant proportion of (quartz) gabbros in its periphery, and of granodiorites, biotite monzogranites and biotite-muscovite monzogranites in its core. AMS study shows that the pluton corresponds to an elongated dome with a N100°E-trending axis. The anisotropy intensity Ppara% is high in the south and in the core of the pluton, whereas it is low in the north. The shape parameter T indicates that the fabric is strongly planar in a large central band oriented NW-SE, whereas it is strongly linear in the western and eastern tips of the pluton. These characteristics suggest that the Bordères-Louron pluton emplaced in two episodes: (1) intrusion of mafic magmas along a N100°E sill parallel to the regional foliation of the host metasediments; and (2) injection of three successive silicic batches (granodiorite, biotite monzogranite, two-micas monzogranite) which pushed aside the early mafic injections. In situ U-Pb dating of zircon grains indicates that the emplacement age of the biotite monzogranite is 309 ± 4 Ma, synchronous with the D 2 dextral transpressive event and close to the ages of the eastern Pyrenean plutons, may be slightly older.

  12. Geochemical evaluation of felsic plutonic rocks in the eastern and southeastern Arabian Shield, Kingdom of Saudi Arabia

    USGS Publications Warehouse

    Du Bray, E.A.; Elliott, James E.; Stoeser, D.B.

    1983-01-01

    In a geochemical evaluation of the eastern and southeastern Arabian Shield, which included collection of 696 rock samples and 694 pan concentrate samples, a province of tin-anomalous granitoid plutons was defined. Pan concentrates collected in and around these plutons were enriched in tin and tungsten relative to the concentrate population. Rock samples of these leucocratic, muscovite-bearing, peraluminous granites contained anomalously high concentrations of lithium, fluorine, beryllium, lead, rubidium, niobium, yttrium, tin, bismuth, silver, and tungsten. Ten tin-anomalous plutons were located in the study area. The plutons are typically small, less than 10 km2 in areal extent, and circular to elliptical in plan view. The resource potential of these latest Proterozoic plutons has not been established; economically exploitable concentrations of tin, tungsten, molybdenum, or zinc may be present, and followup studies are warranted. Further, two of the plutons are characterized by higher than normal total-count radioactivity and have potential for uranium, thorium, or rare-earth element deposits.

  13. Erupted frothy xenoliths may explain lack of country-rock fragments in plutons

    PubMed Central

    Burchardt, Steffi; Troll, Valentin R.; Schmeling, Harro; Koyi, Hemin; Blythe, Lara

    2016-01-01

    Magmatic stoping is discussed to be a main mechanism of magma emplacement. As a consequence of stoping, abundant country-rock fragments should occur within, and at the bottom of, magma reservoirs as “xenolith graveyards”, or become assimilated. However, the common absence of sufficient amounts of both xenoliths and crustal contamination have led to intense controversy about the efficiency of stoping. Here, we present new evidence that may explain the absence of abundant country-rock fragments in plutons. We report on vesiculated crustal xenoliths in volcanic rocks that experienced devolatilisation during heating and partial melting when entrained in magma. We hypothesise that the consequential inflation and density decrease of the xenoliths allowed them to rise and become erupted instead of being preserved in the plutonic record. Our thermomechanical simulations of this process demonstrate that early-stage xenolith sinking can be followed by the rise of a heated, partially-molten xenolith towards the top of the reservoir. There, remnants may disintegrate and mix with resident magma or erupt. Shallow-crustal plutons emplaced into hydrous country rocks may therefore not necessarily contain evidence of the true amount of magmatic stoping during their emplacement. Further studies are needed to quantify the importance of frothy xenolith in removing stoped material. PMID:27804996

  14. Spinel-group minerals in rocks of the Khibiny alkaline pluton, Kola Peninsula

    NASA Astrophysics Data System (ADS)

    Ivanyuk, G. Yu.; Pakhomovsky, Ya. A.; Konopleva, N. G.; Yakovenchuk, V. N.; Men'shikov, Yu. P.; Mikhailova, Yu. A.

    2007-12-01

    Seven spinel-group minerals in various geological settings have been revealed in the rocks of the Khibiny pluton. Hercynite, gahnite, and vuorelainenite occur only in xenoliths of hornfels after volcanic and sedimentary rocks, whereas spinel and magnesiochromite occur in alkaline ultramafic rocks of dike series. Franklinite has been discovered in a low-temperature hydrothermal vein. Ubiquitous magnetite is abundant in foyaite, foidolites, alkaline ultrabasic rocks, and pegmatite and hydrothermal veins and may even be the main mineral in some foidolite varieties. The spinel-group minerals are characterized by various chemical compositions due to the fractionation of nepheline syenites resulting in formation of the Main ring of foidolites and apatite-nepheline ore. Like most other minerals found throughout the pluton, magnetite is characterized by variation in the chemical composition along the radial line from the contact with country Proterozoic volcanic rocks to the geometric center of the pluton. Toward the center, the total Ti and Mn contents in magnetite increase from 5 15 up to 40 at %.

  15. Multiple mafic and felsic magma interaction as exhibited in the Dartmouth Pluton, Avalon zone, southeastern Massachusetts

    SciTech Connect

    Hamidzada, N.A.; Hermes, O.D.; Murray, D.P. . Dept. of Geology)

    1993-03-01

    Dioritic to quartz monzonitic rocks of the Dartmouth Pluton exhibit excellently preserved, diverse features produced by mingling and mixing of mafic and felsic magma during multiple events. The related mafic and hybridized intermediate composition rocks occur both as discrete outcrop-sized masses or as enclaves within quartz monzonite or early-stage mixed rocks. Enclaves are rounded, lack chilled margins, and in some cases exhibit cuspate margins; they range in size from 1m--<1cm. Outcrops dominated by dioritic rock consist of well developed mafic pillows with inter-pillow infillings of hybridized rock that had been subjected to magma mixing during or prior to the final mingling process. Dioritic rocks are fine-grained with sparse plagioclase phenocrysts; they contain small, darker-colored enclaves indicative of preceding magma interaction. Major and trace element variation diagrams for this suite of rocks exhibit general linear trends consistent with mixing processes. Overall, field, petrographic, and geochemical relationships in the Dartmouth Pluton demonstrate: (1) widespread mingling of mafic and felsic magma, (2) variable degrees of mafic and felsic magma mixing, and (3) multiple and repeated episodes of mafic and felsic magma interaction. Significantly, some spatially associated dioritic and granitic rocks, including a 595 Ma alkali feldspar granite formerly considered to be part of the Dartmount Pluton, are geochemically related. Field mapping demonstrates that rocks of the mixed suite are intrusive into these rocks, thus establishing a maximum age, but raising the questions that the suite may be considerably younger.

  16. The mineralogy of the Snake Creek-Williams Canyon pluton, southern Snake Range, Nevada

    USGS Publications Warehouse

    Lee, Donald Edward; Christiansen, Eric H.

    1983-01-01

    The Snake Creek-Williams Canyon pluton of the southern Snake Range crops out over an area of about 30 km 2, about 60 km southeast of Ely, Nev. This Jurassic intrusion displays large and systematic chemical and mineralogical zonation over a horizontal distance of 5 km. Major-element variations compare closely with Dalyls average andesite-dacite-rhyolite over an SiO 2 range of 63 to 76 percent. For various reasons it was originally thought that assimilation played a dominant role in development of the Snake Creek-Williams Canyon pluton. However, based on modeling of more recently obtained trace element and isotopic data, we have concluded that the zonation is the result of in-situ fractional crystallization, with little assimilation at the level of crystallization. This report summarizes data available for each of the mineral species present in the zoned intrusion. Special attention has been paid to trends that might relate to the variation in the chemical petrology of the pluton.

  17. Intrusive rocks and plutonic belts of southeastern Alaska, U.S.A.

    USGS Publications Warehouse

    Brew, David A.; Morrell, Robert P.; Roddick, J.A.

    1983-01-01

    About 30 percent of the 175,000-km2 area of southeastern Alaska is underlain by intrusive igneous rocks. Compilation of available information on the distribution, composition, and ages of these rocks indicates the presence of six major and six minor plutonic belts. From west to east, the major belts are: the Fairweather-Baranof belt of early to mid-Tertiary granodiorite; the Muir-Chichagof belt of mid-Cretaceous tonalite and granodiorite; the Admiralty-Revillagigedo belt of porphyritic granodiorite, quartz diorite, and diorite of probable Cretaceous age; the Klukwan-Duke belt of concentrically zoned or Alaskan-type ultramafic-mafic plutons of mid-Cretaceous age within the Admiralty-Revillagigedo belt; the Coast Plutonic Complex sill belt of tonalite of unknown, but perhaps mid-Cretaceous, age; and the Coast Plutonic Complex belt I of early to mid-Tertiary granodiorite and quartz monzonite. The minor belts are distributed as follows: the Glacier Bay belt of Cretaceous and(or) Tertiary granodiorite, tonalite, and quartz diorite lies within the Fair-weather-Baranof belt; layered gabbro complexes of inferred mid-Tertiary age lie within and are probably related to the Fairweather-Baranof belt; the Chilkat-Chichagof belt of Jurassic granodiorite and tonalite lies within the Muir-Chichagof belt; the Sitkoh Bay alkaline, the Kendrick Bay pyroxenite to quartz monzonite, and the Annette and Cape Fox trondhjemite plutons, all interpreted to be of Ordovician(?) age, together form the crude southern southeastern Alaska belt within the Muir-Chichagof belt; the Kuiu-Etolin mid-Tertiary belt of volcanic and plutonic rocks extends from the Muir-Chichagof belt eastward into the Admiralty-Revillagigedo belt; and the Behm Canal belt of mid- to late Tertiary granite lies within and next to Coast Plutonic Complex belt II. In addition, scattered mafic-ultramafic bodies occur within the Fairweather-Baranof, Muir-Chichagof, and Coast Plutonic Complex belts I and II. Palinspastic

  18. Erupted frothy xenoliths may explain lack of country-rock fragments in plutons.

    PubMed

    Burchardt, Steffi; Troll, Valentin R; Schmeling, Harro; Koyi, Hemin; Blythe, Lara

    2016-11-02

    Magmatic stoping is discussed to be a main mechanism of magma emplacement. As a consequence of stoping, abundant country-rock fragments should occur within, and at the bottom of, magma reservoirs as "xenolith graveyards", or become assimilated. However, the common absence of sufficient amounts of both xenoliths and crustal contamination have led to intense controversy about the efficiency of stoping. Here, we present new evidence that may explain the absence of abundant country-rock fragments in plutons. We report on vesiculated crustal xenoliths in volcanic rocks that experienced devolatilisation during heating and partial melting when entrained in magma. We hypothesise that the consequential inflation and density decrease of the xenoliths allowed them to rise and become erupted instead of being preserved in the plutonic record. Our thermomechanical simulations of this process demonstrate that early-stage xenolith sinking can be followed by the rise of a heated, partially-molten xenolith towards the top of the reservoir. There, remnants may disintegrate and mix with resident magma or erupt. Shallow-crustal plutons emplaced into hydrous country rocks may therefore not necessarily contain evidence of the true amount of magmatic stoping during their emplacement. Further studies are needed to quantify the importance of frothy xenolith in removing stoped material.

  19. Erupted frothy xenoliths may explain lack of country-rock fragments in plutons

    NASA Astrophysics Data System (ADS)

    Burchardt, Steffi; Troll, Valentin R.; Schmeling, Harro; Koyi, Hemin; Blythe, Lara

    2016-11-01

    Magmatic stoping is discussed to be a main mechanism of magma emplacement. As a consequence of stoping, abundant country-rock fragments should occur within, and at the bottom of, magma reservoirs as “xenolith graveyards”, or become assimilated. However, the common absence of sufficient amounts of both xenoliths and crustal contamination have led to intense controversy about the efficiency of stoping. Here, we present new evidence that may explain the absence of abundant country-rock fragments in plutons. We report on vesiculated crustal xenoliths in volcanic rocks that experienced devolatilisation during heating and partial melting when entrained in magma. We hypothesise that the consequential inflation and density decrease of the xenoliths allowed them to rise and become erupted instead of being preserved in the plutonic record. Our thermomechanical simulations of this process demonstrate that early-stage xenolith sinking can be followed by the rise of a heated, partially-molten xenolith towards the top of the reservoir. There, remnants may disintegrate and mix with resident magma or erupt. Shallow-crustal plutons emplaced into hydrous country rocks may therefore not necessarily contain evidence of the true amount of magmatic stoping during their emplacement. Further studies are needed to quantify the importance of frothy xenolith in removing stoped material.

  20. Geochronometry and thermochronometry using nucleogenic 21Ne

    NASA Astrophysics Data System (ADS)

    Farley, K. A.; Flowers, R. M.; Vasconcelos, P. M.

    2011-12-01

    Nucleogenic 21Ne is produced by the interaction of α particles with 18O. While the cross section for this reaction is small (about 1 α in 25 million participates), 21Ne excesses can be measured in a variety of minerals, forming the basis of (U-Th)/Ne chronometry. Previous work focused on thermochronometry of U, Th rich trace minerals. For example, Gautheron et al. (2005) studied nucleogenic Ne in zircon and inferred a closure temperature of ~400 C. Our preliminary Ne diffusion data on Durango apatite suggests Tc ~280 C. The method can also be applied to phases with much lower U and Th contents in which the 21Ne is measurable on old and/or large specimens. We have obtained (U-Th)/Ne ages on ~50 mg samples of iron oxides with ppm-level U and Th and Ne ages of 50-500 Ma. For example, hematites from the Neoproterozoic (?) Urucum BIF yield a 21Ne age of 470 ± 15 Ma and post-depositional hydrothermal hematite in the Redwall Limestone in the Grand Canyon yields an age of 251 ± 11 Ma. In both cases (U-Th)/He ages are more than 100 Myr younger. Outstanding issues with this method are 1) the diffusivity of Ne - are we measuring cooling ages or formation ages?, 2) how well known is the production rate?, and 3) in what minerals is the air component sufficiently small to permit precision measurements of 21Ne excesses?

  1. The Study to Improve Tsunami Preparedness Education in Turkey

    NASA Astrophysics Data System (ADS)

    Sakamoto, Mayumi; Tanırcan, Gülüm; Kaneda, Yoshiyuki; Puskulcu, Seyhun; Kumamoto, Kunihiko

    2016-04-01

    Compared to its long history on disastrous earthquakes, disaster education history in Turkey is rather short. It has just started with an initiative of Disaster Preparedness Education Unit of Bogazici University (BU/DPEU) after 1999 Kocaeli Earthquake. Training modules and materials on disaster preparedness were prepared both for students, teachers and community. Regarding to the school education, the Ministry of National Education (MoNE) reformed their education plan in 2003, and disaster education became one of eight focused components for primary-middle education. In 2011-2014 MoNE had conducted "School-based Disaster Education Project" in collaboration with Japan International Cooperation Agency (JICA). The majority of the school education materials focus more on earthquake and there are very few education programs on tsunami. Within the MarDiM (Earthquake and Tsunami Disaster Mitigation in the Marmara Region and Disaster Education in Turkey) project between Turkey and Japan a multidisciplinary engineering research as well as development of disaster education, tsunami education booklet and video were newly developed in 2015. In order to investigate students' knowledge natural disasters and disaster preparedness with focus on tsunami, a questionnaire based survey was conducted. The survey aims to clarify following questions: 1) how students obtain natural disaster information, 2) how students prepare for natural disaster, 3) knowledge on tsunami (hazard mechanism, evacuation behavior, historical disaster). The study was conducted by BU/DPEU in 2015 and 375 students answered the questionnaire. Results showed that students have more interest on earthquake, flood, tsunami and landslide followed it. Most students have heard about tsunami and the school is a key resource of their information. They know relatively well about tsunami mechanism, however, they have less knowledge on tsunami evacuation behavior and tsunami history in Turkey. In order to let students have

  2. Isotopic Fractionation of 20Ne, 21Ne, and 22Ne in a Simulated Thermal Gradient

    NASA Astrophysics Data System (ADS)

    Jester, B.; Dominguez, G.

    2014-12-01

    Computer simulations allow for the analysis of the thermodynamic properties of systems which are difficult or impossible to do experimentally. Isotopic fractionation in thermal gradients is an example of a system which is not fully understood but could provide background for understanding variations in fractionations like those observed for noble gases in terrestrial and extraterrestrial material. Using a recently developed molecular dynamics simulation focused on the accuracy of the simulated physics, the isotopic fractionation of Neon in a thermal gradient was analyzed in order to provide a correlation between the fractionation and the experimental system's properties. Various ratios of isotopes 20Ne, 21Ne, and 22Ne were simulated in a thermal gradient ranging from 218 K to 233 K for a variety of time scales. Data was collected for various configurations including box sizes on the order of 1 nm to 100 μm. The simulated thermal conductivity was determined and compared with known values. The analysis indicates that the dimensions of the box heavily influence the magnitude of the isotopic fractionation in the thermal gradient.

  3. Distinctly different parental magmas for plutons and lavas in the central Aleutian arc

    NASA Astrophysics Data System (ADS)

    Cai, Y.; Rioux, M. E.; Kelemen, P. B.; Goldstein, S. L.; Bolge, L.; Kylander-Clark, A. R.

    2014-12-01

    While it is generally agreed that continental crust is generated by arc magmatism, average arc lavas are basaltic while the bulk continental crust is andesitic, and this has led to many models for secondary reprocessing of the arc crust in order to form continental crust. We report new data on calc-alkaline plutons in the central Aleutians showing that they have distinctly different sources compared to Holocene tholeiitic lavas. Therefore the lavas are not representative of the net magmatic transfer from the mantle into the arc crust. Eocene to Miocene (9-39 Ma) intermediate to felsic plutonic rocks from the central Aleutian arc show higher SiO2 at a given Mg#, higher ɛNd- and ɛHf-values, and lower Pb isotope ratios than Holocene volcanic rocks from the same region. Instead, the plutonic rocks resemble volcanics from the western Aleutians isotopically, and have chemical compositions similar to bulk continental crust. These data could reflect temporal variation of Aleutian magma source compositions, from Eocene-Miocene "isotopically depleted" and predominantly calc-alkaline to Holocene "isotopically enriched" and predominantly tholeiitic. Alternatively, they may reflect different transport and emplacement processes for the magmas that form plutons and lavas: calc-alkaline magmas with higher Si content and high viscosity may preferentially form plutons, perhaps after extensive mid-crustal degassing of initially high water contents. The latter case implies that the upper and middle arc crust is more like the calc-alkaline bulk composition of the continental crust than the lavas alone. Crustal reprocessing mechanisms that preserve upper and middle arc crust, while removing lower arc crust, can account for the genesis and evolution of continental crust. Since gabbroic lower arc crust extends from ca 20-40 km depth, and is density stable over most of this depth range, "delamination" of dense lithologies [1] may not be sufficient to accomplish this. Alternatively

  4. From Migmatites to Plutons: Power Law Relationships in the Evolution of Magmatic Bodies

    NASA Astrophysics Data System (ADS)

    Soesoo, Alvar; Bons, Paul D.

    2015-07-01

    Magma is generated by partial melting from micrometre-scale droplets at the source and may accumulate to form >100 km-scale plutons. Magma accumulation thus spans well over ten orders of magnitude in scale. Here we provide measurements of migmatitic leucosomes and granitic veins in drill cores from the Estonian Proterozoic basement and outcrops at Masku in SW Finland and Montemor-o-Novo, central Portugal. Despite the differences in size and number of measured leucosomes and magmatic veins, differences in host rock types and metamorphic grades, the cumulative width distribution of the studied magmatic leucosomes/veins follows a power law with exponents usually between 0.7 and 1.8. Published maps of the SE Australian Lachlan Fold Belt were used to investigate the distribution of granitoid pluton sizes. The granites occupy ca. 22 % of the 2.6 × 105 km2 area. The cumulative pluton area distributions show good power law distributions with exponents between 0.6 and 0.8 depending on pluton area group. Using the self-affine nature of pluton shapes, it is possible to estimate the total volume of magma that was expelled from the source in the 2.6 × 105 km2 map area, giving an estimated 0.8 km3 of magma per km2. It has been suggested in the literature that magma batches in the source merge to form ever-bigger batches in a self-organized way. This leads to a power law for the cumulative distribution of magma volumes, with an exponent m V between 1 for inefficient melt extraction, and 2/3 for maximum accumulation efficiency as most of the volume resides in the largest batches that can escape from the source. If m V ≥ 1, the mass of the magma is dominated by small batches; in case m = 2/3, about 50 % of all magma in the system is placed in a single largest batch. Our observations support the model that the crust develops a self-organized critical state during magma generation. In this state, magma batches accumulate in a non-continuous, step-wise manner to form ever

  5. Cooling and exhumation of the Rieserferner Pluton (Eastern Alps, Italy/Austria)

    NASA Astrophysics Data System (ADS)

    Steenken, André; Siegesmund, Siegfried; Heinrichs, Till; Fügenschuh, Bernhard

    2002-03-01

    The Defereggen-Antholz-Vals (DAV) Line marks the southern border of alpine greenschist facies metamorphism within the Austroalpine basement to the south of the western Tauern window. During the Oligocene sinistral-strike slip, coeval with vertical displacement, was accompanied by the syntectonic emplacement of the Rieserferner Pluton along the north side of the fault. To the north of the DAV Line Rb/Sr as well as K/Ar-biotite cooling ages continuously increase from 16 Ma at the Rensen Pluton in the west to 30 Ma at the eastern end of the Rieserferner Pluton. Similar trends are apparent from zircon and apatite fission-track data, which increase eastward from 19 to 29 Ma, and 13 to 16 Ma, respectively. Low cooling rates allow a direct transformation into exhumation rates assuming an average geothermal gradient of 28 °C km-1. The resulting exhumation rates of less than 1 mm year-1 do not affect the depth of isotherms in a geologically significant manner. Hence, variable cooling rates within the basement north of the DAV Line are a result of differential exhumation of individual blocks. High exhumation rates bracketed between the intrusion age of the Rieserferner Pluton at 31+/-3 Ma and the apatite partial annealing zone (PAZ) range between 0.4 and 0.6 mm year-1, whereas final exposure takes place at reduced exhumation rates of 0.2 mm year-1. East-side-down tilting of the block north of the DAV Line, as indicated by variations in exhumation rates, strongly affects the western part of the area studied between the Rensen and the Central Rieserferner Pluton whereas, further east, block rotation becomes less important. A total difference in exhumation of about 2.2 km corresponding to 5° tilting between the Western and Eastern Rieserferner, as indicated by K/Ar-biotite and zircon fission-track data, occurred before going through the PAZ for apatite fission-tracks. Furthermore, the significance of the cooling ages, especially for biotite, is tested by calculating a finite

  6. Development of modal layering in granites: a case study from the Carna Pluton, Connemara, Ireland

    NASA Astrophysics Data System (ADS)

    McKenzie, Kirsty; McCarthy, William; Hunt, Emma

    2016-04-01

    Modal layering in igneous rocks uniquely record dynamic processes operating in magma chambers and also host a large proportion of Earth's strategic mineral deposits. This research investigates the origin of biotite modal layering and primary pseudo-sedimentary structures in felsic magmas, by using a combination of Crystal Size Distribution (CSD) analysis and Electron Probe Microanalysis (EPMA) to determine the mechanisms responsible for the development of these structures in the Carna Pluton, Connemara, Ireland. The Carna Pluton is a composite granodiorite intrusion and is one of five plutons comprising the Galway Granite Complex (425 - 380 Ma). Prominent 30 cm thick modal layers are defined by sharp basal contacts to a biotite-rich (20%) granite, which grades upward over 10 cm into biotite-poor, alkali-feldspar megacrystic granite. The layering strikes parallel to, and dips 30-60° N toward the external pluton contact. Pseudo-sedimentary structures (cross-bedding, flame structures, slumping and crystal graded bedding) are observed within these layers. Petrographic observations indicate the layers contain euhedral biotite and fresh undeformed quartz and feldspar. Throughout the pluton, alkali-feldspar phenocrysts define a foliation that is sub-parallel to the strike of biotite modal layers. Together these observations indicate that the intrusion's concentric foliation, biotite layers and associated structures formed in the magmatic state and due to a complex interaction between magma flow and crystallisation processes. Biotite CSDs (>250 crystals per sample) were determined for nine samples across three biotite-rich layers in a single unit. Preliminary CSD results suggest biotite within basal contacts accumulated via fractional crystallisation within an upward-growing crystal pile, likely reflecting the yield strength of the magma as a limiting factor to gravitational settling of biotite. This is supported by the abrupt decrease in mean biotite crystal size across

  7. Thermochronology and Cooling Histories of Intrusive Suites: Implications for Incremental Pluton Assembly

    NASA Astrophysics Data System (ADS)

    Davis, J.; Coleman, D.; Heizler, M.

    2007-12-01

    Debate persists about the timescales and mechanisms of pluton emplacement and batholith formation. An understanding of whether plutons accumulate as large masses of magma or as an incremental series of pulses, in which the active magma body is small relative to the final pluton, is important for understanding the relationship between volcanoes and plutons. If volcanic eruptions < 1000 km3 are the most common size and large ignimbrites are rare, it follows that most plutons should record accumulations of small volumes of melt that were emplaced over long time intervals (millions to tens of millions of years) and therefore preserve predictable, protracted thermal histories. Modeling predicts observable differences in thermal histories of plutons and their aureoles that can be tested through thermochronology. Application of multiple chronometers (zircon and titanite U-Pb TIMS; hornblende, biotite, and K-feldspar 40Ar/39Ar; zircon and titanite (U-Th)/He) combined with K-feldspar multiple diffusion domain (MDD) modeling were used to determine the thermal history and to calibrate thermal models of two eastern California, Sierra Nevada batholith intrusive suites; the dike-like John Muir Intrusive Suite (JMIS) and the laccolithic Mt. Whitney Intrusive Suite (MWIS), and their wall rocks. Preliminary results of (U-Th)/He zircon data from the JMIS and its wall rock (the Tinemaha granodiorite) show a tight cluster of dates ranging from 75.6 to 70.4 Ma. The JMIS is thought to be mesozonal (8 to 11 km) and these data are interpreted as resulting from exhumation and additional 40Ar/39Ar data are required to determine if the thermal history reflects incremental intrusions. In contrast to the JMIS, preliminary (U-Th)/He zircon data from the MWIS and its wall rock (the Bullfrog pluton) show a wide range in dates ranging from 91.4 to 74.6 Ma that are interpreted to reflect reheating events. Amphibole 40Ar/39Ar inverse isochron dates, K- feldspar age spectra, and (U-Th)/He zircon data

  8. Life Satisfaction and Happiness in Turkey

    ERIC Educational Resources Information Center

    Selim, Sibel

    2008-01-01

    This research aims to investigate life satisfaction and happiness in Turkey. It extends the previous researches on subjective well-being (SWB) for Turkey by considering both happiness and life satisfaction. The previous researches for Turkey are local studies, and their findings cannot be generalized to the population of Turkish society. Given…

  9. Time's Up, Turkey--Pop-Up Thermometers

    ERIC Educational Resources Information Center

    Moyer, Richard; Everett, Susan

    2009-01-01

    Meat thermometers can be awkward to use in terms of placement and avoidance of bones. Because of these problems, each year 30 million Thanksgiving turkeys have a built-in thermometer that pops up when the turkey is properly cooked. Turkey timers are an example of how engineering solved a common, everyday problem. The following 5E learning cycle…

  10. Exhumation of food by turkey vulture

    Treesearch

    Harvey R. Smith; Richard M. DeGraaf; Richard S. Miller

    2002-01-01

    The success of Turkey Vultures (Cathartes aura) as forest scavengers is largely due to their highly developed sense of smell (Owre and Nothington 1961). Stager (1964) conducted a set of experiments with ethyl mercaptan which confirmed the ability of Turkey Vultures to locate odors when no visible object was associated with them. Turkey Vultures fly...

  11. An overview of tumorous diseases of turkeys

    USDA-ARS?s Scientific Manuscript database

    This overview is primarily aimed at addressing various aspects of virus-induced tumorous diseases of turkeys including review of current methods for diagnosis and control of these diseases of turkeys. Virus-induced tumorous diseases of turkeys are caused primarily by retroviruses, namely reticuloend...

  12. Tumorous diseases of turkeys - an update

    USDA-ARS?s Scientific Manuscript database

    This update is primarily focused on addressing various aspects of virus-induced tumorous diseases of turkeys including review of current methods for diagnosis and control of these diseases of turkeys. Virus-induced tumorous diseases of turkeys are caused primarily by retroviruses, namely reticuloend...

  13. Turkey Masquerade. An Idea Worth Trying.

    ERIC Educational Resources Information Center

    Wales, Andrew

    2000-01-01

    Discusses the importance of planning for art projects by first producing sketches and then selecting the best sketch. Illustrates this by describing an activity used with fifth-grade students in which they make cut-paper collage turkeys and turkey disguises. Lists possible turkey disguises. (CMK)

  14. Turkey: Reviews of National Policies for Education.

    ERIC Educational Resources Information Center

    Organisation for Economic Cooperation and Development, Paris (France).

    The first of three parts of this review of Turkey's educational system and national educational policies, the examiner's report, begins by singling out essential features of modern Turkey that affect the provision of education and to which the system is having to respond. These include Turkey's unique geographic situation, its continuing devotion…

  15. Time's Up, Turkey--Pop-Up Thermometers

    ERIC Educational Resources Information Center

    Moyer, Richard; Everett, Susan

    2009-01-01

    Meat thermometers can be awkward to use in terms of placement and avoidance of bones. Because of these problems, each year 30 million Thanksgiving turkeys have a built-in thermometer that pops up when the turkey is properly cooked. Turkey timers are an example of how engineering solved a common, everyday problem. The following 5E learning cycle…

  16. Life Satisfaction and Happiness in Turkey

    ERIC Educational Resources Information Center

    Selim, Sibel

    2008-01-01

    This research aims to investigate life satisfaction and happiness in Turkey. It extends the previous researches on subjective well-being (SWB) for Turkey by considering both happiness and life satisfaction. The previous researches for Turkey are local studies, and their findings cannot be generalized to the population of Turkish society. Given…

  17. Intrusive rocks of the Holden and Lucerne quadrangles, Washington; the relation of depth zones, composition, textures, and emplacement of plutons

    USGS Publications Warehouse

    Cater, Fred W.

    1982-01-01

    The core of the northern Cascade Range in Washington consists of Precambrian and upper Paleozoic metamorphic rocks cut by numerous plutons, ranging in age from early Triassic to Miocene. The older plutons have been eroded to catazonal depths, whereas subvolcanic rocks are exposed in the youngest plutons. The Holden and Lucerne quadrangles span a -sizeable and representative part of this core. The oldest of the formations mapped in these quadrangles is the Swakane Biotite Gneiss, which was shown on the quadrangle maps as Cretaceous and older in age. The Swakane has yielded a middle Paleozoic metamorphic age, and also contains evidence of zircon inherited from some parent material more than 1,650 m.y. old. In this report, the Swakane is assigned an early Paleozoic or older age. It consists mostly of biotite gneiss, but interlayered with it are scattered layers and lenses of hornblende schist and gneiss, clinozoisite-epidote gneiss, and quartzite. Thickness of the Swakane is many thousands of meters, and the base is not exposed. The biotite gneiss is probably derived from a pile of siliceous volcanic rocks containing scattered sedimentary beds and basalt flows. Overlying the Swakane is a thick sequence of eugeosynclinal upper Paleozoic rocks metamorphosed to amphibolite grade. The sequence includes quartzite and thin layers of marble, hornblende schist and gneiss, graphitic schist, and smaller amounts of schist and gneiss of widely varying compositions. The layers have been tightly and complexly folded, and, in places, probably had been thrust over the overlying Swakane prior to metamorphism. Youngest of the supracrustal rocks in the area are shale, arkosic sandstone, and conglomerate of the Paleocene Swauk Formation. These rocks are preserved in the Chiwaukum graben, a major structural element of the region. Of uncertain age, but possibly as old as any of the intrusive rocks in the area, are small masses of ultramafic rocks, now almost completely altered to

  18. Multiple intrusive events in the formation of granite plutons: Evidence from the Lee Vining Diorite, eastern California

    SciTech Connect

    McCarthy, T.C.; Furman, T. . Dept. of Environmental Sciences); Reid, J.B. Jr. . School of Natural Sciences)

    1993-03-01

    The Cretaceous Lee Vining Diorite (eastern Sierra Nevada) preserves important field, petrographic and geochemical evidence for complex intrusive events in a mesozonal magma body. The pluton comprises primarily light grey unfoliated quartz diorite, with color index varying between 10--50. A 1,400 m transect across the pluton yielded samples of (1) mafic diorite from a 300 m thick sill, (2) disaggregated basaltic dikes, (3) rounded mafic inclusions and (4) rounded hornblende-cumulate inclusions in addition to (5) quartz diorite of variable texture and color index. Internal intrusive contacts are observed in several places; the upper contact of the sill is indistinct locally, suggesting a low thermal contrast with host quartz diorite at the time of intrusion. Textural analysis of plagioclase crystals form throughout the pluton indicates a history of pervasive magma mixing. In each thin section, 20--90% of the plagioclase crystals are pitted or corroded, and up to 50% of these crystals are also completely zoned. Disequilibrium plagioclase crystals are not preferentially associated with mafic inclusion, but are distributed randomly within the pluton. Major and trace element analyses of over 40 samples taken along the transect show variations that cannot be explained through simple magma mixing or through progressive crystallization of a single magma body. The pluton is not zoned geochemically, but rather comprises small regions (< 200 m across) of uniform composition that are juxtaposed randomly. Chemical variations across the pluton likely result from both missing of small magma batches and fractional crystallization of mixed magmas. This interpretation is consistent with field and textural requirements for multiple intrusive episodes in the formation of the diorite pluton.

  19. The Middle Fork Plutonic Complex: A plutonic association of coeval peralkaline and metaluminous magmas in the north-central Alaska Range

    SciTech Connect

    Solie, D.N.

    1988-01-01

    The 57 m.y. Middle Fork Plutonic Complex (MFPC) intrudes Paleozoic metasedimentary rocks south of the Farewell Fault zone in the north-central Alaska Range. Though spatially related to the late Cretaceous - Early Tertiary subduction-related Alaska Range batholith, MFPC is more characteristic of an extensional or anorogenic setting. A swarm of basalt, hawaiite and rhyolite dikes east of the complex intruded, and was intruded by, the plutonic rocks. Approximately 30% of the exposed rock in the 125 km[sup 2] complex is hedenbergite - fayalite syenite, [approx equal]20% is peralkalin arfvedsonite-biotite alkali-feldspar granite (AF granite), and [le]20% is pyroxene-olivine-biotite gabbro. The rest is a mixed unit including clinopyroxene-biotite-amphibole diorite, and hornblende-biotite granite (HB granite). K-Ar and Rb-Sr radiometric dating of rock types shows that they are coeval. Their close spatial and temporal relationships led to complex magmatic interactions. Calculated initial [sup 87]Sr/[sup 86]Sr for gabbro and diorite group is around 0.705 to 0.706. HB granites are heterogeneous, but fall mostly around 0.707 to 0.708. Hypersolvus syenites and AF granites form an isochron with initial [sup 87]Sr/[sup 86]Sr of 0.70965. These groupings suggest that at least three different magmas formed the MFPC; scatter of isotopic data reflects mutual contamination and assimilation. Consanguinous hypersolvus syenite and AF granite mineralogy appears to be controlled by fluorine in the magma chamber. Eruptive stratigraphy, as predicted by intrusive history of MFPC, compares favorably with volcanic stratigraphies of peralkaline volcanic systems worldwide, and MFPC may be modelled as the root zone of a peralkaline volcanic system.

  20. Chaotic He-Ne laser

    NASA Astrophysics Data System (ADS)

    Kuusela, Tom A.

    2017-09-01

    A He-Ne laser is an example of a class A laser, which can be described by a single nonlinear differential equation of the complex electric field. This laser system has only one degree of freedom and is thus inherently stable. A He-Ne laser can be driven to the chaotic condition when a large fraction of the output beam is injected back to the laser. In practice, this can be done simply by adding an external mirror. In this situation, the laser system has infinite degrees of freedom and therefore it can have a chaotic attractor. We show the fundamental laser equations and perform elementary stability analysis. In experiments, the laser intensity variations are measured by a simple photodiode circuit. The laser output intensity time series is studied using nonlinear analysis tools which can be found freely on the internet. The results show that the laser system with feedback has an attractor of a reasonably high dimension and that the maximal Lyapunov exponent is positive, which is clear evidence of chaotic behaviour. The experimental setup and analysis steps are so simple that the studies can even be implemented in the undergraduate physics laboratory.

  1. Magma Reservoirs from the Perspective of Supervolcanoes and Granitic Plutons: "Big Red Blobs" and "Balloons and Soda Straws" are Real

    NASA Astrophysics Data System (ADS)

    Christiansen, E. H.

    2016-12-01

    Simple models describing silicic magma reservoirs and their connections with volcanic rocks have been denigrated as "big red blobs" and "balloons-and-soda straws." Although these models are certainly generalized to convey complex relations, there are multiple reasons to accept the existence of large magma chambers and direct connections between volcanoes and plutonic rocks. These include:-Geophysical evidence (seismic, magnetotelluric, and geodetic) for the existence of large bodies of magma in the crust today. Magma is a mixture of liquids, solids, and fluids. It does not have to be melt rich, nor does it need to be mobile and eruptible; it just has to have melt present. -Eruptions of large volumes (>1,000 km3) of dacitic to rhyolitic magma and large collapse calderas (30-50 km across). -The thermal lifetimes of large bodies are extended by high recharge rates. Individual bodies of magma may exist for tens to hundreds of thousands of years.-Geochronological evidence that pluton lifetimes are similar to those of volcanic fields.-Evidence for incremental emplacement of a pluton is not evidence against the former existence of a large magma reservoir, but the natural consequence of ongoing replenishment and crystallization after eruptions cease. Thus, what might have been a large liquid-dominated system at the time of eruption of a large ignimbrite, is subsequently intruded by new batches of magma as it crystallizes and closes down. This destroys the evidence for a large red blob and creates a composite pluton. -Direct and indirect evidence connect plutons to large eruptions. This is shown by field relations, geochronology, as well as chemical, mineralogical, and isotopic similarities of volcanic and plutonic rocks. -Volcanic and plutonic differentiation patterns are very similar, but differ in some ways because cumulates are preserved in the plutonic record and because intrusions continue to differentiate (liquids separate from solids) until the last bit of liquid is

  2. Origin of reverse compositional and textural zoning in granite plutons by localized thermal overturn of stratified magma chambers

    NASA Astrophysics Data System (ADS)

    Trubač, Jakub; Janoušek, Vojtěch; Žák, Jiří; Somr, Michael; Kabele, Petr; Švancara, Jan; Gerdes, Axel; Žáčková, Eliška

    2017-04-01

    This study integrates gravimetry and thermal modelling with petrology, U-Th-Pb monazite and zircon geochronology and whole-rock geochemistry of the early Carboniferous Říčany Pluton, Bohemian Massif, in order to discuss the origin of compositional and textural zoning in granitic plutons and complex histories of horizontally stratified, multiply replenished magma chambers. The pluton consists of two coeval, nested biotite (-muscovite) granite facies: outer one, strongly porphyritic (SPm) and inner one, weakly porphyritic (WPc). Their contact is concealed but is likely gradational over several hundreds of meters. The two facies have nearly identical modal composition, are subaluminous to slightly peraluminous and geochemically evolved. Mafic microgranular enclaves, commonly associated with K-feldspar phenocryst patches, are abundant in the pluton center and indicate a repeated basic magma injection and its multistage interactions with the granitic magma and nearly solidified cumulates. Furthermore, the gravimetric data show that the nested pluton is only a small outcrop of a large anvil-like body reaching the depth of at least 14 km, where the pluton root is expected. Trace-element compositions reveal that the pluton is doubly reversely zoned. On the pluton scale, the outer SRG is geochemically more evolved than the inner WPc. On the scale of individual units, outward whole-rock geochemical variations within each facies (SPm, WPc) are compatible with fractional crystallization dominated by feldspars. The proposed genetic model invokes vertical overturn of a deeper, horizontally stratified anvil-shaped magma chamber. The overturn was driven by reactivation of resident felsic magma from the K-feldspar-rich crystal mush. The energy for the melt remobilization, extraction and subsequent ascent is thought to be provided by a long-lived thermal anomaly above the pluton feeding zone, enhanced by the multiple injections of hot basic magmas. In general, it is concluded

  3. Turkey vulture surveys in Cuba

    USGS Publications Warehouse

    Wotzkow, C.; Wiley, J.W.

    1988-01-01

    Turkey Vultures (Cathartes aura), were surveyed monthly in Cuba from March 1982-January 1983. A total of 25371 vultures were tallied in 7186 km (3.5 vultures/transect km) of roadside counting along main highways leading from the city of La Habana (northwestern Cuba) to the city of Las Tunas (southeast). Numbers of vultures counted declined substantially beyond 200 m from the transect road. Density of vultures observed within 200 m of the road along the transect route was 0.06/ha. Highest counts were obtained in March, April and June. Turkey Vulture flying activity was greatest during the periods 0900-1200 H and 1400-1700 H.

  4. Plutonism in the central part of the Sierra Nevada Batholith, California

    USGS Publications Warehouse

    Bateman, Paul C.

    1992-01-01

    The Sierra Nevada batholith comprises the plutonic rocks of Mesozoic age that underlie most of the Sierra Nevada, a magnificent mountain range that originated in the Cenozoic by the westward tilting of a huge block of the Earth's crust. Scattered intrusions west of the batholith in the western metamorphic belt of the Sierra Nevada and east of the Sierra Nevada in the Benton Range and the White and Inyo Mountains are satellitic to but not strictly parts of the Sierra Nevada batholith. Nevertheless, all the plutonic rocks are related in origin. The batholith lies along the west edge of the Paleozoic North American craton, and Paleozoic and early Mesozoic oceanic crust underlies its western margin. It was emplaced in strongly deformed but weakly metamorphosed strata ranging in age from Proterozoic to Cretaceous. Sedimentary rocks of Proterozoic and Paleozoic age crop out east of the batholith in the White and Inyo Mountains, and metamorphosed sedimentary and volcanic rocks of Paleozoic and Mesozoic age crop out west of the batholith in the western metamorphic belt. A few large and many small, generally elongate remnants of metamorphic rocks lie within the batholith. Sparse fossils from metasedimentary rocks and isotopic ages for metavolcanic rocks indicate that the metamorphic rocks in the remnants range in age from Early Cambrian to Early Cretaceous. Within the map area (the Mariposa 1 0 by 2 0 quadrangle), the bedding, cleavage, and axial surfaces of folds generally trend about N. 35 0 W., parallel to the long axis of the Sierra Nevada. The country rocks comprise strongly deformed but generally coherent sequences; however, some units in the western metamorphic belt may partly consist of melanges. Most sequences are in contact with other sequences, at least for short distances, but some sequences within the batholith are bounded on one or more sides by plutonic rocks. Proterozoic and Paleozoic sedimentary strata east of the Sierra Nevada and Paleozoic strata in

  5. Petrography and geochemistry of the Arroyo de la Virgen and Isla Mala plutons, southern Uruguay: Early proterozoic tectonic implications

    NASA Astrophysics Data System (ADS)

    Preciozzi, F.; Bourne, J. H.

    1992-10-01

    The Arroyo de la Virgen pluton (AVP) and the Isla Mala pluton (IMP) are relatively small zoned intrusions of Early Proterozoic age. Radiometric age determinations suggest that the IMP is a composite pluton. The composition of the AVP ranges from granodiorite to leucogranite, whereas that of the IMP ranges from hornblendite to leucogranite. Both intrusions feature hornblende (with relict clinopyroxene cores) and biotite as mafic minerals. Muscovite and garnet are present in the most evolved members of each suite. Development of secondary chlorite, epidote, and sericite is common. Quartz typically has undulose extinction. The plutons are massive except near the margins of the intrusion. Both intrusions feature a calc-alkaline chemistry, have peraluminous indices of approximately 1.0, and were emplaced at relatively high levels in the crust. Application of several tectonic discriminant diagrams suggests that the IMP formed in an active continental-margin type of tectonic environment, whereas the AVP is a subalkaline, post-orogenic pluton. The ages of the IMP leucogranite and the AVP are similar (2290 and 2225 Ma, respectively). The age of the IMP leucogranite represents the minimum reliable age of the principal metamorphic event in southern Uruguay. A number of small dikes were emplaced into both intrusions approximately 300 million years later and represent a distinct phase of intrusive activity in the region.

  6. Geochemistry of Mesozoic plutons, southern Death Valley region, California: Insights into the origin of Cordilleran interior magmatism

    USGS Publications Warehouse

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

    2002-01-01

    Mesozoic granitoid plutons in the southern Death Valley region of southeastern California reveal substantial compositional and isotopic diversity for Mesozoic magmatism in the southwestern US Cordillera. Jurassic plutons of the region are mainly calc-alkaline mafic granodiorites with ??Ndi of -5 to -16, 87Sr/86Sri of 0.707-0.726, and 206Pb/204Pbi of 17.5-20.0. Cretaceous granitoids of the region are mainly monzogranites with ??Ndi of -6 to -19, 87Sr/86Sri of 0.707-0.723, and 206Pb/204Pbi of 17.4-18.6. The granitoids were generated by mixing of mantle-derived mafic melts and pre-existing crust - some of the Cretaceous plutons represent melting of Paleoproterozoic crust that, in the southern Death Valley region, is exceptionally heterogeneous. A Cretaceous gabbro on the southern flank of the region has an unuasually juvenile composition (??Ndi -3.2, 87Sr/86Sri 0.7060). Geographic position of the Mesozoic plutons and comparison with Cordillera plutonism in the Mojave Desert show that the Precambrian lithosphere (craton margin) in the eastern Mojave Desert region may consists of two crustal blocks separated by a more juvenile terrane.

  7. River Valley pluton, Ontario: A late-Archean/early-Proterozoic anorthositic intrusion in the Grenville Province

    SciTech Connect

    Ashwal, L.D. ); Wooden, J.L. )

    1989-03-01

    The River Valley pluton is a ca. 100 km{sup 2} body of anorthositic and gabbroic rocks located about 50 km northeast of Sudbury, Ontario. The pluton is situated entirely within the Grenville Province, but its western margin is a series of imbricate thrust faults associated with the Grenville Front Tectonic Zone. It is dominated by coarse leuconorite and leucogabbro, with lesser anorthosite, gabbro, and rare ultramafics. Igneous textured rocks are abundant and consist of plagioclase (An{sub 60-70}) charged with Fe-Ti oxide inclusions, low Ca pyroxene (orthopyroxene and/or inverted pigeonite) and augite. The most unfractionated rocks are minor olivine gabbros with Fo{sub 70-80}. A variety of deformed and recrystallized equivalents of the igneous-textured rocks is also present, and these are composed largely of calcic plagioclase and hornblende. An Sm-Nd isochron from 3 igneous-textured leucogabbros and an augite mineral separate gives 2,377 {plus minus} 68 Ma, implying slight disturbance of the Sm-Nd whole-rock-mineral system during later metamorphism. The Rb-Sr system has been substantially disturbed, giving an age of 2,185 {plus minus} 105 Ma, which is similar to internal Pb-Pb isochron ages of 2,165 {plus minus} 130 Ma and 2,100 {plus minus} 35 Ma for two igneous-textured rocks. Initial isotopic ratios for the River Valley pluton correspond to single-stage model parameters of {mu} = 8.06, {epsilon}{sub Nd} = O to {minus}3, and I{sub Sr} = 0.7015 to 0.7021. Collectively, these suggest either an enriched mantle source or crustal contamination of a mantle-derived magma. The crustal component involved must have been older and more radiogenic than the majority of rocks exposed at the surface in the nearby Superior Province.

  8. Volcanic Perspective on Plutonism based on Patterns in Evolution in Long-Lived Continental Volcanic Systems

    NASA Astrophysics Data System (ADS)

    Grunder, A. L.; Harris, R. N.; Walker, B. A.; Giles, D.; Klemetti, E. W.

    2008-12-01

    Volcanic rocks represent a biased view of magmatism, but provide critical quenched samples and temporal constraints of magmatic evolution obscured in the plutonic record. We here draw on the records from the Aucanquilcha Volcanic Cluster (AVC; 10 to 0 Ma) in northern Chile and from the mid-Tertiary volcanic field in east-central Nevada (ECNVF; ~40-32 Ma) to consider how evolutionary patterns of intermediate composition volcanic systems bear on the magmatic reworking of the continental crust by plutons and batholiths. Despite disparate tectonic setting (subduction vs extension) and volumes (70 km crust for the ~300 km 3 AVC versus and ~40 km crust for the ~3000 km 3 ECNVF) both volcanic systems share a history of early compositionally diverse volcanism, followed by a stage of more centralized and voluminous dacitic volcanism, which in turn is followed by waning of volcanism. The compositional change and the rapid increase in magma output rate after about half the lifetime of the system is a characteristic pattern of long- lived continental volcanic systems based on a compilation of volume-composition data. The middle, voluminous stage corresponds to the hottest upper crustal conditions, deduced from Al-in-amphibole geothermobarometry and Ti-in-zircon thermometry of the AVC. The middle stage rocks also have textures indicating hybridization of mixed magmas. Simple thermal models of heat input via intraplating readily allow for generation of partially molten crust above the sill, but they do not emulate the rapid increase of magma after some incubation time. We propose that there is a feedback in which a critical thickness of partially molten crust, consisting in part of magmatic precursors, can be readily convectively stirred and mixed with magma of the underplating sill, rapidly creating a large, hybrid and relatively hot body of magma. Stirring facilitates separation of a liquid-enriched extract. The volume of liquid extracted may be small relative to residual

  9. Mineralogy, geochemistry, and evolution of the Mivehrood skarn and the associated pluton, northwest Iran

    NASA Astrophysics Data System (ADS)

    Alirezaei, Saeed; Einali, Morteza; Jones, Peter; Hassanpour, Shohreh; Arjmandzadeh, Reza

    2016-04-01

    An Upper Miocene (9.12 ± 0.19 Ma; biotite 40Ar/39Ar) shallow pluton and numerous dykes and sills of felsic-intermediate compositions intruded the Upper Cretaceous, flysch-type sediments in the Mivehrood area, northwest Iran. The intrusions caused extensive thermal metamorphism and metasomatism, leading to the formation of hornfels and skarn. A massive skarn, 1-10 m thick, immediate to the intrusive contact, is bordered by a banded skarn, 100-400 m thick, that grades outward into hornfels and original sediments. The Mivehrood pluton is characterized by steep REE pattern, high Al2O3 (14.64-16.4 wt%) and Sr (380-786 ppm), and low MgO (1.3-3.4 wt%), Y (4.8-10.7 ppm), and Yb (0.35-0.95 ppm), characteristics typical of high-silica adakites. Skarn formation started with thermal metamorphism, followed by anhydrous prograde and hydrous retrograde stages. Prograde and retrograde mineral assemblages are developed in both skarns, represented by garnet-clinopyroxene-wollastonite and epidote-actinolite-scapolite-chlorite, respectively. Granditic F-bearing garnet dominates clinopyroxene in both skarns. The banded skarn contains minor scapolite of marialite composition. The calc-silicate mineral assemblages and the mineral chemistry allow the Mivehrood skarn to be classified as a calcic, oxidized skarn. Mass balance assessments suggest that Fe, Si, and S were significantly enriched, and Na, LILEs, and LREEs were strongly depleted, in the massive skarn. In the banded skarn, Na, K, Si, and S were enriched. Significant dehydration and carbon degassing occurred in both skarns. Stockworks, veins, and replacement bodies of pyrite ± chalcopyrite locally occur in the pluton and the dykes and in the skarns. The δ34SCDT values for the sulfides fall in a narrow range around 0.0 ‰, suggesting a magmatic source for sulfur and possibly the hydrothermal water and solutes involved in the skarn formation.

  10. Ti in zircon from the Boggy Plain zoned pluton: implications for zircon petrology and Hadean tectonics

    NASA Astrophysics Data System (ADS)

    Ickert, R. B.; Williams, I. S.; Wyborn, D.

    2011-08-01

    The understanding of zircon crystallization, and of the Ti-in-zircon thermometer, has been enhanced by Ti concentration measurements of zircon from a small, concentrically zoned pluton in south-eastern Australia, the Boggy Plain zoned pluton (BPZP). Zircon crystals from rocks ranging in composition from gabbro to aplite were analysed for U-Th-Pb dating and Ti concentrations by an ion microprobe. Geochronological data yield a 206Pb/238U age of 417.2 ± 2.0 Ma (95% confidence) and demonstrate the presence of older inherited or xenocrystic zircon. Titanium measurements ( n = 158) yield a mean Ti concentration of 11.7 ± 6.1 ppm (2SD) which corresponds to a mean crystallization temperature of 790°C for an α-TiO2 = 0.74 (estimated using mineral equilibria), or 760°C for an α-TiO2 = 1.0. Apparent zircon crystallization temperatures are similar in all intrusive phases, although the gabbro yields slightly higher values, indicating that crystallization occurred at the same temperature in all rock types. This finding is consistent with previous work on the BPZP, which indicates that liquid-crystal sorting (crystal fractionation) was the dominant control on chemical differentiation, and that late, differentiated liquids were similar in composition for all rock types. A simple forward model approximately predicts the range of crystallization temperatures, but not the shape of the distributions, due to sampling biases and complexities in the cooling and crystallization history of the pluton. The distribution of Ti concentrations has a mode at a higher Ti (higher temperature) than the sample set of Hadean detrital zircon. This is consistent with the hypothesis that the skew to low-T in the Hadean dataset is due to the presence of zircon that crystallized from wet anatectic melts.

  11. The chemical and isotopic differentiation of an epizonal magma body: Organ Needle pluton, New Mexico

    USGS Publications Warehouse

    Verplanck, P.L.; Farmer, G.L.; McCurry, M.; Mertzman, S.A.

    1999-01-01

    Major and trace element, and Nd and Sr isotopic compositions of whole rocks and mineral separates from the Oligocene, alkaline Organ Needle pluton (ONP), southern New Mexico, constrain models for the differentiation of the magma body parental to this compositionally zoned and layered epizonal intrusive body. The data reveal that the pluton is rimmed by lower ??(Nd) (~-5) and higher 87Sr/86Sr (~0.7085) syenitic rocks than those in its interior (??(Nd) ~ 2, 87Sr/86Sr ~0.7060) and that the bulk compositions of the marginal rocks become more felsic with decreasing structural depth. At the deepest exposed levels of the pluton, the ??(Nd)~-5 lithology is a compositionally heterogeneous inequigranular syenite. Modal, compositional and isotopic data from separates of rare earth element (REE)-bearing major and accesory mineral phases (hornblende, titanite, apatite, zircon) demonstrate that this decoupling of trace and major elements in the inequigranular syenite results from accumulation of light REE (LREE)-bearing minerals that were evidently separated from silicic magmas as the latter rose along the sides of the magma chamber. Chemical and isotopic data for microgranular mafic enclaves, as well as for restite xenoliths of Precambrian granite wall rock, indicate that the isotopic distinction between the marginal and interior facies of the ONP probably reflects assimilation of the wall rock by ??(Nd) ~-2 mafic magmas near the base of the magma system. Fractional crystallization and crystal liquid separation of the crystally contaminated magma at the base and along the margins of the chamber generated the highly silicic magmas that ultimately pooled at the chamber top.

  12. Survey report: Turkey.

    PubMed

    Kent, M

    1987-06-01

    The 1983 Turkish Population and Health Survey, involving 5398 ever-married women under 50 years of age, revealed that the demand for family planning services in Turkey exceeds current availability. Although almost 3/4 of survey respondents indicated they wanted only 2-3 children, actual fertility rates in the 1978-83 period averaged 4.2 births/woman. The percent of currently married women under 50 years of age using birth control increased from 50% in 1978 to 62% in 1983, but half of this increase was attributable to a greater reliance on withdrawal. Withdrawal was the contraceptive method used by 49% of family planning acceptors in 1983; only 27% reported use of a modern method. Inadequate supplies was the main reason cited for the low use of modern methods, especially in the more rural eastern regions of the country. The prevalence of traditional methods, and an increasing abortion ratio (25.6/100 live births in 1983), indicates a high unmet need for family planning. 78% of the women surveyed in 1983 asserted that they did not want any more children. The 1983 survey also reported an infant mortality rate of 112/1000 live births. Most Turkish women breastfeed their infants for the 1st year of life, but other traditional practices such as reliance on untrained attendants for childbirth and packing earth into the swaddling cloth with the infant have been linked to higher infant mortality. The survey report concluded that improvements in the education and status of women would enhance their acceptance of family planning and contribute to life-styles more promotive of infant survival.

  13. Archaean multiphase Porosozero sanukitoid pluton of the Kola region: petrological, geochronological and geochemical data

    NASA Astrophysics Data System (ADS)

    Kudryashov, Nikolai; Mokrushin, Artem; Petrovsky, Michail; Elizarov, Dmitry

    2013-04-01

    The Porosozero sanukitoid intrusion is located in the greenstone belt of the Kolmozero-Voronja, north-eastern part Fennoscandian (Baltic) Shield. The Porosozero multiphase pluton was formed as a result of the 4 magmatic phases during the period ca. 60 million years. The main phase is represented by a differentiated series of gabbro-diorite - quartz monzodiorite - granodiorite - granite. The zircon TIMS ages of granodiorite and quartz monzodiorites are 2733±6 Ma and 2734±4 Ma, respectively. The second phase is composed of leucogranites formed during intrusion of the residual melt portion from intracrustal source. The age of zircon from leucogranite is 2712±6 Ma. The third phase is represented by the lamprophyre dykes with the zircon age 2680±8 Ma. The late pegmatite veins were formed during the fourth final phase. The volume relationships between the gabbro-diorite, quartz monzodiorites, granodiorites and granites are 5:55:27:13, respectively. The medium weighted composition of the initial melt, calculated from the rock compositions of the first phase is andesite (wt.%): SiO2 = 61.53, TiO2 = 0.58, Al2O3 = 15.74, Fe2O3 = 3.75, FeO = 3.07, MnO = 0.10, MgO = 3.06, CaO = 5.83, Na2O = 3.78, K2O = 2.37. The compositional variation is the result of fractional crystallization. The last magmas may have experienced some crustal contamination. All rocks of the first phase are enriched in Ba (500-800 ppm), Sr (450-700 ppm), K2O (1.8-3.2 wt. %), P2O5 (0.15-0.35), LREE [(La/Yb)N=15-23] and contain high concentrations of Cr (150-400 ppm) and Ni (60-140 ppm), possess high mg# values (0.45-0.65), and show a negative Nb-Ta anomaly. Sm-Nd isotopic data for sanukitoids indicate their formation from a mantle source enriched in LILE and LREE with ɛNd (2740) = +1.02 - +0.36, T(DM)=2.9-2.8 Ga. The Porosozero polyphasic pluton is similar to worldwide Archaean and Phanerozoic magmatic sanukitoide series. The Porosozero pluton formation is determined by the processes of mantle

  14. Miocene zircon crystals in dacite from Ilopango Caldera, El Salvador: Evidence for recycling of plutonic rocks

    NASA Astrophysics Data System (ADS)

    Garrison, J. M.; Korm, S.; Schmitt, A. K.; Economos, R. C.

    2011-12-01

    Ilopango Caldera is located in El Salvador and is part of the Central American Volcanic Arc (CAVA) that extends from southern Mexico to Panama. The volcanic arc is situated on crust that ranges in age from 150-28 Ma and is covered with Miocene-Recent volcanic ash and pyroclastic flow deposits. Several large eruptions are associated with Ilopango Caldera, the most recent are from the Tierra Blanca Joven (TBJ) eruption, which produced massive pyroclastic flows 1600 years BP. Older eruptions from Ilopango Caldera are referred to as the Tierra Blanca (TB) deposits, and the TB2 ignimbrite has been dated at 12,000 years. The objective of this research is to use the ages of zircon crystals from the TBJ and TB2 eruptions to establish and compare storage times for these magma reservoirs. We used a CAMECA ims 1270 at UCLA's NSF National Ion Microprobe Facility in order to obtain U-Pb and U-Th ages for individual zircon crystals from each eruption. Depth profiling and U-Pb analyses were performed on both of the zircon crystals using established analysis techniques. The data show that zircon from both eruptions have 15 Ma old cores with thin rims (few μm) that are consistent with the young eruption ages. In both cases, however the transition from core to rim composition is abrupt and does not record continuous crystallization of the zircon crystals. We conclude that the presence of the old cores is consistent with assimilation of middle Miocene plutonic rock by juvenile magma during Quaternary activity of Ilopango Caldera. The most likely source of 15 Ma old zircon are the plutons associated with middle Miocene explosive volcanism in Central America. Ash deposits recovered from the sea floor (via ODP studies) record extensive explosive volcanism from 13-15 Ma that can be traced to ignimbrite deposits of the Chalatenango Formation in south-central Guatemala and El Salvador. We conclude that 1) the zircon crystals record only brief pre-eruptive crystallization histories for the

  15. Plutonic rock types series: discrimination of various granitoid series and related rocks

    NASA Astrophysics Data System (ADS)

    Lameyre, Jean; Bowden, Peter

    1982-10-01

    The Streckeisen QAP diagram discriminates four characteristic type series among the large variety of granitoids associated in intrusions. Three of them integrate varied compositions from basic to acid terms: (1) the calcalkaline series with its low K (or trondhiemite), medium K (or granodioritic), high K (or monzonitic) variants; (2) the alkaline series with its characteristic syenitic members; (3) the tholeiitic series, deprived of K feldspars. The fourth (4) corresponds to mobilizates associated with migmatites of varied composition but always quartz rich. The generalization in the QAPF system, allowing the plotting of undersaturated alkaline series, provides an excellent visual display of the major associations and trends for the plutonic rocks.

  16. Ductile strain rate recorded in the Symvolon syn-extensional plutonic body (Rhodope core complex, Greece)

    NASA Astrophysics Data System (ADS)

    Cirrincione, Rosolino; Fazio, Eugenio; Ortolano, Gaetano; Fiannacca, Patrizia; Kern, Hartmut; Mengel, Kurt; Pezzino, Antonino; Punturo, Rosalda

    2016-04-01

    The present contribution deals with quantitative microstructural analysis, which was performed on granodiorites of the syn-tectonic Symvolon pluton (Punturo et al., 2014) at the south-western boundary of the Rhodope Core Complex (Greece). Our purpose is the quantification of ductile strain rate achieved across the pluton, by considering its cooling gradient from the centre to the periphery, using the combination of a paleopiezometer (Shimizu, 2008) and a quartz flow law (Hirth et al., 2001). Obtained results, associated with a detailed cooling history (Dinter et al., 1995), allowed us to reconstruct the joined cooling and strain gradient evolution of the pluton from its emplacement during early Miocene (ca. 700°C at 22 Ma) to its following cooling stage (ca. 500-300°C at 15 Ma). Shearing temperature values were constrained by means of a thermodynamic approach based on the recognition of syn-shear assemblages at incremental strain; to this aim, statistical handling of mineral chemistry X-Ray maps was carried out on microdomains detected at the tails of porphyroclasts. Results indicate that the strain/cooling gradients evolve "arm in arm" across the pluton, as also testified by the progressive development of mylonitic fabric over the magmatic microstructures approaching the host rock. References • Dinter, D. A., Macfarlane, A., Hames, W., Isachsen, C., Bowring, S., and Royden, L. (1995). U-Pb and 40Ar/39Ar geochronology of the Symvolon granodiorite: Implications for the thermal and structural evolution of the Rhodope metamorphic core complex, northeastern Greece. Tectonics, 14 (4), 886-908. • Shimizu, I. (2008). Theories and applicability of grain size piezometers: The role of dynamic recrystallization mechanisms. Journal of Structural Geology, 30 (7), 899-917. • Hirth, G., Teyssier, C., and Dunlap, J. W. (2001). An evaluation of quartzite flow laws based on comparisons between experimentally and naturally deformed rocks. International Journal of Earth

  17. Source variation for Mesozoic granitoid plutons in the White-Inyo Range, California, and implications for changes in the lithospheric structure

    NASA Astrophysics Data System (ADS)

    Gammel, E.; Nabelek, P. I.; Phillips, E. H. W.; Scott, S. R.; Sims, K. W. W.

    2015-12-01

    The White-Inyo Range (WIR) of eastern California lies to the east of Owen's Valley and the Sierra Nevada batholith (SNB). Over twenty recognized Mesozoic, granitic to gabbroic plutons intruded into Precambrian and Cambrian sedimentary units that were previously metamorphosed to the greenschist facies. These plutons represent intrusive equivalents of volcanics erupted during two magmatic events at ca. 180-167 Ma and 102-86 Ma (Coleman et al, 2003). The motivation of this study is to understand changes in magma sources over this time period. We propose there is a time-transgressive change in source material in the WIR. Preliminary trace element data suggest that Jurassic plutons were sourced from deep crustal material, whereas later Cretaceous plutons may have had a shallower origin. This is supported by high Sr/Y ratios in the Jurassic plutons (up to 300) and relatively lower ratios in Cretaceous plutons (down to 14). Chiaradia (2015) suggests elevated Sr/Y ratios are directly linked to increasing crustal thickness, therefore the WIR plutons may record the period of crustal thinning in this region or maturation of the crust that allowed shallower melting in the Cretaceous. The highest values also suggest possible adakitic source material. REE patterns suggest that the youngest plutons (e.g. Sage Hen Flat) are more similar to samples collected from the eastern Sierra Nevada batholith than older plutons with higher La/Yb ratios. Relatively flat patterns REE patterns of Tertiary basalts and a late diabase dike in the WIR are also similar to SNB samples. Another goal of this study is to determine the degree of mixing as a function of time during the emplacement of plutons in the range. Field and petrographic analyses suggest that older plutons represent more mafic materials and younger plutons are more granitic with mafic enclaves. We propose either (1) older plutons represent initial lower lithosphere melting, and with time, there is an increase of incorporation of

  18. Early Childhood Inclusion in Turkey

    ERIC Educational Resources Information Center

    Diken, Ibrahim H.; Rakap, Salih; Diken, Ozlem; Tomris, Gozde; Celik, Secil

    2016-01-01

    Inclusion of young children with disabilities into regular preschool classrooms is a common practice that has been implemented for several decades in industrialized nations around the world, and many developing countries including Turkey have been developing and implementing laws, regulation, and services to support inclusion and teaching in…

  19. Suicide in Batman, Southeastern Turkey

    ERIC Educational Resources Information Center

    Altindag, Abdurrahman; Ozkan, Mustafa; Oto, Remzi

    2005-01-01

    The southeastern part of Turkey has comparatively high female suicide rates. We aimed to research social, economic, cultural, and psychiatric reasons of suicides in Batman in a case-controlled psychological autopsy study comparing suicides with matched community controls. The female suicide rate was 9.3 per 100.000 and the female/male ratio was…

  20. Examining Distance Education in Turkey.

    ERIC Educational Resources Information Center

    McIsaac, Marina Stock; And Others

    1988-01-01

    Describes the distance education program at Anadolu University in Turkey and compares its problems and solutions with similar distance programs in other Asian countries. A brief history is presented, enrollment figures are given, and future directions are described. (Author/LRW)

  1. Suicide in Batman, Southeastern Turkey

    ERIC Educational Resources Information Center

    Altindag, Abdurrahman; Ozkan, Mustafa; Oto, Remzi

    2005-01-01

    The southeastern part of Turkey has comparatively high female suicide rates. We aimed to research social, economic, cultural, and psychiatric reasons of suicides in Batman in a case-controlled psychological autopsy study comparing suicides with matched community controls. The female suicide rate was 9.3 per 100.000 and the female/male ratio was…

  2. Early Childhood Inclusion in Turkey

    ERIC Educational Resources Information Center

    Diken, Ibrahim H.; Rakap, Salih; Diken, Ozlem; Tomris, Gozde; Celik, Secil

    2016-01-01

    Inclusion of young children with disabilities into regular preschool classrooms is a common practice that has been implemented for several decades in industrialized nations around the world, and many developing countries including Turkey have been developing and implementing laws, regulation, and services to support inclusion and teaching in…

  3. Thalassemias and hemoglobinopathies in Turkey.

    PubMed

    Canatan, Duran

    2014-01-01

    Thalassemias and hemoglobinopathies are a serious health problem in Turkey. There is a 70-year history of thalassemia in Turkey. The first patient with β-thalassemia major (β-TM) was reported in 1941. The first clinical and hematological studies were published by Aksoy in 1958. The overall incidence of β-thalassemia (β-thal) was reported by Çavdar and Arcasoy to be 2.1% in 1971. Important steps such as written regulations, education and prevention campaigns, have been taken to prevent thalassemia in Turkey by the Ministry of Health (MOH), the Turkish National Hemoglobinopathy Council (TNHC) and the Thalassemia Federation of Turkey (TFT) since 2000. A national hemoglobinopathy prevention program was started in provinces with a high prevalence by the MOH in 2003. While the percentage of premarital screening test was 30.0% of all couples in 2003, it reached 86.0% in 2013. While the number of newborn with thalassemias and hemoglobinopathies was 272 in 2002, it had dropped to 25 in 2010. There has been a 90.0% reduction of affected births in the last 10 years.

  4. Geochemistry, U-Pb geochronology, Sm-Nd and O isotopes of ca. 50 Ma long Ediacaran High-K Syn-Collisional Magmatism in the Pernambuco Alagoas Domain, Borborema Province, NE Brazil

    NASA Astrophysics Data System (ADS)

    Francisco da Silva Filho, Adejardo; de Pinho Guimarães, Ignez; Santos, Lucilene; Armstrong, Richard; Van Schmus, William Randall

    2016-07-01

    The Pernambuco Alagoas (PEAL) domain shows the major occurrence of granitic batholiths of the Borborema Province, NE Brazil, with Archean to Neoproterozoic range of Nd TDM model ages, giving clues on the role of granites during the Brasiliano orogeny. SHRIMP U/Pb zircon geochronological data for seven granitic intrusions of the PEAL domain divide the studied granitoids into three groups: 1) early-to syn-collision granitoids with crystallization ages ca. 635 Ma (Serra do Catú pluton), 2) syn-collision granitoids with crystallization ages 610-618 Ma (Santana do Ipanema, Água Branca, Mata Grande and Correntes plutons) and 3) late-to post-collision granitoids with ages of ca. 590 Ma (Águas Belas, and Cachoeirinha plutons). The intrusions of group 1 and 2, except the Mata Grande and Correntes plutons, show Nd TDM model ages ranging from 1.2 to 1.5 Ga, while the granitoids from group 3, and Mata Grande Pluton and Correntes plutons have Nd TDM model ages ranging from 1.7 to 2.2 Ga. The studied granitoids with ages <600 Ma are high-K, calc-alkaline, shoshonitic and those with ages <600 Ma are transitional high-K calc-alkaline to alkaline. The volcanic arc signatures associated with the Paleoproterozoic Nd TDM model ages are interpreted as inherited from the source rocks. The oldest ages and lower Nd TDM model ages are recorded from granitoids intruded in the southwest part of the PEAL domain, suggesting that these intrusions are associated with slab-tearing during convergence between the PEAL and the Sergipano domains. Zircon oxygen isotopic data in some of the studied plutons, together with the available Nd isotopic data suggest that the Brasiliano orogeny strongly reworked older crust, of either Paleoproterozoic or Tonian ages. The studied granitoids are coeval with calc-alkaline granitoids of the Transversal Zone and Sergipano domains and rare high-K calc-alkaline granitoids from the Transversal Zone domain. Such large volumes of high-K granitoids with

  5. Production of Ne Auger electrons by Ne/+/ bombardment of Mg and Al surfaces

    NASA Technical Reports Server (NTRS)

    Ferrante, J.; Pepper, S. V.

    1976-01-01

    A description is given of experiments which provide evidence for the production of an inner shell vacancy in the Ne by the asymmetric Ne-Mg and Ne-Al collision. In addition, autoionization states of neutral Ne have been observed. These states are to be distinguished from the more usual case in Auger electron spectroscopy of de-excitation of an ion with a core vacancy. The experiments involved the bombardment of Mg and Al surfaces with Ne(+) ions. A LEED-Auger system equipped with an ion gun and a four-grid retarding potential analyzer operated in the usual dN(E)/dE mode was used.

  6. Active NE-SW Compressional Strain Within the Arabian Plate

    NASA Astrophysics Data System (ADS)

    Floyd, M. A.; ArRajehi, A.; King, R. W.; McClusky, S.; Reilinger, R. E.; Douad, M.; Sholan, J.; Bou-Rabee, F.

    2012-12-01

    Motion of the Arabian plate with respect to Eurasia has been remarkably steady over more than 25 Myr as revealed by comparison of geodetic and plate tectonic reconstructions (e.g., McQuarrie et al., 2003, GRL; ArRajehi et al., 2010, Tectonics). While internal plate deformation is small in comparison to the rate of Arabia-Eurasia convergence, the improved resolution of GPS observations indicate ~ NE-SW compressional strain that appears to affect much of the plate south of latitude ~ 30°N. Seven ~ NE-SW oriented inter-station baselines all indicated shortening at rates in the range of 0.5-2 mm/yr, for the most part with 1-sigma velocity uncertainties < 0.4 mm/yr. Plate-scale strain rates exceed 2×10-9/yr. The spatial distribution of strain can not be resolved from the sparse available data, but strain appears to extend at least to Riyadh, KSA, ~ 600 km west of the Zagros Fold and Thrust Belt that forms the eastern, collisional boundary of the Arabian plate with Eurasia (Iran). Geodetic velocities in the plate tectonic reference frame for Arabia, derived from magnetic anomalies in the Red Sea (Chu and Gordon, 1998, GJI), show no significant E-W motion for GPS stations located along the Red Sea coast (i.e., geodetic and plate tectonic spreading rates across the Red Sea agree within their resolution), in contrast to sites in the plate interior and along the east side of the plate that indicate east-directed motions. In addition, NE-SW contraction is roughly normal to ~ N-S striking major structural folds in the sedimentary rocks within the Arabian Platform. These relationships suggest that geodetically observed contraction has characterized the plate for at least the past ~ 3 Myr. Broad-scale contraction of the Arabian plate seems intuitively reasonable given that the east and north sides of the plate are dominated by active continental collision (Zagros, E Turkey/Caucasus) while the west and south sides are bordered by mid-ocean ridge spreading (Red Sea and Gulf of

  7. Mingled mafic and felsic magmas in the Jurassic Eagle Mountain pluton, southeastern California

    SciTech Connect

    Mayo, D.P. . Dept. of Geological Sciences); Wooden, J.L. )

    1993-04-01

    The metalluminous, compositionally expanded Eagle Mountain pluton ([approx] 165 Ma) was epizonally emplaced within Proterozoic metaigneous and Proterozoic-Paleozoic metasedimentary rocks in the Eagle Mountains of southeastern California. The evolution of the pluton involved mingling and partial mixing between mafic and felsic magmas. Heterogeneous rocks consisting of discrete biotite-clinopyroxene microdioritic enclaves (49--54% SiO[sub 2]) enclosed in hornblende-biotite granodiorite (57--61% SiO[sub 2]) grade into complexly mingled microdiorite and granodiorite as the proportion of microdiorite increases. The dioritic enclaves are notably potassic (2.1 [+-] .2 wt. %), containing abundant biotite (up to 23%) and interstitial patches of K-feldspar. These features are attributed to selective potassium enrichment of dioritic magma by diffusion during mingling with host granodioritic magma. A similar phenomenon was observed in experiments by Johnston and Wyllie, and attributed to relatively rapid diffusion of potassium from felsic to mafic magma. Calculated Sr[sub i] for the enclaves, intermediate dioritoids, and three of four analyzed host rocks cluster at 0.7085 [+-] 0.0002. Several homogeneous monzogranites not associated with enclaves have slightly higher Sr[sub i] (up to 0.7094) and define two separate mixing/AFC arrays on a plot of Sr[sub i] vs. 1/Sr, both anchored at the cluster of less radiogenic rocks. Alternatively, relatively rapid self-diffusion of Sr may have contributed to isotopic homogeneity during mingling of magmas from isotopically distinct sources.

  8. Emplacement and geochemical evolution of eocene plutonic rocks in the Colville batholith

    SciTech Connect

    Holder, R.W.

    1986-01-01

    Eocene plutonic rocks in the Colville batholith are divided on the basis of field evidence and chemical composition into, in order of decreasing age, (1) several calc-alkalic biotite-hornblende monzodiorite to granodiorite intrusions referred to as the Devils Elbow suite, and (2) compositionally variable calc-alkalic to alkali-calcic intrusions referred to as the Herron Creek suite. These Eocene suites are distinct from older, more voluminous, leucocratic granite and granodiorite intrusions, designated the Keller Butte suite, which are calcic and characteristically lack hornblende. Results of qualitative and computer modeling of major element variation and quantitative models of trace element variation in the chemically coherent Bridge Creek intrusions, a member of the Herron Creek suite, are compatible with fractionation of plagioclase feldspar + hornblende + biotite + magnetite + apatite from a parent magma of andesitic composition to account for the observed variation. Strongly curved variation trends preclude mixing as the primary mechanism for the observed variation. It is suggested that parallel variation trends in the other Eocene intrusions are also the result of crystal fractionation. Lateral chemical variations including a decrease in silica saturation suggest the chemical characteristics of these rocks reflect those of parental magmas derived from the mantle, with an unknown amount of crustal contribution. Rotated and angular xenoliths, discordant contacts, and temporal and spatial proximity to graben structures indicate that the Eocene plutons were passively implaced into the upper crust along graben-bounding faults during graben formation, the earlier stages of which appear to have been contemporaneous with regional mylonitic deformation.

  9. A possible concealed pluton in Beaverhead and Madison Counties, Montana, and Clark County, Idaho

    USGS Publications Warehouse

    Witkind, Irving Jerome

    1974-01-01

    A northeast-trending magnetic anomaly in parts of Beaverhead and Madison Counties, Mont., and Clark County, Idaho, may reflect the trend, shape, and size of a concealed pluton. The type of rock that forms the pluton(?) is unknown. A small volcanic pipe, possibly a diatreme, is at the southeast end of the high. The pipe, about 92 m (300 ft) in diameter, consists of a rubbly basalt-like matrix through which are scattered xenoliths of Precambrian crystalline rocks and of various Paleozoic and Mesozoic strata. It is uncertain whether the juxtaposition of the pipe and the magnetic high is meaningful or is merely fortuitous. Although no mineralized rock was found in the area underlain by the anomaly, placer gold has been found nearby. Some 113 km (70 mi) to the west, in Custer and Lemhi Counties, Idaho, a similar northeast-trending magnetic high marks the site of the Gilmore mining district. The similarities in trend, shape, and magnitude between the two anomalies suggest that the high in Beaverhead and Madison Counties should be investigated for undetected mineral deposits, possibly by a geochemical survey.

  10. Ancient plutonic processes on Mars inferred from the detection of possible anorthositic terrains

    NASA Astrophysics Data System (ADS)

    Carter, J.; Poulet, F.

    2013-12-01

    The mineralogical diversity preserved on ancient terrains of Mars provides insights into the planet's early geological state and subsequent evolution. The martian crust is predominantly composed of mafic rocks with low silica contents, with the exception of a few localized volcanic sequences that indicate some compositional evolution towards compositions richer in silicate minerals. Anorthosite, which is dominated by the silicate mineral plagioclase, is rare in the Solar System. It is thought to require an evolved magmatic source in which lighter elements have been concentrated. Anorthosite has been observed previously only on Earth within localized continental plutons of intrusive igneous origin, and more widely on the Moon where the anorthositic highland crust is thought to derive from crystallization of a primordial magma ocean. Using near-infrared spectral data obtained by the Mars Reconnaissance Orbiter, we report the detection of iron-bearing plagioclase-rich rocks at eight sites in the southern highlands of Mars with a spectral signature consistent with ferroan anorthosites. The paucity of detections suggests a localized plutonic origin similar to terrestrial anorthosites, although a lunar-like global anorthosite crust on early Mars cannot be entirely excluded. Our detections of anorthositic compositions at several locations on the martian surface suggest that magmatic processes that produce highly evolved melts were active on ancient Mars.

  11. Reworked old crust-derived shoshonitic magma: The Guarany pluton, Northeastern Brazil

    NASA Astrophysics Data System (ADS)

    Ferreira, Valderez P.; Sial, Alcides N.; Pimentel, Marcio M.; Armstrong, Richard; Guimarães, Ignez P.; da Silva Filho, Adejardo F.; de Lima, Mariucha Maria C.; da Silva, Thyego R.

    2015-09-01

    The 572 Ma Guarany stock consists of magmatic epidote-bearing hornblende monzodiorite to biotite granite that intruded Paleoproterozoic orthogneisses about 10 km inland from the coast in northeastern Brazil. Co-magmatic diorite enclaves and dikes are abundant throughout the pluton. The monzodiorite-granite pluton and diorite enclaves are shoshonitic and display continuous trends in variation diagrams. They display chemical and isotopic characteristics of crustal melts, such as enrichment in incompatible elements, high back-calculated initial 87Sr/86Sr ratios (avg. 0.71253), negative εNd (0.57Ga) values (avg. - 14.58), as well as high and variable (+ 9.1 to + 11.1‰VSMOW) δ18O (zircon) values. Correlations between O-isotope and whole-rock silica contents, as well as initial 87Sr/86Sr ratios with 1/Sr concentrations, suggest hybridization of a lower continental crustal melt with more felsic crustal rocks, concomitant with fractional crystallization. Amphibole chemistry and whole rock Zr, TiO2 and P2O5 contents suggest magma solidification at a pressure 7 kbar and near liquidus temperature 900 °C. The parental magma was likely formed by partial melting of old (tDM = 2.0 Ga) amphibolitic lower continental crustal rocks, in a post-collisional setting, probably triggered by underplating of mantle-derived mafic magma during the period of relaxation after collision.

  12. Model of formation of the Khibiny-Lovozero ore-bearing volcanic-plutonic complex

    NASA Astrophysics Data System (ADS)

    Arzamastsev, A. A.; Arzamastseva, L. V.; Zhirova, A. M.; Glaznev, V. N.

    2013-09-01

    The paper presents the results of a study of the large Paleozoic ore-magmatic system in the northeastern Fennoscandian Shield comprising the Khibiny and Lovozero plutons, the Kurga intrusion, volcanic rocks, and numerous alkaline dike swarms. As follows from the results of deep drilling and 3D geophysical simulation, large bodies of rocks pertaining to the ultramafic alkaline complex occur at the lower level of the ore-magmatic system. Peridotite, pyroxenite, melilitolite, melteigite, and ijolite occupy more than 50 vol % of the volcanic-plutonic complex within the upper 15 km accessible to gravity exploration. The proposed model represents the ore-magmatic system as a conjugate network of mantle magmatic sources localized at different depth levels and periodically supplying the melts belonging to the two autonomous groups: (1) ultramafic alkaline rocks with carbonatites and (2) alkali syenites-peralkaline syenites, which were formed synchronously having a common system of outlet conduits. With allowance for the available isotopic datings and new geochronological evidence, the duration of complex formation beginning from supply of the first batches of melt into calderas and up to postmagmatic events, expressed in formation of late pegmatoids, was no less than 25 Ma.

  13. Magma accumulation rates and thermal histories of plutons of the Sierra Nevada batholith, CA

    NASA Astrophysics Data System (ADS)

    Davis, Jesse W.; Coleman, Drew S.; Gracely, John T.; Gaschnig, Richard; Stearns, Michael

    2012-03-01

    Zircon U-Pb geochronology results indicate that the John Muir Intrusive Suite of the central Sierra Nevada batholith, California, was assembled over a period of at least 12 Ma between 96 and 84 Ma. Bulk mineral thermochronology (U-Pb zircon and titanite, 40Ar/39Ar hornblende and biotite) of rocks from multiple plutons comprising the Muir suite indicates rapid cooling through titanite and hornblende closure following intrusion and subsequent slow cooling through biotite closure. Assembly of intrusive suites in the Sierra Nevada and elsewhere over millions of years favors growth by incremental intrusion. Estimated long-term pluton assembly rates for the John Muir Intrusive Suite are on the order of 0.001 km3 a-1 which is inconsistent with the rapid magma fluxes that are necessary to form large-volume magma chambers capable of producing caldera-forming eruptions. If large shallow crustal magma chambers do not typically develop during assembly of large zoned intrusive suites, it is doubtful that the intrusive suites represent cumulates left behind following caldera-forming eruptions.

  14. Plutonic rocks of Jurassic age in the Alaska-Aleutian Range batholith: chemical variation and polarity.

    USGS Publications Warehouse

    Reed, B.I.; Miesch, A.T.; Lanphere, M.A.

    1983-01-01

    Plutonic rocks of Jurassic age exposed on the Pacific side of this batholith form a compositionally continuous calc-alkaline suite that ranges from hornblende gabbro to quartz monzonite. Tonalite and quartz diorite are the dominant rock types. Trend-surface analysis of 102 samples indicates that the direction of slope of the trend is approximately normal to the Jurassic magmatic arc. K2O and SiO2 increase towards the E-SE and the other oxides towards the W-NW. If the chemical trends reflect the approximate geometry of a palaeo-subduction zone, the polarity of the Jurassic magmatic arc is to the NW, i.e. subduction was directed towards the SE. Thus the palaeo-subduction zone is on the opposite side of the arc from the position that has generally been assumed, indicating that the Jurassic plutonic rocks were not generated in response to classical Andean-type convergent plate margins. The magmatic arc may have been formed in an intra-ocean environment and subsequently has been rafted northwards and accreted to this part of the N Pacific rim during the late Mesozoic. Middle and Upper Jurassic clastics underlying Cook Inlet to the SE and derived from the magmatic arc are classified as back-arc deposits, rather than as an arc-trench gap sequence.-L.C.H.

  15. Syn-extensional plutonism and peak metamorphism in the albion-raft river-grouse creek metamorphic core complex

    USGS Publications Warehouse

    Strickland, A.; Miller, E.L.; Wooden, J.L.; Kozdon, R.; Valley, J.W.

    2011-01-01

    The Cassia plutonic complex (CPC) is a group of variably deformed, Oligocene granitic plutons exposed in the lower plate of the Albion-Raft River- Grouse Creek (ARG) metamorphic core complex of Idaho and Utah. The plutons range from granodiorite to garnet-bearing, leucogranite, and during intrusion, sillimanite- grade peak metamorphism and ductile attenuation occurred in the country rocks and normal-sense, amphibolite-grade deformation took place along the Middle Mountain shear zone. U-Pb zircon geochronology from three variably deformed plutons exposed in the lower plate of the ARG metamorphic core complex revealed that each zircon is comprised of inherited cores (dominantly late Archean) and Oligocene igneous overgrowths. Within each pluton, a spread of concordant ages from the Oligocene zircon overgrowths is interpreted as zircon recycling within a long-lived magmatic system. The plutons of the CPC have very low negative whole rock ??Nd values of -26 to -35, and initial Sr values of 0.714 to 0.718, consistent with an ancient, crustal source. Oxygen isotope ratios of the Oligocene zircon overgrowths from the CPC have an average ??18O value of 5.40 ?? 0.63 permil (2SD, n = 65) with a slight trend towards higher ??18O values through time. The ??18O values of the inherited cores of the zircons are more variable at 5.93 ?? 1.51 permil (2SD, n = 29). Therefore, we interpret the plutons of the CPC as derived, at least in part, from melting Archean crust based on the isotope geochemistry. In situ partial melting of the exposed Archean basement that was intruded by the Oligocene plutons of the CPC is excluded as the source for the CPC based on field relationships, age and geochemistry. Correlations between Ti and Hf concentrations in zircons from the CPC suggest that the magmatic system may have become hotter (higher Ti concentration in zircon) and less evolved (lower Hf in zircon concentration) through time. Therefore, the CPC represents prolonged or episodic magmatism

  16. Reconnaissance geochemical exploration of the plutons of quartz monzonite and granite in the Jabal Lababa and Ar Rayth areas, southern Asir, Kingdom of Saudi Arabia

    USGS Publications Warehouse

    Overstreet, W.C.; Assegaff, A.B.; Jambi, Mohammed; Hussain, M.A.; Selner, G.I.; Matzko, J.J.

    1985-01-01

    Three nonmagnetic high-density concentrates containing 1,000 to 15,000 ppm lead were found on the granitic pluton near Ar Rayth. The source of the lead is not galena, and high values for lead appear to be characteristic of the pluton but do not indicate an ore deposit.

  17. Structural control of the Limagne Rift Fault on the Chaîne des Puys

    NASA Astrophysics Data System (ADS)

    Van Wyk de Vries, B.; Tiu, G.; Mossoux, S.; Kervyn, M.; Lagmay, A. A.

    2012-12-01

    The close proximity of the Limagne Fault to the Chaîne des Puys (Massif Central, France) has been noted for a long time. In fact, if the Limagne fault had not raised the Chaîne relative to the Limagne Rift, to create a spectacular skyline of volcanoes, there would probably not have been so much interest in them. Early geologists such as Elie de Beaumont, Davy, Lyell, Murchison, and Von Humbolt, were as much concerned with explaining the escarpment by catastrophism or uniformitarianism, as they were with battling over neptunism and plutonism, or craters of elevation. The questions still stands as to what relationship the monogenetic volcanoes have to the fault, and perhaps: are the volcanoes monogenetic because of the fault? - seeing as just to the south of the rift, stand the Mont Dore-Sancy and Cantal stratovolcanoes. Considering the spatial-temporal relationship, it becomes clear that there are volcanoes on the fault, in the rift, and behind the footwall, but with different ages and configurations. Early volcanoes are cut by the faulting, showing a potential linkage, later volcanoes, as a whole, follow generally the main structural trend NS of the rift, but in detail group around a more NE-SW trend, that can be related to Hercynian structures, and to a major transfer fault linking the Limagne Rift to the Rhine Graben. These trends host some of the youngest volcanoes, and the fault appears to have been more recently active in this area, and the area of some damaging historic earthquakes. Considering the proximity of the fault as an influence in the monogenetic nature of the volcanism, more needs to be known about the state of faulting in the Tertiary in the Massif Central. However, the area of the Chaîne de Puys is highly heterogeneous, with complex associations of Hercynian and Tertiary structures, and thus the crustal structure may be compatible with multiple pathways, and thus a monogenetic tendency. In conclusion, there is a probably spatial and temporal

  18. River Valley pluton, Ontario: A late-Archean/early-Proterozoic anorthositic intrusion in the Grenville Province

    USGS Publications Warehouse

    Ashwal, L.D.; Wooden, J.L.

    1989-01-01

    The River Valley pluton is a ca. 100 km2 body of anorthositic and gabbroic rocks located about 50 km northeast of Sudbury, Ontario. The pluton is situated entirely within the Grenville Province, but its western margin is a series of imbricate thrust faults associated with the Grenville Front Tectonic Zone. It is dominated by coarse leuconorite and leucogabbro, with lesser anorthosite, gabbro, and rare ultramafics. Igneous textured rocks are abundant and consist of plagioclase (An60-70) charged with Fe-Ti oxide inclusions, low Ca pyroxene (orthopyroxene and/or inverted pigeonite) and augite. The most unfractionated rocks are minor olivine gabbros with Fo70-80. A variety of deformed and recrystallized equivalents of the igneous-textured rocks is also present, and these are composed largely of calcic plagioclase and hornblende. Ten samples, including both igneous and deformed lithologies give a Pb-Pb whole-rock isochron of 2560??155Ma, which is our best estimate of the time of primary crystallization. The River Valley pluton is thus the oldest anorthositic intrusive yet reported from the Grenville Province, but is more calcic and augitic than typical massifs, and lacks their characteristic Fe-Ti oxide ore deposits. The River Valley body may be more akin to similar gabbro-anorthosite bodies situated at the boundary between the Archean Superior Province and Huronian supracrustal belt of the Southern Province west of the Grenville Front. An Sm-Nd isochron from 3 igneous-textured leucogabbros and an augite mineral separate gives 2377 ?? 68 Ma, implying slight disturbance of the Sm-Nd whole-rock-mineral system during later metamorphism. The Rb-Sr system has been substantially disturbed, giving an age of 2185 ?? 105 Ma, which is similar to internal Pb-Pb isochron ages of 2165 ?? 130 Ma and 2100 ?? 35 Ma for two igneous-textured rocks. It is uncertain whether these ages correspond to a discrete event at this time or represent a partial resetting of the Rb-Sr and Pb

  19. Petrogenesis of Neogene plutonic rocks from south Ardestan, Iran; mantle-derived arc magmatism

    NASA Astrophysics Data System (ADS)

    Babazadeh, Shahrouz; Ghorbani, Mohammad Reza; Bröcker, Michael; D'Antonio, Massimo; Cottle, John; Gebbing, Thorsten; Carmine Mazzeo, Fabio; Ahmadi, Parham

    2017-04-01

    The south Ardestan region in the Urumieh-Dokhtar arc covers an area of about 250 km2 that is characterized by plutonic rocks with a compositional spectrum ranging from gabbro, gabbro-norite, gabbroic diorite, diorite, tonalite to granodiorite. Gabbroic rocks are mainly tholeiitic in character, whereas the diorites, tonalites and granodiorites show increasingly stronger calc-alkaline affinity. Gradual compositional variation and limited variation in radiogenic isotopic ratios indicate that these different rock types are petrogenetically related and most probably are derived from a common primitive source. U-Pb LA-ICP-MS dating of zircon from four granitoids yielded ages that range from 25 to 24 Ma. For tonalitic rocks, internal Rb-Sr isochron ages (biotite, feldspars) indicate cooling ages that lie in the range 20.4 ± 0.1 to 22.1 ± 0.5 Ma, slightly younger than the zircons' ages. Their uniform initial Sr-Nd isotopic values imply that the major source component has probably been an asthenospheric mantle domain. This is further supported by the mantle-derived geochemical affinity of the plutonic rocks. A geodynamic model is presented in which the asthenospheric upwelling and partial melting in the south Ardestan has been triggered by Late Oligocene-Miocene rollback of the Neotethyan subducting slab. These melts were subsequently slightly modified through assimilation, fractional crystallization (AFC) en-route to the surface (A less than 6%). The trace element rich and high radiogenic Sr signature of some gabbros, this is the likely perturbation and then mobilization of Sr in the rock system during alteration. 43% fractional crystallization dominated by plagioclase and orthopyroxene is found responsible for magmatic evolution from gabbro to gabbroic diorite. Whereas, 44% fractional crystallization of a plagioclase-dominated mineral assemblage that also include clinopyroxene, titanomagnetite and orthopyroxene is found responsible for the evolutionary path from the

  20. Using Oxygen Isotopes of Zircon to Evaluate Magmatic Evolution and Crustal Contamination in the Halifax Pluton, Nova Scotia

    NASA Astrophysics Data System (ADS)

    Murray, K. E.; Lackey, J.; Valley, J. W.; Nowak, R.

    2007-12-01

    Oxygen isotope analysis of zircon (Zrc) is well suited for parsing out the magmatic history in granitoids. The Halifax pluton is the largest pluton (1060 km2) in the peraluminous South Mountain batholith. The Halifax pluton is mapped as a concentrically zoned body, with outer units comprising granodiorite, monzogranite and a mafic porphyry; these units are locally rich in metasedimentary xenoliths and magmatic enclaves. The exterior units surround a more felsic core of leucogranite [1]. Previous oxygen isotope studies of the pluton report high whole rock δ18O values that range from 10.7-11.7‰ [2], and indicate a significant supracrustal component in the source of the pluton. We report the first δ18O(Zrc) values from the Peggy's Cove monzogranite and an associated mafic porphyry. Samples were collected across 30 km of discontinuous exposures of the monzogranite. Values of δ18O(Zrc) vary from 7.71-8.26‰ (average = 8.15±±0.32‰(2 S.D.); n = 10). Small but systematic E-W regional variation in δ18O(Zrc) values suggests heterogeneous magmatic contamination within the monzogranite. Meter-scale magmatic enclaves, observed in close association with pods of diverse xenoliths and smaller enclaves at the western Cranberry Head locality, are slightly enriched in δ18O relative to the host monzogranite. These data combined support a model of magma mingling and heterogeneous mixing at the rim of the pluton, with contamination by high-δ18O rocks. Additional high-δ18O(Zrc) data from granodiorites on the northern margin of the Halifax pluton concur with these observations [3]. Typically, closed magmatic systems show increasing δ18O with SiO2 because more felsic magmas have a greater percentage of high-δ18O minerals such as quartz and feldspar. Thus, the Halifax pluton appears to exhibit an enrichment trend opposite of what would be expected of a closed evolving system. Emplacement mechanisms for the Halifax pluton proposed by previous workers suggest that the outer

  1. Municipal solid waste management strategies in Turkey.

    PubMed

    Turan, N Gamze; Coruh, Semra; Akdemir, Andaç; Ergun, Osman Nuri

    2009-01-01

    Municipal solid waste (MSW) is a major environmental problem in Turkey, as in many developing countries. Problems associated with municipal solid waste are difficult to address, but efforts towards more efficient collection and transportation and environmentally acceptable waste disposal continue in Turkey. Although strict regulations on the management of solid waste are in place, primitive disposal methods such as open dumping and discharge into surface water have been used in various parts of Turkey. This study presents a brief history of the legislative trends in Turkey for MSW management. The study also presents the MSW responsibility and management structure together with the present situation of generation, composition, recycling, and treatment. The results show that approximately 25 million ton of MSW are generated annually in Turkey. About 77% of the population receives MSW services. In spite of efforts to change open dumping areas into sanitary landfills and to build modern recycling and composting facilities, Turkey still has over 2000 open dumps.

  2. Construction of an Upper Crustal Reservoir by Lateral Magma Propagation: New insights from Geochronological Data of La Gloria Pluton, Central Chile

    NASA Astrophysics Data System (ADS)

    Gutiérrez, F. J.; Guillong, M.; Payacán, I. J.; Aravena, A.; Bachmann, O.; Parada, M. A.

    2014-12-01

    La Gloria Pluton (LGP) is a 10 Ma shallow elongated NNW reservoir of 17 km length and 4-6 km width as part of a NS trend of Miocene plutons in Central Chile. New LA-ICPMS U-Pb ages in zircons of La Gloria Pluton indicate that crystallization occurs mostly within an interval between 11.2 to 10 Ma, with southeastward decreasing ages. Zircon crystallization ages are consistently older at the boundaries of the pluton than at the center for a given cross-section. At regional scale the ages of LGP follows a plutonic trend of southward decreasing age: Estero Yerba Loca (10 Ma) and San Francisco Batholith (SFB), in the north; and Cerro Mesón Alto (12.5 Ma) and San Gabriel (SG; 13 Ma), in the south. Both regional and local (within-LGP) age trends suggest: 1) a progressive northward migration of the main deep magmatic source during the Miocene; and 2) a southeastward lateral propagation of the magma during the reservoir construction. The lateral propagation of the magma is also supported by subhorizontal mineral and magnetic lineations with a preferred NNW orientation within LGP. The within-pluton age distribution and internal configuration suggest incremental construction with horizontal propagation of magma within channels. Because the lateral migration of the magma play an important role on the thermal structure of the cooling pluton we perform numerical simulations that account for reheating caused by refilling along the axial core of the pluton . We speculate that pre-existing shallow crustal structures (faults and folds) would allow lateral magma canalization, particularly between the lower highly deformed volcanic Abanico Fm. and the less deformed overlaying volcanic Farellones Fm. The pluton distribution and internal organization in and around LGP suggest incremental construction with vertical and horizontal migration of magma within channels and reservoirs, yielding plutonic complexes with protracted ages and elongated geometries.

  3. Turkey knockdown in successive flocks.

    PubMed

    Evans, R D; Edson, R K; Watkins, K L; Robertson, J L; Meldrum, J B; Novilla, M N

    2000-01-01

    Turkey knockdown was diagnosed in three of five flocks of hen turkeys on a single farm within a 12-mo period. The age of birds in the flocks affected ranged from 6 wk 2 days to 7 wk 4 days. The attack rate ranged from 0.02% to 0.30% with a case fatality rate in affected birds ranging from 0 to 74%. The diagnosis was made on the basis of clinical signs and histopathologic lesions associated with knockdown. The feed in all flocks contained bacitracin methylene disalicylate and monensin (Coban). Affected birds were recumbent, demonstrated paresis, and were unable to vocalize. Postmortem examination revealed few significant lesions although pallor of the adductor muscles and petechiation in adductor and gastrocnemius muscles were noted. Birds that had been recumbent for extended periods were severely dehydrated. Consistent microscopic lesions included degeneration, necrosis, and regeneration of adductor, gastrocnemius, and abdominal muscles. No lesion in cardiac tissue was noted. Results of our investigation indicated that changes in water consumption, vitamin E status, and brooder to finisher movement correlated with the occurrence of knockdown. Turkey knockdown was defined in 1993 as any condition identified in a turkey flock that has affected the neuromuscular system to a degree that a turkey is unable to walk or stand. This definition was later modified to...neuromuscular or skeletal systems to a degree that a turkey is unable to walk or stand properly. Knockdown may be associated with numerous feed, management, or disease factors alone or in combination. Dosage of monensin, feed restriction/gorging, water restriction, heat stress, copper, mycotoxins, sodium chloride in feed, and sulfa drugs have all been suggested as contributing factors; however, laboratory studies to duplicate this have not been successful. This report presents observations from a single farm at which three of five hen flocks in a single year experienced knockdown. When a flock was reported as

  4. [Ne V] Emission in Optically Classified Starbursts

    NASA Astrophysics Data System (ADS)

    Abel, N. P.; Satyapal, S.

    2008-05-01

    Detecting active galactic nuclei (AGNs) in galaxies dominated by powerful nuclear star formation and extinction effects poses a unique challenge. Due to the longer wavelength emission and the ionization potential of Ne4+, infrared [Ne V] emission lines are thought to be excellent AGN diagnostics. However, stellar evolution models predict that Wolf-Rayet stars in young stellar clusters emit significant numbers of photons capable of creating Ne4+. Recent observations of [Ne V] emission in optically classified starburst galaxies require us to investigate whether [Ne V] can arise from star formation activity and not an AGN. In this work, we calculate the optical and IR spectrum of gas exposed to a young starburst and AGN SED. We find: (1) a range of parameters where [Ne V] emission can be explained solely by star formation and (2) a range of relative AGN to starburst luminosities that reproduces the [Ne V] observations, yet leaves the optical spectrum looking like a starburst. We also find that infrared emission-line diagnostics are much more sensitive to the AGNs than optical diagnostics, particularly for weak AGNs. We apply our model to the optically classified, yet [Ne V] emitting, starburst galaxy NGC 3621. We find, when taking the infrared and optical spectrum into account, ~30%-50% of the galaxy's total luminosity is due to an AGN. Our calculations show that [Ne V] emission is almost always the result of AGN activity. The models presented in this work can be used to determine the AGN contribution to a galaxy's power output.

  5. News from KM3NeT

    SciTech Connect

    Katz, Ulrich F.; Collaboration: KM3NeT Collaboration

    2014-11-18

    KM3NeT is a future research infrastructure in the Mediterranean Sea, hosting a multi-cubic-kilometre neutrino telescope and nodes for Earth and Sea sciences. In this report we shortly summarise the genesis of the KM3NeT project and present key elements of its technical design. The physics objectives of the KM3NeT neutrino telescope and some selected sensitivity estimates are discussed. Finally, some first results from prototype operations and the next steps towards implementation – in particular the first construction phase in 2014/15 – are described.

  6. Compositional and kinetic controls on liquid immiscibility in ferrobasalt-rhyolite volcanic and plutonic series

    NASA Astrophysics Data System (ADS)

    Charlier, Bernard; Namur, Olivier; Grove, Timothy L.

    2013-07-01

    We present major element compositions of basalts and their differentiation products for some major tholeiitic series. The dry, low-pressure liquid lines of descent are shown to approach or intersect the experimentally-defined compositional space of silicate liquid immiscibility. Ferrobasalt-rhyolite unmixing along tholeiitic trends in both volcanic and plutonic environments is supported by worldwide occurrence of immiscible globules in the mesostasis of erupted basalts, unmixed melt inclusions in cumulus phases of major layered intrusions such as Skaergaard and Sept Iles, and oxide-rich ferrogabbros closely associated with plagiogranites in the lower oceanic crust. Liquid immiscibility is promoted by low-pressure, anhydrous fractional crystallization that drives the low Al2O3, high FeO liquids into the two-liquid field. Kinetic controls can be important in the development of two-liquid separation. The undercooling that occurs at the slow cooling rates of plutonic environments promotes early development of liquid immiscibility at higher temperature. In contrast rapid cooling in erupted lavas leads to large undercoolings and liquid immiscibility develops at significantly lower temperatures. Unmixing leads to the development of a compositional gap characterized by the absence of intermediate compositions, a feature of many tholeiitic provinces. The compositions of experimental unmixed silica-rich melts coincide with those of natural rhyolites and plagiogranites with high FeOtot and low Al2O3, suggesting the potential role of large-scale separation of immiscible Si-rich liquid in the petrogenesis of late-stage residual melts. No trace of the paired ferrobasaltic melt is found in volcanic environments because of its uneruptable characteristics. Instead, Fe-Ti ± P-rich gabbros are the cumulate products of immiscible Fe-rich melts in plutonic settings. The immiscibility process may be difficult to identify because both melts crystallize the same phases with the same

  7. Oxygen Isotope Perspectives on Magma Sources and Pluton Assembly in Convergent Margin Batholiths

    NASA Astrophysics Data System (ADS)

    Lackey, J.

    2008-12-01

    Oxygen isotope (δ18O) analysis of zircon in the Sierra Nevada batholith (SNB) yields fresh insight on the origin of this and other convergent margin batholiths. Zircon precisely and accurately maps (δ18O) variation by circumventing the effects of differentiation and sub-solidus alteration[1]. New temporal and spatial δ18O patterns are recognized, and the findings have bearing in current debates on the tempo and mode of pluton and intrusive suite assembly [2-4]. At large scales, regional belts of high and low δ18O reveal markedly contrasting budgets of crust and mantle in magma sources at different points during formation of the batholith. Contrary to original thinking, recycling of supracrustal rocks is greater in the western than eastern SNB. Gradients of δ18O show variable input of crust and mantle within these regional belts; however, sharp shifts in δ18O between some belts suggest pre-batholith lithospheric breaks. Generally, δ18O breaks do not coincide with the 0.706 Sri line suggesting isotopic decoupling, either in sources or during crustal contamination. Where present, crustal contamination is limited to veneers on plutons, and is largely restricted to the western SNB. Careful investigation of individual intrusive suites, reveals details of source longevity. In the Tuolumne suite, limited variability of δ18O suggests remarkably source homogeneity despite evidence for protracted emplacement[2,4]. In contrast, the John Muir suite shows distinct trends in its older and younger plutons, with a δ18O transition recorded in the Lake Edison granodiorite. Thus, some suites may draw from stable sources over several million years, with differentiation in the upper crust creating zoning and textural diversity; others record source switching or depletion of sources. Over time, shifts in δ18O in the SNB are punctuated by major pulses of magmatism suggesting reorganization of sources, likely in response to intra-arc deformation[5]. Overall, results show that a

  8. Felsic plutonism in the Al Amar—Idsas area, Kingdom of Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Le Bel, L.; Laval, M.

    A tonalite—trondhjemite suite, calc-alkalic plutons and alkali-feldspar granites dated 670 and 580 Ma, intrude thick volcano-sedimentary rocks of the Al Amar group E of the Al Amar fault and the Abt schist W of the fault. The tonalite—trondhjemite suite (group I) is characterized by low Rb (50 ppm) and Sr (100-400 ppm) and by weakly fractionated rare-earth patterns (La/Yb Nca 2-3) with a weak negative Eu anomaly. Calc-alkalic plutons (group II) are richer in Rb (50-150 ppm), contain variable Sr (50-1000 ppm), and have strongly fractionated rare-earth patterns (La/Yb Nca 6-22) with no Eu anomaly. Alkali-feldspar granite (group III) is characterized by high Rb (150-200 ppm) and shows fractionated rare-earth patterns (La/Yb Nca 6-18) with a well-developed Eu anomaly. Group III includes 'specialized granites' with high Rb (300-400 ppm) and Sn (28-66 ppm), and rare-earth patterns showing a distinctive 'sea gull' profile with a very strong Eu anomaly (Eu*/Eu = 20). Oxygen isotope geochemistry suggests that group I rocks (¯x δ18O ca 7.0) were mantle-derived, and that group II and III rocks intruding the Al Amar group ( δ18O ca 7.9 and 8.8 respectively) were derived by remelting of group I, whereas those intruding Abt schist ( δ18O ca 8.7 and 10.8 respectively) were partially derived by anatexis of the Afif block. Magmatogenesis reflects an island-arc development. Rocks of group I represent the initial subduction phase. Syn- to late-tectonic plutons of group II intruded the arc east of the Al Amar fault and the accretionary prism (Abt schist) to the west, which was in collision with the older Afif block. Post-tectonic group III rocks were emplaced in an already cratonized area.

  9. The geochemistry of volcanic, plutonic and turbiditic rocks from Sumba, Indonesia

    NASA Astrophysics Data System (ADS)

    Lytwyn, J.; Rutherford, E.; Burke, K.; Xia, C.

    2001-06-01

    Rocks that reveal the geology of Sumba for times before the Later Miocene (˜16 Ma) are relatively few and are not particularly well exposed. This has led to uncertainty about the nature of the basement rocks of the island and especially about whether Sumba originated as a fragment of Australia, or of that part of southeastern Eurasia which many authors have called Sundaland. A third possibility is that Sumba is underlain by arc material generated on the ocean floor and is not a fragment of either continent. We have studied the geochemistry of volcanic, plutonic and turbiditic rocks collected from Sumba in an attempt to provide additional insight into the island's origin and history between Late Cretaceous (˜86 Ma) and Early Miocene (˜16 Ma) times. Late Cretaceous to Early Oligocene (˜31 Ma) volcanic rocks on Sumba range compositionally from basalts to andesites, and are of typical oceanic island-arc affinity, exhibiting geochemical characteristics similar to those of high-Al basalts and their derivatives. Compositions indicate evolution along both calc-alkaline and tholeiitic trends. Some samples show indications of possible modifications by slab-derived melts and/or related fluids and also of contamination by turbiditic sediments. Gabbros and diorites collected from the Paleocene Tanadaro intrusion are compositionally similar to the associated volcanic rocks and, we consider, represent the plutonic equivalents of high-Al basalt. The geochemistry of Cretaceous turbiditic sedimentary rocks on Sumba indicates close proximity to an intra-oceanic island-arc environment. These results are consistent with the geochemical, sedimentological, stratigraphic, paleontological and paleomagnetic results of other investigators which together indicate that: (1) Late Cretaceous to Early Oligocene volcanic, plutonic and volcaniclastic rocks of Sumba are island-arc- and forearc-related; (2) the arc involved appears to have been what we refer to as the Great Indonesian Volcanic

  10. Natural radioactivity and radiation index of the major plutonic bodies in Greece.

    PubMed

    Papadopoulos, A; Christofides, G; Koroneos, A; Papadopoulou, L; Papastefanou, C; Stoulos, S

    2013-10-01

    The natural radioactivity of the major plutonic bodies in Greece, as well as the assessment of any potential health hazard due to their usage as decorative building materials is studied. One hundred and twenty one samples from every major plutonic body in Greece, including various rock-types from gabbro to granite, have been measured for their natural radioactivity using γ-spectrometry methodology. According to the experimental results, the natural radioactivity levels were ranged up to 315 Bq kg(-1) for (226)Ra, up to 376 Bq kg(-1) for (232)Th and up to 1632 Bq kg(-1) for (40)K, with arithmetic mean values and standard deviations of 74 (±51), 85 (±54) and 881 (±331) Bq kg(-1) respectively, which are below the international representative mean values for granite stones. The excess on the effective dose received annually indoors due to granite tiles usage is estimated considering a standard room model where granite tiles with 1.5 cm in thickness cover only the floor of the room. The increment on the external γ-radiation effective dose rate shows a Gaussian distribution well dispersed below 0.3 mSv y(-1), presenting a mean value of 0.14 (±0.06) mSv y(-1). In case of the internal α-radiation a log-normal distribution is appeared scattering below 0.5 mSv y(-1) with a mean value 0.19 (±0.13) mSv y(-1), for a well-ventilated living environment. In case of a poor-ventilated room the increment on internal effective dose rate is estimated with a mean value 0.27 (±0.19) mSv y(-1) scattering below 0.8 mSv y(-1). The majority of the samples increase the external as well as the internal dose less than 30% of the maximum permitted limit of the effective dose rate. Therefore, at least from radiological point of view, the plutonic rocks of Greece could be safely used as decorative building materials. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Fowl Cholera Immunization in Turkeys

    PubMed Central

    Brown, John; Dawe, Donald L.; Davis, Richard B.; Foster, John W.; Srivastava, K. K.

    1970-01-01

    Cell fractions of Pastuerella multocida (P-1059) were tested as vaccines against fowl cholera in turkeys. These fractions were culture filtrate, cell wall, and cytoplasm. A second culture filtrate preparation made from cells grown on blood-agar rather than the standard medium was also tested along with a “combination” preparation made by recombination of the cell fractions. Each preparation was tested in three vehicles: saline, alum (0.5%), and Freund Incomplete Adjuvant (50%). The turkeys vaccinated with these preparations were challenged by exposure to an experimental epornitic of fowl cholera. The combination fraction appeared to be the most promising vaccine when compared to the protective action of the commercial bacterin included in the test as a positive control. PMID:5422310

  12. U-Pb ages and Hf isotope compositions of zircons in plutonic rocks from the central Famatinian arc, Argentina

    NASA Astrophysics Data System (ADS)

    Otamendi, Juan E.; Ducea, Mihai N.; Cristofolini, Eber A.; Tibaldi, Alina M.; Camilletti, Giuliano C.; Bergantz, George W.

    2017-07-01

    The Famatinian arc formed around the South Iapetus rim during the Ordovician, when oceanic lithosphere subducted beneath the West Gondwana margin. We present combined in situ U-Th-Pb and Lu-Hf isotope analyses for zircon to gain insights into the origin and evolution of Famatinian magmatism. Zircon crystals sampled from four intermediate and silicic plutonic rocks confirm previous observations showing that voluminous magmatism took place during a relatively short pulse between the Early and Middle Ordovician (472-465 Ma). The entire zircon population for the four plutonic rocks yields coherent εHf negative values and spreads over several ranges of initial εHf(t) units (-0.3 to -8.0). The range of εHf units in detrital zircons of Famatinian metasedimentary rocks reflects a prolonged history of the cratonic sources during the Proterozoic to the earliest Phanerozoic. Typical tonalites and granodiorites that contain zircons with evolved Hf isotopic compositions formed upon incorporating (meta)sedimentary materials into calc-alkaline metaluminous magmas. The evolved Hf isotope ratios of zircons in the subduction related plutonic rocks strongly reflect the Hf isotopic character of the metasedimentary contaminant, even though the linked differentiation and growth of the Famatinian arc crust was driven by ascending and evolving mantle magmas. Geochronology and Hf isotope systematics in plutonic zircons allow us understanding the petrogenesis of igneous series and the provenance of magma sources. However, these data could be inadequate for computing model ages and supporting models of crustal evolution.

  13. Proterozoic subduction and terrane amalgamation in the southwestern Grenville province, Canada: Evidence from ultrapotassic to shoshonitic plutonism

    NASA Astrophysics Data System (ADS)

    Corriveau, Louise

    1990-07-01

    A late Grenvillian (1089-1076 Ma) subduction regime followed by terrane amalgamation is postulated as the paleoenvironment of a 400-km-long belt of potassium-rich alkaline and shoshonitic plutons in the Central metasedimentary belt of the southwestern Grenville province, Canada. Emplacement of the plutons postdates the regional metamorphism in the country rock, but predates major shear zones that form a structural boundary for the plutonic belt. The extent, timing, and magmatic affinities of the suite delineate the Gatineau domain within the current Mont-Laurier terrane of Quebec and are compelling evidence for the allochthonous nature of the Elzevir terrane and its extension eastward to Rideau Lake in Ontario and northward into the Gatineau domain. The belt trends northeast, the emplacement ages are younger to the southeast, and the magmatic affinities are those of island-arc ultrapotassic to shoshonitic rocks. This is interpreted to reflect the existence of a southeast-dipping, northeast-trending subduction zone beneath the combined Elzevir-Gatineau terrane between 1089 and 1076 Ma. Subsequent to subduction, amalgamation of the Elzevir terrane to the other terranes formed the Central metasedimentary belt, which then accreted and collided with the allochthonous polycyclic belt. These events provide evidence that the Ottawan orogeny commenced at ca. 1090 Ma in the Central metasedimentary belt. A modern analogue of this plutonism and its tectonic setting may have been the magmatism and arc-continent collision and subduction setting of the Sunda are, Indonesia.

  14. Transformation of juvenile Izu-Bonin-Mariana oceanic arc into mature continental crust: An example from the Neogene Izu collision zone granitoid plutons, Central Japan

    NASA Astrophysics Data System (ADS)

    Saito, Satoshi; Tani, Kenichiro

    2017-04-01

    Granitic rocks (sensulato) are major constituents of upper continental crust. Recent reviews reveal that the average composition of Phanerozoic upper continental crust is granodioritic. Although oceanic arcs are regarded as a site producing continental crust material in an oceanic setting, intermediate to felsic igneous rocks occurring in modern oceanic arcs are dominantly tonalitic to trondhjemitic in composition and have lower incompatible element contents than the average upper continental crust. Therefore, juvenile oceanic arcs require additional processes in order to get transformed into mature continental crust enriched in incompatible elements. Neogene granitoid plutons are widely exposed in the Izu Collision Zone in central Japan, where the northern end of the Izu-Bonin-Mariana (IBM) arc (juvenile oceanic arc) has been colliding with the Honshu arc (mature island arc) since Middle Miocene. The plutons in this area are composed of various types of granitoids ranging from tonalite to trondhjemite, granodiorite, monzogranite and granite. Three main granitoid plutons are distributed in this area: Tanzawa plutonic complex, Kofu granitic complex, and Kaikomagatake granitoid pluton. Tanzawa plutonic complex is dominantly composed of tonalite and trondhjemite and characterized by low concentration of incompatible elements and shows geochemical similarity with modern juvenile oceanic arcs. In contrast, Kofu granitic complex and Kaikomagatake granitoid pluton consists mainly of granodiorite, monzogranite and granite and their incompatible element abundances are comparable to the average upper continental crust. Previous petrogenetic studies on these plutons suggested that (1) the Tanzawa plutonic complex formed by lower crustal anatexis of juvenile basaltic rocks occurring in the IBM arc, (2) the Kofu granitic complex formed by anatexis of 'hybrid lower crust' comprising of both basaltic rocks of the IBM arc and metasedimentary rocks of the Honshu arc, and (3) the

  15. Constraints on the Depth of Generation and Emplacement of Magma in the Coast Plutonic Complex, British Columbia, From Magmatic Epidote Textures

    NASA Astrophysics Data System (ADS)

    Hamblock, J. M.; Andronicos, C. L.

    2007-12-01

    We have examined magmatic epidote-bearing plutons in the Coast Plutonic Complex to understand the depth at which they were generated and emplaced. Mt. Gamsby, located east of the Coast shear zone between Kitimat and Bella Coola, British Columbia, contains a magmatic epidote-bearing tonalite-quartz diorite pluton. This pluton had a crystallization sequence of pyroxene, amphibole, epidote, plagioclase, and biotite. The lack of garnet is consistent with trace element data, which indicate that garnet was not present in the source region and, therefore, that the magma was sourced at pressures less than ca. 1.4 GPa. Epidote inclusions in plagioclase constrain the pressure during early crystallization of the epidote to greater than 1 GPa. P-T estimates from the pluton and surrounding country rock suggest that the magma migrated to shallower levels and was emplaced at depths of ca. 0.8-1.0 GPa. Magmatic epidote also occurs in the Ecstall, Butedale, and Captain Cove plutons west of the Coast shear zone south of Prince Rupert. In the Captain Cove pluton, textures show that plagioclase crystallized before epidote, and pluton crystallization pressures are estimated to be 0.65-0.75 GPa. These data are consistent with experimental work that indicates that the crystallization of plagioclase before epidote occurs at a lower pressure than epidote before plagioclase. The magmatic epidote in the Ecstall and Butedale plutons commonly occurs as large vermicular grains intergrown with quartzofeldspathic minerals. We interpret this texture to indicate late crystallization of epidote, consistent with prior studies. Pressure estimates for the Ecstall pluton are between ca. 0.5 and 0.8 GPa and vary along strike. The pressure of emplacement of the Butedale pluton is not well constrained, but Al-in-hornblende pressures of 0.6 and 0.8 GPa have been obtained from a portion of the pluton. The pressures in the Butedale and Ecstall plutons are lower than pressures at Mt. Gamsby, which shows early

  16. Pediatric malignancies in Bursa, Turkey.

    PubMed

    Günay, U; Meral, A; Sevinir, B

    1996-01-01

    Turkey is among the countries affected by ionizing radiation from the Chernobyl accident of April 26, 1986. The northern part of Turkey, where the city of Bursa is located, is presumed to be more influenced by the nuclear catastrophe. The radioactive elements in the atmosphere have been examined at various intervals after May 1, 1986 and barium-140 and lanthanum-140, fission agents of uranium-235, have been found in the atmosphere. Their exact concentration could not be measured. The aim of this report is to review the pediatric malignancies diagnosed in our institution between 1986 and 1995, with a view on any significant increase in the number of these cases. The patients were divided into three groups: acute leukemia patients (101 cases), lymphomas (44 cases), and solid tumors (31 cases). All three groups showed a tendency to increase after 1986; the increase in leukemia cases between 1986 and 1995 was found to be significantly higher (p < 0.001) when compared with the years before 1986. The increase in lymphoma and solid tumor cases after 1986 was not found to be significant (p > 0.05). We cannot rule out environmental causes other than the effects of the Chernobyl accident, and we feel that more intense epidemiological studies should be carried out on this subject in other areas of Turkey.

  17. Cerebral encephalomalacia in commercial turkeys.

    PubMed

    Ficken, M D; Cummings, T S; Wages, D P

    1993-01-01

    A flock of 9 1/2-week-old commercial tom turkeys experienced high mortality after consuming a complete feed containing an unidentified toxic substance. Initially, turkeys were found dead. Clinically, the birds were calm and still but became hyperexcitable with noise. A small percentage of birds exhibited torticollis, opisthotonos, circling, ataxia, and blindness. Findings at necropsy and upon microscopic examination were bilaterally symmetrical areas of necrosis of the cerebral hemispheres in the area of the neostriatum that were well demarcated from the surrounding normal neuropil. A feeding trial with the suspect feed in twelve 4-week-old turkey hens induced clinical disease and gross and microscopic brain changes similar to those observed in the field case. Analyses for the following substances in the suspect feed were either negative or within acceptable limits: salt, selenium, furazolidone, monensin, amprolium, 3-nitro-4-hydroxyphenylarsonic acid, aflatoxin, deoxynivalenol, zearalenone, T-2 toxin, ochratoxin, fumonisin, organophosphates, chlorinated hydrocarbons, and carbamates. The toxic component of the feed remains unidentified.

  18. Women and leprosy in Turkey.

    PubMed

    Cakiner, T; Yüksel, A; Soydan, M; Saylan, T; Bahçeci, E

    1993-01-01

    Women in Turkey have many social, cultural and economical problems. Women with leprosy have problems in common with other women as well as those related to physical and social consequences of leprosy. There are 2,414 patients with leprosy in Turkey, registered to Istanbul Leprosy Hospital and 829 of them are females. The mean age and duration of disease of our female leprosy patients are high. Most women with leprosy were born in eastern part of Turkey where prevalence of leprosy is higher and most have moved to western regions. The proportion of women who have some kind of social security is very low. Their economic status is also not good and 79% of patients had stigma about their disease. Three fourths of these cases have been hospitalized some time, for different reasons. Most of them (97.2%) have inactive disease at present. Disability degrees of patients are high. Patients with disability degrees over one constitute 54% of total for eyes, 55% for hands and 51% for feet. High percentage of multibacillary form and long duration of disease, delayed diagnosis, insufficient self-care of patients due to low socio-economic and cultural status and failure of health personnel to control patients periodically may be among the reasons for such high ratios of moderate and severe disabilities. In the light of the data obtained in our study, some measures to alleviate the problems of patients resulting from their socio-economic, cultural and social status have been suggested.

  19. Web life: Mahalo.ne.Trash

    NASA Astrophysics Data System (ADS)

    2014-05-01

    Mahalo.ne.Trash is the personal blog of John Asher Johnson, an astronomer at Harvard University in the US who began blogging in 2007, when he was about to begin a postdoctoral fellowship at the University of Hawaii.

  20. The NeXus data format

    PubMed Central

    Könnecke, Mark; Akeroyd, Frederick A.; Bernstein, Herbert J.; Brewster, Aaron S.; Campbell, Stuart I.; Clausen, Björn; Cottrell, Stephen; Hoffmann, Jens Uwe; Jemian, Pete R.; Männicke, David; Osborn, Raymond; Peterson, Peter F.; Richter, Tobias; Suzuki, Jiro; Watts, Benjamin; Wintersberger, Eugen; Wuttke, Joachim

    2015-01-01

    NeXus is an effort by an international group of scientists to define a common data exchange and archival format for neutron, X-ray and muon experiments. NeXus is built on top of the scientific data format HDF5 and adds domain-specific rules for organizing data within HDF5 files, in addition to a dictionary of well defined domain-specific field names. The NeXus data format has two purposes. First, it defines a format that can serve as a container for all relevant data associated with a beamline. This is a very important use case. Second, it defines standards in the form of application definitions for the exchange of data between applications. NeXus provides structures for raw experimental data as well as for processed data. PMID:26089752

  1. The NeXus data format

    SciTech Connect

    Könnecke, Mark; Akeroyd, Frederick A.; Bernstein, Herbert J.; Brewster, Aaron S.; Campbell, Stuart I.; Clausen, Björn; Cottrell, Stephen; Hoffmann, Jens Uwe; Jemian, Pete R.; Männicke, David; Osborn, Raymond; Peterson, Peter F.; Richter, Tobias; Suzuki, Jiro; Watts, Benjamin; Wintersberger, Eugen; Wuttke, Joachim

    2015-01-30

    NeXus is an effort by an international group of scientists to define a common data exchange and archival format for neutron, X-ray and muon experiments. NeXus is built on top of the scientific data format HDF5 and adds domain-specific rules for organizing data within HDF5 files, in addition to a dictionary of well defined domain-specific field names. The NeXus data format has two purposes. First, it defines a format that can serve as a container for all relevant data associated with a beamline. This is a very important use case. Second, it defines standards in the form of application definitions for the exchange of data between applications. As a result, NeXus provides structures for raw experimental data as well as for processed data.

  2. The NeXus data format

    DOE PAGES

    Könnecke, Mark; Akeroyd, Frederick A.; Bernstein, Herbert J.; ...

    2015-01-30

    NeXus is an effort by an international group of scientists to define a common data exchange and archival format for neutron, X-ray and muon experiments. NeXus is built on top of the scientific data format HDF5 and adds domain-specific rules for organizing data within HDF5 files, in addition to a dictionary of well defined domain-specific field names. The NeXus data format has two purposes. First, it defines a format that can serve as a container for all relevant data associated with a beamline. This is a very important use case. Second, it defines standards in the form of application definitionsmore » for the exchange of data between applications. As a result, NeXus provides structures for raw experimental data as well as for processed data.« less

  3. Exploring the plutonic crust at a fast-spreading ridge:new drilling at Hess Deep

    SciTech Connect

    Gillis, Kathryn M.; Snow, Jonathan E.; Klaus, Adam; Guerin, Gilles; Abe, Natsue; Akizawa, Norikatsu; Ceuleneer, Georges; Cheadle, Michael J.; Adriao, Alden de Brito; Faak, Kathrin; Falloon, Trevor J.; Friedman, Sarah A.; Godard, Marguerite M.; Harigane, Yumiko; Horst, Andrew J.; Hoshide, Takashi; Ildefonse, Benoit; Jean, Marlon M.; John, Barbara E.; Koepke, Juergen H.; Machi, Sumiaki; Maeda, Jinichiro; Marks, Naomi E.; McCaig, Andrew M.; Meyer, Romain; Morris, Antony; Nozaka, Toshio; Python, Marie; Saha, Abhishek; Wintsch, Robert P.

    2013-02-28

    Integrated Ocean Drilling Program (IODP) Hess Deep Expedition 345 was designed to sample lower crustal primitive gabbroic rocks that formed at the fast-spreading East Pacific Rise (EPR) in order to test models of magmatic accretion and the intensity of hydrothermal cooling at depth. The Hess Deep Rift was selected to exploit tectonic exposures of young EPR plutonic crust, building upon results from ODP Leg 147 as well as more recent submersible, remotely operated vehicle, and near-bottom surveys. The primary goal was to acquire the observations required to test end-member crustal accretion models that were in large part based on relationships from ophiolites, in combination with mid-ocean ridge geophysical studies. This goal was achieved with the recovery of primitive layered olivine gabbros and troctolites with many unexpected mineralogical and textural relationships, such as the abundance of orthopyroxene and the preservation of delicate skeletal olivine textures.

  4. Pb isotopes in Ascension Island rocks: oceanic origin for the gabbroic to granitic plutonic xenoliths

    NASA Astrophysics Data System (ADS)

    Weis, D.

    1983-02-01

    The Pb isotopic compositions and U and Pb concentrations of the lava series (alkali basalt to comendite) and of their plutonic xenoliths (gabbro to alkaline granite) of Ascension Island are reported. The data are used to evaluate the source of the xenoliths which formed two differentiation suites: the acidic and intermediate xenoliths together with most of the lavas on the one hand, and the gabbroic xenoliths and a basaltic tuff on the other hand. The Pb isotopic compositions imply a mantle origin for the source magmas of the xenoliths and confirm the possibility of generating granitic rocks in an oceanic environment by fractional crystallization of a mantle-derived magma whose geochemical and isotopic characteristics are comparable to the source magmas of oceanic island basalts.

  5. Magmatic construction and duration of solidification of Searchlight pluton, Eldorado Mountains, Nevada (USA)

    NASA Astrophysics Data System (ADS)

    Miller, J. S.; Cates, N. L.; Miller, C. F.; Wooden, J. L.; Means, M. A.; Ericksen, S.

    2003-12-01

    The process of chamber construction and the residence time of magma in mid- to upper crustal magma bodies have been illuminated by recent advances in high-resolution geochronology. Most work has so far concentrated on young volcanic systems; few geochrononlogic data have addressed magma chamber longevity and history from studying plutons. Plutons offer an important complementary record of magma processing and solidification, and can therefore reveal much about the internal workings of magma chambers. The Miocene Searchlight pluton (Nevada, USA) is a spectacular example of a very thick magma chamber (10-12 km). Crystal accumulation (mafic quartz monzonite cumulate), coupled with roof-down solidification (upper quartz monzonite) resulted in segregation of evolved felsic melt in the chamber interior (middle granite). Initially horizontal and gradational internal contacts and coplanar magmatic fabrics between all major units, geochemical mass balance, and very limited isotopic variation among major units, suggest that the entire pluton was molten at one time. However, the time inteval over which the chamber solidified was not well known. New TIMS and in situ ion microprobe U/Pb dating of zircon, combined with our earlier and ongoing field and isotopic studies, now appear to document a protracted magma chamber history. TIMS and ion microprobe dating (Stanford/USGS SHRIMP-RG) was done on two samples, and a third sample was dated by ion microprobe only. A multi-grain, multi-fraction discordia lower intercept age of 16.7+/-0.5 Ma (MSWD=22) was obtained by TIMS from the lower mafic quartz monzonite cumulate. Ion probe dating of zircons from the same sample yielded a 206Pb/238U age of 16.9+/-0.2 Ma (MSWD=1.3; N=24) in agreement with the TIMS lower intercept age. A discordia lower intercept age of 15.7+/-0.4 Ma (MSWD=3.7, one concordant point at 15.8 Ma) was obtained from the middle granite unit. Ion probe dating of zircons from the same sample yielded a 206Pb/238U age of 16

  6. Numerical simulations of late-stage magma flow in La Gloria pluton, central Chile

    NASA Astrophysics Data System (ADS)

    Gutierrez, F. J.; Payacan, I.; Bachmann, O.; Parada, M.

    2012-12-01

    To better understand the internal dynamics of small, shallow, silicic magma reservoirs, we performed 2-D time-dependent fluid dynamical numerical simulations of a cooling magma encased in the upper crust. This model takes into account the main magmatic phases (crystals, melt, and exsolved H2O), whose stability fields were calibrated by the MELTS thermodynamic software. The results of those simulations were compared to the composition, mineralogy, and AMS data obtained for La Gloria Pluton (LGP), a 10 Ma old intrusion with c. 2.5 km of vertical exposure located in the southern Andes. LGP represents a particularly simple case of a shallow silicic magma reservoir of about 250 km3. LGP was assembled in a few pulses and cooled over a short time interval where subsolidus reequilibration was not pervasive, allowing identification of early and late magmatic conditions. LGP is vertically zoned from granodiorite/quartz monzodiorite to quartz monzonite towards the roof. Hornblende, bitotite, and minor magnetite are ubiquitous mafic phases. AMS samples were collected at 46 sites to determine the magnetic anisotropy susceptibility tensor. The magnetic fabric has an oblate shape. Lineations are weak and have a N-NW trend with a nearly horizontal dip. Foliations are more pronounced, having NW trends and dips that vary gradually from vertical at the walls to horizontal at the center and near the roof of the chamber. After 2 to 6 k.y. of simulated evolution, the resulting convection pattern in the crystallizing reservoir is consistent with the magnetic fabric, largely produced in the shear zone between the convecting liquid-dominated core and the growing solidification fronts adjacent to the walls. The bulk of the reservoir remains fairly homogeneous through time due to convection stirring. Magnetic lineations represent axisymmetric convection parallel to the main pluton elongation direction, whereas magnetic foliations represent shear localization near the magma locking point

  7. The probable continuum between emplacement of plutons and mare volcanism in lunar crustal evolution

    NASA Technical Reports Server (NTRS)

    Pieters, Carle M.

    1991-01-01

    A scenario for the formation of the Moon is advanced and is argued to be consistent with both known data and the leading hypothesis regarding the formation of the Moon. It is concluded that, although the volume of mare basalts is estimated to be only 0.1 percent of the lunar total, this value should not be taken to represent the amount of partial melt produced within the lunar interior, nor should the mare basalts be viewed as representing the only products of internal heating. The actual amount of magnetic activity is certain to be substantially larger, but cannot be estimated without a global assessment of lunar highland heterogeneity and the character, scale, and abundance of lunar plutons.

  8. The probable continuum between emplacement of plutons and mare volcanism in lunar crustal evolution

    NASA Astrophysics Data System (ADS)

    Pieters, Carle M.

    1991-06-01

    A scenario for the formation of the Moon is advanced and is argued to be consistent with both known data and the leading hypothesis regarding the formation of the Moon. It is concluded that, although the volume of mare basalts is estimated to be only 0.1 percent of the lunar total, this value should not be taken to represent the amount of partial melt produced within the lunar interior, nor should the mare basalts be viewed as representing the only products of internal heating. The actual amount of magnetic activity is certain to be substantially larger, but cannot be estimated without a global assessment of lunar highland heterogeneity and the character, scale, and abundance of lunar plutons.

  9. The plutonic-volcanic connection: are we even on the right track? (Invited)

    NASA Astrophysics Data System (ADS)

    Lundstrom, C.; Chakraborty, P.; Zambardi, T.

    2013-12-01

    The connection between silicic volcanic and plutonic rocks is full of contradictions. Foremost, granitic plutons reflect long slow incremental emplacement yet vast amounts of aphyric ignimbrite can be erupted rapidly. Heat flow, geophysical tomography, geochronology, geochemistry and petrology all provide observations, yet we are far from any consensus. The two most popular suggestions for forming ignimbrites, extraction of partial melt from a granitic upper crust reservoir or lower crustal hot zone melting, are each inconsistent with some observations/constraints. 100% melting of a granite mush, which may be consistent with many observations, was previously proposed1 but dismissed due to the large amount of latent heat needed to completely melt a mush. This work first presents new non-traditional isotope ratio data (Fe, Si) for plutonic and volcanic rocks suites showing that like Harker diagrams, volcanics and plutonics produce identical systematic behavior with differentiation. δ56Fe forms upwardly curving trends with increasing silica whereas δ30Si increases linearly. The logical deduction is that volcanics reflect 100% mobilization of a granite mush (not necessarily melting). While the origin of NTSI variations remains debated, the systematic NTSI trends are consistent with prediction of a top-down thermal migration zone refining (TMZR) process2. In part 2, we assume TMZR generates a granitic mush and propose that an instability in this mush leads to a runaway effect that results in eruption of aphyric ignimbrite. Experiments show that wet andesite evolves to granite at the cold (400°C) end of a thermal gradient3 with hydrous peralkaline melt existing interstitially. Previous work4 shows that such melts show retrograde immiscibility, segregating into a water rich melt and a water poor melt with temperature increase. Thus, as the mush builds down into hot crust, it crosses the immiscibility boundary triggering release of the water-rich phase; buoyant rise and

  10. Ordovician volcanic and plutonic complexes of the Sakmara allochthon in the southern Urals

    NASA Astrophysics Data System (ADS)

    Ryazantsev, A. V.; Tolmacheva, T. Yu.

    2016-11-01

    The Ordovician terrigenous, volcanic-sedimentary and volcanic sequences that formed in rifts of the active continental margin and igneous complexes of intraoceanic suprasubduction settings structurally related to ophiolites are closely spaced in allochthons of the Sakmara Zone in the southern Urals. The stratigraphic relationships of the Ordovician sequences have been established. Their age and facies features have been specified on the basis of biostratigraphic and geochronological data. The gabbro-tonalite-trondhjemite complex and the basalt-andesite-rhyolite sequence with massive sulfide mineralization make up a volcanic-plutonic association. These rock complexes vary in age from Late Ordovician to Early Silurian in certain structural units of the Sakmara Allochthon and to the east in the southern Urals. The proposed geodynamic model for the Ordovician in Paleozoides of the southern Urals reconstructs the active continental margin, whose complexes formed under extension settings, and the intraoceanic suprasubduction structures. The intraoceanic complexes display the evolution of a volcanic arc, back-, or interarc trough.

  11. A topaz- and amazonite-bearing leucogranite pluton in eastern Xinjiang, NW China and its zoning

    NASA Astrophysics Data System (ADS)

    Gu, Lian-xing; Zhang, Zun-zhong; Wu, Chang-zhi; Gou, Xiao-qin; Liao, Jing-juan; Yang, Hao

    2011-10-01

    The highly evolved Baishitouquan (BST) beryl-mineralised and topaz-bearing amazonite granite pluton is situated in the eastern Tianshan orogen of northwestern China. This pluton exhibits five well-exposed lithological zones, which, gradational from the lowest level, are leucogranite (zone-a), amazonite-bearing granite (zone-b), amazonite granite (zone-c), topaz-bearing amazonite granite (zone-d) and topaz albite granite (zone-e). The rocks are composed mainly of quartz, albite, and K-feldspar with varying amounts of topaz and amazonite. Quartz and topaz phenocrysts are the earliest phases that crystallised from the melt. Amazonite which replaced albite and K-feldspar was formed at the late magmatic stage or during the magmatic-hydrothermal transition. Geochemically, this pluton is characterised by high F (>2 wt.%) and Rb (499.5-1087.04 ppm), low P 2O 5 (⩽0.06 wt.%), Na 2O > K 2O, A/NKC = 1.00-1.11, low ratios of K/Rb, Al/Ga, Y/Ho, Zr/Ha and Nb/Ta, Σ14 REE = 28.6-231.9 ppm with gull wing-shaped distribution patterns (La CN/Lu CN = 0.11-0.68, Eu/Eu * = 0.0005-0.0110) and tetrad effects, and δ 18O = 9.75-7.32‰. Melt and fluid-melt inclusions coexist with liquid and vapour inclusions. The rocks were originated from a highly evolved granitic magma. The BST pluton exhibits transition in the following aspects from zone-a to zone-e: (1) As quartz and topaz phenocrysts progressively increase in size and crystal euhedral shape, rock textures change from equigranular to porphyritic. (2) Amazonite begins to appear in zone-b and becomes most concentrated in zone-c, whereas topaz begins to appear in zone-d becoming highly concentrated in zone-e. (3) Li and (Al + Ti) increase in white mica. (4) Petrochemically, there are general trends of increasing F, Al 2O 3 and Na 2O, and decreasing SiO 2, (Fe 2O 3 + FeO + MgO + MnO) and K 2O. Plots of normative compositions on the Qz-Ab-Or diagram move gradually towards the Ab apex. (5) Overall, Cr, Ni, Co, V, W, Nb, Zr, U, Th and Y

  12. Transport and Depositional Model for Large Country Rock Blocks Within the Searchlight Pluton, Southern Nevada

    NASA Astrophysics Data System (ADS)

    Perrault, D. S.; Furbish, D. J.; Miller, C. F.

    2006-05-01

    Searchlight pluton, a steeply tilted, 10 km thick Miocene intrusion in the Colorado River Extensional Corridor, exposes a zone with abundant, 5-400 m long blocks of Proterozoic gneiss. Blocks are present within a pair of subparallel horizons that make up a 2 km-thick zone and extend about 6 km laterally away from the pluton's north margin slightly oblique to the initially subhorizontal boundary between the pluton's middle unit (granite) and lower unit (qtz monzonite). Blocks are a variety of Precambrian metasedimentary gneisses, granitic gneisses, and mylonites. Blocks are commonly polylithologic and well foliated, with long and intermediate dimensions parallel to both their own foliation and that of the granitic host. Their average aspect ratio is ~ 4:1. Blocks within these horizons are interpreted as stoped (detached country rock that experience gravity- induced displacement) based on several lines of evidence. First, the distribution and abundances of blocks are not consistent with an isolated panel of wall rock (screen). The zone is laterally discontinuous (local abundances vary from ~ 0-40 %); transects a gradational (cm-m scale) internal contact at a slightly oblique angle; and tapers away from the pluton's margin. Second, while block foliations are homoclinal and show fairly consistent attitudes from block to block, block foliations are discordant with wall rock foliations at the same stratigraphic level (adjacent north wall). Third, mush disturbance features such as schlieren and enhanced feldspar foliation beneath blocks suggest a downward compaction. We interpret the blocks to have been emplaced after wall collapse events. We are using scaled settling experiments to clarify how blocks move within viscous fluids and interact with crystal mushes. The experiments, involving tabular ceramic blocks with density ρ = 1.75-2.20 g cm-3 settling in shampoo (ρ = 1.02 g cm-3) with viscosity μ = 20.35 Pa s, are scaled to order-of-magnitude by the particle Reynolds

  13. MicroBooNE Detector Move

    SciTech Connect

    Flemming, Bonnie; Rameika, Gina

    2014-06-25

    On Monday, June 23, 2014 the MicroBooNE detector -- a 30-ton vessel that will be used to study ghostly particles called neutrinos -- was transported three miles across the Fermilab site and gently lowered into the laboratory's Liquid-Argon Test Facility. This video documents that move, some taken with time-lapse camerad, and shows the process of getting the MicroBooNE detector to its new home.

  14. MicroBooNE Detector Move

    ScienceCinema

    Flemming, Bonnie; Rameika, Gina

    2016-07-12

    On Monday, June 23, 2014 the MicroBooNE detector -- a 30-ton vessel that will be used to study ghostly particles called neutrinos -- was transported three miles across the Fermilab site and gently lowered into the laboratory's Liquid-Argon Test Facility. This video documents that move, some taken with time-lapse camerad, and shows the process of getting the MicroBooNE detector to its new home.

  15. Jurassic plutons in the Desolation wilderness, northern Sierra Nevada batholith, California: A new segment in the Jurassic magmatic arc

    SciTech Connect

    Sabine, C. . Quaternary Sciences Center)

    1993-04-01

    A 164[+-]7 Ma U-P zircon date establishes a Middle- to Late-Jurassic age for the Pyramid Peak granite and synplutonic dioritoids and hybrid rocks that comprise the Crystal Range suite, located southwest of Lake Tahoe. A Jurassic age is also assigned to the Keiths Dome quartz monzonite and the Desolation Valley and Camper Flat granodiorites (Loomis', 1983, Early Granitic Group) which are distinctly older than surrounding Cretaceous granitoids. The Keiths Dome quartz monzonite, the oldest pluton of the group, may be as old as 180 Ma and is distinguished by ductile shear zones and recrystallization textures which indicate an episode of deformation not undergone by other plutons. The Camper flat and Desolation Valley granodiorites are the youngest plutons of the group. ENE-trending microdiorite dikes filled extensional fractures, perpendicular to the direction of shortening, in all Jurassic plutons but on none of the Cretaceous bodies. Jurassic plutons may help constrain ages of metasedimentary and metavolcanic rocks and associated structures in the Mount Tallac roof pendant. The Pyramid Peak granite intrudes the Sailor Canyon Formation which bears Late Pliensbachian ammonites (Fisher, 1990), and the Keiths Dome quartz monzonite intrudes the overlying Tuttle Lake Formation and transects faults and shear zones in the pendant. Initial Sr isotope ratios for the Pyramid Peak granite range between 0.705427 and 0.706874, spanning the 0.706 value taken by some to mark the western limit of sialic lower crust. Data suggest an isotopically mixed source containing mantle and crustal components. Such an environment is not inconsistent with a passive continental margin where mafic magma invades rifted continental crust.

  16. Petrogenesis of the Late Eocene Tarom-e-`Olya shoshonitic plutonic rocks from the Alborz-Azarbayjan zone, NW Iran

    NASA Astrophysics Data System (ADS)

    Nazarinia, Asma; Rashidnejad Omran, Nematollah; Arvin, Mohsen; Ahmadi, Parham

    2017-04-01

    The Late Eocene Tarom-e-`Olya pluton is one of the plutonic bodies cropped out in the Alborz-Azarbayjan zone in the NW of Iran. The pluton, with NW-SE trend, is intruded into the Eocene Sedimentry- volcanic rocks and comprises mainly of monzonite and quartz monzonite rocks with subordinate monzogranite, monzodiorite and quartz monzodiorite. They are I-type metaluminous in nature and shoshonitic in composition, characterized by rather high total alkalies (K2O> Na2O, ranging from 0.9 to 2wt %). On primitive mantle normalized trace element spider diagrams the pluton shows strong enrichment of large-ion lithophile elements (LILE) and depletion in high-field strength elements (HFSE) such as Nb, Ta and Ti. The Chondrite- normalized REE patterns are characterized by slightly enrichments of LREE over MREE and flat heavy REE Patterns [(Gd/Yb) N = 0.80-1.87], high (La/Yb) N = 6.38-9.89 and negative Eu anomaly [(Eu/Eu*) N= 0.46 -1.38]. These are typical geochemical features of subduction related magmatic rocks. The negative Eu anomaly suggests an important role for plagioclase and K-feldespar during fractional crystallization. The geochemical features indicate that a small degree of partial melting (1-5%) of lithospheric mantle source, previously undergone metasomatism due to infiltration of fluids and melts released from the subducted Neotethyan slab, generated the parental magma in a post-Collisional tectonic setting. The melting resulted from slab roll back of the down going Neotethyan oceanic crust in the final stages of subdction beneath the Central Iran that facilitated upwelling of hot asthenospheric mantle which in turn caused lithospheric extension and promote decompression melting of the metasomatized mantle wedge. Later, extensive fractional crystallization accompanied by minor crustal assimilation led to evolution of the intermediate acidic composition of the Tarom-e-`Olya pluton. Key words: Tarom-e-`Olya, Shoshonitic, Alborz-Azarbayjan zone, Neotethys

  17. Spatially controlled Fe and Si isotope variations: an alternative view on the formation of the Torres del Paine pluton

    NASA Astrophysics Data System (ADS)

    Gajos, Norbert A.; Lundstrom, Craig C.; Taylor, Alexander H.

    2016-11-01

    We present new Fe and Si isotope ratio data for the Torres del Paine igneous complex in southern Chile. The multi-composition pluton consists of an approximately 1 km vertical exposure of homogenous granite overlying a contemporaneous 250-m-thick mafic gabbro suite. This first-of-its-kind spatially dependent Fe and Si isotope investigation of a convergent margin-related pluton aims to understand the nature of granite and silicic igneous rock formation. Results collected by MC-ICP-MS show a trend of increasing δ56Fe and δ30Si with increasing silica content as well as a systematic increase in δ56Fe away from the mafic base of the pluton. The marginal Torres del Paine granites have heavier Fe isotope signatures (δ56Fe = +0.25 ± 0.02 2se) compared to granites found in the interior pluton (δ56Fe = +0.17 ± 0.02 2se). Cerro Toro country rock values are isotopically light in both Fe and Si isotopic systems (δ56Fe = +0.05 ± 0.02 ‰; δ30Si = -0.38 ± 0.07 ‰). The variations in the Fe and Si isotopic data cannot be accounted for by local assimilation of the wall rocks, in situ fractional crystallization, late-stage fluid exsolution or some combination of these processes. Instead, we conclude that thermal diffusion or source magma variation is the most likely process producing Fe isotope ratio variations in the Torres del Paine pluton.

  18. U-Pb Zircon Geochronology of the Emigrant Gap Composite Pluton, Northern Sierra Nevada, California: Implications for the Nevadan Orogeny

    USGS Publications Warehouse

    Girty, G. H.; Yoshinobu, S.; Wracher, M.D.; Girty, M.S.; Bryan, K.A.; Skinner, J.E.; McNulty, B.A.; Bracchi, K.A.; Harwood, D.S.; Hanson, R.E.

    1993-01-01

    The undeformed Emigrant Gap composite pluton postdates the Lower to Middle Jurassic Sailor Canyon and Middle Jurassic Tuttle Lake Formations. According to earlier workers, these latterformations contain main and late phase Nevadan-aged (155 +/-3 Ma) spaced, slaty, phyllitic, and crenulation cleavage. Recently discovered fossils indicate that the upper part of the Sailor Canyon Formation can be no older than early Bajocian and no younger than Bathonian. The Tuttle Lake Formation stratigraphically overlies the Sailor Canyon Formation and thus probably includes middle to late Bajocian and/or Bathonian strata.The results of U-Pb work suggest that the Emigrant Gap composite pluton is composed of units that range in age from 168 +/-2 Ma (latest Bathonian to early Callovian) to 163-164 Ma (late Callovian). These new data, when combined with observations summarized above, imply that the Tuttle Lake Formation is older than the undeformed oldest unit of the Emigrant Gap composite pluton (i.e., latest Bathonian or early Callovian), and thus was probably deposited and deformed sometime between middle Bajocian and middle late Bathonian time. Hence, the cleavage contained within the Sailor Canyon and Tuttle Lake Formations could not have formed during the Late Jurassic Nevadan orogeny 155 +/-3 Ma as suggested by earlier workers.Within the foothills belt, just to the west of the Emigrant Gap composite pluton, a pronounced contractional deformation occurred sometime between 200 and 163 Ma (Early to Middle Jurassic). This middle Mesozoic deformation apparently was the result of a collision between an oceanic arc and continental North America. Because of the gross similarity in timing of structures produced during this collision and structures in the wall rocks of the Emigrant Gap composite pluton, we suggest that the latter Middle Jurassic structures are also the result of arc-continent collision, albeit a slightly more continentward expression.

  19. Europium mass balance in polymict samples and implications for plutonic rocks of the lunar crust

    SciTech Connect

    Korotev, R.L.; Haskin, L.A. )

    1988-07-01

    From correlations of SM concentration and Sm/Eu ratio with Th concentration for a large number of polymict samples from various locations in the lunar highlands and the value of 0.91 {mu}g/g for the mean Th concentration of the highlands surface crust obtained by the orbiting gamma-ray experiments. The authors estimate the mean concentrations of Sm and Eu in the lunar surface crust to be between 2 and 3 {mu}g/g Sm and 0.7 and 1.2 {mu}g/g Eu. The compositional trends indicate that there is no significant enrichment or depletion of Eu, on the average, compared to Sm relative to chondritic abundances, i.e., there is no significant Eu anomaly in average upper crust. Although rich in plagioclase ({approximately}70%), the upper crust does not offer evidence for a gross vertical separation of plagioclase from the final liquid from which it crystallized. This and the chondritic ratio of Eu/Al in average highlands material imply that the net effect of the processes that led to formation of the lunar crust was to put most of the Al and incompatible elements in the crust. Among plutonic rocks, only plagioclase in rocks from the magnesian suite can supply the excess Eu in the polymict rocks. Owing to the intermediate value of the mean Mg/Fe ratio of the crust, a significant fraction of the mafic rocks of the lunar highlands must have lower Mg/Fe ratios than the norites and troctolites of the magnesian-suite of plutonic rocks. A large fraction of the plagioclase in the lunar crust is associated not with ferroan anorthosite, but with more mafic rocks. There is little evidence in the Eu data that the lunar crust ever consisted of a thick shell of nearly pure plagioclase, as envisioned in some formulations of the magma ocean model of its formation.

  20. Metamorphism and plutonism around the middle and south forks of the Feather River, California

    USGS Publications Warehouse

    Hietanen, Anna Martta

    1976-01-01

    The area around the Middle and South Forks of the Feather River provides information on metamorphic and igneous processes that bear on the origin of andesitic and granitic magmas in general and on the variation of their potassium content in particular. In the north, the area joins the Pulga and Bucks Lake quadrangles studied previously. Tectonically, this area is situated in the southern part of an arcuate segment of the Nevadan orogenic belt in the northwestern Sierra Nevada. The oldest rocks are metamorphosed calcalkaline island-arc-type andesite, dacite, and sodarhyolite with interbedded tuff layers (the Franklin Canyon Formation), all probably correlative with Devonian rocks in the Klamath Mountains. Younger rocks form a sequence of volcanic, volcaniclastic, and sedimentary rocks including some limestone (The Horseshoe Bend Formation), probably Permian in age. All the volcanic and sedimentary rocks were folded and recrystallized to the greenschist facies during the Nevadan (Jurassic) orogeny and were invaded by monzotonalitic magmas shortly thereafter. A second lineation and metamorphism to the epidote-amphibolite facies developed in a narrow zone around the plutons. In light of the concept of plate tectonics, it is suggested that the early (Devonian?) island-arc-type andesite, dacite, and sodarhyolite (the Franklin Canyon Formation) were derived from the mantle above a Benioff zone by partial melting of peridotite in hydrous conditions. The water was probably derived from an oceanic plate descending to the mantle. Later (Permian?) magmas were mainly basaltic; some discontinuous layers of potassium-rich rhyolite indicate a change into anhydrous conditions and a deeper level of magma generation. The plutonic magmas that invaded the metamorphic rocks at the end of the Jurassic may contain material from the mantle, the subducted oceanic lithosphere, and the downfolded metamorphic rocks. The ratio of partial melts from these three sources may have changed with time

  1. Petrology and geochemistry of the Russian peak pluton, Klamath Mountains, northern California

    SciTech Connect

    Cotkin, S.J.

    1987-01-01

    The Jurassic Russian Peak pluton consists of an older peridotite-to-quartz diorite complex intruded by younger granodiorite. U-Pb ages of 159 Ma have been obtained for both units. The peridotite-to-quartz diorite complex consists principally of quartz diorite; however, cumulate ultramafic rocks occur where it is in contact with Ordovician serpentinite, and the following zonation from serpentinite to quartz diorite is present: peridotite, pyroxenite, hornblendite, eucrite, and diorite. In order to evaluate the petrogenesis of the pluton a combination of field, petrographic, microprobe, X-ray fluorescence, and instrumental neutron activation analysis, and Rb-Sr data have been collected. Major and trace element modeling indicates that quartz-rich quartz diorite formed by crystallization, quartz-poor quartz diorite by accumulation of crystals plus trapped liquid, and ultramafic rocks by assimilation of serpentinite. Granodiorite on the other hand can be modeled by crystallization alone, with the precipitation of plagioclase, amphibole, and biotite accounting for the major and minor element variations. REE modeling indicates that a garnet-clinopyroxene amphibolite is a plausible source. A variety of techniques have been used to decipher the conditions of crystallization in each unit, including a comparison of paragenesis with crystallization experiments, geological thermometry and barometry, and phase equilibria. Pressure of intrusion is considered to have been approximately 3 kbar. The peridotite-to-quartz diorite complex intruded at about 1000/sup 0/C and was completely crystalline at 790/sup 0/C. Granodiorite intruded at somewhat lower temperatures and was completely crystalline at about 700/sup 0/C. The oxygen fugacity for both units was slightly above QFM. At its solidus, granodiorite was saturated with H/sub 2/O, which may account for the pervasive deuteric alteration of this unit.

  2. Ferrobasalt-rhyolite immiscibility in tholeiitic volcanic and plutonic series (Invited)

    NASA Astrophysics Data System (ADS)

    Charlier, B.; Namur, O.; Kamenetsky, V. S.; Grove, T. L.

    2013-12-01

    One atmosphere experiments show that silicate liquid immiscibility develops between Fe-rich and Si-rich melts below 1000-1020°C in compositionally diverse lavas that represent classical tholeiitic trends, such as Mull, Iceland, Snake River Plain and Sept Iles. Extreme iron enrichment along the evolution trend is not necessary; immiscibility also develops during iron depletion and silica enrichment after Fe-Ti oxide saturation. Natural liquid lines of descent for major tholeiitic series also approach or intersect the experimentally-defined compositional space of immiscibility. The importance of ferrobasalt-rhyolite unmixing in both volcanic and plutonic environments is supported by worldwide occurrence of immiscible globules in the mesostasis of erupted basalts, and by unmixed melt inclusions in cumulus phases of major layered intrusions such as Sept Iles, Skaergaard and Sudbury. A clear case of liquid immiscibility is also recorded in intrusive tholeiitic gabbros from the Siberian Large Igneous Province and is evidenced by textures and compositions of millimeter-sized silicate melt pools trapped in native iron. An important implication of immiscibility in natural ferrobasaltic provinces is the development of a compositional gap characterized by the absence of intermediate compositions, a major feature observed in many tholeiitic provinces and referred to as the Daly gap. The compositions of experimental silica-rich immiscible melts coincide with those of natural rhyolites with high FeOtot and low Al2O3, which suggests a potential role for large-scale immiscibility in the petrogenesis of late-stage ferroan silicic melts. No evidence for the paired ferrobasaltic melt is observed in volcanic provinces, probably because of its uneruptable characteristics. Instead, Fe-Ti×P-rich gabbros crystallized at depth and are the cumulate products of immiscible Fe-rich melts in plutonic settings, a feature clearly evidenced in the Sept Iles intrusion. The production of

  3. Geology and geochemistry of the Mount Riley-Mount Cox pluton, Dona Ana County, New Mexico

    SciTech Connect

    Zimbelman, D.R.; Siems, D.F.; Kilburn, J.E.; Hubert, A.E.

    1985-01-01

    The Mount Riley-Mount Cox area is comprised of a relatively homogeneous pluton of rhyodacite rising some 1600 feet above the La Mesa surface. The pluton, of apparent Tertiary age, intrudes Cretaceous sedimentary rocks and Tertiary ( ) latite and tuff. The rhyodacite is holocrystalline, light gray to pinkish gray, porphyritic to microporphyritic, and locally banded. Phenocrysts include hornblende, quartz, biotite, and calcite. The phenocrysts range in size from 0.2 to 2 mm and make up one to fifteen percent of the rock. The phenocrysts often display a glomerophyric texture within a trachytic groundmass. The groundmass ranges from cryptocrystalline to very fine grained and is composed of plagioclase, quartz, potassium feldspar, hornblende/biotite, and iron-oxide material. Locally, the rhyodacite displays millimeter-scale banding and a poikilitic texture consisting of quartz oikiocrysts and plagioclase chadocrysts. The rhyodacite averages 68.74%, SiO/sub 2/, 0.39% TiO/sub 2/, 16.40% Al/sub 2/O/sub 3/, 2.87% Fe/sub t/, 0.10% MnO, 1.21% MgO, 2.56% CaO, 3.79% Na/sub 2/O, and 3.96% K/sub 2/O. The rhyodacite is cut by veins and veinlets of brown to white calcite. The veins attain a maximum thickness of one meter, are locally bordered by calcite-cemented breccia zones, and locally include pyrite. The veins trend north or northwest, consistent with regional trends for the Rio Grande rift and the Texas Lineament, respectively. Sixty-five samples of rhyodacite, breccia, and vein were analyzed for 31 elements by emission-spectrographic methods. Trace-element data suggestive of hydrothermal mineralization was not recognized.

  4. Electromagnetic Transition Strengths in 27Ne

    NASA Astrophysics Data System (ADS)

    Loelius, Charles; Iwasaki, Hironori; Whitmore, Kenneth; Grinder, Mara; Elder, Robert; Lunderberg, Eric; Elman, Brandon; Longfellow, Brenden; Gade, Alexandra; Bazin, Daniel; Weisshaar, Dirk; Bender, Peter; Belarge, Joe; Kobayashi, Nobu; Petri, Marina; Heil, Sebastian; Mathy, Michael; Syndikus, Ina; Hufnagel, Alexander

    2016-09-01

    Previous measurements have established that halo nuclei are well characterized by their electromagnetic properties, with the E1 transition strengths reflecting a large neutron radius, and M1 transition strengths characterizing the dominant s wave strength. The 1/2+ excited state of 27Ne is close to the neutron separation energy and is expected to have a single valence neutron in the s orbital, and therefore has the potential to exhibit halo effects. Furthermore, neighboring isotopes 26Ne, 28Ne demonstrate substantial deformation, so that 27Ne should serve as an excellent benchmark for investigating the interplay between halo and deformation effects. We present here results of a new measurement of the lifetime of the 27Ne 1/2+ excited state, performed at the NSCL using the Recoil Distance Method with the TRIPLEX Plunger in conjunction with GRETINA. In addition, a Coulomb-excitation measurement of 27Ne has been performed using a novel application of the TRIPLEX plunger. The resulting transition strengths have been extracted and their implications are discussed.

  5. Excitation functions of the {sup 20}Ne+{sup 20}Ne system

    SciTech Connect

    Barrow, S.P.; Zurmuehle, R.; Murgatroyd, J.T.; Wimer, N.G.; Miao, Y.; Pohl, K.R.; Wuosmaa, A.H.; Betts, R.R.; Freer, M.; Glagola, B.

    1995-04-01

    A differentially pumped windowless {sup 20}Ne gas target and a {sup 20}Ne beam produced with the ATLAS accelerator at Argonne National Laboratory were used to measure angle-averaged excitation functions for binary decay of {sup 20}Ne+{sup 20}Ne into low-lying states of {sup 20}Ne+{sup 20}Ne and {sup 24}Mg+{sup 16}O, in the region of excitation energy in {sup 40}Ca from 51.4 to 58.2 MeV ({sup 20}Ne beam energies from 61.8 to 75.4 MeV). The {sup 20}Ne+{sup 20}Ne mass partition displays little correlated structure and there exists no evidence of intermediate width resonances in these channels with branching ratios comparable to those seen in the {sup 24}Mg+{sup 24}Mg system. Angular distributions for the elastic channel are consistent with those obtained using optical-model calculations. The exictation functions for the low-lying channels in {sup 24}Mg+{sup 16}O do contain some structures, with widths varying from 400 to 800 keV in the c.m. system.

  6. Structural evolution of the Rieserferner Pluton: insight into the localization of deformation and regional tectonics implications

    NASA Astrophysics Data System (ADS)

    Ceccato, Alberto; Pennacchioni, Giorgio

    2016-04-01

    The Rieserferner pluton (RFP, Eastern Alps, 32.2±0.4 Ma, Romer et al. 2003) represents a relatively deep intrusion (12-15 km; Cesare, 1994) among Periadriatic plutons. The central portion of the RFP consists of dominant tonalites and granodiorites that show a sequence of solid-state deformation structures developed during pluton cooling and exhumation. This sequence includes: (1) quartz veins, filling two set of steeply-dipping joints trending respectively E-W and NW-SE, commonly showing a millimetric grain size and associated with strike-slip displacement. (2) Quartz- and locally epidote-filled shallowly E-dipping joint set, commonly exploited as discrete derived from both the quartz veins and the host tonalite. These mylonites show a composite sense of shear with a first stage of left-lateral strike-slip followed by a top-to-E dip-slip (normal) movement. The synmylonitic assemblage includes biotite + plagioclase + white mica + epidote ± sphene ± garnet. (3) Set of N-S-trending steeply-dipping joints. These joints are concentrated in zones 1-2 m wide, separated by otherwise un-jointed domains a few tens to hundred meters wide, and are commonly exploited as brittle-ductile faults with dominant dip-slip (normal) kinematics. The mineral assemblage of fault rocks includes white mica + calcite ± chlorite ± quartz. The joints/faults are locally involved in folding. (4) Mafic dikes, dated at 26.3±3 Ma (Steenken et al., 2000), locally injecting the N-S trending set of joints. (5) Cataclasite- and pseudotachylyte-bearing faults also forming a set of steeply-dipping N-S-trending structures. These faults are commonly associated with epidote veins surrounded by bleaching haloes. (6) Zeolite-bearing faults marked by whitish cataclasites, fault gouges and mirror-like surfaces. These faults have a complex oblique- to strike-slip kinematics with an overall N-S trending lineation. As observed in other plutons (e.g. Adamello; Pennacchioni et al., 2006), the network of

  7. Salmonella Levels in Turkey Neck Skins, Drumstick Bones, and Spleens in Relation to Ground Turkey.

    PubMed

    Cui, Yue; Guran, Husnu S; Harrison, Mark A; Hofacre, Charles L; Alali, Walid Q

    2015-11-01

    The objective of this study was to determine Salmonella levels (presence and numbers) in turkey drumstick bone, spleen, and neck skin samples in relation to Salmonella contamination levels in ground turkey at the flock level. Over a 10-month period, a total of 300 samples of each turkey part (i.e., neck skin, spleen, and drumstick) from 20 flocks were collected at a commercial turkey processing plant after the evisceration step. Turkey flocks included in this study were classified as "targeted" and "nontargeted" based on the company's historical ground turkey contamination data. A flock that originated from a turkey farm that had previously produced one or more flocks with ≥20% Salmonella prevalence in ground turkey was labeled as a targeted flock (n = 13). The remaining seven flocks with <20% prevalence were labeled as nontargeted. All samples collected were tested for Salmonella presence and numbers by using most-probable-number and selective enrichment methods. Further genotypic analysis (pulsed-field gel electrophoresis) of the isolates was performed. Ground turkey samples were collected and analyzed for Salmonella levels by the cooperating turkey company. The outside surface of bone and spleen were sterilized prior to Salmonella analysis. The overall Salmonella prevalence in neck skin, drumstick bone, spleen, and ground turkey samples was 42.0, 9.3, 6.7, and 14.5%, respectively. Salmonella prevalence in neck skin, spleen, drumstick bone, and ground turkey from the targeted flocks was significantly (P < 0.05) higher than those from nontargeted flocks. There was a significant relationship between Salmonella presence in neck skin (when most probable numbers were ≥2 log) and Salmonella-positive ground turkey lot. Based on our findings, Salmonella was detected internally in drumstick bones and spleens at low levels, whereas Salmonella presence at higher levels in neck skin may indicate a flock with greater potential for Salmonella contamination of ground turkey.

  8. Mineral chemistry, crystallization conditions and geodynamic implications of the Oligo-Miocene granitoids in the Biga Peninsula, Northwest Turkey

    NASA Astrophysics Data System (ADS)

    Aysal, Namık

    2015-06-01

    Widespread plutonic rocks in NW Turkey occur within the southward-younging and overlapping magmatic belts across the Aegean region. Post-collisional magmatism is represented by a series of granitoidic intrusions and volcanic successions. K-Ar and U-Pb LA-ICP-MS zircon dating of the Kazdağ and Yenice plutons yielded ages between 20.5 ± 0.5 Ma and 27.89 ± 0.17 Ma (Late Oligocene-Early Miocene). The granitoid samples are high-K calc-alkaline and metaluminous to slightly peraluminous. The 87Sr/86Sr values for the granitoids, enclaves and leucocratic rocks range between 0.705168 and 0.708357. The initial 143Nd/144Nd ratios calculated for the crystallization ages of ca. 23-27 Ma are between 0.512425 and 0.512614, and the εNd values vary from -3.5 to 0.2. The Nd TDM model ages range between 0.73 and 1.13 Ga. These samples are enriched in LILEs and LREE and depleted in HFSEs with negative Eu anomalies, indicating that the melts were derived from an enriched lithospheric mantle modified by subducted slab-derived melts. Energy constrained-assimilation and fractional crystallization (EC-AFC) modelling indicates that fractional crystallization and crustal assimilation modified the parent magma's composition during its residence in the upper crust. The mineral chemistry of amphiboles, pyroxenes, biotites and feldspars is used to constrain the pressure (P), temperature (T), oxygen fugacity (logƒO2) and water contents (H2Omelt) during the crystallization of the magmas in the studied granitoids. The clinopyroxene temperatures are in the range of 823-910 ± 45 °C. The amphibole temperatures for the studied plutonic rocks are in the range of 707-926 °C (mean = 798 ± 45 °C), and the crystallization depths are estimated to be in the interval of 1.02-10.2 km. The NW Anatolian plutonic rocks can be considered to have been equilibrated at the oxygen fugacities of calcic amphiboles (logƒO2) between -8.99 and -13.96 bars (mean = -12.11 bar) and H2Omelt contents between 1.63% and

  9. Management guidelines for Merriam's wild turkeys

    Treesearch

    Richard W. Hoffman; Harley G. Shaw; Mark A. Rumble; Brian F. Wakeling; Cheryl M. Mollohan; Sanford D. Schemnitz; Ron Engel-Wilson; Dan A. Hengel

    1993-01-01

    The Merriam's wild turkey (Meleagris gallopavo merriami) is a bird of the western United States. Early naturalists found it here. This is where its range has been expanded through transplants. This is where it has become a valuable sport hunting and aesthetic resource. This is where it must be managed. To understand Merriam's wild turkey...

  10. Extreme Forms of Child Labour in Turkey

    ERIC Educational Resources Information Center

    Degirmencioglu, Serdar M.; Acar, Hakan; Acar, Yuksel Baykara

    2008-01-01

    Two little known forms of child labour in Turkey are examined. The process through which these children are made to work has parallels with the experiences of slaves. First, a long-standing practice from Northwestern Turkey of parents hiring children to better-off farmers is examined. Further, a more recent problem is examined where children are…

  11. Characteristics of Inclusive Classrooms in Turkey

    ERIC Educational Resources Information Center

    Melekoglu, Macid Ayhan

    2014-01-01

    In this paper, inclusive classrooms in Turkey are described in terms of the characteristics of both classroom teachers and students with special needs. Participants of this study consisted of 54 teachers working in inclusive classrooms and 54 students with mild intellectual disabilities in those classrooms in Turkey. Data for this study were…

  12. Citizenship Education in Turkey: Inclusive or Exclusive

    ERIC Educational Resources Information Center

    Ince, Basak

    2012-01-01

    This paper scrutinises citizenship education in Turkey from the foundation of the Turkish Republic (1923) to the present and explores the extent to which it encourages inclusive or exclusive concepts of national identity and citizenship. In Turkey, where there are citizens belonging to ethnic and religious minorities, civic education plays a…

  13. Enteric parvovirus infections of chickens and turkeys

    USDA-ARS?s Scientific Manuscript database

    Chicken and turkey parvoviruses are members of the Parvovirus family. Comparative sequence analysis of their genome structure revealed that they should form a new genus within the vertebrate Parvovirinae subfamily. The first chicken and turkey parvoviruses were identified by electron microscopy duri...

  14. Rights of the Child in Turkey.

    ERIC Educational Resources Information Center

    Naqvi, Yasmin

    This report to the United Nations Convention on the Rights of the Child contains observations of the World Organisation Against Torture (OMCT) concerning the application of the Convention by Turkey and observations regarding violence against girls in Turkey. The report is presented in three major parts. Part 1 asserts that despite the considerable…

  15. Government Publications and Gray Literature in Turkey

    ERIC Educational Resources Information Center

    Anameric, Hakan

    2009-01-01

    This paper investigates bibliographic control of government publications and gray literature in Turkey, in order to determine what further measures are needed to support researchers in both Turkey and abroad. It reports the circumstances surrounding the creation of "The Bibliography of Government Publications" prepared in 1971, and…

  16. Talking Turkey at the Wildwood Education Center.

    ERIC Educational Resources Information Center

    Warren, Mike

    1994-01-01

    A vocational education program at the Wildwood Education Center (Hornell, NY) enabled 9th and 10th grade special education students to design, build, and market turkey calls. A module on wildlife management piqued student interest in wildlife calls and turkey hunting and led to the project. The program improved vocational skills and increased…

  17. Issues of Identification of Giftedness in Turkey

    ERIC Educational Resources Information Center

    Sahin, Füsun

    2013-01-01

    The purpose of the study, giving rise to this article is to highlight factors that play a role in the identification of gifted students through analysis of literature and current issues in Turkey. The article points out differences between what is typically found in literature and what occurs in Turkey. It is based on a review of definitions and…

  18. Citizenship Education in Turkey: Inclusive or Exclusive

    ERIC Educational Resources Information Center

    Ince, Basak

    2012-01-01

    This paper scrutinises citizenship education in Turkey from the foundation of the Turkish Republic (1923) to the present and explores the extent to which it encourages inclusive or exclusive concepts of national identity and citizenship. In Turkey, where there are citizens belonging to ethnic and religious minorities, civic education plays a…

  19. Government Publications and Gray Literature in Turkey

    ERIC Educational Resources Information Center

    Anameric, Hakan

    2009-01-01

    This paper investigates bibliographic control of government publications and gray literature in Turkey, in order to determine what further measures are needed to support researchers in both Turkey and abroad. It reports the circumstances surrounding the creation of "The Bibliography of Government Publications" prepared in 1971, and…

  20. Extreme Forms of Child Labour in Turkey

    ERIC Educational Resources Information Center

    Degirmencioglu, Serdar M.; Acar, Hakan; Acar, Yuksel Baykara

    2008-01-01

    Two little known forms of child labour in Turkey are examined. The process through which these children are made to work has parallels with the experiences of slaves. First, a long-standing practice from Northwestern Turkey of parents hiring children to better-off farmers is examined. Further, a more recent problem is examined where children are…

  1. Of the importance of a leaf: the ethnobotany of sarma in Turkey and the Balkans.

    PubMed

    Dogan, Yunus; Nedelcheva, Anely; Łuczaj, Łukasz; Drăgulescu, Constantin; Stefkov, Gjoshe; Maglajlić, Aida; Ferrier, Jonathan; Papp, Nora; Hajdari, Avni; Mustafa, Behxhet; Dajić-Stevanović, Zora; Pieroni, Andrea

    2015-04-03

    Sarma - cooked leaves rolled around a filling made from rice and/or minced meat, possibly vegetables and seasoning plants - represents one of the most widespread feasting dishes of the Middle Eastern and South-Eastern European cuisines. Although cabbage and grape vine sarma is well-known worldwide, the use of alternative plant leaves remains largely unexplored. The aim of this research was to document all of the botanical taxa whose leaves are used for preparing sarma in the folk cuisines of Turkey and the Balkans. Field studies were conducted during broader ethnobotanical surveys, as well as during ad-hoc investigations between the years 2011 and 2014 that included diverse rural communities in Croatia, Bosnia and Herzegovina, Serbia, Kosovo, Albania, Macedonia, Bulgaria, Romania, and Turkey. Primary ethnobotanical and folkloric literatures in each country were also considered. Eighty-seven botanical taxa, mainly wild, belonging to 50 genera and 27 families, were found to represent the bio-cultural heritage of sarma in Turkey and the Balkans. The greatest plant biodiversity in sarma was found in Turkey and, to less extent, in Bulgaria and Romania. The most commonly used leaves for preparing sarma were those of cabbage (both fresh and lacto-fermented), grape vine, beet, dock, sorrel, horseradish, lime tree, bean, and spinach. In a few cases, the leaves of endemic species (Centaurea haradjianii, Rumex gracilescens, and R. olympicus in Turkey) were recorded. Other uncommon sarma preparations were based on lightly toxic taxa, such as potato leaves in NE Albania, leaves of Arum, Convolvulus, and Smilax species in Turkey, of Phytolacca americana in Macedonia, and of Tussilago farfara in diverse countries. Moreover, the use of leaves of the introduced species Reynoutria japonica in Romania, Colocasia esculenta in Turkey, and Phytolacca americana in Macedonia shows the dynamic nature of folk cuisines. The rich ethnobotanical diversity of sarma confirms the urgent need to

  2. Geochemical and Isotopic Data for Oligocene Ignimbrites, Calderas, and Granitic Plutons, Southern Stillwater Range and Clan Alpine Mountains: Insights into the Volcanic-Plutonic Connection and Crustal Evolution in Western Nevada

    NASA Astrophysics Data System (ADS)

    John, D. A.; Colgan, J. P.; Watts, K. E.; Henry, C.; Cousens, B.

    2015-12-01

    Oligocene calderas and underlying plutons in the southern Stillwater Range (SSR) and Clan Alpine Mountains (CAM) in western Nevada were tilted (40->90°) by large-magnitude Miocene extension and unconformably overlain by 15-13 Ma intermediate and mafic lava flows. New geologic mapping, geochemistry, and Ar-Ar and U-Pb dating document 2 brief periods of magmatism resulting in 5 nested calderas and related plutons in sections locally ≥9 km thick. Early magmatism at ~29 Ma included the Deep Canyon caldera in CAM, and in the SSR, pre-caldera rhyolites, ~5 km of pre- and post-collapse intermediate lavas and rhyolite tuff that filled Job Canyon caldera (JC, ~29.4 to 28.8 Ma), and the >4-5 km thick IXL pluton (~28.5 Ma) that intruded JC and is compositionally similar to the tuff and lava flows. The second period included 3 ignimbrite units in 3 calderas: small-volume tuff of Louderback Mountains (LM, low-silica rhyolite; ≥600 m thick; ~25.3 Ma); multiple cooling units of tuff of Poco Canyon (PC, high-silica rhyolite; ≤4.5 km thick; ~25.3 Ma); and ≥2500 km3 of tuff of Elevenmile Canyon (EC, trachydacite to rhyolite; ≤4.5 km thick; 25.1 Ma) that covers ~1600 km2 and extends east from SSR to the northern Desatoya Mountains. The composite Freeman Creek pluton (granodiorite, ~25.0 Ma; granite, ~24.8 Ma) and Chalk Mountain rhyolite porphyry (~25.2 Ma) and granite (~24.8 Ma) plutons intruded LM, PC and EC calderas. Radiogenic isotopes in all caldera units are similar (Sri~0.7050, ΕNd~0.0), while oxygen isotope compositions are variable (δ18Oquartz=5.7-8.4‰, δ18Ozircon=4.1-6.3‰), corresponding to a magmatic range of 5.6-7.6‰, including <6‰ values for JC and lower PC rhyolites. U-Pb zircon dating shows homogeneous age populations and few/no xenocrysts or antecrysts. These data show that (1) thick plutons (>2-5 km) underlie compositionally and temporally related caldera-filling ignimbrites, (2) caldera-forming cycles are isotopically variable, requiring

  3. A paleomagnetic and magnetic fabric study of the Illapel Plutonic Complex, Coastal Range, central Chile: Implications for emplacement mechanism and regional tectonic evolution during the mid-Cretaceous

    NASA Astrophysics Data System (ADS)

    Ferrando, Rodolfo; Roperch, Pierrick; Morata, Diego; Arriagada, César; Ruffet, Gilles; Córdova, Maria Loreto

    2014-03-01

    The Illapel Plutonic Complex (IPC), located in the Coastal Range of central Chile (31°-33° S), is composed of different lithologies, ranging from gabbros to trondhjemites, including diorites, tonalites and granodiorites. U/Pb geochronological data shows that the IPC was amalgamated from, at least, four different magmatic pulses between 117 and 90 Ma (Lower to mid-Cretaceous). We present new paleomagnetic results including Anisotropy of Magnetic Susceptibility (AMS) from 62 sites in the plutonic rocks, 10 sites in country rocks and 7 sites in a mafic dyke swarm intruding the plutonic rocks.

  4. Wildlife of southern forests habitat & management (Chapter 9): Wild Turkey

    Treesearch

    James G. Dickson

    2003-01-01

    A traditional and very important game species of southern forests is the wild turkey (Meleagris gallopavo). The wild turkey is a truly wild creature and inspires an amazing level of admiration and devotion among turkey hunters. Wild turkeys have stout legs that support the heavy bird and are used to scratch for food, and short powerful wings...

  5. A 2 Million Year History of Plutonism and Volcanism in the Searchlight Magma System, Eldorado Mountains, Nevada (USA)

    NASA Astrophysics Data System (ADS)

    Miller, J.; Miller, C.; Wooden, J.; Perrault, D.; Hodge, K.; Faulds, J.; Cates, N.; Means, M.

    2006-12-01

    Subvolcanic plutons provide an important record of magma processing and solidification of upper crustal magma bodies but rarely can they be compared with volcanic output from the same magma system. In the Colorado River extensional corridor of southern Nevada, steep tilting caused by crustal extension has exposed outstanding examples of large intrusions that have complementary volcanic output. One of the best examples is the 12 km thick Searchlight pluton and its overlying volcanic cover. Earlier work in the pluton documented vertical growth, wherein crystal accumulation (mafic quartz monzonite cumulate) and roof-down solidification (upper quartz monzonite) resulted in segregation of evolved felsic melt in the chamber interior (middle granite). This general evolutionary sequence is mirrored by lava flow stratigraphy in steeply tilted volcanic sections that are structurally above the roof of Searchlight pluton. We have obtained more than 400 ion microprobe U/Pb zircon ages (Stanford/USGS SHRIMP-RG) on more than 20 samples for the pluton and overlying volcanic rocks in order to temporally link the volcanic rocks with the intrusive rocks. The oldest unit from Searchlight pluton is a gabbro pod near the northern margin of the lower Searchlight quartz monzonite that yielded a 206Pb/238U age of 17.7±0.3 Ma (all age errors reported are 1σ; MSWD ~1 or lower except where noted) but the main lower quartz monzonite from structurally deep has a 206Pb/238U age of 16.9±0.2 Ma. This age is the same age as trachydacite porphyry dikes and pods (16.6±0.3 Ma) that intrude upper Searchlight (but not lower Searchlight) and an identical trachydacite lava flow from near the base of a sequence of trachydacite flows above the pluton (16.9±0.4 Ma; MSWD 1.9). Samples of the middle granite and a gabbro that interacts with the granite are interpreted to be the last materials to solidify in the pluton and have 206Pb/238U ages ranging from 15.9-16.2 Ma but with MSWD's >3. Distinct age peaks

  6. The history of liver transplantation in Turkey.

    PubMed

    Moray, Gökhan; Arslan, Gülnaz; Haberal, Mehmet

    2014-03-01

    Liver transplantation is the definitive treatment for end-stage liver diseases. The first successful liver transplant was performed in the United States by Thomas Starzl in 1967. The first successful solid organ transplant in Turkey was a living-related kidney transplant performed by Dr. Haberal in 1975. After much effort by Dr. Haberal, the Turkish parliament enacted a law about organ transplantation in 1979. After clinical and experimental studies, the first liver transplant in Turkey was performed by Dr. Haberal in 1988. The first successful partial living-donor liver transplant in children in Turkey was performed by the same team on March 15, 1990. On April 24, 1990, the first living-donor liver transplant was performed on a child in Turkey using a left lateral segment by Dr. Haberal and coworkers. On May 16, 1992, Dr. Haberal performed a simultaneous living-donor liver and kidney transplantation to an adult from the same donor. There currently are 30 liver transplantation centers in Turkey. According to data from the Ministry of Health, there presently are 2065 patients in Turkey who are waiting for a liver transplantation. From January 2002 to June 2013, there were 6091 liver transplants performed in Turkey (4020 living-donor [66% ] and 2071 deceased donor liver transplants [34% ]). From January 2011 to June 2013, there were 2514 patients who had liver transplants in Turkey, and 437 patients (17%) died. The number of liver transplants per year in Turkey reached 1000 transplants in 2012 and more than 1150 transplants in 2013 (15.1/million/y). Therefore, Turkey has one of the highest volumes of liver transplantation per population worldwide, with 90% survival within 1 year after transplantation.

  7. MicroBooNE: The Search For The MiniBooNE Low Energy Excess

    SciTech Connect

    Kaleko, David

    2017-01-01

    This thesis describes work towards the search for a low energy excess in MicroBooNE. What MicroBooNE is, what the low energy excess is, and how one searches for the latter in the former will be described in detail.

  8. Cross section analyses in MiniBooNE and SciBooNE experiments

    SciTech Connect

    Katori, Teppei

    2015-05-15

    The MiniBooNE experiment (2002-2012) and the SciBooNE experiment (2007-2008) are modern high statistics neutrino experiments, and they developed many new ideas in neutrino cross section analyses. In this note, I discuss selected topics of these analyses.

  9. Palaeomagnetic constraints from granodioritic plutons (Jiaodong Peninsula): New insights on Late Mesozoic continental extension in Eastern Asia

    NASA Astrophysics Data System (ADS)

    Charles, Nicolas; Chen, Yan; Augier, Romain; Gumiaux, Charles; Lin, Wei; Faure, Michel; Monié, Patrick; Choulet, Flavien; Wu, Fuyuan; Zhu, Rixiang; Wang, Qingchen

    2011-08-01

    Mechanism and kinematics of the Late Mesozoic continental extension event of Eastern Asia are still debated. In order to better constrain its evolution, two granodioritic plutons of the Jiaodong Peninsula have been chosen as targets for a time-constrained palaeomagnetic study. Indeed, plutons are devoid of visible deformation, did not experience rotation along horizontal axis and are precisely dated by U/Pb and 40Ar/ 39Ar methods. Multidomain (MD) magnetite has been identified as the principal magnetic remanent carrier. The interpolation of existing and new U/Pb and 40Ar/ 39Ar ages revealed that characteristic remanent magnetisation was acquired in a narrow range of 116 ± 2 Ma. Twenty out of 27 sites present stable magnetic directions calculated from high-temperature or high-coercive components. The observations of the solo normal magnetic polarity for this palaeomagnetic collection and of the magnetic remanent age consistent with the Cretaceous Normal Superchron (CNS) argue that the characteristic magnetic remanence may be considered as primary. Detailed field observations of the intrusive relationship between the plutons and country rocks and Anisotropy of Magnetic Susceptibility (AMS) study reveal the absence of the subsequent deformation of plutons, or rigid rotation of plutons along a horizontal axis. Two palaeomagnetic poles have been therefore calculated from these plutons. Among 12 out 15 Cretaceous palaeomagnetic poles, including the two new poles provided by this study, from the Jiaodong Peninsula and on both sides of Tan-Lu and Muping-Jimo faults are statistically consistent. As a result, the Jiaodong Peninsula behaved as a rigid block as internal deformation appears negligible. The remaining three derived poles are probably due to the secular variation or/and the vicinity of fault zones near of the palaeomagnetic sampling site. Thus, they can not be applied to the peninsula-scaled tectonics. Comparison of these time-constrained Cretaceous

  10. 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

  11. Multimedia and children in Turkey.

    PubMed

    Tuncer, A M; Yalçin, S S

    1999-01-01

    Multimedia will be regarded as essential tools for children to create their new world. The effects of television on young children's life have been well studied. Television differs, however, from other media, including the movies, in its pervasive impact on children. Children spend more time watching television than any other activity except sleeping. Overall 31% of children spent at least 4 hours a day watching television during weekday and 71.7% during weekend in Turkey. Television's influence on children is a function of the length of time they spend watching and the cumulative effect of what they see. Television may be a cause as well as a solution for many serious childhood problems. Excessive viewing of television has also been linked to aggressive behavior, violence, childhood obesity. On the other hand, television may act as a socializing agent and as a learning tool if the recommendations of American Academy of Pediatrics is learned by pediatricians, parents and broadcasters. The use of home personal computers in urban residence increased from 3.2% in 1993 to 6.5% by January 1998 in Turkey. Around 20% of computer households reported owing a modem. Internet has been using only for 5 years in Turkey. Nearly 40% of computer households also used CD-ROM equipment. The percentage of schools that have a computer laboratory is only 2.64%. On the other hand, multimedia allows students to move away from a uniform education for everyone to assert individual identity, liberalize education and management. It seems likely that, within the next few years, most of the countries with substantial internet infrastructure will use the internet as the major medium for disseminating information, including information on children. To prepare students for such a world demands that educational systems make the best possible use of all knowledge and technologies currently available.

  12. First report of Caulerpa taxifolia (Bryopsidales, Chlorophyta) on the Levantine coast (Turkey, Eastern Mediterranean)

    NASA Astrophysics Data System (ADS)

    Cevik, Cem; Yokes, Mehmet Baki; Cavas, Levent; Erkol, Levent Itri; Derici, Osman Baris; Verlaque, Marc

    2007-09-01

    Since its first accidental introduction into the Mediterranean Sea, Caulerpa taxifolia (Vahl) C. Agardh has spread to six Mediterranean countries and has become a major ecological problem. On the basis of morphological and molecular studies (nuclear ribosomal internal transcribed spacer (ITS)), we report for the first time C. taxifolia on the Levantine coast (Gulf of Iskenderun, SE Turkey). Phylogenetic analysis revealed that the Iskenderun isolate differs from the invasive aquarium strain first observed in Monaco, and falls in another SW Pacific clade (NE Australia, New Caledonia). The introduction in Turkey by shipping (ballast waters or anchor gears of oil tankers) is possible because C. taxifolia was found in the Gulf of Iskenderun, which is a major Eastern Mediterranean petrochemical region. On the other hand, C. taxifolia strains are available in aquarium shops in Turkey, suggesting aquarium dumping as another possible cause. As far as the intense maritime traffic of the region is concerned, further dispersals of this exotic C. taxifolia strain in the Mediterranean Sea are to be expected.

  13. Suicide in Batman, southeastern Turkey.

    PubMed

    Altindag, Abdurrahman; Ozkan, Mustafa; Oto, Remzi

    2005-08-01

    The southeastern part of Turkey has comparatively high female suicide rates. We aimed to research social, economic, cultural, and psychiatric reasons of suicides in Batman in a case-controlled psychological autopsy study comparing suicides with matched community controls. The female suicide rate was 9.3 per 100.000 and the female/male ratio was 1.72/1. The suicides most frequently occurred in young females, mean age 20.7. The most frequent method (45%) was hanging. The most frequent stressful life events were health problems and family disruption. High suicide rates among females may be related to negative social status of females living in the region.

  14. [The urbanization rate in Turkey].

    PubMed

    Widy-kwiatkowska, J

    1994-01-01

    Data from the annual statistical report on Turkey for 1990 and the results of research from 1985 and 1990 were utilized and compared with the trends of urbanization observed in the 1969 work of Z. Siemek on Turkey. In 1990, Turkey had about 56.5 million people with an average annual natural growth rate of 2.6% and an unemployment rate of 16%. The rural population made up 41% of the total populace. Urbanization was on the increase, from 47% in 1980, to 55% in 1985, and 59% in 1990. Urbanization in Ankara, because of its location in the center of Turkey, was particularly active in the regions of Anatolia, although it was still isolated in terms of intensified development. Istanbul's The population of Istanbul numbered 6,754,000 people in 1990. It is the major industrial center of the country with about 20% of industrial plants and 17% of the work force in the manufacturing industry. The largest degree of urbanization was demonstrated by Ankara: in 1927 its population numbered only 74,500 people, in 1965 about 902,000 inhabitants, and in 1990 about 2,837,000 people. During the period 1985-90, only 2 out of 73 provinces experienced a decline of the urban population: Kirikkale from 70.4% to 69.7% (because of the dynamic development of the Central region) and Istanbul from 95.4% to 92.4%. During this same period, Kirikkale's urban population, compared with the nation's total urban population, also declined from 0.9% to 0.7% because of immigration of both urban and rural people to other, more attractive provinces. The growth of urban population in the province of Istanbul varied from 1% to 10% during the period and made up 20.3% of the entire urban population. The Central region underwent a large degree of urbanization characterized by industrial-agricultural development. The city of Sivas became a center of communication. In the Central and Kurd regions, urbanization proceeded fast owing to the development of the Black Sea region and the immigration of Kurds from Iraq

  15. Ediacaran to Cambrian magmatic suites in the Rio Grande do Norte domain, extreme Northeastern Borborema Province (NE of Brazil): Current knowledge

    NASA Astrophysics Data System (ADS)

    do Nascimento, Marcos Antonio Leite; Galindo, Antonio Carlos; de Medeiros, Vladimir Cruz

    2015-03-01

    The Ediacaran-Cambrian plutonic activity is one of the most important geological features of the Rio Grande do Norte Domain (Borborema Province, NE Brazil). It is represented by several batholiths, stocks and dykes. Based on the petrographic, geochemical and geochronological characteristic of different rocks, this plutonic activity can be grouped in six separate suites: shoshonitic (Shos), porphyritic high-K calc-alkaline (PHKCalcAlk), equigranular high K calc-alkaline (EHKCalcAlk), calc-alkaline (CalcAlk), alkaline (Alk) and charnockitic alkaline (ChAlk). Geochemically, the Shos, CalcAlk and Alk suites are differentiated from the others, while ChAlc can be distinguished from the others in some diagrams. The greatest difficulty lies in distinguishing between the chemically similar PHKCalcAlk and EHKCalcAlk. To this end, existing geochronological data as well as related petrographic and textural field aspects may be used to distinguish the two mentioned suites (PHKCalcAlk and EHKCalcAlk). Petrographically, the Shos suite has composition between gabbro/diorite and quartz monzonite. Monzogranites (with subordinate granodiorites and quartz monzonites) predominate in both PHKCalcAlk and EHKCalcAlk. Calc is composed of granodiorites to tonalites. Alc is formed by alkali feldspar granites (with subordinate alkali feldspar quartz syenites and syenogranites), whereas ChAlc has quartz mangerites and charnockites. The suites were emplaced between the Ediacaran (635-541 Ma) and Cambrian (541-485 Ma), predominantly in the Ediacaran, based on 34 U-Pb datings (zircon, titanite, monazite and columbite-tantalite), 17 Rb-Sr (whole rock) and 1 Sm-Nd (total rock and mineral) internal isochrons. The Shos suite has U-Pb ages varying from 599 ± 16 (Poço Verde pluton) to 579 ± 7 (Acari and São João do Sabugi plutons), slightly older than those of the PHKCalcAlk suite, which ranges between 591 ± 4 Ma (Totoró pluton) and 544 ± 7 Ma (São José de Espinharas pluton). The Calc

  16. Composition of coarse-grained magnetite from pegmatite dikes related to plutons of quartz monzonite in the Jabal Lababa area, Kingdom of Saudi Arabia

    USGS Publications Warehouse

    Overstreet, William C.; Mousa, Hassan; Matzko, John J.

    1985-01-01

    Crystals of magnetite as large as 30 mm long and 7 mm thick are locally present in quartz-rich zones of interior and exterior pegmatite dikes related to plutons of quartz monzonite in the Jabal Lababa area. Niobium, tin, and yttrium are strongly enriched in six specimens of magnetite from interior pegmatite dikes in a small pluton where these elements form geochemical anomalies in nonmagnetic heavy-mineral concentrates from wadi sediment. Less abundant anomalous elements in the magnetite are molybdenum, lead, and zirconium, which also tend to be present in anomalous amounts in the nonmagnetic concentrates from the niobium-bearing pluton. The most anomalous trace element in the magnetite is zinc, which is at least 10 times as abundant as it is in the quartz monzonite plutons or in the nonmagnetic concentrates. The capacity of magnetite to scavenge molybdenum, zinc, niobium, lead, tin, yttrium, and zirconium suggests the possible utility of magnetite as a geochemical sample medium.

  17. Model uncertainties at MicroBooNE

    NASA Astrophysics Data System (ADS)

    Castillo Fernández, R.; Del Tutto, M.; Dytman, S.; Furmanski, A.; Jen, C.-M.; MicroBooNE collaboration

    2017-09-01

    The MicroBooNE experiment is a 170 ton Liquid Argon Time Projection Chamber (LArTPC) experiment designed for short-baseline neutrino physics, located at surface level in the Booster Neutrino Beam (BNB) at Fermilab. A muon neutrino-argon charged current (CC) cross section measurement in the energy range of ∼200 MeV - 2 GeV has recently been started. These proceedings describe our first steps to understand the potential of MicroBooNE to distinguish between di?erent theories for modeling nuclear effects in neutrino scattering and the interaction model systematics that apply to MicroBooNE measurements (in particular to the muon neutrino CC event selection), before the first neutrino-argon cross sections can be derived.

  18. Tracheal mucus transport rate in normal turkeys and in turkeys infected with Bordetella avium (Alcaligenes faecalis).

    PubMed

    Ficken, M D; Edwards, J F; Lay, J C; Tveter, D E

    1986-01-01

    Using the radiopharmaceutical 99mtechnetium-sulfur colloid, the tracheal mucus transport rate (TMTR) was measured in healthy unanesthetized turkeys and in turkeys infected with Bordetella avium. The TMTR of uninfected turkeys was 35.6 +/- 14.4 cm/min. The TMTR of B. avium-infected turkeys was normal on days 0 through 14 postexposure (PE), despite heavy bacterial colonization of the tracheal epithelium. On day 21 PE, the TMTR of B. avium-infected turkeys was significantly depressed (P less than or equal to 0.01) compared with that of control turkeys. Depressed transport was associated with extensive loss of ciliated epithelium from the tracheal mucosa and replacement of the normal mucosa by immature nonciliated epithelium or metaplastic squamous epithelium.

  19. Evolution of Mutnovsky Volcano, Kamchatka with Implications for Arc Pluton Growth

    NASA Astrophysics Data System (ADS)

    Simon, A.; Robertson, K.; Smith, E. I.; Kiryukhin, A. V.; Selyangin, O.; Mulcahy, S. R.; Walker, J. D.

    2011-12-01

    are consistent with the downward building of the sub-volcanic pre-eruptive magma plumbing system at Mutnovsky and have implications for the emplacement and iterative assembly of sub-volcanic plutons in arc environments. The model pressures yield calculated pre-eruptive magma storage depths that deepen from 13 km for Mutnovsky I and II, to 16 km for Mutnovsky III, to 30 km Mutnovsky IV. These data imply the potential for amalgamation of the residual magma chambers into a large pluton provided that the erupted volume of material from Mutnovsky I, II, III and IV represents a small fraction of the total pre-eruptive magma volume beneath each volcanic center.

  20. Temporal Evolution of Volcanic and Plutonic Magmas Related to Porphyry Copper Ores Based on Zircon Geochemistry

    NASA Astrophysics Data System (ADS)

    Dilles, J. H.; Lee, R. G.; Wooden, J. L.; Koleszar, A. M.

    2015-12-01

    Porphyry Cu (Mo-Au) and epithermal Au-Ag ores are globally associated with shallow hydrous, strongly oxidized, and sulfur-rich arc intrusions. In many localities, long-lived magmatism includes evolution from early andesitic volcanic (v) and plutonic (p) rocks to later dacitic or rhyolitic compositions dominated by plutons. We compare zircon compositions from three igneous suites with different time spans: Yerington, USA (1 m.y., p>v), El Salvador, Chile (4 m.y., p>v), and Yanacocha, Peru (6 m.y., v>p). At Yerington granite dikes and ores formed in one event, at ES in 2 to 3 events spanning 3 m.y., and at Yanacocha in 6 events spanning 5 m.y. At both ES and Yanacocha, high-Al amphiboles likely crystallized at high temperature in the mid-crust and attest to deep magmas that periodically recharged the shallow chambers. At Yanacocha, these amphiboles contain anhydrite inclusions that require magmas were sulfur-rich and strongly oxidized (~NNO+2). The Ti-in-zircon geothermometer provides estimates of 920º to 620º C for zircon crystallization, and records both core to rim cooling and locally high temperature rim overgrowths. Ore-related silicic porphyries yield near-solidus crystallization temperatures of 750-650°C consistent with low zircon saturation temperatures. The latter zircons have large positive Ce/Ce* and small negative Eu/Eu*≥0.4 anomalies attesting to strongly oxidized conditions (Ballard et al., 2001), which we propose result from crystallization and SO2 loss to the magmatic-hydrothermal ore fluid (Dilles et al., 2015). The Hf, REE, Y, U, and Th contents of zircons are diverse in the magma suites, and Th/U vs Yb/Gd plots suggest a dominant role of crystal fractionation with lesser roles for both crustal contamination and mixing with high temperature deep-sourced mafic magma. Ce/Sm vs Yb/Gd plots suggest that magma REE contents at <900°C are dominated by early crystallization of hornblende and apatite, and late crystallization (~<780°C) of titanite

  1. Rock-magnetic properties of single zircon crystals sampled from the Tanzawa tonalitic pluton, central Japan

    NASA Astrophysics Data System (ADS)

    Sato, M.; Yamamoto, S.; Yamamoto, Y.; Ohno, M.; Tsunakawa, H.; Maruyama, S.

    2015-12-01

    This paper reports on the rock-magnetic properties of single zircon crystals, which are essential for future work establishing the paleointensity method using single zircon crystals. Zircon crystals used in this study were sampled from the Nakagawa River, which crosses the Tanzawa tonalitic pluton in central Japan. Rock-magnetic measurements were conducted on 1037 grains of zircons, but many of these measurements are below the limits of the sensitivity of the magnetometers employed. Isothermal remanent magnetizations (IRMs) of 876 zircon crystal are below the practical resolution of this study; we infer that these crystal contain no or only minute quantities of ferromagnetic minerals. The other zircon crystals contain enough magnetic minerals to be measured in the DC SQUID magnetometer. For 81 zircon crystals, IRM intensity (MIRM) are larger than 4 × 10-12 Am2, while natural remanent magnetization (NRM) intensity (MNRM) are below 4 × 10-12 Am2, indicating that these crystals are inappropriate for the paleomagnetic study. For the samples that had values of MNRM ≥ 4 × 10-12 Am2 and MIRM ≥ 4 × 10-12 Am2, combining the rock-magnetic parameter, we proposed the sample selection criteria for future study of paleointensity experiments using single zircon crystals. In the case that the samples had high Bc values (>10 mT) or high MNRM/MIRM values (>~0.1), main remanence carriers are probably pyrrhotite and these samples are inappropriate for the paleointensity study. In the case that the samples had low Bc values (<10 mT) and low MNRM/MIRM values (<~0.1), main remanence carrier seem to be nearly pure magnetite with PSD grain sizes and these samples are expected to appropriate for the paleointensity study. Total thermoremanent magnetization (TRM) acquisition experiments were also carried out for 12 samples of the zircon crystals satisfying the above criteria. The TRM intensity was comparable with that of NRM, and a rough estimation of the paleointensity using NRM

  2. Rock-magnetic properties of single zircon crystals sampled from the Tanzawa tonalitic pluton, central Japan

    NASA Astrophysics Data System (ADS)

    Sato, Masahiko; Yamamoto, Shinji; Yamamoto, Yuhji; Okada, Yoshihiro; Ohno, Masao; Tsunakawa, Hideo; Maruyama, Shigenori

    2015-09-01

    This paper reports on the rock-magnetic properties of single zircon crystals, which are essential for future work establishing the reliable paleointensity method using single zircon crystals. Zircon crystals used in this study were sampled from the Nakagawa River, which crosses the Tanzawa tonalitic pluton in central Japan. Rock-magnetic measurements were conducted on 1037 grains of zircons, but many of these measurements are below the limits of the sensitivity of the magnetometers employed. Isothermal remanent magnetizations (IRMs) of 876 zircon crystal are below the practical resolution of this study; we infer that these crystals contain no or only minute quantities of ferromagnetic minerals. The other zircon crystals contain enough magnetic minerals to be measured in the DC SQUID magnetometer. For 81 zircon crystals, IRM intensities ( M IRM) are larger than 4 × 10-12 Am2, while natural remanent magnetization (NRM) intensities ( M NRM) are below 4 × 10-12 Am2, indicating that these crystals are inappropriate for the paleomagnetic study. For the samples that had values of M NRM ≥ 4 × 10-12 Am2 and M IRM ≥ 4 × 10-12 Am2 (80 zircons), combining the rock-magnetic parameter, we proposed the sample-selection criteria for future study of paleointensity experiments using single zircon crystals. In the case that the samples had high coercivity ( B c) values (>10 mT) or high M NRM/ M IRM values (>~0.1), main remanence carriers are probably pyrrhotite and these samples are inappropriate for the paleointensity study. In the case that the samples had low B c values (<10 mT) and low M NRM/ M IRM values (<~0.1), main remanence carriers seem to be nearly pure magnetite with pseudo-single-domain grain sizes, and these samples are expected to appropriate for the paleointensity study. Total thermoremanent magnetization (TRM) acquisition experiments were also carried out for 12 samples satisfying the above criteria. The TRM intensity was comparable with that of NRM, and a

  3. Duality of magmatism in the plutonic sequence of the Sumail Nappe, Oman

    NASA Astrophysics Data System (ADS)

    Juteau, T.; Ernewein, M.; Reuber, I.; Whitechurch, H.; Dahl, R.

    1988-09-01

    Detailed field mapping of the crustal sequence in several areas of the Sumail Ophiolite Nappe, mainly in the Fizh, the Salahi and the Haylayn blocks, and comparisons with other well-studied areas, have shown that the crustal sequence was constructed by two distinct, although nearly contemporaneous, magmatic series: The first, a gabbroic series, was emplaced during the accretion stage at an oceanic spreading centre which formed the layered gabbro unit, the high-level isotropic gabbro unit and their by-products, the sheeted dyke complex and the lower extrusives. Fine-grained homogeneous, planar-laminated gabbros commonly occur at the top of the layered gabbro sequence. In some specific areas (Wadi Haymiliyah and Wadi Rajmi), these are strongly differentiated Fe-Ti-rich gabbronorites and norites, which coincide with large-scale discontinuities within the plutonic sequence, interpreted as axial discontinuities of the spreading magma chambers. The second series, an ultramafic wehrlitic series, is locally rooted in the upper mantle (i.e., the impregnated dunitic transition zone). This has intruded the whole crustal sequence up to the pillow lavas. Countless discordant and concordant wehrlitic bodies intruded the plutonic sequence, making up 20-40% of it in volume. We describe the various settings and forms of these intrusions, which were largely underestimated in previous studies. We also describe their mineralogy and textures, and show with chemical and mineralogical arguments that these bodies evolved as relatively closed systems, independently from each other. We infer from the study of the contacts that the gabbros were still hot and consolidated just at the moment of the wehrlitic intrusion. At the base of the crust however, indications of immiscibility between gabbros and wehrlites are common, suggesting that both magmatic series were quite contemporaneous. The wehrlites are commonly isotropic and may exhibit an internal layering of the dunite

  4. Uplift and subduction erosion in southwestern Mexico since the Oligocene: pluton geobarometry constraints

    NASA Astrophysics Data System (ADS)

    Morán-Zenteno, Dante J.; Corona-Chavez, Pedro; Tolson, Gustavo

    1996-06-01

    Details of the late Oligocene to Middle Miocene uplift and tectonic erosion episodes of the southwestern continental margin of Mexico can be inferred using Al tot geobarometry of igneous hornblendes, geochronology, and field relations. On the basis of such analyses carried out between Acapulco and Huatulco we find the following: (1) Calc-alkaline batholiths exposed along the coast from Acapulco to Huatulco, mostly in the 35-25 Ma age range, were emplaced at depths between 13 and 20 km. (2) The contact relationships between these plutons and their host rocks, and the exposure of volcanic counterparts, 70 km from the coastline, indicate a landward decrease in the amount of uplift. (3) A comparison of the time differences between intrusion and cooling ages of batholiths along the coast suggest that cooling rates were, in general, higher between Acapulco and Huatulco than those along the margin between Puerto Vallarta and Manzanillo, 700 km northwest of Acapulco. (4) The uplift of this coastal belt occurred during the late stages of magmatism and after its cessation, triggering intensive subaerial erosion of supracrustal rocks and the exposure of midcrustal rocks such as granitic batholiths and amphibolite facies metamorphic assemblages of the Xolapa Complex. These findings, in conjunction with the geometry of the present continental margin, as well as the offshore tectonic and stratigraphic features, support previous interpretations of very active late Oligocene to Middle Miocene subduction erosion after the onset of strike-slip tectonics related to the detachment and subsequent eastward displacement of the Chortis block. Subduction erosion involved both trench sediments and crystalline (continental framework) rocks. Different rates of continental framework erosion are assessed on the basis of the bathymetric fluctuations of the upper slope trench sediments and the age of the accretionary prism. Subsidence of the offshore continental basement suggests intense episodes

  5. Review of ''Draft - Area Recommendation Report for the Crystalline Repository Project'', January 1986. [Rolesville pluton and Elk River complex

    SciTech Connect

    Butler, J.R.

    1986-03-13

    The Draft-Area Recommendation Report identifies portions of crystalline rock bodies as proposed potentially acceptable sites for consideration as repositories of high-level radioactive waste. The review is in three parts. Part I is a general summary of the main comments, written in semi-technical language and without detailed documentation or references. It includes summaries of comments on the two preliminary candidate areas for a nuclear-waste repository in North Carolina (Rolesville pluton and Elk River complex) and on the rest of the report. The following two parts are written in the technical language of a geological report and include both documentation and references for each of the points discussed: Part II - Rolesville pluton, Site SE-4; Part III - Elk River complex, Site SE-5.

  6. Rejuvenation of deeper magma reservoirs during differentiation: an example recorded in a post-plutonic dyke swarm S-Adamello (N-Italy)

    NASA Astrophysics Data System (ADS)

    Hurlimann, N.; Nandedkar, R.; Muntener, O.; Ulmer, P.

    2012-04-01

    The Adamello Batholith (42-29 Ma) is located in the Northern Italian Alps. It intruded into the Southern Alpine basement and its Permo-Triassic cover. In the Southern part a series of late dykes intruded into gabbroic and mainly tonalitic plutonic bodies. Models for volcanic eruptions of intermediate to silicic magmas are associated with the intrusion of fresh mafic magma into a magma reservoir, triggering eruption of the resident more evolved magma. Here we present an example of a series of post-plutonic dykes ranging from picro-basalts to dacites that indicates rejuvenation processes. Distinct phases of magma intrusion are documented by compositionally distinct dykes. Various degrees of magma mingling are widespread in this sequence. Primitive primary magmas occur as picro-basaltic dykes that are consistent with mantle-separation conditions of 28 kbar and 1370° C constrained, by multiple saturation experiments (Ulmer 1988). More evolved magmas in the same dyke swarm are homogeneous amphibole-plagioclase-phyric basaltic-andesites to dacites, which are almost devoid of mingling textures. Textures and mineral zoning patterns indicate a continuous differentiation process for these intermediate magmas at mid-crustal depth. In contrary, the mingled magmas display amphibole textures from pristine to complete pseudomorphs now present as clinopyroxene. Plagioclase and amphibole show reverse zoning and the common occurrence of bands or cores with sieve textures, indicating resorption processes of crystals related to the interaction with high-temperature mafic magma. Chilled margins and liquid apophyses of the mingled basalts and basaltic-andesites show crystallization of microphenocrysts of olivine+clinopyroxene+plagioclase at the emplacement level. In strongly mingled parts of the dykes resorbed amphibole is overgrown by fresh amphibole corresponding in composition to the microphenocrysts. Trace-element partition-coefficients between the cryptocrystalline matrix and

  7. The distribution, geochronology and geochemistry of early Paleozoic granitoid plutons in the North Altun orogenic belt, NW China: Implications for the petrogenesis and tectonic evolution

    NASA Astrophysics Data System (ADS)

    Meng, Ling-Tong; Chen, Bai-Lin; Zhao, Ni-Na; Wu, Yu; Zhang, Wen-Gao; He, Jiang-Tao; Wang, Bin; Han, Mei-Mei

    2017-01-01

    Abundant early Paleozoic granitoid plutons are widely distributed in the North Altun orogenic belt. These rocks provide clues to the tectonic evolution of the North Altun orogenic belt and adjacent areas. In this paper, we report an integrated study of petrological features, U-Pb zircon dating, in situ zircon Hf isotope and whole-rock geochemical compositions for the Abei, 4337 Highland and Kaladawan Plutons from north to south in the North Altun orogenic belt. The dating yielded magma crystallization ages of 514 Ma for the Abei Pluton, 494 Ma for the 4337 Highland Pluton and 480-460 Ma for the Kaladawan Pluton, suggesting that they are all products of oceanic slab subduction because of the age constraint. The Abei monzogranites derived from the recycle of Paleoproterozoic continental crust under low-pressure and high-temperature conditions are products of subduction initiation. The 4337 Highland granodiorites have some adakitic geochemical signatures and are sourced from partial melting of thickened mafic lower continental crust. The Kaladawan quartz diorites are produced by partial melting of mantle wedge according to the positive εHf(t) values, and the Kaladawan monzogranite-syenogranite are derived from partial melting of Neoproterozoic continental crust mixing the juvenile underplated mafic material from the depleted mantle. These results, together with existing data, provide significant information about the evolution history of oceanic crust subduction during the 520-460 Ma. The initiation of subduction occurred during 520-500 Ma with formation of Abei Pluton; subsequent transition from steep-angle to flat-slab subduction at ca.500 Ma due to the arrival of buoyant oceanic plateaus, which induces the formation of 4337 Highland Pluton. With ongoing subduction, the steep-angle subduction system is reestablished to cause the formation of 480-460 Ma Kaladawan Pluton. Meanwhile, it is this model that account for the temporal-spatial distribution of these early

  8. Forceful emplacement of the Eureka Valley-Joshua Flat-Beer Creek composite pluton into a structural basin in eastern California; internal structure and wall rock deformation

    NASA Astrophysics Data System (ADS)

    Morgan, Sven; Law, Richard; de Saint Blanquat, Michel

    2013-11-01

    Anisotropy of Magnetic Susceptibility parameters have been analyzed at 311 locations in the Eureka Valley-Joshua Flat-Beer Creek (EJB) pluton of eastern California. The large amount of data has allowed for the AMS parameters to be contoured using techniques that both reveal map-scale trends and emphasize small-scale differences. The contour maps suggest that magnetic susceptibility is dominantly controlled by composition of the magma but may also be affected by emplacement-related strain as the magma chamber inflated and forced the wall rocks outward. Pluton construction involved two major pulses of different composition magmas that were emplaced sequentially but with overlapping periods of crystallization. The magmas initially intruded as sill-like bodies into a structural basin. The magnetic foliation of the pluton cuts across internal magmatic contacts on the map scale and is parallel to local contacts between the pluton and surrounding metasedimentary wall rocks. The magnetic fabric is similar in orientation and symmetry to intense flattening strains recorded in the aureole rocks. The metasedimentary wall rocks have been shortened between 60 and 70% and this strain magnitude is approximately equal on the west, south, and east margins of the pluton. Strain in the wall rocks is dominantly flattening and concentrated into a narrow (1 km wide) inner aureole. Mapping of bedding/cleavage intersection lineations south of the pluton indicates that the magma made room for itself by translating the wall rocks outward and rotating the already inward dipping wall rocks of the structural basin to sub-vertical. Stretching of the inner aureole around an expanding magma chamber was responsible for the intense shortening. Limited data on the Marble Canyon pluton to the south of the EJB pluton indicates a very similar emplacement process.

  9. A paleomagnetic and stable isotope study of the pluton at Rio Hondo near Questa, New Mexico: implications for CRM related to hydrothermal alteration

    USGS Publications Warehouse

    Hagstrum, J.T.; Johnson, C.M.

    1986-01-01

    Paleomagnetic and rock magnetic data combined with stable isotope data from the middle Tertiary pluton along the Rio Hondo in northern New Mexico suggest that its magnetic remanence has both thermal (TRM) and high-temperature chemical (CRM) components. Oxygen isotope temperatures indicate that magnetite associated with the more rapidly cooled higher levels of the pluton, and with mafic inclusions and cogenetic rhyolitic dikes sampled at lower levels of exposure, ceased subsolidus recrystallization and isotopic exchange above its Curie temperature (580??C) in the presence of a magmatic fluid. Continued cooling imparted a TRM to these portions of the pluton. The more slowly cooled granodiorite at lower levels has quartz-magnetite isotopic temperatures that are below the Curie temperature of magnetite implying that its magnetization is high-temperature CRM. Sub-Curie isotopic temperatures for other granitic plutons in the western U.S.A. suggest that CRM may be commonly derived from subsolidus interactions between magnetite and magmatic fluids in plutonic rocks. A meteoric-hydrothermal system generated by the cooling Rio Hondo pluton, and not by younger adjacent intrusions, resulted in limited alteration along zones of high permeability near the southern margin of the Rio Hondo pluton, and in more prevasive alteration of the pluton to the north. The meteoric-hydrothermal alteration occurred at relatively high temperatures (> 350??C) and, with the exception of local chloritization, caused little visible alteration of the rocks. The isotopic ratios indicate that little of the magnetite could have grown from or exchanged with a meteoric-hydrothermal fluid. ?? 1986.

  10. Understanding Urban Regeneration in Turkey

    NASA Astrophysics Data System (ADS)

    Candas, E.; Flacke, J.; Yomralioglu, T.

    2016-06-01

    In Turkey, rapid population growth, informal settlements, and buildings and infrastructures vulnerable to natural hazards are seen as the most important problems of cities. Particularly disaster risk cannot be disregarded, as large parts of various cities are facing risks from earthquakes, floods and landslides and have experienced loss of lives in the recent past. Urban regeneration is an important planning tool implemented by local and central governments in order to reduce to disaster risk and to design livable environments for the citizens. The Law on the Regeneration of Areas under Disaster Risk, commonly known as the Urban Regeneration Law, was enacted in 2012 (Law No.6306, May 2012). The regulation on Implementation of Law No. 6306 explains the fundamental steps of the urban regeneration process. The relevant institutions furnished with various authorities such as expropriation, confiscation and changing the type and place of your property which makes urban regeneration projects very important in terms of property rights. Therefore, urban regeneration projects have to be transparent, comprehensible and acceptable for all actors in the projects. In order to understand the urban regeneration process, the legislation and projects of different municipalities in Istanbul have been analyzed. While some steps of it are spatial data demanding, others relate to land values. In this paper an overview of the urban regeneration history and activities in Turkey is given. Fundamental steps of the urban regeneration process are defined, and particularly spatial-data demanding steps are identified.

  11. DAΦNE status and upgrade plans

    NASA Astrophysics Data System (ADS)

    Zobov, M.; DAΦNE Collaboration Team

    2008-12-01

    The Frascati Φ-factory DAΦNE has successfully completed experimental runs for the three main detectors, KLOE, FINUDA and DEAR. The best peak luminosity achieved so far is 1.6 × 1032 cm-2 s-1, while the best daily integrated luminosity is 10 pb-1. At present the DAΦNE team is preparing an upgrade of the collider based on the novel crab waist collision scheme. The upgrade is aimed at pushing the luminosity towards 1033cm-2s-1. In this paper we describe present collider performance and discuss ongoing preparatory work for the upgrade.

  12. The Ajo Mining District, Pima County, Arizona--Evidence for Middle Cenozoic Detachment Faulting, Plutonism, Volcanism, and Hydrothermal Alteration

    USGS Publications Warehouse

    Cox, Dennis P.; Force, Eric R.; Wilkinson, William H.; More, Syver W.; Rivera, John S.; Wooden, Joseph L.

    2006-01-01

    Introduction: The Ajo porphyry copper deposit and surrounding Upper Cretaceous rocks have been separated from their plutonic source and rotated by detachment faulting. Overlying middle Cenozoic sedimentary and volcanic rocks have been tilted and show evidence for two periods of rotation. Following these rotations, a granitic stock (23.7?0.2 Ma) intruded basement rocks west of the Ajo deposit. This stock was uplifted 2.5 km to expose deep-seated Na-Ca alteration.

  13. Adakitic-like magmatism in western Ossa-Morena Zone (Portugal): Geochemical and isotopic constraints of the Pavia pluton

    NASA Astrophysics Data System (ADS)

    Lima, S. M.; Neiva, A. M. R.; Ramos, J. M. F.

    2013-02-01

    Granitic rocks are a major component of the Earth's continental crust and occur in a wide variety of tectonic settings. Their chemical and isotopic characterization is crucial to the recognition of the potential sources and mechanisms involved in their generation. In this study, we present the first whole rock chemical and isotopic (Sr-Nd-O) data for the Pavia pluton (328-317 Ma), located near the western border of the Ossa-Morena Zone (Évora Massif, Portugal). Major and trace element geochemistry suggests that the different granitic phases composing this intrusive body (enclaves, granites (s.l.) and crosscutting dikes) represent independent magma pulses and the majority is similar to TTGs and adakites. The little Sr-Nd-O isotopic variation, with (87Sr/86Sr)328 = 0.70428-0.70560, ɛNd328 ranging between - 3.4 and + 0.4 and δ18O varying from + 5.6‰ to + 8.4‰ implies an isotopically similar protolith for all phases. The most viable mechanism for the generation of the Pavia pluton adakitic-like magmatism is assimilation-fractional crystallization of a mantle-derived magma. This mechanism was also invoked to explain the genesis of other plutons within the Évora Massif but they have a distinct chemistry (typical arc calc-alkaline rocks). The chemical differences between them and the Pavia pluton granitic rocks are interpreted as the result of lower degrees of crustal assimilation and higher degrees of contamination of mantle-derived magmas by the sinking slab (after subduction blocking and subsequent slab break-off).

  14. Ion-adsorption REEs in regolith of the Liberty Hill pluton, South Carolina, USA: An effect of hydrothermal alteration

    USGS Publications Warehouse

    Bern, Carleton R.; Yesavage, Tiffany; Foley, Nora K.

    2017-01-01

    Ion-adsorbed rare earth element (REE) deposits supply the majority of world heavy REE production and substantial light REE production, but relatively little is known of their occurrence outside Southeast Asia. We examined the distribution and forms of REEs on a North American pluton located in the highly weathered and slowly eroding South Carolina Piedmont. The Hercynian Liberty Hill pluton experiences a modern climate that includes ~ 1500 mm annual rainfall and a mean annual temperature of 17 °C. The pluton is medium- to coarse-grained biotite-amphibole granite with minor biotite granite facies. REE-bearing phases are diverse and include monazite, zircon, titanite, allanite, apatite and bastnäsite. Weathered profiles were sampled up to 7 m-deep across the ~ 400 km2 pluton. In one profile, ion-adsorbed REEs plus yttrium (REE + Y) ranged up to 581 mg/kg and accounted for up to 77% of total REE + Y in saprolite. In other profiles, ion-adsorbed REE + Y ranged 12–194 mg/kg and only accounted for 3–37% of totals. The profile most enriched in ion-adsorbed REEs was located along the mapped boundary of two granite facies and contained trioctahedral smectite in the saprolite, evidence suggestive of hydrothermal alteration of biotite at that location. Post-emplacement deuteric alteration can generate easily weathered REE phases, particularly fluorocarbonates. In the case of Liberty Hill, hydrothermal alteration may have converted less soluble to more soluble REE minerals. Additionally, regolith P content was inversely correlated with the fraction ion-adsorbed REEs, and weathering related secondary REE-phosphates were found in some regolith profiles. Both patterns illustrate how low P content aids in the accumulation of ion-adsorbed REEs. The localized occurrence at Liberty Hill sheds light on conditions and processes that generate ion-adsorbed REEs.

  15. Formation of rhyolite at the Okataina Volcanic Complex, New Zealand: New insights from analysis of quartz clusters in plutonic lithics

    NASA Astrophysics Data System (ADS)

    Graeter, K.; Beane, R. J.; Deering, C. D.; Gravley, D. M.; Bachmann, O.

    2014-12-01

    Granitoid lithic clasts from the 0.7 ka Kaharoa eruption at the Tarawera volcano (Okataina Volcanic Complex, Taupo Volcanic Zone, New Zealand) - the world's most productive region where rhyolite volcanism is currently active - give insight into the processes of rhyolite formation. The plutonic lithic clasts of the Kaharoa eruption consist of (1) quartz phenocrysts, which are often grouped into clusters of two to eight quartz grains, (2) plagioclase phenocrysts with anorthitic cores and albitic rims, and (3) interstitial potassium feldspar. Quartz orientations obtained through electron backscatter diffraction (EBSD) methods show that 78% of the 82 analyzed clusters have at least one pair of quartz grains with matched dipyramidal faces that are in either parallel or Esterel twin orientation. Variations in cathodoluminescence (CL) zoning patterns of the quartz suggest that quartz clusters in the plutonic lithics formed after initial crystal growth and that many quartz crystals were subject to one or more resorption events. Thus, individual quartz crystals with different magmatic histories came together into preferred orientations to form clusters; this process is indicative of oriented quartz synneusis and suggests a history of crystal accumulation. The quartz clusters are interpreted to have formed as part of a crystal cumulate mush within a shallow magma chamber where quartz crystals rotated into contact along their dipyramidal faces during hindered settling and/or compaction. Therefore, the preservation of oriented quartz clusters from the Kaharoa plutonic lithics provides direct evidence for synchronous, shallow pluton formation from a cumulate mush during active volcanism. This result is consistent with a model whereby melt-rich, high-silica rhyolite formation occurs via interstitial melt extraction from a low-silica rhyolite mush in the shallow crust.

  16. Regional geochemical study of the felsic plutonic rocks in the Nuqrah Quadrangle, sheet 25E, Kingdom of Saudi Arabia

    USGS Publications Warehouse

    Hall, W.E.; Dellinger, David; Selner, G.I.

    1985-01-01

    Pan-concentration samples collected from wadis draining the north end of Jabal Safad contain anomalous Sn, Mo, Pb, and La. Four samples contain 250 to 1,000 ppm of tin. The tin anomaly is associated with a small aplitic pluton intrusive into the Jabal Safad alkalic granite complex. A brief reconnaissance of the area did not reveal any greisen or cassiterite mineralization. However, further exploration work in the area is recommended.

  17. High temperature fracturing and ductile deformation during cooling of a pluton: The Lake Edison granodiorite (Sierra Nevada batholith, California)

    NASA Astrophysics Data System (ADS)

    Pennacchioni, Giorgio; Zucchi, Eleonora

    2013-05-01

    In the Bear Creek area of the Sierra Nevada batholith, California, the high temperature postmagmatic deformation structures of the Lake Edison granodiorite include steeply-dipping orthogneiss foliations, joints, and ductile shear zones that nucleated on joints and leucocratic dykes. Exploitation of segmented joints resulted in sharply bounded, thin shear zones and in large slip gradients near the shear zone tips causing the deformation of the host rock at contractional domains. The orthogneiss foliation intensifies towards the contact with the younger Mono Creek granite and locally defines the dextral Rosy Finch Shear Zone (RFSZ), a major kilometre-wide zone crosscutting the pluton contacts. Joints predominantly strike at N70-90°E over most of the Lake Edison pluton and are exploited as sinistral shear zones, both within and outside the RFSZ. In a narrow (˜250 m thick) zone at the contact with the younger Mono Creek granite, within the RFSZ, the Lake Edison granodiorite includes different sets of dextral and sinistral shear zones/joints (the latter corresponding to the set that dominates over the rest of the Lake Edison pluton). These shear zones/joints potentially fit with a composite Y-R-R' shear fracture pattern associated with the RFSZ, or with a pattern consisting of Y-R-shear fractures and rotated T' mode I extensional fractures. The mineral assemblage of shear zones, and the microstructure and texture of quartz mylonites indicate that ductile deformation occurred above 500 °C. Joints and ductile shearing alternated and developed coevally. The existing kinematic models do not fully capture the structural complexity of the area or the spatial distribution of the deformation and magmatic structures. Future models should account more completely for the character of ductile and brittle deformation as these plutons were emplaced and cooled.

  18. Jim River and Hodzana plutons, Alaska: the role of assimilation in the petrogenesis of syenite and granite

    SciTech Connect

    Blum, J.D.; Blum, A.E.; Dillon, J.T.

    1985-01-01

    Early Cretaceous plutonic rocks in central Alaska intrude both Devonian to Jurassic oceanic rocks of the Angayuchum terrane (AT) and early Paleozoic to Precambrian continental metasediments of the Ruby terrane (RT). Most plutons intrude only the RT and are biotite and two-mice granite. The Hodzana pluton intrudes both fault-bounded terranes, constraining movement between them to the emplacement age of about 110 million years, and is mainly biotite-amphibole granite with some monzodiorite. Modal and chemical data from the Jim River and Hodzana plutons define two distinct compositional trends. One trend is monzonitic to syenitic while the other is mostly granitic. The two suites are the same age, yet cannot be related by simple differentiation due to a pronounced chemical discontinuity. Rb-Sr whole-rock isochrons yield an age of 112 million years and (87Sr/86Sr)o of .7078 for the syenitic suite, and an age of 108 million years and (87Sr/86Sr)o of .7079 for the granitic suite. The authors suggest that the monzonite represents a primary magma that formed in the lower crust or mantle and initiated upper crustal melting as it intruded the AT and RT. Assimilation of continental crust could have allowed the portion of the magma that intruded the RT to evolve from a monzonite to a granite. Fractionation of these two parent magmas may have resulted in the contemporaneous syenitic and granitic suites. The two suites may reflect the contrasting composition of assimilated wallrock across the AT-RT boundary. Isotopic studies of the wallrocks are in progress and may help to constrain the amount and composition of crust that was assimilated where the magma intruded the AT versus the RT.

  19. Map showing distribution and classification of felsic plutonic rocks in the eastern Arabian Shield, Kingdom of Saudi Arabia

    USGS Publications Warehouse

    Du Bray, E.A.

    1983-01-01

    This 1:500,000-scale compilation shows the distribution of felsic plutonic rocks, lithologic types, and associated mineralization in an area between lat 21° and 24°30’ N., long 43°30’ and 46° E. It is part of a shieldwide compilation being done within the framework of Saudi Arabian Deputy Ministry for Mineral Resources projects 2.04 and 3.12.

  20. MicroBooNE: The Search For The MiniBooNE Low Energy Excess

    NASA Astrophysics Data System (ADS)

    Kaleko, David

    This thesis describes work towards the search for a low energy excess of electromagnetic events in the MicroBooNE detector. A background primer on the current state of neutrino physics is provided, including a description of the MiniBooNE detector and its published observation of an excess of electromagnetic events at low energies. A description of the MicroBooNE Liquid Argon Time Projection Chamber (LArTPC) detector is given, along with a description of the event selection and reconstruction algorithms developed to select electron neutrino charge-current interactions. A MiniBooNE-like signal is simulated in MicroBooNE with assumptions about the origin of the excess, and the sensitivity to observe such a signal above backgrounds in MicroBooNE is computed. An additional analysis is presented which constrains a dominant background in the MicroBooNE low energy excess search: the beam-intrinsic electron neutrino interactions which come from kaon decay in the beam-line. An essential step in this analysis is to reconstruct the energy of muon neutrino charge-current interactions in which the muon produced in the interaction escapes the detector. A publication detailing the algorithm which leverages the phenomenon of multiple Coulomb scattering to reconstruct the energy of escaping muons is provided as an appendix.

  1. Plutonic rocks in the Mineoka-Setogawa ophiolitic mélange, central Japan: Fragments of middle to lower crust of the Izu-Bonin-Mariana Arc?

    NASA Astrophysics Data System (ADS)

    Ichiyama, Yuji; Ito, Hisatoshi; Hokanishi, Natsumi; Tamura, Akihiro; Arai, Shoji

    2017-06-01

    A Paleogene accretionary complex, the Mineoka-Setogawa Belt, is distributed around the Izu Collision Zone, central Japan. Plutonic rocks of gabbro, diorite and tonalite compositions are included as fragments and dykes in an ophiolitic mélange in this belt. Zircon U-Pb dating of the plutonic rocks indicates that they were formed at ca. 35 Ma simultaneously. These ages are consistent with Eocene-Oligocene tholeiite and calc-alkaline arc magmatism in the Izu-Bonin-Mariana (IBM) Arc and exclude several previous models for the origin of the Mineoka-Setogawa ophiolitic rocks. The geochemical characteristics of these plutonic rocks are similar to those of the Eocene-Oligocene IBM tholeiite and calc-alkaline volcanic rocks as well as to the accreted middle crust of the IBM Arc, the Tanzawa Plutonic Complex. Moreover, their lithology is consistent with those of the middle and lower crust of the IBM Arc estimated from the seismic velocity structure. These lines of evidence strongly indicate that the plutonic rocks in the Mineoka-Setogawa ophiolitic mélange are fragments of the middle to lower crust of the IBM Arc. Additionally, the presence of the Mineoka-Setogawa intermediate to felsic plutonic rocks supports the hypothesis that intermediate magma can form continental crust in intra-oceanic arcs.

  2. Is the southeast Coast Plutonic Complex the consequence of accretion of the insular superterrane Evidence from U-Pb zircon geochronometry in the northern Washington Cascades

    SciTech Connect

    Walker, N.W. ); Brown, E.H. )

    1991-07-01

    Zircon U-Pb geochronometry of orthogneisses and plutons in the southwestern crystalline core of the North Cascades, coupled with fabric and textural studies of the orthogneisses, plutons, and their metamorphic host rocks, indicates extensive synmetamorphic plutonism at 89-96 Ma. Metamorphic mineral assemblages define a culmination composed of an axial kyanite-sillimanite zone rimmed by lower grade zones. High-grade index minerals are typically syntectonic to posttectonic. Metamorphic fabrics are characterized by an orogen-parallel, northwest-striking, steep foliation that contains a subhorizontal stretching and mineral lineation interpreted to be the product of ductile strike-slip deformation. This fabric is crosscut by 96-92 Ma plutons yet is imprinted on 92-89 Ma orthogneisses, suggesting spatially diachronous fabric development during orogeny. Documentation of the spatial and temporal coincidence of magmatism with the peak of orogeny, together with the kinematic significance of the metamorphic fabric, precludes generation of the metamorphic fabric and plutons in response to thrust loading. The authors suggest that this part of the Coast Plutonic Complex evolved as a transpressional magmatic arc.

  3. Structure, emplacement and lateral expansion of the San José tonalite pluton, Peninsular Ranges batholith, Baja California, México

    NASA Astrophysics Data System (ADS)

    Johnson, S. E.; Fletcher, J. M.; Fanning, C. M.; Vernon, R. H.; Paterson, S. R.; Tate, M. C.

    2003-11-01

    The 108 km 2 San José pluton forms part of the Jurassic to Cretaceous Peninsular Ranges batholith of northern Baja California, México. The pluton was formed by three nested, southward-migrating intrusive pulses, and the internal contacts between them indicate juxtaposition while the adjoining pulses were magmas. SHRIMP U-Pb zircon data indicate that the entire pluton was emplaced in less than 4.4 m.y.; ages of the individual pulses cannot be separated at the 95% confidence interval, owing primarily to low uranium content of zircon. Detailed structural data and geologic mapping are consistent with a component of asymmetrical, lateral expansion at the site of emplacement. The direction of maximum lateral expansion may have been controlled by thermal, compositional and resulting rheological gradients in the surrounding wall rocks. A carapace of predominantly solid-state deformation marks the northern two-thirds of the pluton, and the early stages of this fabric may have formed in the presence of a small amount of melt. Lack of evidence for syn- to post-emplacement regional ductile deformation around the pluton suggests that this carapace was deformed during the lateral expansion of the pluton.

  4. Paleoproterozoic structural frame of the Yetti domain (Eglab shield, Algeria): Emplacement conditions of the Tinguicht late pluton from magnetic fabric study

    NASA Astrophysics Data System (ADS)

    Merabet, Nacer-eddine; Mahdjoub, Yamina; Henry, Bernard; Abtout, Abdeslam; Maouche, Said; Kahoui, Mohamed; Lamali, Atmane; Ayache, Mohamed

    2016-02-01

    The Tinguicht pluton is part of the ˜2.07 Ga post-collisional magmatic suites that intruded the Yetti Paleoproterozoic volcano-sedimentary series of the western part of the Eglab Shield (West African Craton). It represents one of the most recent units of these suites. This pluton, with a NW-SE elliptic shape, is unfoliated, and its deformational structures are practically restricted to fracturing and faulting. New structural, microstructural and aeromagnetic data are presented in order to analyze in particular the relationship between the Tinguicht pluton emplacement and the related NNW-SSE major mega-shear zone, separating the Yetti and Eglab domains. To constrain the context of the regional post-collisional evolution of the Eglab shield, a structural analysis was performed by mapping the magnetic structures (foliation and lineation) using AMS. The combination of the results of all the used approaches leads to a new and enriched image of this granitic pluton and of its tectonic emplacement context. The elliptic shape of the granitic body and the AMS strain pattern are consistent with the presence of a NNW-SSE major structure. NNW-SSE is also one of the major directions highlighted by the aeromagnetic data. This study thus evidences the role of the pre-existing major shear zones in controlling emplacement of post-collisional Paleoproterozoic plutons like Tinguicht, as shown for Drissa pluton in the Eglab domain earlier.

  5. A tale of 10 plutons - Revisited: Age of granitic rocks in the White Mountains, California and Nevada

    USGS Publications Warehouse

    McKee, E.H.; Conrad, J.E.

    1996-01-01

    40Ar/39Ar incremental heating analysis and conventional K-Ar age determinations on plutonic rocks of the White Mountains define two stages of magmatic emplacement: Late Cretaceous, between ca. 90 Ma and 75 Ma, and Middle-Late Jurassic, between ca. 180 and 140 Ma. The Jurassic stage can be divided into two substages, 180-165 Ma and 150-140 Ma. Thermal effects of the younger plutons on the older granitoids partially to completely reset ages, making it difficult to determine the age of emplacement and cooling of several of the plutons even by 40Ar/39Ar incremental heating analyses. New data together with published ages and regional geochronological synthesis of the Sierra Nevada batholith indicate that regions within the batholith have coherent periods or episodes of magmatic activity. In the White Mountains and Sierra Nevada directly to the west there was little or no activity in Early Jurassic and Early Cretaceous time; magmatism took place during relatively short intervals of 15 m.y. or less in the Middle and Late Jurassic and Late Cretaceous periods. The new K-Ar and 40Ar/39Ar analyses of granitoids from the White Mountains help, but do not completely clarify the complex history of emplacement, cooling, and reheating of the batholith.

  6. Regional geochemical study of the felsic plutonic rocks in the Nuqrah quadrangle, sheet 25E, Kingdom of Saudi Arabia

    SciTech Connect

    Hall, W.E.; Dellinger, D.; Selner, G.I.

    1985-01-01

    A regional geochemical investigation of the felsic plutonic rocks of the Nuqrah quadrangle, sheet 25 E, Kingdom of Saudi Arabia, in which pan concentrates of 384 wadi samples, and 145 rock samples, were collected, defined two separate and distinct anomalous areas. One area contains Jabal Tuwalah and Jabal Awja, and the other is at the north end of Jabal Safad. Both pan concentrates and the rock samples in the Jabal Tuwalah and Jabal Awja areas contain high concentrations of Be, F, La, Mo, Nb, Pb, Th, U, Sn, Y, and Zr, and the plutons underlying those areas are characterized by high total-count radioactivity. These elements are sited in highly evolved alkalic granites and have not been concentrated into a potentially metalliferous deposit related to a hydrothermal ore system. They may be a potential metal source of the future. Pan-concentration samples collected from wadis draining the north end of Jabal Safad contain anomalous Sn, Mo, Pb, and La. Four samples contain 250 to 1000 ppM of tin. The tin anomaly is associated with a small aplitic pluton intrusive into the Jabal Safad alkalic granite complex. A brief reconnaissance of the area did not reveal any greisen or cassiterite mineralization. However, further exploration work in the area is recommended. 23 refs., 10 figs., 3 tabs.

  7. Emplacement and deformation of the Fomopéa pluton: Implication for the Pan-African history of Western Cameroon

    NASA Astrophysics Data System (ADS)

    Njanko, T.; Nédélec, A.; Kwékam, M.; Siqueira, R.; Esteban, L.

    2010-03-01

    The Fomopéa pluton (622-613 Ma) is located in the western part of the Pan-African belt in Cameroon. It comprises of 3 units: biotite-hornblende granitoids (BHG), biotite monzogranites (BmG) and edenite syenogranites (EsG). The BHG unit displays magnetic fabrics characterized by foliations gently dipping towards the ESE and ENE-trending lineations (D1 event). Microstructures are magmatic to submagmatic. In discrete N-S deformation bands (D2), lineations are rotated towards the North and microstructures indicate solid-state deformation at mid- to low-T conditions, with kinematic indicators pointing to a sinistral motion. The second unit, BmG, displays lineation trajectories suggesting emplacement during the D2 event. The EsG unit displays fabrics consistent with a later emplacement, with no superposed deformation. The last event (D3) corresponds to a dextral shear zone, that runs along the southeastern border of the Fomopéa pluton. It was responsible for protomylonitic deformation of the granitic rocks in greenschist facies conditions, whereas the core of the shear zone registered higher temperatures and strain. This shear zone induced a rejuvenation of the Rb/Sr isotopic system in the pluton at ca 572 Ma. It belongs to the Central Cameroon shear zone system, regarded as the prolongation of the dextral Patos shear zone system in Brazil.

  8. Contrasting magmatic structures between small plutons and batholiths emplaced at shallow crustal level (Sierras de Córdoba, Argentina)

    NASA Astrophysics Data System (ADS)

    Pinotti, Lucio P.; D'Eramo, Fernando J.; Weinberg, Roberto F.; Demartis, Manuel; Tubía, José María; Coniglio, Jorge E.; Radice, Stefania; Maffini, M. Natalia; Aragón, Eugenio

    2016-11-01

    Processes like injection, magma flow and differentiation and influence of the regional strain field are here described and contrasted to shed light on their role in the formation of small plutons and large batholiths their magmatic structures. The final geometric and compositional arrangement of magma bodies are a complex record of their construction and internal flow history. Magma injection, flow and differentiation, as well as regional stresses, all control the internal nature of magma bodies. Large magma bodies emplaced at shallow crustal levels result from the intrusion of multiple magma batches that interact in a variety of ways, depending on internal and external dynamics, and where the early magmatic, growth-related structures are commonly overprinted by subsequent history. In contrast, small plutons emplaced in the brittle-ductile transition more likely preserve growth-related structures, having a relatively simple cooling history and limited internal magma flow. Outcrop-scale magmatic structures in both cases record a rich set of complementary information that can help elucidate their evolution. Large and small granitic bodies of the Sierra Pampeanas preserve excellent exposures of magmatic structures that formed as magmas stepped through different rheological states during pluton growth and solidification. These structures reveal not only the flow pattern inside magma chambers, but also the rheological evolution of magmas in response to temperature evolution.

  9. Dynamics of gas phase Ne(*) + NH3 and Ne(*) + ND3 Penning ionisation at low temperatures.

    PubMed

    Jankunas, Justin; Bertsche, Benjamin; Jachymski, Krzysztof; Hapka, Michał; Osterwalder, Andreas

    2014-06-28

    Two isotopic chemical reactions, Ne(*) + NH3, and Ne(*) + ND3, have been studied at low collision energies by means of a merged beams technique. Partial cross sections have been recorded for the two reactive channels, namely, Ne(*) + NH3 → Ne + NH3(+) + e(-), and Ne(*) + NH3 → Ne + NH2(+) + H + e(-), by detecting the NH3(+) and NH2(+) product ions, respectively. The cross sections for both reactions were found to increase with decreasing collision energy, Ecoll, in the range 8 μeV < Ecoll < 20 meV. The measured rate constant exhibits a curvature in a log(k)-log(Ecoll) plot from which it is concluded that the Langevin capture model does not properly describe the Ne(*) + NH3 reaction in the entire range of collision energies covered here. Calculations based on multichannel quantum defect theory were performed to reproduce and interpret the experimental results. Good agreement was obtained by including long range van der Waals interactions combined with a 6-12 Lennard-Jones potential. The branching ratio between the two reactive channels, Γ = [NH2(+)]/[NH2(+)] + [NH3(+)], is relatively constant, Γ ≈ 0.3, in the entire collision energy range studied here. Possible reasons for this observation are discussed and rationalized in terms of relative time scales of the reactant approach and the molecular rotation. Isotopic differences between the Ne(*) + NH3 and Ne(*) + ND3 reactions are small, as suggested by nearly equal branching ratios and cross sections for the two reactions.

  10. Distribution of manganese between coexisting biotite and hornblende in plutonic rocks

    USGS Publications Warehouse

    Greenland, L.P.; Gottfried, D.; Tilling, R.I.

    1968-01-01

    The distribution of manganese between coexisting biotite and hornblende for 80 mineral pairs from igneous rocks of diverse provenance (including Southern California, Sierra Nevada, Boulder, and Boulder Creek batholiths and the Jemez Mountains volcanics) has been determined by neutron activation analysis. Data on the distribution ratio (Kd = Mnhornblende Mnbiotite) indicate that an equilibrium distribution of Mn is closely approached, though not completely attained, in most samples from plutonic environments. Comparison of Kd values of mineral pairs with bulk chemical composition of host rocks reveals no correlation. Because initial crystallization temperatures vary with rock composition, the lack of correlation of composition with Kd suggests that the equilibrium distribution of Mn between biotite and hornblende reflects exchange at subsolidus temperatures rather than initial crystallization temperatures. The highest Kd values are for volcanic rocks, in which rapid quenching prevents subsolidus redistribution of Mn. For sample pairs from the Southern California and Sierra Nevada batholiths there is a positive correlation of Kd with TiO2 content of biotite. Though the evidence is not compelling, Kd may also correlate with the rate of cooling and/or the presence or absence of sphene in the rock. ?? 1968.

  11. Nd and Sr isotopic signatures of Mesozoic plutons in northeastern North America

    SciTech Connect

    Foland, K.A.; Jiang-feng, C.; Gilbert, L.A.; Hofmann, A.W.

    1988-08-01

    Nd and Sr initial isotope ratios are reported for 17 Mesozoic plutons of the Monteregian Hills and White Mountain series provinces in northeastern North America. Some variation in the isotopic ratios at most localities is caused by crustal-contamination processes. When the crustal assimilation effects are taken into account, the initial ratios for apparently uncontaminated, mantle-derived parental magmas show only restricted range in /sup 87/Sr//sup 86/Sr (0.7032 to 0.7040) and epsilon/sub Nd/ (T) (+5.4 to +2.3), which are inversely correlated. These ratios characterize alkaline to subalkaline magmas emplaced over more than 400 km/sup 2/ and about 80 m.y. The isotopic and trace-element characteristics are broadly similar to those of many modern ocean-island basalts, specifically the New England Seamounts, suggesting similar time-integrated, lithophile-element-depleted mantle sources. The results are consistent with plume-related mantle sources deeper than the subcontinental mantle.

  12. Metamorphism and plutonism in the Quetico Belt, Superior Province, N.W. Ontario

    NASA Technical Reports Server (NTRS)

    Percival, J. A.

    1986-01-01

    The Quetico Belt lies between the metavolcanic Wawa-Shebandowan and Wabigoon Belts. It consists of marginal metasedimentary rocks and central pelitic, gneissic and plutonic rocks. Metamorphism is Barrovian, at depths less than 10 km, and grade increases from margins to core of the belt: the outermost pelites are at chlorite-muscovite grade; inward a garnet-andalusite zone formed throughout the inner margin; and the central zone ranges form garnet-andalusite in the west and garnet-sillimanite-muscovite to garnet-sillimanite-cordierite and rare kyanite 6 to 150 km to the east. This increase is correlated with granitic intrusives. Migmatites in the core have intrusive leucosomes in the west and locally derived ones in the east. Isograd surfaces are steep where the belt is narrow and dip gently where it is wide. The Quetico Park intrusive complex of the central region of the Quetico Belt shows a zonation across it 20 to 50 km width from older, medium grained biotite composition to younger, coarse to pegmatitic granitic composition. Sediment of the Quetico basin had its source in the bordering metavolcanic belts and was deposited ca. 2.75 to 2.70 Ga ago. Boundaries of the belt dip inward, so it essentially is a graben of inter-arc or back-arc type.

  13. Young cumulate complex beneath Veniaminof caldera, Aleutian arc, dated by zircon in erupted plutonic blocks

    USGS Publications Warehouse

    Bacon, C.R.; Sison, T.W.; Mazdab, F.K.

    2007-01-01

    Mount Veniaminof volcano, Alaska Peninsula, provides an opportunity to relate Quaternary volcanic rocks to a coeval intrusive complex. Veniaminof erupted tholeiitic basalt through dacite in the past ???260 k.y. Gabbro, diorite, and miarolitic granodiorite blocks, ejected 3700 14C yr B.P. in the most recent caldera-forming eruption, are fragments of a shallow intrusive complex of cumulate mush and segregated vapor-saturated residual melts. Sensitive high-resolution ion microprobe (SHRIMP) analyses define 238U-230Th isochron ages of 17.6 ?? 2.7 ka, 5+11/-10 ka, and 10.2 ?? 4.0 ka (2??) for zircon in two granodiorites and a diorite, respectively. Sparse zircons from two gabbros give 238-230Th model ages of 36 ?? 8 ka and 26 ?? 7 ka. Zircons from granodiorite and diorite crystallized in the presence of late magmatic aqueous fluid. Although historic eruptions have been weakly explosive Strombolian fountaining and small lava effusions, the young ages of plutonic blocks, as well as late Holocene dacite pumice, are evidence that the intrusive complex remains active and that evolved magmas can segregate at shallow levels to fuel explosive eruptions. ?? 2007 The Geological Society of America.

  14. Natural radioactivity distribution and gamma radiation exposure of beach sands close to Kavala pluton, Greece

    NASA Astrophysics Data System (ADS)

    Papadopoulos, Argyrios; Koroneos, Antonios; Christofides, Georgios; Stoulos, Stylianos

    2015-10-01

    This study aims to evaluate the activity concentrations of 238U, 226Ra, 232Th, 228Th and 40K along the beaches of Kavala being adjacent to the rock-types of the Kavala pluton. These ranged from 14-940, 16-1710, 26- 4547, 27-4488 and 194-1307 Bq/kg respectively, representing the highest values of natural radioactivity measured in sediments of Greece. The (%wt.) heavy magnetic (HM) (allanite, amphibole, mica, clinopyroxene, magnetite and hematite) fraction, the heavy non-magnetic (HNM) (monazite, zircon, titanite and apatite) fraction and the total heavy fraction (TH), were correlated with the concentrations of the measured radionuclides in the bulk samples. The heavy fractions seem to control the activity concentrations of 238U and 232Th of all the samples, showing some local differences in the main 238U and 232Th mineral carrier. The measured radionuclides in the beach sands were normalized to the respective values measured in the granitic rocks, which are their most probable parental rocks, so as to provide data upon their enrichment or depletion. The annual equivalent dose varies between 0.01 and 0.35 mSv y-1 for tourists and from 0.03 to 1.48 mSv y-1 for local people working on the beach.

  15. Geochemical Database for the Boulder Batholith and Its Satellitic Plutons, Southwest Montana

    USGS Publications Warehouse

    du Bray, Edward A.; Lund, Karen; Tilling, Robert I.; Denning, Paul D.; DeWitt, Ed

    2009-01-01

    Geochemical data presented in this report pertain to Cretaceous igneous intrusions of the Boulder batholith and its satellitic plutons in southwest Montana. The geographic area addressed in this compilation is approximately bounded by lats 45.6 deg and 46.7 deg N. and longs 112.75 deg and 111.5 deg W. These data were compiled in order to establish the geologic framework for world-class mineral deposits of the Butte district. Although these deposits and their host rocks have been the subject of many investigations, the petrologic characteristics of associated intrusive rocks have not been systematically compiled, synthesized, or interpreted. Abundant late Mesozoic intrusions in the study area are probably byproducts of subduction-related processes, including back-arc magmatism that prevailed along the west edge of the North American plate during this interval. The ultimate goal of this effort will be an evaluation of the time-space-compositional evolution of Mesozoic magmatism associated with the Boulder batholith and identification of genetic associations between magmatic and mineralizing processes in this region.

  16. A petrologic comparison of Triassic plutonism in the San Gabriel and Mule Mountains, southern California

    SciTech Connect

    Barth, A.P. ); Tosdal, R.M.; Wooden, J.L. )

    1990-11-10

    Triassic magmatism in the southwest US Cordillera forms a semicontinuous magmatic arc extending from northwestern Nevada to southeastern California. Quartz monzodioritic and quartz monzonitic rocks and associated diorites and granites are widespread in southeastern California, and the authors suggest that these rocks represent exposure of a structurally deeper part of the Triassic arc, where it was emplaced into comparatively thick Proterozoic crust. Elemental and isotopic data suggest that Triassic quartz monzodiorites and quartz monzonites in the Mule and San Gabriel Mountains were derived from a relatively undepleted, nonradiogenic mafic lithospheric source, with virtually no upper crustal interaction. Very limited data for associated Triassic ( ) diorites indicate a wide range in composition and a surprisingly radiogenic isotopic signature. Younger Triassic( ) granites record a strong geochemical signature of interaction with continental crust, including inherited zircon and high initial Sr ratios but comparatively less radiogenic Pb isotopic compositions. The major and trace element geochemistry of Late Triassic plutonic rocks in southeastern California is similar in many respects to akalic components of the Triassic arc in the Mojave Desert. However, contemporaneous rocks farther north have a calc-alkalic signature, perhaps reflecting the variation in age and composition of lithosphere across which the Triassic arc was constructed.

  17. Phase equilibria of a fluorine-rich leucogranite from the St. Austell pluton, Cornwall

    SciTech Connect

    Weidner, J.R.; Martin, R.F.

    1987-06-01

    Highly evolved leucogranitic rocks in the St. Austell pluton, Cornwall, of Hercynian age, contain accessory muscovite, topaz and fluorite. The authors have studied the H/sub 2/O-saturated melting behavior of one representative sample. Its solidus and liquidus pass through the points 663 and 725/sup 0/C, respectively, at 1 kbar, 640 and 665/sup 0/C at 2 kbar, 610 and 717/sup 0/C at 4 kbar, and 608 and 700+/sup 0/C at 8 kbar. Plagioclase is on the liquidus at low pressure, and topaz is on the liquidus at 4 kbar. The fluorite is consumed in the formation of the first-formed liquid. Calcium can partition into an evolved granitic melt if complexed by fluorine. The fluorite appears to be largely primary in fresh fluorite granite at St. Austell, and not to reflect the albitization of oligoclase in the surrounding biotite granite. Such fluorine-rich leucogranites can be expected to be of subsolvus character.

  18. Evolution and geochemistry of the Tertiary calc-alkaline plutons in the Adak Island region of the central Aleutian oceanic island arc

    NASA Astrophysics Data System (ADS)

    Kay, Suzanne; Citron, Gary P.; Kay, Robert W.; Jicha, Brian; Tibbetts, Ashley

    2014-05-01

    Calc-alkaline plutons are major crustal building blocks of continental margin mountain belts like the Mesozoic to Tertiary Andes and the Sierra Nevada, but are rare in oceanic island arcs. Some of the most calc-alkaline I-type island arc plutons are in the Central Aleutians with the most extreme signatures, as indicated by FeO/MgO ratios of < ~2 at 48-70% wt. % SiO2, in the ~10 km wide Oligocene Hidden Bay pluton on southern Adak Island and the 10 km wide Miocene Kagalaska pluton to the north on eastern Adak and the adjacent Kagalaska Island. Although small compared to most continental plutons, similarities in intrusive units, mineralogy and chemistry suggest common formation processes. The Aleutian calc-alkaline plutonic rocks mainly differ from continental plutons in having more oceanic like isotopic (87Sr/86Sr = 0.703-0.7033; Epsilon Nd = 9-7.8) and LIL (e.g., higher K/Rb) ratios. The Adak region plutons differ from Tertiary plutons on Unalaska Island further east in being more K-rich and in having a more oxidized and lower-temperature mineralogy. From a regional perspective, the Adak area plutons intrude Eocene/Oligocene Finger Bay Formation mafic volcanic and sedimentary rocks and postdate the small ~38 Ma tholeiitic Finger Bay pluton. The chemistry of these older magmatic rocks is basically similar to that of young Central Aleutian magmatic rocks with boninites and arc tholeiitic magmas seemingly being absent. The formation of the calc-alkaline plutons seems to require a sufficient crustal thickness, fluid concentration and contractional stress such that magma chambers can stabilize significant amounts of pargasitic hornblende. Seismic receiver function analyses (Janiszewski et al., 2013) indicate the modern Adak crust is ~ 37 km thick. Existing and new hornblende, plagioclase and biotite Ar/Ar ages from 16 Hidden Bay pluton and Gannet Lake stock gabbro, porphyritic diorite, diorite, granodiorite, leucogranodiorite and aplite samples range from 34.6 to 30

  19. MiniBooNE oscillation searches

    SciTech Connect

    Brice, Stephen J.

    2008-01-01

    The range of oscillation analyses being pursued by the MiniBooNE collaboration is described. Focus is given to the various searches for electron neutrino appearance, but the disappearance of muon neutrinos and the appearance search for electron anti-neutrinos are covered as well.

  20. Data ingestion into NeQuick 2

    NASA Astrophysics Data System (ADS)

    Nava, B.; Radicella, S. M.; Azpilicueta, F.

    2011-12-01

    NeQuick 2 is the latest version of the NeQuick ionosphere electron density model developed at the Aeronomy and Radiopropagation Laboratory of the Abdus Salam International Centre for Theoretical Physics (ICTP) - Trieste, Italy with the collaboration of the Institute for Geophysics, Astrophysics and Meteorology of the University of Graz, Austria. It is a quick-run model particularly designed for trans-ionospheric propagation applications that has been conceived to reproduce the median behavior of the ionosphere. To provide 3-D specification of the ionosphere electron density for current conditions, different ionosphere electron density retrieval techniques based on the NeQuick adaptation to GPS-derived Total Electron Content (TEC) data and ionosonde measured peak parameters values have been developed. In the present paper the technique based on the ingestion of global vertical TEC map into NeQuick 2 will be validated and an assessment of the capability of the model to reproduce the ionosphere day-to-day variability will also be performed. For this purpose hourly GPS-derived global vertical TEC maps and hourly foF2 values from about 20 ionosondes corresponding to one month in high solar activity and one month in low solar activity period will be used. Furthermore, the first results concerning the ingestion of space-based GPS-derived TEC data will be presented.

  1. NE-TWIGS update: Incorporating tree quality

    Treesearch

    Daniel A. Yaussy

    1993-01-01

    A method to distribute tree quality was incorporated into the NE-TWIGS individual-tree growth and yield simulator. The program uses potential tree grade to allow changes in actual tree grade over time. Volume is reported by grade and value is calculated using tree grades. Example screens are shown.

  2. Tonian granitic magmatism of the Borborema Province, NE Brazil: A review

    NASA Astrophysics Data System (ADS)

    Guimarães, Ignez P.; de Fatima L. de Brito, Maria; de A. Lages, Geysson; da Silva Filho, Adejardo F.; Santos, Lucilene; Brasilino, Roberta G.

    2016-07-01

    Tonian granitoids, today augen-gneisses and migmatites, showing crystallization ages ranging from 870 Ma to 1000 Ma occur in the Borborema Province, NE Brazil. The majority of them have ages within the 925-970 Ma interval. Few intrusions with ages of ∼1.0 Ga and <900 Ma occur in the Transversal and South subprovinces. The Tonian granitoids constitute the most expressive magmatic rocks of the Cariris Velhos event. The studied granitoids (herein CVG -Cariris Velhos granitoids) intrude slightly older bimodal (but mostly felsic) volcanic successions and metasedimentary sequences in the Transversal and South subprovinces. Tonian granitoids are unknown in the North subprovince. The CVG comprise mainly coarse-grained augen-gneisses of granite to granodiorite composition. Fe-rich biotite (annite) is the main mafic mineral phase, constituting up to 15% of the modal composition. Garnet, muscovite and tourmaline occur as accessory phases in many plutons. The CVG augen-gneisses have high SiO2 (>71%) and alkali contents, they vary from slightly peraluminous to slightly metaluminous, and from slightly magnesian to typical ferrroan rocks. In the migmatized orthogneisses the SiO2 contents are usually <70%. Trace element variations in the CVG are extensive, reflecting the migmatization recorded in some plutons and/or distinct sources. They are Ca-, Sr- and Nb-poor, showing variable Ba (100-1260 ppm), Rb (164-400 ppm) and Zr (144-408 ppm) contents, and high abundances of Y (>40 ppm). The chondrite normalized REE patterns are characterized by strong to moderate negative Eu anomalies (Eu/Eu* = 0.23-0.70). In general, the spidergram patterns show deep troughs at Ti, P, Ba and Sr and less pronounced Nb-Ta troughs. These patterns are similar to those reported for anorogenic granites evolved from mixtures of magmas from both crustal and mantle sources. The CVG exhibit TDM model ages ranging from 1.9 to 1.1Ga, with slightly negative to slightly positive ƐNd(t) values, suggesting the

  3. Applied andrology in chickens and turkeys

    USDA-ARS?s Scientific Manuscript database

    The theories and practices of applied andrology in commercial poultry species (turkey, layer chicken and broiler chicken) are reviewed. Poultry male reproductive biology, including reproductive anatomy and spermatogenesis, is compared with mammalian livestock species. A detailed description of pou...

  4. Impact of the Chernobyl accident on Turkey

    SciTech Connect

    Fields, D.E.; Ozluoglu, N.; Yalcintas, M.G.

    1987-01-01

    In this paper, we present and discuss measurements of radionuclide concentrations made in Turkey during the Chernobyl event and perform preliminary analyses of the internal and external doses associated with exposure to these materials. 15 refs., 1 tab.

  5. Counseling in Turkey: An Evolving Field

    ERIC Educational Resources Information Center

    Stockton, Rex; Guneri, Oya Yerin

    2011-01-01

    This article provides a brief history of counseling and addresses the current issues and future trends of counseling in Turkey. Special emphasis is placed on the factors that impede the development of school counseling as a discipline.

  6. Counseling in Turkey: An Evolving Field

    ERIC Educational Resources Information Center

    Stockton, Rex; Guneri, Oya Yerin

    2011-01-01

    This article provides a brief history of counseling and addresses the current issues and future trends of counseling in Turkey. Special emphasis is placed on the factors that impede the development of school counseling as a discipline.

  7. Turkey: Background and U.S. Relations

    DTIC Science & Technology

    2016-08-26

    self-reliance since the Cold War allows Turkey relatively greater opportunity for an assertive role in foreign policy. The record of U.S.-Turkey...U.S. and Turkish military and diplomatic dealings with a number of different stakeholders, including Russia and Iran; and (3) Turkish efforts to stop...harmonizing their priorities and actions. This may stem partly from differences in how each of the two countries evaluates the other’s importance in

  8. Turkey as an Emerging Energy Hub

    DTIC Science & Technology

    2010-06-01

    and to lesser degrees from Azerbaijan, Iran, Algeria and Nigeria. Turkey imports from Russia, Azerbaijan and Iran by pipelines, but from Algeria ...renewable energy sources in Turkey are solar, thermal, wind, geothermal, photovoltaic energy and new programs such as hydrogen energy, and fuel cells.78...percent from Algeria ; and 11 percent from other countries.210 According to estimates, by 2030, Europe’s oil import requirements will be increased by 20

  9. Using the concentration-volume (C-V) fractal model in the delineation of gold mineralized zones within the Tepeoba porphyry Cu-Mo-Au, Balikesir, NW Turkey

    NASA Astrophysics Data System (ADS)

    Kumral, Mustafa; Abdelnasser, Amr; Karaman, Muhittin; Budakoglu, Murat

    2016-04-01

    The Tepeoba porphyry Cu-Mo-Au mineralization that located at the Biga peninsula (W Turkey) developed around the Eybek pluton concentrated at its southern contact. This mineralization that hosted in the hornfels rocks of Karakaya Complex is associated with three main alteration zones; potassic, phyllic and propylitic alterations along the fault controlled margins of the Eybek pluton and quartz stockwork veining as well as brecciation zones. As well as two mineralized zones were occurred in the mine area; hypogene and oxidation/supergene zone. The hypogene zone has differentiated alteration types; high potassic and low phyllic alteration, while the oxidation/supergene zone has high phyllic and propylitic alterations. This work deals with the delineation of gold mineralized zone within this porphyry deposit using the concentration-volume (C-V) fractal model. Five zones of gold were calculated using its power-law C-V relationship that revealed that the main phase of gold mineralization stated at 5.3083 ppm Au concentration. In addition, the C-V log-log plot shows that the highly and moderately Au mineralization zone developed in western part of deposit correlated with oxidation zone related to propylitic alteration. On the other hand, its weakly mineralization zone has a widespread in the hypogene zone related to potassic alteration. This refers to the enrichment of gold and depletion of copper at the oxidation/supergene zone is due to the oxidation/supergene alteration processes that enrich the deposits by the meteoric water. Keywords: Concentration-volume (C-V) fractal model; gold mineralized zone; Tepeoba porphyry Cu-Mo-Au; Balikesir; NW Turkey.

  10. Geochemical behavior of rare earth elements of the hydrothermal alterations within the Tepeoba porphyry Cu-Mo-Au deposits at Balikesir, NW Turkey

    NASA Astrophysics Data System (ADS)

    Doner, Zeynep; Abdelnasser, Amr; Kiran Yildirim, Demet; Kumral, Mustafa

    2016-04-01

    This work reports the geochemical characteristics and behavior of the rare earth elements (REE) of the hydrothermal alteration of the Tepeoba porphyry Cu-Mo-Au deposit located in the Anatolian tectonic belt at Biga peninsula (Locally Balikesir province), NW Turkey. The Cu-Mo-Au mineralization at this deposit hosted in the hornfels rocks and related to the silicic to intermediate intrusion of Eybek pluton. It locally formed with brecciated zones and quartz vein stockworks, as well as the brittle fracture zones associated with intense hydrothermal alteration. Three main alteration zones with gradual boundaries formed in the mine area in the hornfels rock that represents the host rock, along that contact the Eybek pluton; potassic, propylitic and phyllic alteration zones. The potassic alteration zone that formed at the center having high amount of Cu-sulfide minerals contains biotite, muscovite, and sericite with less amount of K-feldspar and associated with tourmalinization alteration. The propylitic alteration surrounds the potassic alteration having high amount of Mo and Au and contains chlorite, albite, epidote, calcite and pyrite. The phyllic alteration zone also surrounds the potassic alteration containing quartz, sericite and pyrite minerals. Based on the REE characteristics and content and when we correlate the Alteration index (AI) with the light REEs and heavy REEs of each alteration zone, it concluded that the light REEs decrease and heavy REEs increase during the alteration processes. The relationships between K2O index with Eu/Eu* and Sr/Sr* reveals a positive correlation in the potassic and phyllic alteration zones and a negative correlation in the propylitic alteration zone. This refers to the hydrothermal solution which is responsible for the studied porphyry deposits and associated potassic and phyllic alterations has a positive Eu and Sr anomaly as well as these elements were added to the altered rock from the hydrothermal solution. Keywords: Rare

  11. Electron impact excitation of the Ne II and Ne III fine structure levels

    NASA Astrophysics Data System (ADS)

    Wang, Q.; Loch, S. D.; Pindzola, M. S.; Cumbee, R.; Stancil, P. C.; Ballance, C. P.; McLaughlin, B. M.

    2016-05-01

    Electron impact excitation cross sections and rate coefficients of the low lying levels of the Ne II and Ne III ions are of great interest in cool molecular environments including young stellar objects, photodissociation regions, active galactic nuclei, and X-ray dominated regions. We have carried out details computations for cross sections and rate coefficients using the Dirac R-matrix codes (DARC), the Breit-Pauli R-matrix codes (BP) and the Intermediate Coupling Frame Transformation (ICFT) codes, for both Ne II and Ne III. We also compare our results with previous calculations. We are primarily interested in rate coefficients in the temperature range below 1000 K, and the focus is on obtaining the most accurate rate coefficients for those temperatures. We present both a recommended set of effective collision strengths and an indication of the uncertainties on these values. Work at Auburn University and UGA partly supported by NASA Grant NNX15AE47G.

  12. Salt toxicosis in commercial turkeys.

    PubMed

    Wages, D P; Ficken, M D; Cook, M E; Mitchell, J

    1995-01-01

    Salt toxicosis was confirmed in a flock of 20,000 thirteen-week-old tom turkeys experiencing an increase in mortality. Clinical signs included polydipsia, diarrhea, ataxia, incoordination, tremors that progressed to depression, sternal and lateral recumbency accompanied by torticollis, and death. Mortality over a 5-day period was 6.7%. Necropsy lesions included pallor and dehydration of pectoral muscles, hepatic congestion, and fluid-filled small and large intestines. Microscopic lesions consisted of bilaterally symmetrical areas of necrosis within the cerebral hemispheres accompanied by vascular congestion and edema, as well as hyalinization of the glomerular capillary walls of the kidney and eosinophilic granular casts in the renal tubules. Average salt concentration in the feed from affected houses with 8.04%.

  13. Nutrition and gastric cancer in Turkey.

    PubMed

    Yalçin, Suayib

    2009-01-01

    Gastric cancer remains to be one of leading causes of cancer deaths despite worldwide decreasing incidence. In Turkey gastric cancer incidence is 9.6/100,000 in men and 5.7/100,000 in females. Gastric cancer is also one of the leading causes of cancer deaths in Turkey with a crude death rate of 5.84/100,000 in men, 3.7/100,000 in women. The mean age of patients diagnosed with gastric cancer is 56 years in Turkey. The relatively high rate of gastric cancer in Turkey is mainly due to dietary factors. The traditional food preservation such as salt curing or smoking and lack of refrigeration of food play a significant role in gastric cancer development in the country. There are etiological and epidemiological differences among geographical regions in Turkey. Gastric cancer is seen much more often in the central, northeastern, and eastern part of Turkey. Increased HP pylori infection is also another important reason for increased incidence of gastric cancer in some parts of the country.

  14. Sulfachlorpyrazine residues depletion in turkey edible tissues.

    PubMed

    Łebkowska-Wieruszewska, B I; Kowalski, C J

    2010-08-01

    Sulfachlorpyrazine (SCP) is currently used to treat coccidian infections in turkeys; however, there is no information available about the withdrawal period necessary for the turkey to be safe for human consumption. A high performance liquid chromatography method with ultraviolet-visible light detection was adapted and validated for the determination of SCP in turkey tissues. The procedure is based on isolation of the (SCP sodium) compound from edible turkey tissues (muscles, liver, kidneys, and fat with skin) with satisfactory recovery (72.80 +/- 1.40) and specificity. The residue depletion of SCP in turkeys was conducted after a dose of 50 mg/kg body weight/day had been administrated orally for 3 days. After treatment has been discontinued residue concentrations were detected in tissues on the 7th day. The highest SCP concentrations were measured in muscles. Based on the results presented in this study, it could be assumed that a withdrawal period of 21 days, before medicated turkeys could be slaughtered, would be sufficient to ensure consumer safety.

  15. Izmit, Turkey 1999 Earthquake Interferogram

    NASA Image and Video Library

    2001-03-30

    This image is an interferogram that was created using pairs of images taken by Synthetic Aperture Radar (SAR). The images, acquired at two different times, have been combined to measure surface deformation or changes that may have occurred during the time between data acquisition. The images were collected by the European Space Agency's Remote Sensing satellite (ERS-2) on 13 August 1999 and 17 September 1999 and were combined to produce these image maps of the apparent surface deformation, or changes, during and after the 17 August 1999 Izmit, Turkey earthquake. This magnitude 7.6 earthquake was the largest in 60 years in Turkey and caused extensive damage and loss of life. Each of the color contours of the interferogram represents 28 mm (1.1 inches) of motion towards the satellite, or about 70 mm (2.8 inches) of horizontal motion. White areas are outside the SAR image or water of seas and lakes. The North Anatolian Fault that broke during the Izmit earthquake moved more than 2.5 meters (8.1 feet) to produce the pattern measured by the interferogram. Thin red lines show the locations of fault breaks mapped on the surface. The SAR interferogram shows that the deformation and fault slip extended west of the surface faults, underneath the Gulf of Izmit. Thick black lines mark the fault rupture inferred from the SAR data. Scientists are using the SAR interferometry along with other data collected on the ground to estimate the pattern of slip that occurred during the Izmit earthquake. This then used to improve computer models that predict how this deformation transferred stress to other faults and to the continuation of the North Anatolian Fault, which extends to the west past the large city of Istanbul. These models show that the Izmit earthquake further increased the already high probability of a major earthquake near Istanbul. http://photojournal.jpl.nasa.gov/catalog/PIA00557

  16. Izmit, Turkey 1999 Earthquake Interferogram

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This image is an interferogram that was created using pairs of images taken by Synthetic Aperture Radar (SAR). The images, acquired at two different times, have been combined to measure surface deformation or changes that may have occurred during the time between data acquisition. The images were collected by the European Space Agency's Remote Sensing satellite (ERS-2) on 13 August 1999 and 17 September 1999 and were combined to produce these image maps of the apparent surface deformation, or changes, during and after the 17 August 1999 Izmit, Turkey earthquake. This magnitude 7.6 earthquake was the largest in 60 years in Turkey and caused extensive damage and loss of life. Each of the color contours of the interferogram represents 28 mm (1.1 inches) of motion towards the satellite, or about 70 mm (2.8 inches) of horizontal motion. White areas are outside the SAR image or water of seas and lakes. The North Anatolian Fault that broke during the Izmit earthquake moved more than 2.5 meters (8.1 feet) to produce the pattern measured by the interferogram. Thin red lines show the locations of fault breaks mapped on the surface. The SAR interferogram shows that the deformation and fault slip extended west of the surface faults, underneath the Gulf of Izmit. Thick black lines mark the fault rupture inferred from the SAR data. Scientists are using the SAR interferometry along with other data collected on the ground to estimate the pattern of slip that occurred during the Izmit earthquake. This then used to improve computer models that predict how this deformation transferred stress to other faults and to the continuation of the North Anatolian Fault, which extends to the west past the large city of Istanbul. These models show that the Izmit earthquake further increased the already high probability of a major earthquake near Istanbul.

  17. Turkey vulture and California condor

    USGS Publications Warehouse

    Pattee, O.H.; Wilbur, S.R.; Pendleton, Beth Giron

    1989-01-01

    Populations of turkey vultures in the western states appear stable, with no evidence of recent significant changes in distribution. Turkey vultures occupy a variety of habitats, nest in diverse situations and utilize a wide variety of carrion. Consequently, no particular limiting factor is likely to have a major effect on the total population. California condor numbers, in contrast, have continued to decline. With the capture of the last wild bird in 1987, the species has been extirpated from the wild. Reestablishment will depend on production and introduction of captive-reared birds, hopefully within the next 10 years. In the 18th century, condors inhabited areas along the Pacific coast from British Columbia to Baja California. Since 1950, the range has been restricted to a six county area adjacent to the southern San Joaquin Valley of California. Within this area, there appears to be no shortage of suitable nest sites; all recently used nest sites are within federally-controlled lands. Suitable foraging grounds have continued to diminish and are now largely limited to private rangelands and some Bureau of Land Management rangelands within the foothills of the San Joaquin Valley. Only these areas continue to supply the large mammal carcasses that the California condor needs for survival. The habitat of the condor is subject to a variety of land use practices and development pressures. Excessive mortality, coupled with low reproductive potential, continues to threaten the recovery of the species. Development of management practices to reduce mortality, particularly those that are contaminant-related, and of a preserve design to insure adequate habitat for the reintroduced population are still necessary for eventual recovery of the species.

  18. Izmit, Turkey 1999 Earthquake Interferogram

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This image is an interferogram that was created using pairs of images taken by Synthetic Aperture Radar (SAR). The images, acquired at two different times, have been combined to measure surface deformation or changes that may have occurred during the time between data acquisition. The images were collected by the European Space Agency's Remote Sensing satellite (ERS-2) on 13 August 1999 and 17 September 1999 and were combined to produce these image maps of the apparent surface deformation, or changes, during and after the 17 August 1999 Izmit, Turkey earthquake. This magnitude 7.6 earthquake was the largest in 60 years in Turkey and caused extensive damage and loss of life. Each of the color contours of the interferogram represents 28 mm (1.1 inches) of motion towards the satellite, or about 70 mm (2.8 inches) of horizontal motion. White areas are outside the SAR image or water of seas and lakes. The North Anatolian Fault that broke during the Izmit earthquake moved more than 2.5 meters (8.1 feet) to produce the pattern measured by the interferogram. Thin red lines show the locations of fault breaks mapped on the surface. The SAR interferogram shows that the deformation and fault slip extended west of the surface faults, underneath the Gulf of Izmit. Thick black lines mark the fault rupture inferred from the SAR data. Scientists are using the SAR interferometry along with other data collected on the ground to estimate the pattern of slip that occurred during the Izmit earthquake. This then used to improve computer models that predict how this deformation transferred stress to other faults and to the continuation of the North Anatolian Fault, which extends to the west past the large city of Istanbul. These models show that the Izmit earthquake further increased the already high probability of a major earthquake near Istanbul.

  19. Turkey origin reovirus-induced immune dysfunction in specific-pathogen free and commercial turkey poults

    USDA-ARS?s Scientific Manuscript database

    Recently, pathogenesis studies using genetically distinct turkey-origin reoviruses (TRVs) revealed that poults infected with certain TRV isolates had moderate to severe bursal atrophy, suggesting virus-induced immune dysfunction. In order to characterize the effect of TRV infection on the turkey imm...

  20. Factors Influencing International Students' Choice to Study in Turkey and Challenges They Experience in Turkey

    ERIC Educational Resources Information Center

    Özoglu, Murat; Gür, Bekir S.; Coskun, Ipek

    2015-01-01

    Turkey is increasingly becoming a regional hub for international students. The number of international students in Turkish universities has grown by almost 300% in the last decade. The current internationalization efforts of the Turkish government and universities have the potential to make Turkey an even more attractive destination for…

  1. Factors Influencing International Students' Choice to Study in Turkey and Challenges They Experience in Turkey

    ERIC Educational Resources Information Center

    Özoglu, Murat; Gür, Bekir S.; Coskun, Ipek

    2015-01-01

    Turkey is increasingly becoming a regional hub for international students. The number of international students in Turkish universities has grown by almost 300% in the last decade. The current internationalization efforts of the Turkish government and universities have the potential to make Turkey an even more attractive destination for…

  2. Policy Options for Turkey: A Critique of the Interpretation and Utilization of PISA Results in Turkey

    ERIC Educational Resources Information Center

    Gur, Bekir S.; Celik, Zafer; Ozoglu, Murat

    2012-01-01

    In this article we provide a critique of the interpretation and utilization of Programme for International Student Assessment (PISA) results by the National Education Authorities in Turkey. First, we define and explain what OECD's PISA is. Second, we make an overview of the media coverage in Turkey of the PISA 2003 and 2006 results. Third, we…

  3. Calculation of electron wave functions and refractive index of Ne

    NASA Astrophysics Data System (ADS)

    Zhu, Min; Liu, Wei; Zhang, Tao

    2008-10-01

    The radial wave functions of inner electron shell and outer electron shell of a Ne atom were obtained by the approximate analytical method and tested by calculating the ground state energy of the Ne atom. The equivalent volume of electron cloud and the refractive index of Ne were calculated. The calculated refractive index agrees well with the experimental result. Relationship between the refractive index and the wave function of Ne was discovered.

  4. Variable Deletion of French "Ne": A Cross-Stylistic Perspective.

    ERIC Educational Resources Information Center

    Armstrong, Nigel

    2002-01-01

    Considers the socio-stylistic distinction of the French variable morpho-syntactic particle "ne." The interspeaker axes of variation in "ne" are summarized, and intraspeaker data deriving from a corpus of spoken French are considered. Examines intraspeaker variation in "ne" by focusing on the use of the variable by a single speaker in both speech…

  5. Late magmatic stage of the zoned Caleu pluton (Central Chile): insights from zircon crystallization conditions

    NASA Astrophysics Data System (ADS)

    Molina, P. G.; Parada, M.; Gutierrez, F. J.; Chang-Qiang, M.; Jianwei, L.; Yuanyuan, L.

    2012-12-01

    The Caleu pluton consists of three N-S elongated lithological zones: Gabbro-Diorite Zone (GDZ), Tonalite Zone (TZ) and Granodiorite Zone (GZ); western, middle and eastern portions of the pluton, respectively. The zones are thought to be previously differentiated in a common, isotopically depleted (Sr-Nd), subjacent magma reservoir at a 4 kbar equivalent depth. The emplacement should have occurred at the climax of the Cretaceous rifting. We present preliminary results of U238/Pb206 zircon geochronology; zircon saturation, Tsat(Zrn), and crystallization temperatures (Ti-in-Zrn); as well as relative oxidation states at time of crystallization, based on: (i) the sluggish REE and HFSE subsolidus diffusivities in zircon; (ii) the behavior of Ti4+↔Si4+ and Ce4+↔Zr4+ isovalent replacement, in addition to a constrained TiO2 activity in almost all typical crustal rocks; and (iii) relative oxidation states at time of crystallization, respectively. The latter are obtained by interpolation of the partition coefficients of trivalent (REE) and tetravalent (HFSE) curves in Onuma diagrams for each zircon, and then estimating relative Ce(IV)/Ce(III) ratios. Results obtained from 4 samples (a total of 77 zircon grains) collected from the three mentioned lithological zones indicate U/Pb ages of approximately 99.5 ±1.5 Ma, 96.8 ±0.6 Ma, and 94.4 +2.2 -0.8 Ma; and Ti-in Zrn ranges of ca. 720-870°C, ca. 680-820°C and ca. 750-840°C, for the GDZ, TZ and GZ samples, respectively. On the other hand Tsat(Zrn) of ca. 750-780°C in the TZ, and ca. 830-890°C in the GZ, were obtained. As expected saturation temperatures are similar or higher than Ti-in-Zrn obtained in zircon grains of TZ and GZ, respectively. Cathodoluminiscence images in zircon suggest a magmatic origin, due to absence of complex zoning patterns and fairly well conserved morphologies. Exceptionally the GDZ sample zircons show evidence of inheritance, indicating a xenocrystic and/or antecrystic origin. A relative Ce

  6. Growth of a Large Composite Magma System: the EJB Pluton, Eastern California.

    NASA Astrophysics Data System (ADS)

    Matty, D. J.; Vervoort, J.; Dufrane, A.; Hart, G.; Student, J.; Morgan, S.

    2008-12-01

    The composite EJB pluton crops out in the White-Inyo Mountains of eastern California, and comprises the Eureka Valley monzonite (EVM), the Joshua Flat quartz monzonite (JFQM), the Beer Creek granite (BCG), and an unnamed diorite. While sometimes equivocal, field relationships suggest that the EVM was emplaced first, followed by the JFQM, and finally the BCG; the diorite predates the BCG. Sylvester and others (GSAB, 1978) reported zircon U-Pb ages of 179±2 Ma for the EVM and 174±5 Ma for the JFQM. Coleman and others (GSAB, 2003) determined a U-Pb age of 179±3 Ma (via Pb-loss trajectory) for the BCG. Because of the uncertainty in the ages and ambiguous field relations, the sequence and duration of EJB magmatism remain unclear. To understand more fully the timing of EJB magmatism, we separated zircons from 12 samples collected from each of the main EJB units. These samples were characterized using light microscopy, SEM and CL techniques. U-Pb ages were determined from individual zircons by LA-ICP-MS following the method of Chang and others (G3, 2006). For the ages reported below, the reported uncertainties are based on factors within the analysis, but do not include external factors such as sample/standard bias or other matrix effects. Overall uncertainty in LA-ICPMS U-Pb geochronology is hard to assess, but we estimate that all ages reported below are subject to a minimum 2% uncertainty. We determined a concordant U-Pb age of 180±2 Ma for the EVM, which agrees with the results of Sylvester and others (1978). The unnamed diorite produced a concordant U-Pb age of 177±3 Ma. Concordant U-Pb ages of 172±2, 172±3, 173±2, 174±2, and 175±2 Ma were determined for individual samples of the JFQM and agree with the age reported by Sylvester and others (1978) of 174±5 Ma. Concordant U-Pb ages of 168±4, 168±3, 169±1, 172±2, and 172±2 Ma were determined for individual BCG samples. Within the reported error, there is no difference in age between individual samples of

  7. The Fractal Behavior of Crystal Distribution of la Gloria Pluton, Chile

    NASA Astrophysics Data System (ADS)

    Gutiérrez, F. J.; Payacán, I. J.; Pasten, D.; Aravena, A.; Gelman, S. E.; Bachmann, O.; Parada, M. A.

    2013-12-01

    We utilize fractal analysis to study the spatial distributions of crystals in a 10 Ma granitic intrusion (La Gloria pluton) located in the central Chilean Andes. Previous work determined the crystal size distribution (CSD) and anisotropy of magnetic susceptibility (AMS) tensors throughout this pluton. Using orthogonal thin sections oriented along the AMS tensor axes, we have applied fractal analysis in three magmatic crystal families: plagioclase, ferromagnesian minerals (biotite and amphibole), and Fe-Ti oxides (magnetite with minor ilmenite). We find that plagioclase and ferromagnesian minerals have a Semi-logarithmic CSD (S-CSD), given by: log(n/n0)= -L/C (1) where n [mm-4], n0 [mm-4], L [mm] and C [mm] are crystal density, intercept (nucleation density; L=0), size of crystals (three axes) and characteristic length, respectively. In contrast, Fe-Ti oxides have a Fractal CSD (F-CSD, power law size distribution), given by: log(n)= - Dn log(L) + n1 (2) where Dn and n1 [log(mm-4)] are a non-dimensional proportionality constant and the logarithm of the initial crystallization density (n1 = log(n(L=1 mm))), respectively. Finally, we calculate the fractal dimension (D0) by applying the box-counting method on each crystal thin section image, using: log(N) = -D0 log(ɛ) (3) where N and ɛ are the numbe