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Sample records for limestone lisburne field

  1. Preliminary microfacies analysis and cyclicity of the Wahoo Limestone, Lisburne Field, North Slope, Alaska

    SciTech Connect

    Morgan, S.K.; Watts, K.F.

    1995-05-01

    A well from the Lisburne field near Prudhoe Bay was examined in core, thin section, and on well logs for comparison with Wahoo Limestone in the Arctic National Wildlife Refuge (ANWR). Carbonate cycles (parasequences) are well developed in both areas but the greater abundance of terrigenous sediment and associated carbonate facies indicate that the study well is located in a more landward position on the Wahoo carbonate ramp, closer to a source of terrigenous sediment. This report presents the preliminary results of microfacies analyses that have been conducted on 424 of a total 1,115 thin sections from the study well. The stratigraphic nomenclature extended from ANWR (the type locality of the Wahoo Limestone) is different that the terminology previously used for the subsurface Lisburne Group near Prudhoe Bay. We distinguish informal lower and upper members within the Mississippian to Pennsylvanian Wahoo Limestone which overlies the Mississippian Alapah Limestone. Our upper Alapah corresponds to the middle Alapah of previous workers. Our lower Wahoo Limestone member corresponds to the upper Alapah of previous workers. Our upper Wahoo Limestone member corresponds to the previous Wahoo Limestone and is the major hydrocarbon reservoir at the Lisburne field, which is characterized by well-developed carbonate cycles (parasequences).

  2. Distinguishing scales of fracturing in Lisburne field, Prudhoe Bay Alaska

    SciTech Connect

    Jameson, J. )

    1991-08-01

    This talk illustrates the value of combining geological and engineering data in the description of reservoir fracture systems. Examples are taken from a nearly ten-year study of Lisburne field, a middle Carboniferous, shallow marine, shelfal, carbonate structure. Fractures occur on many scales ranging from millimeter size, stratabound microfractures to tectonic faults with decameter offsets. Patterns are complex due to several stages of burial, uplift, erosion, and tilting. Most fractures are filled with calcite. Performance data shows that two fracture sets dominate reservoir behavior: (1) small-scale fractures developed along an unconformity (the subunconformity alteration zone: SAZ); and (2) large tectonic faults. SAZ fractures are open due to dissolution associated with late burial dolomitization. Thus, distribution of SAZ is related to a mappable diagenetic event. SAZ fractures provide rapid interwell communication along the unconformity and crossflow from underlying pay layers. On a much larger scale, pressure information and tracers reveal that major faults provide both vertical and lateral communications throughout many parts of the reservoir. Lisburne fracturing has both beneficial and adverse effects on reservoir behavior. Faults act as natural collectors of oil, reducing the number of development wells, depleting low permeability pay, and providing vertical pressure support. On the negative side, SAZ fracture systems create unwanted pressure gradients, high gas-to-oil ratios, and have led to deferral of waterflooding. Because heterogeneities like those in the Lisburne field can have drastic effects on a reservoir, early recognition is essential for developing planning.

  3. Interactions between early and late diagenesis in reservoir formation, Lisburne field, Prudhoe Bay, Alaska

    SciTech Connect

    Jameson, J.

    1989-03-01

    The Lisburne field is an example of a giant carbonate oil field where reservoir porosity formed due to several distinct, diagenetic events. The later stages of diagenesis occurred during relatively deep burial and often exploited preexisting pathways. Although burial diagenesis is generally perceived as being destructive to porosity and permeability, the Lisburne field is an example where late processes combine to enhance reservoir properties. The earliest porosity formed during the Pennsylvanian as shallow-marine carbonates of the Wahoo formation, which were subaerially exposed at the close of some depositional cycles. Early porosities are moldic and minor intercrystalline, occurring at shoal and near shoal facies. The second stage of porosity development is intercrystalline, associated with Permian-Triassic burial and ferroan dolomitization at depths of 1000-2000 ft (800-1600 m). Trace element gradients and isotopic data indicate the overlying Kavik shales were a source of fluids. In general, ferroan dolomites formed by overgrowth on early (.Pennsylvanian) dolomite. The youngest porosity is moldic and Cretaceous/Tertiary age. Burial fabrics such as stylolites and sutured grain contacts are often probably associated with burial expulsion of fluids from Cretaceous shales on the eastern side of the field. Although each stage of porosity is volumetrically significant, the reservoir quality of the Lisburne field is best in areas affected by all three stages of diagenesis. The second and third stages of porosity development are particularly important to reservoir quality.

  4. Lisburne Group (Mississippian and Pennsylvanian), potential major hydrocarbon objective of Arctic Slope, Alaska

    USGS Publications Warehouse

    Bird, Kenneth J.; Jordan, Clifton F.

    1977-01-01

    may be found on the north in offshore areas. Shows of oil and gas and a saltwater flow of 1,470 bbl/day have been recorded from this sandstone facies. Shales of Permian and Cretaceous ages unconformably overlie the Lisburne, providing adequate sealing beds above potential reservoirs. Impermeable limestone (completely cemented grainstone) and thin beds of shale may serve as seals within the Lisburne, but the possibility of fractures in these units may negate their sealing capability. The most favorable source rock for Lisburne hydrocarbons appears to be Cretaceous shale that unconformably overlies the Lisburne east of Prudhoe Bay. This shale is reported to be a rich source rock and is the most likely source for the entire Prudhoe Bay field. A source within the Lisburne or within the underlying Kayak Shale is postulated for oil shows in the southernmost Lisburne wells. This postulated source may be in a more basinal facies of the Lisburne and may be similar to dark shale in the upper Lisburne in thrust slices to dark shale in the upper Lisburne in thrust slices in the Brooks Range. Coal in the underlying Endicott Group is a possible source for dry gas. At present, much of this coal probably is in a gas-generating regime downdip from the Prudhoe Bay field. Stratigraphic traps involving the Lisburne Group may have resulted from widespread Permian and Cretaceous unconformities. Structural traps related to normal faulting may be present along the trend of the Barrow arch, and faulted anticlines are numerous in the foothills of the Brooks Range. Combination traps are possible along the trend of the Barrow arch.

  5. THE INFLUENCE OF FOLD AND FRACTURE DEVELOPMENT ON RESERVOIR BEHAVIOR OF THE LISBURNE GROUP OF NORTHERN ALASKA

    SciTech Connect

    Wesley K. Wallace; Catherine L. Hanks; Jerry Jensen; Michael T. Whalen

    2002-01-01

    The Carboniferous Lisburne Group is a major carbonate reservoir unit in northern Alaska. The Lisburne is detachment folded where it is exposed throughout the northeastern Brooks Range, but is relatively undeformed in areas of current production in the subsurface of the North Slope. The objectives of this study are to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of detachment folds and their truncation by thrust faults. (2) The influence of folding on fracture patterns. (3) The influence of deformation on fluid flow. (4) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics. The Lisburne in the main axis of the Brooks Range is characteristically deformed into imbricate thrust sheets with asymmetrical hanging wall anticlines and footwall synclines. In contrast, the Lisburne in the northeastern Brooks Range is characterized by symmetrical detachment folds. The focus of our 2000 field studies was at the boundary between these structural styles in the vicinity of Porcupine Lake, in the Arctic National Wildlife Refuge. The northern edge of thrust-truncated folds in Lisburne is marked by a local range front that likely represents an eastward continuation of the central Brooks Range front. This is bounded to the north by a gently dipping panel of Lisburne with local asymmetrical folds. The leading edge of the flat panel is thrust over Permian to Cretaceous rocks in a synclinal depression. These younger rocks overlie symmetrically detachment-folded Lisburne, as is extensively exposed to the north. Six partial sections were measured in the Lisburne of the flat panel and local range front. The Lisburne here is about 700 m thick and is interpreted to consist primarily of the Wachsmuth and Alapah Limestones, with only a thin veneer of Wahoo Limestone. The Wachsmuth (200 m) is gradational between the underlying Missippian Kayak Shale and the overlying Mississippian Alapah, and

  6. Influence of pre-Mississippian paleogeology on Carboniferous Lisburne Group, Arctic National Wildlife refuge, northeastern Alaska

    SciTech Connect

    Watts, K.F.; Carlson, R.; Imm, T.; Gruzlovic, P.; Hanks, C.

    1988-02-01

    The Carboniferous Lisburne Group of northern Alaska formed an extensive carbonate platform, which was later deformed as part of the Brooks Range fold and thrust belt. In the northeast, the Lisburne Group is parautochthonous and analogous to that at Prudhoe Bay. The Lisburne's paleogeography and facies relationships pertain to assessment of the petroleum potential of the Arctic National Wildlife Refuge (ANWR). The Franklinian paleogeology, unconformably underlying the Ellesmerian sequence, has influenced sedimentation patterns in the Lisburne Group. The transgressive Endicott Group (Kekiktuk Conglomerate and Kayak, Shale) and Lisburne Group thin northward over Franklinian basement highs. In the Sadlerochit Mountains, the Katakturuk Dolomite formed a paleotopographic high over which the Endicott Group inched out and the Lisburne Group thinned. Shallow-marine oolitic grainstone developed in the cyclic Pennsylvanian Wahoo Limestone.

  7. Regional stratigraphic framework of the Lisburne Group of ANWR

    SciTech Connect

    Watts, K.F.; Carlson, R.C.; Harris, A.G.

    1995-05-01

    The Carboniferous Lisburne Group, a major carbonate platform succession, is widely exposed in the Brooks Range and forms an extensive hydrocarbon target in the subsurface of the North Slope of Alaska. Gradationally beneath carbonates of the Lisburne Group, terrigenous sediments of the Mississippian Endicott Group (conglomerate and sandstone of the Kekiktuk Formation overlain by the Kayak Shale) were derived from local and northern (Ellesmerian) source areas. Locally, at the Endicott-Lisburne transition, sandy limestones of the Itkilyariak Formation record another phase of siliciclastic influx that lies above and/or is a lateral equivalent of the Kayak Shale and Lisburne Group in areas adjacent to paleotopographic highs. This siliciclastic to carbonate transition represents a major transgressive succession that onlaps northward over the sub-Mississippian unconformity, a regional angular unconformity and sequence boundary in northern Alaska. The age and nature of onlap depend upon the paleotopography of the underlying sub-Mississippian rocks and regional passive margin subsidence. The Lisburne Group is a thick succession of carbonate rocks subdivided into the Alapah Limestone and overlying Wahoo Limestone, both having informal members.

  8. THE INFLUENCE OF FOLD AND FRACTURE DEVELOPMENT ON RESERVOIR BEHAVIOR OF THE LISBURNE GROUP OF NORTHERN ALASKA

    SciTech Connect

    Wesley K. Wallace; Catherine L. Hanks; Michael T. Whalen; Jerry Jensen; Paul K. Atkinson; Joseph S. Brinton

    2000-05-01

    The Lisburne Group is a major carbonate reservoir unit in northern Alaska. The Lisburne is detachment folded where it is exposed throughout the northeastern Brooks Range, but is relatively undeformed in areas of current production in the subsurface of the North Slope. The objectives of this study are to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of detachment folds and their truncation by thrust faults. (2) The influence of folding and lithostratigraphy on fracture patterns. (3) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics. (4) The influence of lithostratigraphy and deformation on fluid flow. The results of field work during the summer of 1999 offer some preliminary insights: The Lisburne Limestone displays a range of symmetrical detachment fold geometries throughout the northeastern Brooks Range. The variation in fold geometry suggests a generalized progression in fold geometry with increasing shortening: Straight-limbed, narrow-crested folds at low shortening, box folds at intermediate shortening, and folds with a large height-to-width ratio and thickened hinges at high shortening. This sequence is interpreted to represent a progressive change in the dominant shortening mechanism from flexural-slip at low shortening to bulk strain at higher shortening. Structural variations in bed thickness occur throughout this progression. Parasitic folding accommodates structural thickening at low shortening and is gradually succeeded by penetrative strain as shortening increases. The amount of structural thickening at low to intermediate shortening may be inversely related to the local amount of structural thickening of the Kayak Shale, the incompetent unit that underlies the Lisburne. The Lisburne Limestone displays a different structural style in the south, across the boundary between the northeastern Brooks Range and the main axis of the Brooks Range fold

  9. Field trial of a pulsed limestone diversion well

    USGS Publications Warehouse

    Sibrell, Philip L.; Denholm, C.; Dunn, Margaret

    2013-01-01

    The use of limestone diversion wells to treat acid mine drainage (AMD) is well-known, but in many cases, acid neutralization is not as complete as would be desired. Reasons for this include channeling of the water through the limestone bed, and the slow reaction rate of the limestone gravel. A new approach to improve the performance of the diversion well was tested in the field at the Jennings Environmental Education Center, near Slippery Rock, PA. In this approach, a finer size distribution of limestone was used so as to allow fluidization of the limestone bed, thus eliminating channeling and increasing particle surface area for faster reaction rates. Also, water flow was regulated through the use of a dosing siphon, so that consistent fluidization of the limestone sand could be achieved. Testing began late in the summer of 2010, and continued through November of 2011. Initial system performance during the 2010 field season was good, with the production of net alkaline water, but hydraulic problems involving air release and limestone sand retention were observed. In the summer of 2011, a finer size of limestone sand was procured for use in the system. This material fluidized more readily, but acid neutralization tapered off after several days. Subsequent observations indicated that the hydraulics of the system was compromised by the formation of iron oxides in the pipe leading to the limestone bed, which affected water distribution and flow through the bed. Although results from the field trial were mixed, it is believed that without the formation of iron oxides and plugging of the pipe, better acid neutralization and treatment would have occurred. Further tests are being considered using a different hydraulic configuration for the limestone sand fluidized bed.

  10. Results and synthesis of integrated geologic studies of the carboniferous Lisburne Group of Northeastern Alaska. Final report

    SciTech Connect

    Watts, K.F.

    1995-05-01

    The primary objective of this project was to develop an integrated database to characterize reservoir heterogeneities resulting from numerous small-scale shallowing-upward cycles (parasequences) comprising the Pennsylvanian Wahoo 1imestone. The Wahoo Limestone is the upper part of an extensive carbonate platform sequence of the Carboniferous Lisburne Group which is widely exposed in the Brooks Range and is a widespread hydrocarbon reservoir unit in the subsurface of the North Slope of Alaska. A leading goal is to determine lateral and vertical variations in the complex mosaic of carbonate facies comprising the Wahoo. Aspects of rock units adjacent to the Wahoo, the underlying Endicott Group and Alapah Limestone and overlying Echooka Formation are also discussed. This report includes an overview of the regional geological framework; a discussion of biostratigraphic results; a summary of diagenetic studies; and preliminary results of comparative studies of a cored well in the Lisburne oil field. A computerized database system (the Wahoo database) was developed and is explained in a users manual. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  11. Lisburne Group (Mississippian-Lower Permian) petrography, paragenesis, and hydrocarbon potential, central Brooks Range, Alaska

    SciTech Connect

    Krutak, P.R.

    1989-03-01

    Subsurface Lisburne Group (Wahoo) rocks at Prudhoe Bay-Kuparuk fields produce 2 million bbl of oil/day and contain 2-3 billion bbl of oil in place. Lisburne reservoirs are early diagenetic dolomites encased in thick platform carbonates. Petrographic and geochemical study of 264 samples from eight newly discovered surface Lisburne sections comprising 4568 ft of strata in the Central Brooks Range provide new data concerning paragenesis and hydrocarbon potential of Lisburne facies farther west. A generalized paragenetic sequence for Lisburne equivalents of this region is (1) initial carbonate skeletal growth (both aragonite and calcite) during the Carboniferous, (2) subsequent recrystallization and inversion of aragonite to calcite, the change to calcite proceeding throughout late Paleozoic and Permian-Triassic time, (3) dolomitization in the Middle and Late Carboniferous, (4) chertification and silicification, postdating slightly or overlapping dolomitization, (5) development of porosity (moldic, intracrystal, etc.) in the middle to late Mesozoic, (6) formation of fracture porosity concurrent with the Brooks Range orogeny during Middle Jurassic-Cretaceous time, (7) oil generation, migration, and emplacement in Late Cretaceous-Tertiary time. Lisburne dolomites from the Central Brooks Range bear heavy hydrocarbons. Rock-Eval pyrolysis indicates part of the section is in the oil window and near the peak wet-gas generation zone. Shale samples from this region display thermal alteration indices and vitrinite reflectance values near the oil floor and also indicate potential for sourcing dry gas. Conodont color alteration indices show part of the Lisburn could produce dry gas.

  12. Mississippian conodonts, Lisburne Group, St. Lawrence Island, Alaska

    SciTech Connect

    Lane, H.R.; Ressmeyer, P.F.

    1985-04-01

    Late Mississippian conodonts recovered from two sections of the Lisburne Group exposed along the Ongoveyuk River, western St. Lawrence Island, are few, poorly preserved, yet relatively diverse. At the West Fork and East Fork Ongoveyuk sections, the lower, dark-colored, cherty beds yield conodonts that belong in the upper part of Lane Faunal Unit 8. They are correlatives of the upper St. Louis Formation in the Mississippi River Valley and, in northwest Alaska, are equivalent to the upper Nasorak and Kogruk Formations (Lisburne Group) along Nasorak Creek near Point Hope, and the Kogruk Formation at the Trail Creek, De Long Mountains, Misheguk Mountain quadrangle. The upper, light-colored, thicker-bedded interval at the West Fork exposure yields conodonts assignable to Lane Faunal unit 9 of latest Meramecian and earliest Chesterian age. This fauna occurs widely over North America in beds that correlate with the St. Genevieve Limestone in the Mississippi River Valley. On the Lisburne Peninsula, this interval correlates with at least a portion of the Kogruk Formation exposed at Niak Creek and Cape Lewis north of Point Hope. Conodont alteration indices (CAI) are very high and variable, ranging from 5.5 to 8.0, suggesting they resulted from contact rather than regional metamorphism.

  13. Conodont biostratigraphy and biofacies of the Lisburne Group

    SciTech Connect

    Harris, A.G.; Krumhardt, A.P.; Watts, K.F.

    1995-05-01

    Conodont data from the Lisburne Group are presented in three parts. Part 1 summarizes the thesis work of Andrea P. Krumhardt on the conodont biostratigraphy and biofacies of the Wahoo Limestone in the eastern Sadlerochit Mountains. This is virtually the same report as Krumhardt and others. A more detailed report on the Wahoo Limestone is in the final stages of preparation as a US Geological Survey Professional Paper. The major results of this study include the precise determination of the Mississippian-Pennsylvanian boundary within the lower member of the Wahoo Limestone and establishment of a conodont biostratigraphy for the Pennsylvanian part of the Wahoo that is applicable to northern Alaska. Conodont biofacies are related to depositional environments and compared with carbonate microfacies analyses; both indicate high-energy, chiefly normal-marine conditions in the northern part ANWR. Part 2 describes the conodont zonation used for the middle Carboniferous in northern Alaska and the criteria used for assigning ages. A series of chronostratigraphic diagrams illustrates age variations and correlation of the Lisburne Group in ANWR, at two localities in the central Brooks Range, and in wells in the National Petroleum Reserve in Alaska. Part 3 includes a map showing conodont color alteration indices. Variations in the thermal history of different parts of ANWR are related to the tectonics of the northeastern Brooks Range.

  14. Quarry Quest. A Field Trip Guide to the Indiana Limestone District, Monroe and Lawrence Counties, Indiana.

    ERIC Educational Resources Information Center

    Shewmaker, Sherman N.

    This guide provides information for planning a field trip to the Indiana Limestone District. This district, located in Monroe and Lawrence Counties, Indiana, is responsible for material that has dominated the building-limestone market in the United States for nearly a century. A few of the many well-known buildings using Indiana limestone are the…

  15. The Influence of fold and fracture development on reservoir behavior of the Lisburne Group of northern Alaska

    SciTech Connect

    Wesley K. Wallace; Catherine L. Hanks; Jerry Jensen: Michael T. Whalen; Paul Atkinson; Joseph Brinton; Thang Bui; Margarete Jadamec; Alexandre Karpov; John Lorenz; Michelle M. McGee; T.M. Parris; Ryan Shackleton

    2004-07-01

    The Carboniferous Lisburne Group is a major carbonate reservoir unit in northern Alaska. The Lisburne is folded and thrust faulted where it is exposed throughout the Brooks Range, but is relatively undeformed in areas of current production in the subsurface of the North Slope. The objectives of this study were to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of folds and their truncation by thrust faults. (2) The influence of folding on fracture patterns. (3) The influence of deformation on fluid flow. (4) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics. Symmetrical detachment folds characterize the Lisburne in the northeastern Brooks Range. In contrast, Lisburne in the main axis of the Brooks Range is deformed into imbricate thrust sheets with asymmetrical hangingwall anticlines and footwall synclines. The Continental Divide thrust front separates these different structural styles in the Lisburne and also marks the southern boundary of the northeastern Brooks Range. Field studies were conducted for this project during 1999 to 2001 in various locations in the northeastern Brooks Range and in the vicinity of Porcupine Lake, immediately south of the Continental Divide thrust front. Results are summarized below for the four main subject areas of the study.

  16. Passive treatment of acid mine drainage in systems containing compost and limestone: Laboratory and field results

    SciTech Connect

    Watzlaf, G.R.; Pappas, D.M.

    1996-12-31

    Passive, down-flow systems, consisting of compost and limestone layers, termed successive alkalinity producing systems (SAPS), may be well suited for treatment of mine drainage containing ferric iron and/or aluminum. A column, simulating a SAPS, has been operated in the laboratory for 52 weeks. The 0.16-m diameter column consisted of a 0.30-m thick layer of limestone, a 0.76-m thick layer of spent mushroom compost thick layer of limestone, a 0.76-m thick layer of spent mushroom compost and 0.91 m of free standing water. Actual AMD (pH = 3.02, acidity = 218 mg/L (as CaCO{sub 3}), SO{sub 4} = 600 mg/L, Fe = 16.0 mg/L, Mn = 12.1 mg/L, and Al = 17.1 mg/L) was applied to the column at a rate of 3.8 mL/min. Effluent pH has remained above 6.2 (6.2-7.9) in the column system. A SAPS located in Jefferson County, PA has been monitored for the past 4.5 years. The SAPS has an approximate area of 1000 m{sup 2} and contains a 0.4-m thick layer of limestone, a 0.2-m thick layer of spent mushroom compost, and 1.5 m of free standing water. Mine water (acidity = 335 mg/L (as CaCO{sub 3}), SO{sub 4} = 1270 mg/L, Fe = 246 mg/L, Mn = 38.4 mg/L, and Al = <0.2 mg/L) flowed into the SAPS at a rate of 140 L/min. Water samples from the field and laboratory systems have been collected at strategic locations on a regular basis and analyzed for pH, alkalinity, acidity, Fe{sup 2+}, total Fe, Mn, Al, SO{sub 4}, Ca, Mg, Na, Co, Ni, and Zn. Alkalinity has been generated in both field and laboratory systems by a combination of limestone dissolution and sulfate reduction. The column generated an average of 378 mg/L of alkalinity; 74% due to limestone dissolution and 26% due to bacterial reduction of sulfate. The field SAPS generated an average of 231 mg/L of alkalinity and exhibited seasonal trends.

  17. Diagenesis of the Lisburne Group, northeastern Brooks Range, Alaska

    SciTech Connect

    Carlson, R.C.; Goldstein, R.H.; Enos, P.

    1995-05-01

    Petrographic cathodoluminescence studies of the cement stratigraphy of the Lisburne Group yield insights on its diagenetic history. Crosscutting relationships between features of subaerial exposure and calcite cements show that early generations of nonferroan, nonluminescent and multibanded-luminescent calcites are synchronous with or postdated by subaerial exposure surfaces within the Lisburne. Surfaces of subaerial exposure occur at 18 horizons within the Lisburne and are distinguished by features as laminated crusts, rhizoliths, autoclastic breccia, fissure fills, mud cracks, and erosional surfaces. Crosscutting relationships also occur between calcite cements and clasts in karst breccias and conglomerates that formed along the sub-Permian unconformity at the top of the Lisburne. The sub-Permian unconformity postdates later generations of calcite cement. These cements formed in the following sequence: nonferroan to low-ferroan, dully luminescent calcite; ferroan, very-dully luminescent calcite; and second generation of nonferroan, multibanded calcite. The crosscutting relationships not only constrain the timing of cement precipitation, but also suggest that the cements probably were precipitated from meteoric groundwaters introduced during subaerial exposure of the Lisburne platform. Late cements in the Lisburne postdate the Permian Echooka Formation. These cements are low-ferroan, moderately-bright to dully luminescent calcite, followed by a second generation of ferroan, very-dully luminescent calcite. Features of compaction and pressure solution are coincident with the precipitation of the late ferroan calcite and further constrain its timing to deep burial of the Lisburne. The youngest phase of calcite cement precipitated in the Lisburne Group is nonferroan, very-dully luminescent calcite. It commonly fills tectonically-induced shear fractures, indicating precipitation after the onset of Cretaceous (and/or Cenozoic) tectonism in the northeastern Brooks Range.

  18. Carboniferous conodonts, algae, and foraminifers from Lisburne Group, Prudhoe Bay, Alaska

    SciTech Connect

    Carr, T.R.; Mamet, B.L.

    1985-04-01

    continuous cores from the ARCO/Exxon South Point State 1 and Pingut State 1 wells at Prudhoe Bay penetrated the Carboniferous Wahoo and Alapah Limestones of the Lisburne Group. The upper Alapah and the entire Wahoo were examined for conodonts, foraminifers, and algae. The Alapah and Wahoo Limestones contain abundant but low-diversity foraminifer and conodont faunas. The succession of foraminifers and conodonts is used to develop a detailed local zonation for well-to-well correlations. The larger scale aspects of the zonation permit correlation of the Alapah and Wahoo Limestones with the Carboniferous section in western Europe as well as the Mississippian and Pennsylvanian sequences of North America. The Alapah Limestone is characterized by foraminifers of zones 16s through 19. Conodonts from the uppermost Alapah (zone 19) include Gnathodus girtyi simplex and Rhachistognathus muricatus and are assigned to the muricatus zone. The boundary between the Alapah and the overlying Wahoo coincides with a nondiagnostic interval between foraminifer zones 19 and 20 and with the first appearance of rare specimens of Declinognathodus noduliferous. The first appearance of D. noduliferous is coincident with the mid-Carboniferous boundary and occurs in close proximity to the Mississippian-Pennsylvanian boundary in North American. Foraminifer zones 20 and 21 are easily recognized in the Wahoo and can be integrated with four conodont zones. The conodont zones in the Wahoo are believed to be sensitive to environmental fluctuations and may be of only local biostratigraphic significance.

  19. Depositional history of Sunniland Limestone (Lower Cretaceous), Raccoon Point field, Collier County, Florida

    SciTech Connect

    Richards, J.A.

    1988-09-01

    The Sunniland Limestone (Lower Cretaceous), consisting of carbonate rock and anhydrite, bears the only oil and gas production in southern Florida. Raccoon Point field, Collier County, Florida, is one of 13 fields discovered along the Sunniland producing trend, producing from paleotopographic highs associated with shelfal patch reefs and high-energy bioclastic deposits. Deposition of the Sunniland Limestone, as determined from detailed stratigraphic and microfacies analysis (using core, thin sections, and well logs), occurred in three transgressive-regressive packages or sequences: the lower, middle, and upper Sunniland. Each sequence is further divided into successive shallowing-upward intervals or parasequences. The dolomite reservoirs at Raccoon Point field occur at the top of the middle Sunniland and within the upper Sunniland. They are interpreted as high-energy deposits formed from bioclastic debris and as a network between rudist mounds. Reservoir development in the middle Sunniland is most likely due to the diagenesis associated with restrictive hypersaline conditions and subaerial exposure when sea level dropped at the end of middle Sunniland deposition. Creation of upper Sunniland reservoir was probably influenced by diagenetic fluids derived from the restricted conditions associated with intertidal-flat and supratidal-sabkha environments, in which the overlying sediments were deposited. Anhydrite and dolomitized carbonate rock from these environments dominate the upper Sunniland and form the overall top seal.

  20. Lithofacies and stratigraphy of the Lisburne and Etivluk groups in the Lisburne 1 well and adjacent outcrops

    USGS Publications Warehouse

    Dumoulin, Julie A.; Bird, Kenneth J.

    2002-01-01

    The Lisburne 1 well in the thrust belt of the central Brooks Range penetrated 17,000 ft of imbricated, chiefly Ellesmerian sequence strata in the Endicott Mountains allochthon. Five thrust repeats of the Lisburne Group (Carboniferous) and overlying Etivluk Group (Permian-Jurassic) were drilled. Lithofacies analyses of >350 thin sections of cores and cuttings, and biostratigraphy based on foraminifers and conodonts, allow detailed correlation with coeval units in adjacent outcrops and provide data on the depositional setting and reservoir and source rock potential of these strata. The late Early- Late Mississippian (Osagean-Chesterian) Lisburne Group consists mainly of skeletal wackestone to grainstone, locally completely dolomitized. An interval of abundant glauconite and detrital quartz in the lower Lisburne may mark a sequence-bounding unconformity. Dolostone in the upper part of the unit has maximum porosities of 10-13% and common residual hydrocarbons. The uppermost Lisburne is thinly interbedded mudstone, chert, and shale that are locally dolomitic, phosphatic, spiculitic, and organic-rich; conodonts from this interval in outcrop represent an outer shelf to slope biofacies. The Etivluk Group here encompasses the Siksikpuk and Otuk Formations. The Siksikpuk is mainly varicolored shale and radiolarian chert, with a basal interval of glauconitic, pyritic sandstone. Phosphatic and organic-rich shale, radiolarian chert, and pelecypod coquinas make up the Otuk. Outcrop and subsurface data indicate that the Lisburne Group in this area accumulated near the seaward margin of a shallow-water carbonate platform that drowned during the Late Mississippian; outer shelf or deeper conditions predominated throughout deposition of the upper Lisburne and the Etivluk Group.

  1. Deposition, diagenesis, and porosity relationships within Noodle Creek limestone (Wolfcampian), Rough Draw Field, Fisher County, Texas

    SciTech Connect

    Atteiga, A.; Alonzo, D.J.

    1986-03-01

    Noodle Creek limestone reservoirs of Rough Draw field represent tabular biostromes that contain the same biota found in phylloid algal mounds. The Noodle Creek contains three carbonate intervals, separated by shales, which range in thickness from 25 to 30 ft. Production occurs from the lower two carbonates. In ascending order, Noodle Creek limestones exhibit a vertical sequence of four subtidal deposition facies: (1) algal-plate-boundstone, (2) algal-intraclast-boundstone, (3) peloid-foraminiferal-boundstone/grainstone, and (4) foraminiferal grainstone facies. The principal binder-encruster, which formed the boundstone fabric, is an enigmatic, tubular, branched, nonseptate foram or alga. Other binder-encrusters include tubiphytes and several encrusting forams. Relatively soon after deposition, each Noodle Creek carbonate interval was exposed subaerially and subjected to freshwater diagenesis. Dissolution of aragonitic phylloid algae created much secondary porosity in the lower intervals. Vadose cements, consisting of scalenohedral crusts and meniscoid patterns, were followed by phreatic cements consisting of blocky equant calcite, ferroan calcite, and ferroan dolomite, which occluded most porosity in many intervals. Most oil is produced from grainstones and phylloid algal-rich facies wherein residual primary and secondary porosity was enhanced by late-stage dissolution that occurred during burial diagenesis.

  2. Cement stratigraphy of the Lisburne Group, northeastern Brooks Range, Alaska

    SciTech Connect

    Carlson, R.C.; Goldstein, R.H. . Geology Dept.)

    1992-01-01

    Cement stratigraphy serves as a descriptive framework for the interpretation of the diagenetic history of the Carboniferous Lisburne Group, northeastern Brooks Range, Alaska. The Lisburne is a sequence of shallow-water, marine carbonate rocks that have experienced a wide spectrum of diagenetic events: early marine diagenesis, early subaerial exposure, significant erosion and karstification following final Lisburne deposition, deep burial of at least 3,000 meters, compressional tectonism, and final uplift into modern mountain ranges. Compositional zones in the calcite cements were identified by using stains for ferroan calcite and cathodoluminescence microscopy. The cements are, from oldest to youngest: A1-nonferroan, nonluminescent or multibanded calcite; B1-nonferroan to low-ferroan, dull luminescent calcite; C1-ferroan, very-dull luminescent calcite; B2-nonferroan, dull luminescent calcite; A2-nonferroan calcite with 1 or 2 sets of nonluminescent and bright zones; C2-ferroan, very-dull luminescent calcite; Be-nonferroan, dull luminescent calcite. Petrographic studies of cross-cutting relationships show that A1 cements predate or are synchronous with surfaces of subaerial exposure within the Lisburne Group. The cross-cutting relationships include truncation of cements by early fractures, non-marine fissure fills, and at clast margins of autoclastic breccias. Similarly, B1 and C1 cements predate the major unconformity at the top of the Lisburne Group, hence, these cements are pre-Permian in age and may well have precipitated from fresh groundwaters introduced during development of the sub-Permian unconformity. B2 and C2 cements are present in the Permian Echooka formation overlying the Lisburne Group and, thus, can be dated as post-Pennsylvanian. B3 cements are Cretaceous or younger in age.

  3. Biostratigraphy and dolomite porosity trends of the Lisburne Group

    USGS Publications Warehouse

    Armstrong, Augustus K.; Mamet, Bernard L.

    1970-01-01

    This preliminary study is based on measured and carefully collected sections of the Lisburne Group (fig. 1, sees. 1-29). The outcrops extend from Cape Lisburne (sec. 1) in the west to Egaksrak River (sec. 29) in northeastern Alaska and are used as the basic building blocks for the carbonate facies maps and the cross section. Lithologic and foraminifera samples were collected at 10-foot intervals and rugose corals were collected within each section where found. The rock material was cut into thin section, and petrographic and microfossil studies were made to determine environments of deposition, facies, diagenetic changes, and microfossil content. Coral collections were studied in thin section.

  4. Mississippian clastic-to-carbonate transition in the northeastern Brooks Range, Alaska: Depositional cycles of the Endicott and Lisburne Groups

    SciTech Connect

    Lepain, D.L.; Crowden, R.K.; Watts, K.F. )

    1990-05-01

    The Ellesmerian sequence in northeastern Alaska consists of a thick succession of Mississippian to Lower Cretaceous platform carbonate and terrigenous clastic rocks. At the base of the Ellesmerian sequence, clastic rocks of the Endicott Group are the lower part of a major transgressive sequence that passes gradationally upward into carbonates of the Lisburne Group. In the Endicott Group, the basal Kekiktuk Conglomerate was deposited in fluvial and marginal marine environments. A broad suite of tidally influenced, shallow-marine environments are recorded in the overlying Kayak Shale. The transition into carbonate platform rocks of the Lisburne Group is recorded in a series of depositional cycles developed within the upper half of the Kayak Shale. In the lower beds of the transition, the depositional cycles are multiple upward-thickening and upward-coarsening successions composed of (1) organic-rich siltstone containing flaser-bedded and lenticular-bedded fine-grained sandstone, (2) fine-grained, ripple-laminated quartzarenite, and (3) an intensely bioturbated horizon of medium- to coarse-grained quartzarenite that contains scattered brachiopods, bryozoa, and crinoids. Each cycle is terminated by a sharp transgressive surface that consists of a thin shale drape. Near the top of the Kayak Shale, the coarse-grained horizons become increasingly replaced by wackestone, grainstone, and coralline boundstone. Despite the lithologic change, the vertical upward-thickening and upward-coarsening cycles continue in the basal limestone of the Lisburne Group. Repeated upward-shallowing episodes, followed by coastal onlap, are likely mechanisms for this cyclicity and suggests a genetic relation between both the clastic and carbonate depositional cycles.

  5. Fracture propagation and fluid transport in palaeogeothermal fields and man-made reservoirs in limestone

    NASA Astrophysics Data System (ADS)

    Philipp, S. L.; Reyer, D.; Meier, S.

    2009-04-01

    Geothermal reservoirs are rock units from which the internal heat can be extracted using water as a transport means in an economically efficient manner. In geothermal reservoirs in limestone (and similar in other rocks with low matrix permeability), fluid flow is largely, and may be almost entirely, controlled by the permeability of the fracture network. No flow, however, takes place along a particular fracture network unless the fractures are interconnected. For fluid flow to occur from one site to another there must be at least one interconnected cluster of fractures that links these sites (the percolation threshold must be reached). In order to generate permeability in man-made reservoirs, interconnected fracture systems are formed either by creating hydraulic fractures or by massive hydraulic stimulation of the existing fracture system in the host rock. For effective stimulation, the geometry of the fracture system and the mechanical properties of the host rock (particularly rock stiffnesses and strengths) must be known. Here we present results of a study of fracture systems in rocks that could be used to host man-made geothermal reservoirs: the Muschelkalk (Middle Triassic) limestones in Germany. Studies of fracture systems in exposed palaeogeothermal fields can also help understand the permeability development in stimulated reservoirs. We therefore present data on the infrastructures of extinct fracture-controlled geothermal fields in fault zones in the Blue Lias (Lower Jurassic), Great Britain. In fault zones there are normally two main mechanical and hydrogeological units. The fault core, along which fault slip mostly occurs, consists mainly of breccia and other cataclastic rocks. The fault damage zone comprises numerous fractures of various sizes. During fault slip, the fault core may transport water (if its orientation is favourable to the hydraulic gradient in the area). In the damage zone, however, fluid transport through fracture networks depends

  6. Early Mississippian (Tournaisian) ostracodes from the Lisburne test well, northern Alaska

    SciTech Connect

    Sohn, I.G.

    1989-01-01

    Anita G. Harris processed limestone sample 27660-PC, core 18, from a depth of 4968.84 to 4970.98 m in the Lisburne No. 1 test well, National Petroleum Reserve in Alaska, and recovered poorly preserved silicified ostracodes. The well is located in the disturbed belt, SE{1/4} sec. 17, T. 11 S., R. 16 W., lat 68{degree}29 0.54381, long 155{degree}41 35.510. A crushed duplicate sample from a depth of 4968.84 to 4970.37 m yielded a few unidentifiable fragments and steinkerns and one carapace of Microcheilinella Geis, 1933. The crushed limestone was dissolved in acetic acid, from which the fine material was periodically removed, and yielded additional poorly preserved replaced ostracodes, including some that were not represented in the original sample. The ostracodes indicate a probable Kinderhookian and (or) Osagan age for the rocks. The assemblage differs, on the species level, from congeneric Meramecian ostracodes in the Brooks Range, and there are a few taxa not found in the Meramecian assemblages. In addition to the ostracodes, steinkerns of minute gastropods and pelecypods, brachiopod and echinoderm spines, fish teeth, fragments of bryozoans, and one conodont were recovered. These associated fossils confirm that marine shelf environment indicated by the ostracodes: Because of poor preservation and meager representation of conspecific specimens, the ostracodes are illustrated in open nomenclature. The presently known stratigraphic ranges of the known genera are indicated.

  7. Limestone Caverns

    ERIC Educational Resources Information Center

    Powell, Richard L.

    1970-01-01

    Describes the origin of limestone caverns, using Mammoth Cave as an example, with particular reference to the importance of groundwater information of caverns, the present condition of groundwater, and how caverns develop within fluctuating groundwater zones. (BR)

  8. Limestone geomorphology

    SciTech Connect

    Trudgill, S.

    1985-01-01

    This book focuses on recent work on geomorphological processes and relates them to established theories of landform development. Special attention is paid to soil processes, marine geomorphology, chemical processes and future work on process-form relationships in the context of dated sequences of cave deposits. There are discussions of limestone landforms and other carbonate rocks, caves, hydrological networks, features of karst, morphometry, and coastal landforms and solution chemistry of limestones.

  9. Depositional setting and geochemistry of phosphorites and metalliferous black shales in the Carboniferous-Permian Lisburne Group, Northern Alaska

    USGS Publications Warehouse

    Dumoulin, Julie A.; Slack, John F.; Whalen, Michael T.; Harris, Anita G.

    2011-01-01

    oxygenation of the atmosphere and oceans during the Carboniferous evolution of large vascular land plants. Black shales within the phosphorite sections have up to 20.2 weight percent Corg and are potential petroleum source rocks. Locally, these strata also are metalliferous, with up to 1,690 ppm Cr, 2,831 ppm V, 551 ppm Ni, 4,670 ppm Zn, 312 ppm Cu, 43.5 ppm Ag, and 12.3 ppm Tl; concentrations of these metals covary broadly with Corg, suggesting coupled redox variations. Calculated marine fractions (MF) of Cr, V, and Mo, used to evaluate the paleoredox state of the bottom waters, show generally high CrMF/MoMF and VMF/MoMF ratios that indicate deposition of the black shales under suboxic denitrifying conditions; Re/Mo ratios also plot mainly within the suboxic field and support this interpretation. Predominantly seawater and biogenic sources are indicated for Cr, V, Mo, Zn, Cd, Ni, and Cu in the black shales, with an additional hydrothermal contribution inferred for Zn, Cd, Ag, and Tl in some samples. Lisburne Group phosphorites formed in the Ikpikpuk Basin and along both sides of the mud- and chert-rich Kuna Basin, which hosts giant massive sulfide and barite deposits of the Red Dog district. Lisburne Group phosphatic strata are coeval with these deposits and formed in response to a nutrient-rich upwelling regime. Phosphate deposition occurred mainly in suboxic bottom waters based on data for paleoredox proxies (Cr, V, Mo, Re) within contemporaneous black shales. Recent global reconstructions are consistent with Carboniferous upwelling in northern Alaska, but differ in the type of upwelling expected (zonal versus meridional). Paleoenvironmental data suggest that meridional upwelling may better explain phosphorite deposition in the Lisburne Group.

  10. Lithostratigraphy, microlithofacies, and conodont biostratigraphy and biofacies of the Wahoo Limestone (Carboniferous), eastern Sadlerochit Mountains, Northeast Brooks Range, Alaska

    SciTech Connect

    Krumhardt, A.P.; Harris, A.G.; Watts, K.F.

    1996-12-31

    The Lisburne Group (chiefly Carboniferous) is a wide-spread succession of platform carbonate rocks that apparently developed along a south-facing passive continental margin in northern Alaska. Marine transgressions onlapped northward across northeast Alaska allowing the Lisburne platform to extend over terrigenous deposits of the Endicott Group and local pre-Mississippian paleotopographic highs. The Wahoo Limestone is the youngest formation of the Lisburne Group in northeasternmost Alaska, ranging from latest Mississippian (latest Chesterian) to Middle Pennsylvanian (at least early Atokan) in age. The Wahoo Limestone was systematically sampled for lithostratigraphy and conodont biostratigraphy and biofacies at a relatively continuous section (about 262 m in thickness) in the eastern Sadlerochit Mountains. Existing Carboniferous conodont zonations could not be readily applied to the study section because most zonal indicators are absent. Species diversity is low for a section that spans at least 10 million years. Twenty-four species, distributed among 14 genera, were identified in 72 productive samples; no new species were distinguished. The following biostratigraphic zones and faunal intervals were recognized: Upper muricatus Subzone (latest Chesterian); noduliferus-primus Zone (earliest Morrowan); minutus Fauna (Morrowan) containing a lower subdivision (lower minutus Fauna of early to middle? Morrowan age); and an Idiognathodus Fauna (Morrowan? to early Atokan). The presence of Idiognathodus incurvus? and Rhachistognathus minutus subspp. above the first occurrence of the foraminifer Pseudostaffella sp. in the uppermost part of the Wahoo Limestone indicates that the youngest beds are early Atokan in age. The Mississippian-Pennsylvanian boundary is placed at 56 m above the base of the lower member of the Wahoo Limestone on the basis of the lowest occurrence of Declinognathodus noduliferus japonicus above forms transitional from Gnathodus girtyl simplex.

  11. Permian {open_quotes}Wolfcamp{close_quotes} limestone reservoirs: Powell Ranch field, Eastern Midland Basin

    SciTech Connect

    Montgomery, S.L.

    1996-09-01

    Deep-water carbonate channel reservoirs form important oil reservoirs along the toe of the Eastern Shelf of the Permian basin in west Texas. In northwestern Glasscock County, these `Wolfcamp` reservoirs are Leonardian (Early Permian) in age and define high-energy channels incised into surrounding carbonate detritus and basinal shale. Porous grain-flow material filling these channels, along with encasing detritus, was derived from the shallow shelf located six miles to the east. Reservoirs are in packstone and grainstone facies and have significant interparticle and moldic porosity. Relevant exploration began in the 1960s, but expanded slowly thereafter due to lack of success caused by complex patterns of channel occurrence. Results of a three-dimensional (3-D) seismic survey conducted in 1990 have greatly enhanced the identification and mapping of productive channels in the Powell Ranch field complex. Wells in this complex are capable of flowing 400-1200 bbl of oil per day, and have reserves ranging from 0.2 to 1.3 MBO. The new 3-D data have improved the relevant geologic model and dramatically increased rates of drilling success. Application of such data to this setting offers a potential model for other parts of the Permian basin.

  12. The Influence of Fold and Fracture Development on Reservoir Behavior of the Lisburne Group of Northern Alaska

    SciTech Connect

    Wallace, Wesley K.; Hanks, Catherine L.; Whalen, Michael T.; Jensen1, Jerry; Shackleton, J. Ryan; Jadamec, Margarete A.; McGee, Michelle M.; Karpov1, Alexandre V.

    2001-07-23

    The Carboniferous Lisburne Group is a major carbonate reservoir unit in northern Alaska. The lisburne is detachment folded where it is exposed throughout the northeastern Brooks Range, but is relatively underformed in areas of current production in the subsurface of the North Slope. The objectives of this study are to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of detachment folds and their truncation by thrust faults, (2) The influence of folding on fracture patterns, (3) The influence of deformation on fluid flow, and (4) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics.

  13. Conodont biostratigraphy and biofacies of the Wahoo Limestone (Carboniferous), Sadlerochit Mountains, northeast Brooks Range, Alaska

    SciTech Connect

    Krumhardt, A.P. ); Harris, A.G. )

    1990-05-01

    The Wahoo Limestone forms the upper part of the Lisburne Group (Carboniferous) in the Sadlerochit Mountains. The Lisburne Group is a thick (> 600 m) sequence of platform carbonate rocks that extends across the Brooks Range of northern Alaska and beneath the North Slope. At Prudhoe Bay, the Lisburne Group forms a major hydrocarbon reservoir. In the easternmost Sadlerochit Mountains, the Wahool Limestone is divisible into informal lower (64 m) and upper (192 m) members. The basal 46 m is chiefly bryozoan and pelmatozoan packstone that formed on a relatively shallow platform during the latest Mississippian lower muricatus subzone (as shown by the occurrence of the zonal index with representatives of Cavusgnathus). Cavusgnathus is dominant in this part of the section and occurs with representatives of Kladognathus, Ghathodus, Adetognathus, Hindeodus, and Rhachistognathus (in order of decreasing abundance). Declinognathodus noduliferus, the index for the base of the Pennsylvanian, first occurs at 49 m above the base of the Wahoo and 1 m above a discontinuity surface that marks the Mississippian-Pennsylvanian boundary. The unconformity represents the highest conodont subzone of the Mississippian and probably part of the earliest Pennsylvanian. Previously, the Mississippian-Pennsylvanian boundary was placed t the lower-upper Wahoo contact based on endothyroids; conodont data now indicate that this boundary is 15 m lower. The remaining lower Wahoo is possibly of noduliferus-primus zone age and chiefly yields, in order of decreasing abundance, species of Adetognathus, Declinognathodus, and Rhachistognathus, as well as redeposited Mississipian conodonts. The lower 15 m of the upper member of the Wahoo contains silty (5-40%) carbonate rock types that yield very few conodonts. Conodonts no older than the minutus-sinuatus zone are relatively abundant from 15 to 106 m above the base of the upper Wahoo.

  14. Reconnaissance investigation of the Lisburne Group in the Cobblestone Creek area, Chandler Lake quadrangle, Alaska

    USGS Publications Warehouse

    Dumoulin, Julie A.; Whalen, Michael T.

    2015-01-01

    A reconnaissance investigation of the Carboniferous Lisburne Group in the Cobblestone Creek area, Chandler Lake Quadrangle, yields insights into its resource potential and regional relations. Locally porous vuggy dolostone with hydrocarbon reservoir potential occurs in the lower Lisburne in the three most southerly of five thrust sheets, and contains traces of dead oil in two of these sheets. The dolostones are coarse crystalline, commonly cross-bedded, and at least in part of Osagean (late Early Mississippian) age; they have pelmatozoan grainstone protoliths that likely formed in sand shoals of the midramp to inner ramp. Similar, coeval porous dolostones occur in the Lisburne from Skimo Creek to Itkillik Lake, ~70 km west and 10 km east of the Cobblestone Creek area, respectively. We also examined the uppermost Lisburne Group at several localities in the Cobblestone Creek area, mainly in the northernmost thrust sheet where the rocks are as young as Morrowan (Early Pennsylvanian). Cobblestone sections contain more supportstone than equivalent strata at Skimo Creek, and overlying Permian successions also differ between the two areas. These lithologic contrasts may reflect different rates of tectonically controlled subsidence, and (or) changes in sediment input, along the late Paleozoic continental margin.

  15. Laboratory and field evaluation of a flushable oxic limestone drain for treatment of net-acidic drainage from a flooded anthracite mine, Pennsylvania, USA

    USGS Publications Warehouse

    Cravotta, C.A., III

    2008-01-01

    This paper demonstrates the use of dissolution-rate data obtained in the laboratory to indicate the potential quality of effluent from a field-scale oxic limestone drain (OLD) treatment system for neutralization of dilute acidic mine drainage (AMD). Effluent from the Reevesdale Mine South Dip Tunnel, a large source of AMD and base flow to the Wabash Creek and Little Schuylkill River in the Southern Anthracite Coalfield of east-central Pennsylvania, is representative of AMD with low concentrations but high loadings of dissolved Fe, Al and other metals because of a high flow rate. In January 2003, rapid neutralization of the AMD from the Reevesdale Mine was achieved in laboratory tests of its reaction rate with crushed limestone in closed, collapsible containers (Cubitainers). The tests showed that net-alkaline effluent could be achieved with retention times greater than 3 h and that effluent alkalinities and associated dissolution rates were equivalent for Fe(OH)3-coated and uncoated limestone. On the basis of the laboratory results, a flushable OLD containing 1450 metric tons of high-purity calcitic limestone followed by two 0.7-m deep wetlands were constructed at the Reevesdale Mine. During the first year of operation, monthly data at the inflow, outflow and intermediate points within the treatment system were collected (April 2006-2007). The inflow to the treatment system ranged from 6.8 to 27.4 L/s, with median pH of 4.7, net acidity of 9.1 mg/L CaCO3, and concentrations of dissolved Al, Fe and Mn of 1.0, 1.9 and 0.89 mg/L, respectively. The corresponding effluent from the OLD had computed void-volume retention times of 4.5-18 h, with median pH of 6.6, net acidity of -93.2 mg/L CaCO3, and concentrations of dissolved Al, Fe and Mn of <0.1, 0.08 and 0.52 mg/L, respectively. The wetlands below the OLD were effective for retaining metal-rich solids flushed at monthly or more frequent intervals from the OLD, but otherwise had little effect on the effluent quality

  16. Depositional setting and reservoir quality of the Frome Clay Limestone reservoir (middle Jurassic), Wytch Farm Field southern England

    SciTech Connect

    Gutteridge, P.; Robinson, P.

    1996-12-31

    The middle Jurassic of southern England was a southerly-dipping carbonate ramp system with shallow oolitic carbonates passing down-dip into mudstone with isolated bioclastic carbonate banks. Several of these banks are present at outcrop and in the subsurface and one, the Frome Clay Limestone, forms a reservoir in the Wytch Farm Oilfield. These banks formed as a result of prolific growth of the oyster Liostrea below wave base on the mid- to distal part of the carbonate ramp. The banks are of the order of 100sm across and up to 45m thick. The Frome Clay Limestone reservoir was initiated as a sheet which was followed by upward growth over a more restricted area, probably influenced by in sea level rise. Off-bank facies include: Trigonia wackestone and bioturbated argillaceous wackestone, the latter facies was also deposited as the bank was established. Bank facies include: Liostrea clay packstone with Liostrea valves in a clay matrix with nodular carbonate cement, and Liostrea grainstone. These facies form the bulk of the reservoir and contain the best reservoir quality. Minor facies include lenses of intraclast clay packstone formed by storm reworking and whole Liostrea clay packstone which represent areas of Liostrea growth. Clay-rich limestones contain the best reservoir quality which is controlled by a balance between compaction and cementation. Precipitation of carbonate cement reduces compaction, keeping intergranular pores open. Occlusion of porosity is prevented by the clay matrix which inhibits cementation.

  17. Depositional setting and reservoir quality of the Frome Clay Limestone reservoir (middle Jurassic), Wytch Farm Field southern England

    SciTech Connect

    Gutteridge, P. ); Robinson, P. )

    1996-01-01

    The middle Jurassic of southern England was a southerly-dipping carbonate ramp system with shallow oolitic carbonates passing down-dip into mudstone with isolated bioclastic carbonate banks. Several of these banks are present at outcrop and in the subsurface and one, the Frome Clay Limestone, forms a reservoir in the Wytch Farm Oilfield. These banks formed as a result of prolific growth of the oyster Liostrea below wave base on the mid- to distal part of the carbonate ramp. The banks are of the order of 100sm across and up to 45m thick. The Frome Clay Limestone reservoir was initiated as a sheet which was followed by upward growth over a more restricted area, probably influenced by in sea level rise. Off-bank facies include: Trigonia wackestone and bioturbated argillaceous wackestone, the latter facies was also deposited as the bank was established. Bank facies include: Liostrea clay packstone with Liostrea valves in a clay matrix with nodular carbonate cement, and Liostrea grainstone. These facies form the bulk of the reservoir and contain the best reservoir quality. Minor facies include lenses of intraclast clay packstone formed by storm reworking and whole Liostrea clay packstone which represent areas of Liostrea growth. Clay-rich limestones contain the best reservoir quality which is controlled by a balance between compaction and cementation. Precipitation of carbonate cement reduces compaction, keeping intergranular pores open. Occlusion of porosity is prevented by the clay matrix which inhibits cementation.

  18. Limestone compaction: an enigma

    USGS Publications Warehouse

    Shinn, Eugene A.; Halley, Robert B.; Hudson, J. Harold; Lidz, Barbara H.

    1977-01-01

    Compression of an undisturbed carbonate sediment core under a pressure of 556 kg/cm2 produced a “rock” with sedimentary structures similar to typical ancient fine-grained limestones. Surprisingly, shells, foraminifera, and other fossils were not noticeably crushed, which indicates that absence of crushed fossils in ancient limestones can no longer be considered evidence that limestones do not compact.

  19. Retrieving both phase and amplitude information of Green's functions by ambient seismic wave field cross-correlation: A case study with a limestone mine induced seismic event

    NASA Astrophysics Data System (ADS)

    Kwak, S.; Song, S. G.; Kim, G.; Shin, J. S.

    2015-12-01

    Recently many seismologists have paid attention to ambient seismic field, which is no more referred as noise and called as Earth's hum, but as useful signal to understand subsurface seismic velocity structure. It has also been demonstrated that empirical Green's functions can be constructed by retrieving both phase and amplitude information from ambient seismic field (Prieto and Beroza 2008). The constructed empirical Green's functions can be used to predict strong ground motions after focal depth and double-couple mechanism corrections (Denolle et al. 2013). They do not require detailed subsurface velocity model and intensive computation for ground motion simulation. In this study, we investigate the capability of predicting long period surface waves by the ambient seismic wave field with a seismic event of Mw 4.0, which occurred with a limestone mine collapse in South Korea on January 31, 2015. This limestone-mine event provides an excellent opportunity to test the efficiency of the ambient seismic wave field in retrieving both phase and amplitude information of Green's functions due to the single force mechanism of the collapse event. In other words, both focal depth and double-couple mechanism corrections are not required for this event. A broadband seismic station, which is about 5.4 km away from the mine event, is selected as a source station. Then surface waves retrieved from the ambient seismic wave field cross-correlation are compared with those generated by the event. Our preliminary results show some potential of the ambient seismic wave field in retrieving both phase and amplitude of Green's functions from a single force impulse source at the Earth's surface. More comprehensive analysis by increasing the time length of stacking may improve the results in further studies. We also aim to investigate the efficiency of retrieving the full empirical Green's functions with the 2007 Mw 4.6 Odaesan earthquake, which is one of the strongest earthquakes occurred

  20. Use of borehole radar reflection logging to monitor steam-enhanced remediation in fractured limestone-results of numerical modelling and a field experiment

    USGS Publications Warehouse

    Gregoire, C.; Joesten, P.K.; Lane, J.W., Jr.

    2006-01-01

    Ground penetrating radar is an efficient geophysical method for the detection and location of fractures and fracture zones in electrically resistive rocks. In this study, the use of down-hole (borehole) radar reflection logs to monitor the injection of steam in fractured rocks was tested as part of a field-scale, steam-enhanced remediation pilot study conducted at a fractured limestone quarry contaminated with chlorinated hydrocarbons at the former Loring Air Force Base, Limestone, Maine, USA. In support of the pilot study, borehole radar reflection logs were collected three times (before, during, and near the end of steam injection) using broadband 100 MHz electric dipole antennas. Numerical modelling was performed to predict the effect of heating on radar-frequency electromagnetic (EM) wave velocity, attenuation, and fracture reflectivity. The modelling results indicate that EM wave velocity and attenuation change substantially if heating increases the electrical conductivity of the limestone matrix. Furthermore, the net effect of heat-induced variations in fracture-fluid dielectric properties on average medium velocity is insignificant because the expected total fracture porosity is low. In contrast, changes in fracture fluid electrical conductivity can have a significant effect on EM wave attenuation and fracture reflectivity. Total replacement of water by steam in a fracture decreases fracture reflectivity of a factor of 10 and induces a change in reflected wave polarity. Based on the numerical modelling results, a reflection amplitude analysis method was developed to delineate fractures where steam has displaced water. Radar reflection logs collected during the three acquisition periods were analysed in the frequency domain to determine if steam had replaced water in the fractures (after normalizing the logs to compensate for differences in antenna performance between logging runs). Analysis of the radar reflection logs from a borehole where the temperature

  1. Lithofacies, Age, and Sequence Stratigraphy of the Carboniferous Lisburne Group in the Skimo Creek Area, Central Brooks Range

    USGS Publications Warehouse

    Dumoulin, Julie A.; Whalen, Michael T.; Harris, Anita G.

    2008-01-01

    The Lisburne Group, a mainly Carboniferous carbonate succession that is widely distributed across northern Alaska, contains notable amounts of oil and gas at Prudhoe Bay. Detailed studies of the Lisburne in the Skimo Creek area, central Brooks Range, delineate its lithofacies, age, conodont biofacies, depositional environments, and sequence stratigraphy and provide new data on its hydrocarbon source-rock and reservoir potential, as well as its thermal history, in this area. We have studied the Lisburne Group in two thrust sheets of the Endicott Mountains allochthon, herein called the Skimo and Tiglukpuk thrust sheets. The southern, Skimo Creek section, which is >900 m thick, is composed largely of even-bedded to nodular lime mudstone and wackestone intercalated with intervals of thin- to thick-bedded bioclastic packstone and grainstone. Some parts of the section are partially to completely dolomitized and (or) replaced by chert. A distinctive, 30-m-thick zone of black, organic-rich shale, lime mudstone, and phosphorite is exposed 170 m below the top of the Lisburne. The uppermost 40 m of section is also distinctive and made up of dark shale, lime mudstone, spiculite, and glauconitic grainstone. The northern, Tiglukpuk Creek section, which is similar to the Skimo Creek section but only ~760 m thick, includes more packstone and grainstone and less organic-rich shale. Analyses of conodonts and foraminifers indicate that both sections range in age from late Early Mississippian (Osagean) through Early Pennsylvanian (early Morrowan) and document a hiatus of at least 15 m.y. at the contact between the Lisburne and the overlying Siksikpuk Formation. No evidence of subaerial exposure was observed along this contact, which may represent a submarine erosional surface. Lithofacies and biofacies imply that the Lisburne Group in the study area was deposited mainly in midramp to outer-ramp settings. Deepest water strata are mud rich and formed below storm or fair-weather wave

  2. Downflow limestone beds for treatment of net-acidic, oxic, iron-laden drainage from a flooded Anthracite Mine, Pennsylvania, USA: 1. Field evaluation

    USGS Publications Warehouse

    Cravotta, C.A., III; Ward, S.J.

    2008-01-01

    Passive-treatment systems that route acidic mine drainage (AMD) through crushed limestone and/or organic-rich substrates have been used to remove the acidity and metals from various AMD sources, with a wide range of effects. This study evaluates treatment of net-acidic, oxic, iron-laden AMD with limestone alone, and with organic-rich compost layered with the limestone. In the fall of 2003, a treatment system consisting of two parallel, 500-m2 downflow cells followed by a 400-m2 aerobic settling pond and wetland was installed to neutralize the AMD from the Bell Mine, a large source of AMD and baseflow to the Schuylkill River in the Southern Anthracite Coalfield, in east-central Pennsylvania. Each downflow cell consisted of a lower substrate layer of 1,090 metric tons (t) of dolomitic limestone (60 wt% CaCO3) and an upper layer of 300 t of calcitic limestone (95 wt% CaCO3); one of the downflow cells also included a 0.3 m thick layer of mushroom compost over the limestone. AMD with pH of 3.5-4.3, dissolved oxygen of 6.6-9.9 mg/L, iron of 1.9-5.4 mg/L, and aluminum of 0.8-1.9 mg/L flooded each cell to a depth 0.65 m above the treatment substrates, percolated through the substrates to underlying, perforated outflow pipes, and then flowed through the aerobic pond and wetland before discharging to the Schuylkill River. Data on the flow rates and chemistry of the effluent for the treatment system indicated substantial neutralization by the calcitic limestone but only marginal effects from the dolomitic limestone or compost. Because of its higher transmissivity, the treatment cell containing only limestone neutralized greater quantities of acidity than the cell containing compost and limestone. On average, the treatment system removed 62% of the influent acidity, 47% of the dissolved iron, 34% of the dissolved aluminum, and 8% of the dissolved manganese. Prior to treatment of the Bell Discharge, the Schuylkill River immediately below its confluence with the discharge had p

  3. The Influence of Fold and Fracture Development on Reservoir Behavior of the Lisburne Group of Northern Alaska

    SciTech Connect

    Wallace, Wesley K.; Hanks, Kathrine L.; Whalen, Michael T.; Jensen, Jerry; Lorenz, J.; Atkinson, P.K.; Brinton, J.S.; Karpov, A.V.

    2001-02-27

    The objectives of this study were to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of detachment folds and their truncation by thrust faults, (2) The influence of folding and lithostratigraphy on fracture patterns, (3) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics, and (4) The influence of lithostratigraphy and deformation on fluid flow.

  4. Foraminiferal zonation and carbonate facies of Carboniferous (Mississippian and Pennsylvanian) Lisburne group, central and eastern Brooks range, Arctic Alaska

    USGS Publications Warehouse

    Armstrong, Augustus K.; Mamet, Bernard L.; Dutro, J. Thomas

    1970-01-01

    The Lisburne Group carbonate rocks of the central and eastern Brooks Range contain foraminiferal assemblages assigned to zones of late Tournaisian (Osage) to early Moscovian (Atoka) age. Representatives of both Eurasiatic and American cratonic microfaunas permit correlation with the original Carboniferous type sections in western Europe as well as with the standard Mississippian and Pennsylvanian sequences in the Mid-Continent region of North America. Correlation anomalies in the lower part of the sequence are discussed.

  5. The Influence of Fold and Fracture Development on Reservoir Behavior of the Lisburne Group of Northern Alaska

    SciTech Connect

    Wallace, W.K.; Hanks, C.L.; Whalen, M.T.; Jensen, J.; Atkinson, P.K.; Brinton, J.S.

    2001-01-09

    The objectives of this study were to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of detachment folds and their truncation by thrust faults, (2) The influence of folding and lithostratigraphy on fracture patterns, (3) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics, and (4) The influence of lithostratigraphy and deformation on fluid flow.

  6. Scaling on a limestone flooring

    NASA Astrophysics Data System (ADS)

    Carmona-Quiroga, P. M.; Blanco-Varela, M. T.; Martínez-Ramírez, S.

    2012-04-01

    Natural stone can be use on nearly every surface, inside and outside buildings, but decay is more commonly reported from the ones exposed to outdoor aggressively conditions. This study instead, is an example of limestone weathering of uncertain origin in the interior of a residential building. The stone, used as flooring, started to exhibit loss of material in the form of scaling. These damages were observed before the building, localized in the South of Spain (Málaga), was inhabited. Moreover, according to the company the limestone satisfies the following European standards UNE-EN 1341: 2002, UNE-EN 1343: 2003; UNE-EN 12058: 2004 for floorings. Under these circumstances the main objective of this study was to assess the causes of this phenomenon. For this reason the composition of the mortar was determined and the stone was characterized from a mineralogical and petrological point of view. The last material, which is a fossiliferous limestone from Egypt with natural fissure lines, is mainly composed of calcite, being quartz, kaolinite and apatite minor phases. Moreover, under different spectroscopic and microscopic techniques (FTIR, micro-Raman, SEM-EDX, etc) samples of the weathered, taken directly from the buildings, and unweathered limestone tiles were examined and a new mineralogical phase, trona, was identified at scaled areas which are connected with the natural veins of the stone. In fact, through BSE-mapping the presence of sodium has been detected in these veins. This soluble sodium carbonate would was dissolved in the natural waters from which limestone was precipitated and would migrate with the ascendant capilar humidity and crystallized near the surface of the stone starting the scaling phenomenon which in historic masonry could be very damaging. Therefore, the weathering of the limestone would be related with the hygroscopic behaviour of this salt, but not with the constructive methods used. This makes the limestone unable to be used on restoration

  7. Structural studies in limestone sulfidation

    SciTech Connect

    Fenouil, L.A.; Lynn, S.

    1993-05-01

    This study investigates the sulfidation of limestone at high temperatures (700--900{degree}C) as the first step in the design of a High-Temperature Coal-Gas Clean-Up system using millimeter-size limestone particles. Several workers have found that the rate of this reaction significantly decreases after an initial 10 to 15% conversion of CaCO{sub 3} to CaS. The present work attempts to explain this feature. It is first established that millimeter-size limestone particles do not sinter at temperatures up to the CaCO{sub 3} calcination point (899{degree}C at 1.03 bar CO{sub 2} partial pressure). It is then shown that CaS sinters rapidly at 750 to 900{degree}C if CO{sub 2} is present in the gas phase. Scanning Electron Microscope (SEM) photographs and Electron Dispersive Spectroscopy (EDS) data reveal that the CaS product layer sinters and forms a quasi-impermeable coating around the CaCO{sub 3} grains that greatly hinders more H{sub 2}S from reaching the still unreacted parts of the stone. Moreover, most of the pores initially present within the limestone structure begin to disappear or, at least, are significantly reduced in size. From then on, subsequent conversion is limited by diffusion of H{sub 2}S through the CaS layer, possibly by S{sup 2{minus}} ionic diffusion. The kinetics is then adequately described by a shrinking-core model, in which a sharp front of completely converted limestone is assumed to progress toward the center of the pellet. Finally, experimental evidence and computer simulations using simple sintering models suggest that the CaS sintering, responsible for the sharp decrease in the sulfidation rate, is surface-diffusion controlled.

  8. CALCIUM CARBONATE DISSOLUTION RATE IN LIMESTONE CONTRACTORS

    EPA Science Inventory

    The rate of carbonate mineral dissolution from limestone was studied using a rotating disk apparatus and samples of limestone of varied composition. he purpose of this study was to determine the effect of limestone composition on the kinetics of carbonate mineral dissolution. he ...

  9. The age of the Ocala limestone

    USGS Publications Warehouse

    Cooke, Charles Wythe

    1916-01-01

    In 1881 Eugene A. Smith announced the presence, underlying large areas in both western and peninsular Florida, of limestone which he correlated with the Vicksburg limestone of Mississippi and Alabama and designated by the term Vicksburg limestone. Among the localities he mentioned specifically are Marianna, in Jackson County, and Ocala, in Marion County.

  10. CALCIUM CARBONATE DISSOLUTION RATE IN LIMESTONE CONTACTORS

    EPA Science Inventory

    The rate of carbonate mineral dissolution from limestone was studied using a rotating disk apparatus and samples of limestone of varied composition. The purpose of this study was to determine the effect of limestone composition on the kinetics of carbonate mineral dissolution. Th...

  11. LIMESTONE BED CONTACTORS FOR CONTROL OF CORROSION AT SMALL WATER UTILITIES

    EPA Science Inventory

    Corrosion control by use of limestone contactors was evaluated both in the laboratory and at a field installation. As water is transported through a packed bed of limestone, calcium carbonate dissolves and the pH, calcium ion concentration, and alkalinity increase. A mathematical...

  12. Analysis of reservoir heterogeneities due to shallowing-upward cycles in carbonate rocks of the Pennsylvanian Wahoo Limestone of Northeastern Alaska. Annual report, October 1990--September 1991

    SciTech Connect

    Watts, K.

    1992-09-01

    The primary objective of this project is to develop an integrated database to characterize reservoir heterogeneities resulting from numerous small-scale shallowing-upward cycles (parasequences) comprising the carboniferous Pennsylvanian Wahoo Limestone. The Wahoo Limestone is the upper formation of an extensive carbonate platform sequence of the Carboniferous Lisburne Group which is widely exposed in the Brooks Range and is a widespread hydrocarbon reservoir unit in the subsurface of the North Slope of Alaska. A principal goal is to determine lateral and vertical variations in the complex mosaic of carbonate facies comprising the Wahoo Limestone. This report presents the preliminary results of research accomplished by a team of specialists in carbonate petrology, biostratigraphy, and diagenesis during the 1990--1991 fiscal year.It includes a summary of regional geological framework studies, a discussion conodont analyses, an overview of diagenetic studies, a brief description of progress in computerized database development, and appendices containing some of the new data on petrographic analyses, conodont analyses, and locality and sample information. Our correlation scheme, which uses cyclic stratigraphy, biostratigraphy, and cement stratigraphy, will allow interpretation of the depositional history and paleogeographic evolution of the region. We have developed predictive facies models and will make paleogeographic maps to illustrate different stages in the history of the Wahoo carbonate ramp. Our detailed analyses of the Wahoo Limestone will provide a basis for interpreting correlative rocks in the adjacent subsurface of the coastal plain of ANWR, a potential hydrocarbon lease-sale area. In a broader sense, our work will provide an excellent generic example of carbonate shallowing-upward cycles which typify carbonate sediments.

  13. Analysis of reservoir heterogeneities due to shallowing-upward cycles in carbonate rocks of the Pennsylvanian Wahoo Limestone of Northeastern Alaska

    SciTech Connect

    Watts, K.

    1992-09-01

    The primary objective of this project is to develop an integrated database to characterize reservoir heterogeneities resulting from numerous small-scale shallowing-upward cycles (parasequences) comprising the carboniferous Pennsylvanian Wahoo Limestone. The Wahoo Limestone is the upper formation of an extensive carbonate platform sequence of the Carboniferous Lisburne Group which is widely exposed in the Brooks Range and is a widespread hydrocarbon reservoir unit in the subsurface of the North Slope of Alaska. A principal goal is to determine lateral and vertical variations in the complex mosaic of carbonate facies comprising the Wahoo Limestone. This report presents the preliminary results of research accomplished by a team of specialists in carbonate petrology, biostratigraphy, and diagenesis during the 1990--1991 fiscal year.It includes a summary of regional geological framework studies, a discussion conodont analyses, an overview of diagenetic studies, a brief description of progress in computerized database development, and appendices containing some of the new data on petrographic analyses, conodont analyses, and locality and sample information. Our correlation scheme, which uses cyclic stratigraphy, biostratigraphy, and cement stratigraphy, will allow interpretation of the depositional history and paleogeographic evolution of the region. We have developed predictive facies models and will make paleogeographic maps to illustrate different stages in the history of the Wahoo carbonate ramp. Our detailed analyses of the Wahoo Limestone will provide a basis for interpreting correlative rocks in the adjacent subsurface of the coastal plain of ANWR, a potential hydrocarbon lease-sale area. In a broader sense, our work will provide an excellent generic example of carbonate shallowing-upward cycles which typify carbonate sediments.

  14. Ca-rich carbonates associated with ultrabasic-ultramafic melts: Carbonatite or limestone xenoliths? A case study from the late Miocene Morron de Villamayor volcano (Calatrava Volcanic Field, central Spain)

    NASA Astrophysics Data System (ADS)

    Lustrino, Michele; Prelević, Dejan; Agostini, Samuele; Gaeta, Mario; Di Rocco, Tommaso; Stagno, Vincenzo; Capizzi, Luca Samuele

    2016-07-01

    The volcanic products of the late Miocene Morron de Villamayor volcano (Calatrava Volcanic Field, central Spain) are known for being one of the few outcrops of leucitites in the entire circum-Mediterranean area. These rocks are important because aragonite of mantle origin has been reported as inclusion in olivine macrocrysts. We use petrographic observations, mineral compositions, as well as oxygen and carbon isotope ratios coupled with experimental petrology to understand the origin of carbonate phase in these olivine-phyric rocks. Groundmass and macrocryst olivines range from δ18OVSMOW of +4.8‰, typical of mantle olivine values, to +7.4‰, indicating contamination by sedimentary carbonate. Carbonates are characterized by heavy oxygen isotope compositions (δ18OVSMOW >+24‰), and relatively light carbon isotopes (δ13CPDB <-11‰), resembling skarn values, and distinct from typical mantle carbonatite compositions. Petrography, mineral compositions such as low Mg# of clinopyroxene and biotite, low Ca# and low incompatible element abundance of the carbonate, and isotopic ratios of O and C, do not support a mantle origin for the carbonate. Rather, the carbonate inclusions found in the olivine macrocrysts are interpreted as basement limestone fragments entrapped by the rising crystallizing magma. Comparison with experimental carbonatitic and silicate-carbonatitic melts indicates that low-degree partial melts of a carbonated peridotite must have a dolomitic rather than the aragonitic/calcitic composition as those found trapped in the Morron de Villamayor olivine macrocrysts.

  15. LIMESTONE AND LIME NEUTRALIZATION OF FERROUS IRON ACID MINE DRAINAGE

    EPA Science Inventory

    The U.S. Environmental Protection Agency conducted a 2-yr study on hydrated lime and rock-dust limestone neutralization of acid mine drainage containing ferrous iron at the EPA Crown Mine Drainage Control Field Site near Rivesville, West Virginia. The study investigated optimizat...

  16. Geochemistry of oil-field water from the North Slope

    SciTech Connect

    Kharaka, Y.K.; Carothers, W.W.

    1989-01-01

    Knowledge of the chemical composition of oil-field water is important in understanding the origin and migration of petroleum as well as the water mineral reactions that affect the porosity and permeability of the reservoir rocks. This knowledge is essential in interpreting electric logs and in determining potential pollution, corrosion, and disposal problems of water produced with oil and gas. Finally, the chemical composition of water is an important factor in determining the conditions (temperature, pressure) for the formation of clathrates. This chapter reports detailed chemical analyses of seven formation-water samples from wells within the NPRA and one surface-and two formation-water samples from the Prudhoe Bay oil field. The authors also report {delta}D and {delta}{sup 18}O values for eight of the water samples as well as analyses for gases from six wells. The formation-water samples were obtained from depths ranging from about 700 to 2800 m and from reservoir rocks ranging in age from Mississippian (Lisburne Group) to Triassic. The reservoir rocks are sandstone except for sample 79-AK-5, which was obtained from a limestone interbedded with sandstone. Generally, the pre-Cretaceous sandstone reservoir rocks on the North Slope have a similar mineral composition. Van de Kamp (1979) gave the following description of these sandstones: Quartz (usually monocrystalline) and chert are the major components; carbonate and clay are variable. Carbonate occurs as detrital grains and as cement, siderite being the most common type. Siderite can form as much as 30 percent of the rock. Clay occurs as a common matrix, generally making up less than 10 percent of the rock. Accessory minerals include pyrite, plagioclase, microcline, glauconite, zircon, sphene, tourmaline, and muscovite.

  17. Experimental Investigation of Flash Weakening in Limestones

    NASA Astrophysics Data System (ADS)

    di Toro, G.; Tisato, N.; Quaresimin, M.; de Rossi, N.

    2010-12-01

    Frictional properties of limestone and dolostone are crucial to understand earthquake mechanics where seismic ruptures nucleate and propagate in carbonate rocks (e.g., Mw 6.3 L’Aquila 2009 earthquake). We performed 27 rock friction experiments in a compression-torsion apparatus on ring-shaped (50/60 and 70/80 mm int/ext diameter) 100% CaCO3-samples at sub-seismic to seismic slip rates (0.05 to 350 mm/s), small displacements (50-60 mm) and under normal stresses of 3-8 MPa. The experiments involved four steps: 1) loading step to apply the normal stress, 2) “low-speed” step to verify the low-speed behavior, 3) “high-speed” step to determine the velocity dependence and, 4) final deceleration step to stop the experiment. The friction coefficient gradually increased during the low-speed step (0.05 mm/s and 7 mm displacement) from 0 to 0.7-0.8, a typical value for friction in limestone. During the high-speed step, slip rate was abruptly (< 0.04 s) increased in about 5 mm of slip to 250 mm/s (for 30 mm displacement, samples 50/60 mm in diameter) and to 350 mm/s (for 40 mm displacement, samples 70/80 mm in diameter). All experiments show a dramatic decrease, up to 60%, in friction for slip rates > 100 mm/s. During the final deceleration step (< 7 mm of slip in < 0.04 s), the friction coefficient recovered its initial value (0.7). A possible weakening mechanism is flash heating-induced thermal decomposition of calcite (CaCO3 -> CaO + CO2) at asperity contacts. In the experiments, weakening was contemporaneous with a peripheral temperature increase of 60-170°C measured with an infrared camera. This temperature range yields a lower limit to the temperature achieved in the slipping zone and at the asperity contacts. Energy Dispersive Spectroscopy equipped with Field Emission Scanning Electron Microscope (FE-SEM), X-Ray powder diffraction and Raman Spectroscopy analyses did not detect decarbonation products (CaO, Ca(OH)2) in the slipping zone. Instead, FE

  18. CO2 mitigation via accelerated limestone weathering

    USGS Publications Warehouse

    Rau, G.H.; Knauss, K.G.; Langer, W.H.; Caldeira, K.

    2004-01-01

    The climate and environmental impacts of the current, carbon-intensive energy usage demands that effective and practical energy alternatives and CO2 mitigation strategies be found. A discussion on CO2 mitigation via accelerated limestone weathering covers limestone and seawater availability and cost; reaction rates and densities; effectiveness in CO2 sequestration; and environmental impacts and benefits.

  19. LIMESTONE SCRUBBER SLURRY AUTOMATIC CONTROL SYSTEMS

    EPA Science Inventory

    The report utilizes current understanding of limestone scrubbers for flue gas desulfurization (FGD) to develop an effort into the optimization of automatic control for the recirculating slurry processes. The acknowledged methods of mathematical modeling, computer simulation, and ...

  20. CO2 mitigation via accelerated limestone weathering

    USGS Publications Warehouse

    Rau, G.H.; Knauss, K.G.; Langer, W.H.; Caldeira, K.

    2004-01-01

    Accelerated weathering of limestone (AWL: CO22+ + CaCO3 + H2O ??? Ca2+ + 2HCO3- as a low-tech, inexpensive, high-capacity, environmentally-friendly CO2 capture and sequestration technology was evaluated. With access to seawater and limestone being essential to this approach, significant limestone resources were close to most CO2-emitting power plants along the coastal US. Waste fines, representing > 20% of current US crushed limestone production (> 109 tons/yr), could be used as an inexpensive source of AWL carbonate. AWL end-solution disposal in the ocean would significantly reduce effects on ocean pH and carbonate chemistry relative to those caused by direct atmospheric or ocean CO2 disposal. Indeed, the increase in ocean Ca2+ and bicarbonate offered by AWL should enhance growth of corals and other calcifying marine organisms.

  1. Acid mine treatment with open limestone channels

    SciTech Connect

    Ziemkiewicz, P.F.; Brant, D.L.; Skousen, J.G.

    1996-12-31

    Acid mine drainage (AMD) is often associated with mining of pyritic coal and metal deposits. Typical AMD associated with coal mines in the eastern US can have acidity and iron concentrations ranging from the teens to the thousands of mg/l. Aluminum and manganese can be present in concentrations ranging from zero to the low hundreds of mg/l. Much attention has been devoted to developing inexpensive, limestone (LS)-based systems for treating AMID with little or no maintenance. However, LS tends to coat with metal hydroxides when exposed to AMID in an oxidized state, a process known as {open_quotes}armoring{close_quotes}. It is generally assumed that once armored, LS ceases to neutralize acid. Another problem is that the hydroxides tend to settle into plug the pore spaces in LS beds forcing water to move around rather than through the LS. While both are caused by the precipitation of metal hydroxides, armoring and plugging are two different problems. Plugging of LS pores can be avoided by maintaining a high flushing rate through the LS bed. Armoring, however, occurs regardless of water velocity. This study investigated the influence of armoring on LS solubility and the implications of armoring and plugging on the construction of open (oxidizing) LS channels for treating AMD. We evaluated the AMID treatment performance of armored and unarmored LS in oxidizing environments both in laboratory and field studies.

  2. Weight losses of marble and limestone briquettes exposed to outdoor environments in the eastern United States

    SciTech Connect

    Youngdahl, C.A.

    1987-08-01

    Weight losses of marble and limestone samples exposed to outdoor environments at field sites in the eastern United States have been monitored in studies initiated in 1984. The prodcedures are described, and the results are tabulated and discussed. A rate of marble loss approximately equivalent to 16 ..mu..m of surface recession per year was found in North Carolina, and losses of this order were also observed in New Jersey, New York, and Washington, DC. Limestone weight losses were much higher than for marble in the first year; loss of extraneous materials from the porous limestone appeared to be a likely contributor to the overall loss. The rate of limestone loss diminished in the second year, though it continued to be higher than for marble. Exposures are continuing in a planned 10-yr program of tests. 8 refs., 3 figs., 5 tabs.

  3. EPA'S (ENVIRONMENTAL PROTECTION AGENCY'S) PROGRAM FOR EVALUATION AND DEMONSTRATION OF LOW-COST RETROFIT LIMB (LIMESTONE INJECTION MULTISTAGE BURNER) TECHNOLOGY

    EPA Science Inventory

    The paper discusses program objectives, approaches, current status and results, future activities, and schedules for EPA's program for research and development, field evaluation, and demonstration of Limestone Injection Multistage Burner (LIMB) technology. Primary emphasis is on:...

  4. Crystalline marble beats limestone for fluegas desulfurization

    SciTech Connect

    1996-05-01

    NovaCon Energy Systems, Inc. (Bedford, NY) has developed an alternative to conventional limestone sorbents. The new process uses a class of marble, selected with a proprietary model. Recent pilot- and full-scale demonstrations in pulverized-coal (PC) and circulating fluidized bed (CFB) boilers suggest that these patented sorbents outperform conventional limestone for the simultaneous control of SOx, NOx, and particulates during the combustion of coal and sulfur-rich fuels, such as oil, mixed municipal waste and used tires. Dubbed thermally active marbles (TAMs), these sorbents are chemically identical to grainy limestone (whose main constituent is calcium carbonate or calcite). However, thanks to the increased pressures and temperatures experienced during their geologic history, these metamorphic minerals have a regular crystalline structure that offers some advantages in the combustion zone. TAMs, on the other hand, enjoy better calcium-utilization rates because upon heating, they cleave along inter- and intra-crystalline faces, continuously exposing fresh surfaces. By minimizing the self-extinguishment suffered by limestone sorbents, TAMs are effective over operating temperatures from 1,200 F to 2,800 F, which is 400 F higher than other calcium-based sorbents. This allows them to be injected closer to the burner or combustion grate to maximize residence time in the unit.

  5. 21 CFR 184.1409 - Ground limestone.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Chemicals Codex, 3d Ed. (1981), p. 173, which is incorporated by reference. Copies are available from the... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ground limestone. 184.1409 Section 184.1409 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...

  6. SOURCE ASSESSMENT: CRUSHED LIMESTONE, STATE OF THE ART

    EPA Science Inventory

    This report describes a study of atmospheric emissions from the crushed limestone industry. Crushed limestone plants emit particulates from drilling, blasting, transport on unpaved roads, crushing, screening, conveying, and stockpiling. The emission factor for total particulate f...

  7. Acidic stream mitigation by limestone sand addition

    SciTech Connect

    Brant, D.L.; Marich, A.J. Jr.; Largent, K.L.

    1996-12-31

    The Town Line Run watershed comprises an area of 3,600 wooded acres. The tributaries feeding the stream consist of sandstone springs that do not contribute alkalinity to the watershed, leaving the stream susceptible to acid precipitation. This has a negative affect on Iser`s Run, a native brook trout fishery above the confluence with Town Line Run. The objective in stream liming is to improve water chemistry by increasing pH, alkalinity, and reducing acidity, aluminum, and iron. Introducing crushed limestone directly into a stream from a dump truck is an inexpensive but temporary solution to accomplish this objective. In this type of liming operation, a bed of limestone is spread down the stream channel by the momentum of the stream from the introduction point, rather than manually. Water moving across this bed dissolves the limestone, increasing the pH, alkalinity, and calcium while decreasing the acidity, iron, and aluminum concentrations of the water. The size of the limestone particles is important for this purpose because particles that are too small (<150 microns) will carried away, while particles that are too large (>1000 microns) will remain at the introduction point. Our study placed 80 tons of sand-sized limestone (85% calcite) in the stream channel at a single point. Water samples were collected monthly at the following sites (1) directly upstream of the addition site, (2) 100 yards downstream of the site, and (3) 2500 yards downstream of the site. Other sample locations include (4) upstream and (5) downstream of the Town Line Run- Iser`s Run confluence and the Casselman River upstream (6) and downstream (7) of Town Line Run. The samples were analyzed for pH. Specific conductivity, Alkalinity, Acidity, Iron, Manganese, Aluminum, and Sulfate.

  8. Mineralogical characterization of the Shelburne marble and the Salem limestone

    SciTech Connect

    McGee, E.S.

    1989-01-01

    Samples of Shelburne marble and Salem limestone were selected to represent marbles and limestones used in buildings and monuments. The Royal variety of Shelburne marble is a white marble predominantly composed of calcite but has heterogeneously distributed gray inclusions. The select buff Salem limestone is a beige, homogeneous, fossiliferous limestone, predominantly composed of fragments of echinoderms and bryozoans. The author reports that both samples are appropriate test stones for the National Acid Precipitation Assessment Program stone exposure studies.

  9. Physicochemical characterizations of limestone for fluidized-bed coal combustion

    SciTech Connect

    Fuller, E.L. Jr.; Yoos, T.R. III; Walia, D.S.

    1981-05-01

    This study is an investigation of the physicochemical characteristics of three limestone samples, Quincy limestone (-20 + 60), Franklin limestone (-12 + 30), and Franklin limestone (-6 + 16), currently being tested at Oak Ridge National Laboratory for use in a fluidized-bed coal combustion unit. By correlating the chemistry, mineralogy, and surface area of these samples with empirical data obtained at Argonne National Laboratory, the sulfur capture ability and performance of these limestones can be loosely predicted. X-ray fluorescence and neutron activation analysis revealed a very high calcium content and very low concentrations of other elements in the three samples. X-ray diffraction patterns and petrographic examination of the limestone grains detected essentially no dolomite in the Quincy limestone or the fine Franklin limestone samples. The coarse Franklin limestone sample showed dolomite to be present in varying amounts up to maximum of 2.75%. Limited surface chemistry investigations of the samples were undertaken. Limestone and dolostone resources of the Tennessee Valley Authority region are widespread and abundant, and judged sufficient to meet industrial demand for many years. No problems are anticipated in securing limestone or dolostone supplies for a commercial fluidized-bed combustion plant in the Tennessee Valley Authority region. Transportation facilities and costs for limestone or dolostone will influence the siting of such a commercial fluidized-bed combustion plant. The most promising location in the Tennessee Valley Authority region at this time is Paducah, Kentucky.

  10. Limestone reaction in calcium aluminate cement–calcium sulfate systems

    SciTech Connect

    Bizzozero, Julien Scrivener, Karen L.

    2015-10-15

    This paper reports a study of ternary blends composed of calcium aluminate cement, calcium sulfate hemihydrate and limestone. Compressive strength tests and hydration kinetics were studied as a function of limestone and calcium sulfate content. The phase evolution and the total porosity were followed and compared to thermodynamic simulation to understand the reactions involved and the effect of limestone on these binders. The reaction of limestone leads to the formation of hemicarboaluminate and monocarboaluminate. Increasing the ratio between sulfate and aluminate decreases the extent of limestone reaction.

  11. Limestone calcination during pulsating combustion

    SciTech Connect

    James, R.E. III ); Richards, G.A. )

    1992-01-01

    METC is currently conducting research on enhanced calcination during pulsating combustion as part of the Heat Engines program. It has been shown elsewhere that rapid, high temperature calcination will result in a calcined product with relatively large surface area, as desired for sulfur capture. It is proposed that such a process may occur during pulsating combustion where the oscillating pressure/velocity field around a particle increases the heat/mass transfer to and from the particle. To test this hypothesis, calcination tests in progress at METC use a novel form of pulse combustion called thermal'' pulse combustion, operating at 60000 BTUH, 100 Hz, and 5--15 psig peak-to- peak amplitude. Two configurations are being studied during the testing: one configuration is injection of sorbent into a refractory lined drop tube being heated by the pulse combustor, and the other configuration is injection of the sorbent into the pulse combustor through its centerbody and along the tailpipe at various positions. To understand the observed behavior, a characterization study of the pulse combustor is being conducted. Different flow rates, equivalence ratios, and injection positions are being tested.

  12. Kinematic hardening of a porous limestone

    NASA Astrophysics Data System (ADS)

    Cheatham, J. B.; Allen, M. B.; Celle, C. C.

    1984-10-01

    A concept for a kinematic hardening yield surface in stress space for Cordova Cream limestone (Austin Chalk) developed by Celle and Cheatham (1981) has been improved using Ziegler's modification of Prager's hardening rule (Ziegler, 1959). Data to date agree with the formulated concepts. It is shown how kinematic hardening can be used to approximate the yield surface for a wide range of stress states past the initial yield surface. The particular difficulty of identifying the yield surface under conditions of unloading or extension is noted. A yield condition and hardening rule which account for the strain induced anisotropy in Cordova Cream Limestone were developed. Although the actual yield surface appears to involve some change of size and shape, it is concluded that true kinematic hardening provides a basis for engineering calculations.

  13. [Effect of limestone and magnesite application on remediation of acidified forest soil in Chongqing, China].

    PubMed

    Yang, Yong-sen; Duan, Lei; Jin, Teng; Zhao, Da-wei; Zhang, Dong-bao; Hao, Ji-ming

    2006-09-01

    Effect of limestone and magnesite application on remediation of a typical acidified soil under a masson pine (Pinus massoniana) forest at Tieshanping, Chongqing in southwest China was studied through field experiments. The changes of soil water chemistry in different layers within one year after application of limestone or magnesite indicated that the remediation agents leaded to the recovery of acidified soil by significant increase of pH value and concentration of relative cation, i.e., Ca2+ or Mg2+, and notable decrease of inorganic monomeric aluminum (Ali). However, the accelerated leaching of NO3- and SO4(2-) might somewhat counteract the positive effects. Since the limestone powder applied was much finer and thus more soluble than the magnesite powder, it seemed that the addition of limestone was more effective than that of magnesite. However, the application of magnesite could probably improve the nutrient uptake and growth of plant, and thus limestone and magnesite should be used together. The change of soil water chemistry was much more notable in upper layer of soil than lower, which means that it will take long time to achieve the whole profile soil remediation. PMID:17117649

  14. Stratigraphy and diagenesis of the Mississippian Lodgepole Limestone, Williston Basin, North Dakota

    SciTech Connect

    Grover, P.W. )

    1996-01-01

    Stratigraphic correlation of the Lodgepole Limestone (Bottineau Interval) indicates a sequence of three clinoform-shaped wedges that filled in the early Williston Basin. To date four productive 100m thick mounds have been discovered in the Lodgepole Limestone at Dickinson Field. The mounds seem to have nucleated at the toe of slope of the first highstand system tract and were subsequently buried by the second highstand systems tract. By isopaching each of the systems tracts one can predict were other mounds might have nucleated. Burial depth of the Bakken Shale-Lodgepole Limestone contact grade from 0.6 km at the edge of the Williston Basin to 3.4 km in the center. With increased depth the basal Lodgepole Limestone shows three phases of dolomitization, which are: small clear early dolomite; later iron rich fracture filling saddle dolomite and a later iron rich dolomite that seems to follow stylolites. Pre-oil migration mineralization of the overlying limestone include minor amounts of: anhydrite, pyrite, iron poor sphalerite, late iron rich sphalerite, chalcopyrite and celestite.

  15. Stratigraphy and diagenesis of the Mississippian Lodgepole Limestone, Williston Basin, North Dakota

    SciTech Connect

    Grover, P.W.

    1996-12-31

    Stratigraphic correlation of the Lodgepole Limestone (Bottineau Interval) indicates a sequence of three clinoform-shaped wedges that filled in the early Williston Basin. To date four productive 100m thick mounds have been discovered in the Lodgepole Limestone at Dickinson Field. The mounds seem to have nucleated at the toe of slope of the first highstand system tract and were subsequently buried by the second highstand systems tract. By isopaching each of the systems tracts one can predict were other mounds might have nucleated. Burial depth of the Bakken Shale-Lodgepole Limestone contact grade from 0.6 km at the edge of the Williston Basin to 3.4 km in the center. With increased depth the basal Lodgepole Limestone shows three phases of dolomitization, which are: small clear early dolomite; later iron rich fracture filling saddle dolomite and a later iron rich dolomite that seems to follow stylolites. Pre-oil migration mineralization of the overlying limestone include minor amounts of: anhydrite, pyrite, iron poor sphalerite, late iron rich sphalerite, chalcopyrite and celestite.

  16. Simulation of Hypervelocity Penetration in Limestone

    SciTech Connect

    Antoun, T; Glenn, L; Walton, O; Goldstein, P; Lomov, I; Liu, B

    2005-05-31

    A parameter study was performed to examine the (shock) damage obtained with long-rod and spherical mono-material penetrators impacting two varieties of limestone. In all cases, the impacts were assumed to be normal to the plane of the rock and at zero angle of attack (in the case of the rods). Impact velocities ranged to 15 km/s but most calculations were performed at 4 and 6 km/s and the penetrator mass was fixed at 1000 kg. For unlined underground structures, incipient damage was defined to occur when the peak stress, {sigma}{sub pk}, exceeds 1 kb (100 MPa) and the applied impulse per unit area, I{sub pk}, exceeds 1 ktap (1 kb-{micro}s). Severe damage was assumed to occur when {sigma}{sub pk} exceeds 1 kb and I{sub pk} exceeds 1000 ktaps. Using the latter definition it was found that severe damage in hard, non-porous limestone with spherical impactors extended to a depth of 9 m on-axis for an impact velocity of 4 km/s and 12 m at 6 km/s. Cylinders with length-to-diameter (L/D) ratio of 8.75 achieved depth to severe damage of 23 m and 40 m, respectively under the same conditions. For a limestone medium with 2% initial gas porosity, the latter numbers were reduced to 12 m and 18 m.

  17. Micromechanics of inelastic compaction in two allochemical limestones

    NASA Astrophysics Data System (ADS)

    Vajdova, Veronika; Baud, Patrick; Wu, Lily; Wong, Teng-fong

    2012-10-01

    To investigate inelastic compaction in limestone we deformed in conventional triaxial configuration samples of two allochemical limestones: Indiana and Majella limestone with porosity of 14-16% and 30%, respectively. We described the microstructures associated with the damage evolution. Inelastic compaction in both limestones was associated with pore collapse that seemed to initiate from stress concentrations at the surface of a pore. Cataclasis appeared to develop preferentially around the macropores, in agreement with a recent study on a micritic limestone. Our new observations however showed that the spatial distribution of damage in the allochemical limestones can be complicated by its uneven partitioning among the allochems, micrite and sparite. In Indiana limestone, many allochems remain relatively intact even after the cement has undergone significant microcracking, with the implication that significant strength contrast exists between the allochems and cement. In Majella limestone, the asymmetry in damage intensity is not as pronounced, suggesting a less pronounced mechanical contrast between allochems and cement. In both limestones, significant mechanical twinning was observed in samples deformed to relatively high level of strain. We applied to our data a model, that treats a limestone as a dual porosity medium, with the total porosity partitioned between macroporosity and microporosity.

  18. In situ calcite formation in limestone-saturated water leaching of acid rock waste.

    PubMed

    Smart, Roger St C; Miller, Stuart D; Stewart, Warwick S; Rusdinar, Yuni; Schumann, Russell E; Kawashima, Nobuyuki; Li, Jun

    2010-07-15

    The result of leaching of a 75% acid rock/25% limestone column with limestone-saturated solution has shown that the pH of the effluent recovered from 2.5, after apparent loss of acid neutralizing capacity after 4 years with water leaching, to pH 7 in less than 3 years. Bulk assay results, XRD and SEM/EDS analyses of samples from the column at 384 weeks (pH 3.6) and 522 weeks (pH 6.9) during this recovery have suggested that this is due to formation in situ of fine calcite. Calcite, initially blended to the column material at 25 wt.% was not found in the XRD of the 384 week sample but is clearly found in the 522 week XRD. This increased calcite content appears to be derived from the limestone-saturated water as finely divided solid precipitated in the drying cycles in the column. This result is confirmed by assessment of the 522 week sample as non-acid forming. Loss of some reactive aluminosilicate minerals, formation of secondary, precipitated, surface-attached gypsum and loss of fine secondary jarosite occurs across this pH range but fine, surface-attached jarosite is still found in the 522 week sample implying relatively slow dissolution kinetics. In comparison with the 384 week sample, armouring of highly reacted pyrite particles by surface layers of iron oxyhydroxides and aluminosilicates has become more extensive at 522 weeks after return of the pH to neutral values. This is consistent with results from Freeport field samples from limestone blended test pads where pyrite armouring was also substantially increased at higher pH. The results suggest that it may be possible to effectively maintain neutral pH and passivate pyrite, reducing oxidation rates by more than an order of magnitude, using limestone-saturated solution dump feed rather than bulk limestone blending or covers. PMID:20452647

  19. CO2 MITIGATION VIA ACCELERATED LIMESTONE WEATHERING

    SciTech Connect

    Rau, G H; Knauss, K G; Langer, W H; Caldeira, K G

    2004-02-27

    The climate and environmental impacts of our current, carbon-intensive energy usage demands that effective and practical energy alternatives and CO2 mitigation strategies be found. As part of this effort, various means of capturing and storing CO2 generated from fossil-fuel-based energy production are being investigated. One of the proposed methods involves a geochemistry-based capture and sequestration process that hydrates point-source, waste CO2 with water to produce a carbonic acid solution. This in turn is reacted and neutralized with limestone, thus converting the original CO2 gas to calcium bicarbonate in solution, the overall reaction being:

  20. Limestone types used from the classic Karst region in Slovenia

    NASA Astrophysics Data System (ADS)

    Kramar, Sabina; Mirtič, Breda; Mladenović, Ana; Rožič, Boštjan; Bedjanič, Mojca; Kortnik, Jože; Šmuc, Andrej

    2014-05-01

    The paper presents a variety of limestones from the Karst Region that is one of the most interesting areas containing reserves of natural stones in Slovenia. The region is mainly composed of Cretaceous shallow-water limestone, with the most common type currently excavated being the rudist limestone of the Lipica Formation, which dates to the Santonian to Campanian. Limestones of this formation are mainly represented by a light grey, thick-bedded to massive Lipica limestone rich in (largely fragmented) rudists. Rudist shells can be either relatively well preserved (such as in Lipica Fiorito quarried limestone) or almost completely disintegrated and intensively endolitised (Lipica Unito quarried limestone). Beside the Lipica Formation, natural stone types have been excavated from two other formations or members in the Karst region: the Repen Formation (Repen and Kopriva limestones), and the Tomaj Limestone (dark, laminated limestone within the Lipica Formation). As documented, the region has been associated with the quarrying and processing of stone at least for over two thousand years, i.e. since the Roman period. Although a large number of quarries in all mentioned formations are documented in the Karst region, many are inactive nowadays. Some of the quarries are declared as geological monuments of national importance or officially protected as a natural monument. Karst limestones are considered the highest quality calcareous natural stones in Slovenia. They are characterised by high density, low water absorption and low open porosity; consequently they also exhibit high frost and salt resistance as well as high compressive and flexural strength. Besides in the Karst region and other parts of Slovenia, the Karst limestones were used in the construction of several important buildings and monuments in many other European Countries, and worldwide. Nowadays, they are most commonly used in the construction of façade cladding, pavements, window sills, staircases, indoor

  1. Evaluation of Different Modeling Approaches to Simulate Contaminant Transport in a Fractured Limestone Aquifer

    NASA Astrophysics Data System (ADS)

    Mosthaf, K.; Rosenberg, L.; Balbarini, N.; Broholm, M. M.; Bjerg, P. L.; Binning, P. J.

    2014-12-01

    It is important to understand the fate and transport of contaminants in limestone aquifers because they are a major drinking water resource. This is challenging because they are highly heterogeneous; with micro-porous grains, flint inclusions, and being heavily fractured. Several modeling approaches have been developed to describe contaminant transport in fractured media, such as the discrete fracture (with various fracture geometries), equivalent porous media (with and without anisotropy), and dual porosity models. However, these modeling concepts are not well tested for limestone geologies. Given available field data and model purpose, this paper therefore aims to develop, examine and compare modeling approaches for transport of contaminants in fractured limestone aquifers. The model comparison was conducted for a contaminated site in Denmark, where a plume of a dissolved contaminant (PCE) has migrated through a fractured limestone aquifer. Multilevel monitoring wells have been installed at the site and available data includes information on spill history, extent of contamination, geology and hydrogeology. To describe the geology and fracture network, data from borehole logs was combined with an analysis of heterogeneities and fractures from a nearby excavation (analog site). Methods for translating the geological information and fracture mapping into each of the model concepts were examined. Each model was compared with available field data, considering both model fit and measures of model suitability. An analysis of model parameter identifiability and sensitivity is presented. Results show that there is considerable difference between modeling approaches, and that it is important to identify the right one for the actual scale and model purpose. A challenge in the use of field data is the determination of relevant hydraulic properties and interpretation of aqueous and solid phase contaminant concentration sampling data. Traditional water sampling has a bias

  2. Three-Dimensional pore space and strain localization distribution in Majella limestone.

    NASA Astrophysics Data System (ADS)

    Ji, Yuntao; Hall, Stephen; Baud, Patrick; Wond, Teng-fong

    2015-04-01

    Brittle-ductile transition in porous rock is a topic of importance in many geological applications. Traditionally pore space in rock is characterized using optical and scanning electron microscopes (SEM). Advances in 3-dimensional imaging techniques such as X-ray computed tomography (CT) and laser scanning confocal microscopy have furnished enhanced perspective on pore geometry complexity. In particular, X-ray CT has been used widely for characterizing porous clastic rocks such as sandstone, whose void space is dominated by relatively equant pores connected by throats that are sufficiently large for direct imaging by X-ray microCT. However, standard techniques for CT imaging are not directly applicable to a carbonate rock because of the geometric complexity of its pore space. In this study, we first characterized the pore structure in Majella limestone. MicroCT data was partitioned into three distinct domains: macropores, solid grains and an intermediate domain made up of voxels of solid embedded with micropores below the resolution. A morphological analysis of the microCT images shows that both the solid and intermediate domains in Majella limestone are interconnected as it has been previously reported in a less porous limestone. We however show that the macroporosity in Majella limestone is fundamentally different, in that it has a percolative backbone which may contribute to significant enhancement of its permeability. We then present the first application of 3D-volumetric Digital Image Correlation (DIC) to a very porous limestone. If images of a rock sample are acquired before and after deformation, then DIC can be used to infer the displacement and strain fields. In our study, four Majella limestone samples were triaxially compressed at confining pressures ranging from 5 MPa to 25 MPa and another under hydrostatic conditions up to 60 MPa. For each of these five samples, two CT images were acquired before and after the deformation. We then used the Tomo

  3. The mechanics of intersecting echelon veins and pressure solution seams in limestone

    NASA Astrophysics Data System (ADS)

    Seyum, Solomon; Pollard, David D.

    2016-08-01

    Many studies that describe the formation of echelon vein arrays relate the causative stresses implicitly to the deformation, reliant on simple shear kinematics, such that the vein-to-array angle and the array width are the primary physical quantities. In contrast, we identify twelve physical quantities to describe echelon veins in two dimensions, including coeval, vein-intersecting, pressure solution seams. A finite element method is used to reproduce vein shapes in linear elastic and elastic-perfectly plastic model limestone. Model vein geometries are designed using values within the range of geometries measured from echelon veins at Raplee Anticline and Comb Monocline, Utah. Four physical quantities are significant for describing echelon vein shapes: vein spacing, vein-array angle, limestone elastic stiffness, and closing of orthogonal pressure solution seams. Pressure solution seam closing influences the mechanical interaction between adjacent veins, and for a range of conditions, causes a nearly linear vein opening distribution (triangular shapes) and encourages straight vein propagation, both of which approximate field measurements. Model results show that small spacing of veins with seams and large vein-array angles promote straight vein traces in limestone with stiffness typical of laboratory measurements, given the physical geologic conditions inferred from the burial history of the limestone strata.

  4. Acidification-neutralization processes in a lignite mine spoil amended with fly ash or limestone.

    PubMed

    Seoane, S; Leirós, M C

    2001-01-01

    A laboratory experiment was conducted to investigate the longterm effects of amending sulfide-rich lignite mine spoil with fly ash (originating from a coal-fired power station and largely comprised of aluminosilicates) and/or agricultural limestone. The experiment was carried out with soil moisture maintained at field capacity or alternate cycles of wetting and drying. Results obtained suggest that the principal acidification processes were oxidation of sulfide and formation of hydroxysulfate (FeOHSO4), whereas the main neutralization processes were weathering of aluminosilicates in fly ash-treated samples and dissolution of calcium carbonate in limestone-treated samples. The highest dose of limestone rapidly raised the pH of the spoil, but this increase was not maintained throughout the one-year experiment. In contrast, fly ash-treated samples showed a more sustained increase in pH, attributable to the gradual weathering of aluminosilicates. The best results (i.e., good short- and long-term neutralization) were obtained in samples treated with both fly ash and limestone. The low liming capacity of the fly ash (47.85 cmol kg(-1)) means that it must be used in large quantities, an advantage in achieving the further aim of disposing of the fly ash. PMID:11476521

  5. Pressure solution inhibition in a limestone-chert composite multilayer: Implications for the seismic cycle and fluid flow

    NASA Astrophysics Data System (ADS)

    Petracchini, Lorenzo; Antonellini, Marco; Billi, Andrea; Scrocca, Davide; Trippetta, Fabio; Mollo, Silvio

    2015-04-01

    Pressure solution seams (PSSs) are frequent features in carbonate rocks undergoing tectonic shortening. In particular, pervasive, anticline-axis-parallel, bed-normal PSSs are known to develop during layer-parallel-shortening of (marly) carbonate rocks in fold-thrust belts. These pressure solution features can impact subsequent fracture development, fluid circulation, and strain localization including the seismic cycle. It is here demonstrated that the occurrence of frequent and continuous chert layers may strengthen a limestone sequence and inhibit pressure solution under layer-parallel-shortening. Field observations and laboratory determinations are reported from marly limestone with continuous chert layers of the Scaglia Fm. (Cingoli anticline, northern Apennines, Italy) exhumed from a depth of c. 1 km. In these outcrops, bed-normal solution seams do not occur or they occur only where infrequent chert layers have been shortened by small thrusts. In analogy with laminae-reinforced composite materials, a model is developed explaining the field observations with the strengthening effect of chert in the chert-limestone composite multilayer. During layer-parallel-shortening, the composite multilayer deforms under equal strain boundary conditions. In this situation, the tectonic load is mostly supported by the stiff and frequent chert layers and the strain of the whole chert-limestone composite remains in the elastic field, so that pressure solution seam development is prevented in the limestone beds. Our model may be applied down to a depth of a few kilometers in the upper crust that is relevant for the seismic cycle and fluid flow.

  6. STEAM INJECTION INTO FRACTURED LIMESTONE AT LORING AIR FORCE BASE

    EPA Science Inventory

    A research project on steam injection for the remediation of spent chlorinated solvents from fractured limestone was recently undertaken at the former Loring AFB in Limestone, ME. Participants in the project include the Maine Department of Environmental Protection, EPA Region I,...

  7. REACTION OF H2S AND SULFUR WITH LIMESTONE PARTICLES

    EPA Science Inventory

    The paper gives results of a study of the direct-displacement reaction of limestone with hydrogen sulfide (H2S) over the temperature range 570-850 C in a differential reactor. It is one of several possible mechanisms of sulfur capture in limestone-injection multistage burners whi...

  8. [Analysis of trace elements in limestone for archeological functions

    SciTech Connect

    Blanc, A.; Holmes, L.; Harbottle, G.

    1998-12-31

    Numerous quarries in the Lutetian limestone formations of the Paris Basin provided stone for the building and the decoration of monuments from antiquity to the present. To determine the origin of stone used for masonry and sculptures in these monuments, a team of geologists and archaeologists has investigated 300 quarries and collected 2,300 samples. Petrographic and paleontologic examination of thin sections allows geologists to distinguish Lutetian limestones from Jurassic and Cretaceous limestones. Geologists also seek to formulate hypotheses regarding the origin of Lutetian limestones used for building and sculpture in the Paris region. In the search for the sources of building and sculptural stone, the analytical methods of geologists are limited because often several quarries produce the same lithofacies. A new tool is now available, however, to attack questions of provenance raised by art historians. Because limestones from different sources have distinctive patterns of trace-element concentrations, compositional analysis by neutron activation allows one to compare building or sculptural stone from one monument with stone from quarries or other monuments. This analytical method subjects a powdered limestone sample to standard neutron activation analysis procedures at Brookhaven National Laboratory. With the help of computer programs, the compositional fingerprints of Lutetian limestones can be determined and stored in a database. The limestone database contains data for approximately 2,100 samples from monuments, sculptures and quarries. It is particularly rich in samples from the Paris Basin.

  9. LOW NOX COMBUSTION SYSTEMS WITH SO2 CONTROL USING LIMESTONE

    EPA Science Inventory

    The paper describes EPA work on low NOx combustion systems with SO2 control using limestone. Although SO2 control in low NOx systems for both stoker and pulverized-coal-fired furnaces is under investigation at EPA, most of the current work is with pulverized coal. EPA's Limestone...

  10. Microfacies and diagenesis of the reefal limestone, Callovian Tuwaiq Mountain Limestone Formation, central Saudi Arabia

    NASA Astrophysics Data System (ADS)

    EL-Sorogy, Abdelbaset S.; Almadani, Sattam A.; Al-Dabbagh, Mohammad E.

    2016-03-01

    In order to document the microfacies and diagenesis of the reefal limestone in the uppermost part of the Callovian Tuwaiq Mountain Limestone Formation at Khashm Al-Qaddiyah area, central Saudi Arabia, scleractinian corals and rock samples were collected and thin sections were prepared. Coral framestone, coral floatstone, pelloidal packstone, bioclastic packstone, bioclastic wacke/packstone, algal wackestone and bioclastic foraminiferal wacke/packstone were the recorded microfacies types. Cementation, recrystallization, silicification and dolomitization are the main diagenetic alterations affected the aragonitic skeletons of scleractinian corals. All coral skeletons were recrystallized, while some ones were dolomitized and silicified. Microfacies types, as well as the fossil content of sclearctinian corals, bivalves, gastropods, brachiopods and foraminifera indicated a deposition in environments ranging from shelf lagoon with open circulation in quiet water below wave base to shallow reef flank and organic build up for the uppermost reefal part of the Tuwaiq Formation in the study area.

  11. Faunas of Mississippian oolitic limestones: Evidence from Salem Limestone, southern Indiana

    SciTech Connect

    Feldman, H.R. )

    1989-08-01

    In the Salem Limestone of southern Indiana, a correlation exists between the faunal assemblage and abundance of grains with superficial oolitic coatings in grainstones. Coarse, poorly sorted fossiliferous grainstones are dominated by an echinoderm-bryozoan-brachiopod assemblage of fossils with few mollusks. The presence of large whole fossils, such as articulated crinoid calyces, suggest limited transport of skeletal components. Grainstones, dominated by grains with superficial coatings, and foraminifers tend to contain a diverse mollusk-dominated assemblage of gastropods, bivalves, rostroconchs, chitins, and scaphopods. These fossils are disarticulated, but generally are not fragmented even though many of them are thin and delicate. Echinoderms, brachiopods, and bryozoans are repsented in the mollusk-domdinated assemblage almost exclusively by well-rounded and coated fragments, suggesting that they are not in situ. The presence of similar molluscan assemblages in other Mississippian coated-grain grainstones from Alabama (the Monteagle Limestone) and Oklahoma (an unnamed limestone) indicates that the assemblage may have been wide-spread. Mississippian grainstones dominated by oolites (which are not prominent in the Salem) generally have very few fossils.

  12. United Arab Emirates limestones: impact of petrography on thermal behavior

    NASA Astrophysics Data System (ADS)

    Alaabed, Sulaiman; Soltan, Abdel Monem; Abdelghany, Osman; Amin, Bahaa Eldin Mahmoud; El Tokhi, Mohamed; Khaleel, Abbas; Musalim, Abdullah

    2014-12-01

    The thermal behavior of selected limestones from representative localities of the United Arab Emirates is investigated for their suitability for soft-burnt lime production. The limestone samples were collected from the Ghalilah, Musandam, Shauiba, Muthaymimah, Dammam and Asmari formations. The samples were characterized for petrography, mineral and chemical composition, together with physico-mechanical characteristics. Investigative methods included transmitted light microscopy (TLM), cathodoluminescence (CLM) and scanning electron microscopy (SEM), as well as X-ray micro-tomography (μ-CT), XRD, XRF and Archimedes method. The limestone samples were fired in an electrical muffle furnace for 0.25, 0.5, 1 and 2 hours at 800, 900, 1,000 and 1,100 °C. After firing the lime grains were tested to determine their hydration rate and microfabric. The Ghalilah and Musandam limes show the lowest and highest maximum hydration rates, respectively, due mainly to the impure nature of the former, and the smaller lime crystallites and dominance of post-calcination micro-cracks of the latter. The Dammam and Asmari limes preserve a "ghost" microfabric of the original limestone. Higher allochem contents impose lower activation energy requirements for calcination, which implies earlier calcination of the allochems. The Musandam, Shauiba and Muthaymimah limestones may be useful for the production of reactive soft-burnt lime under the applied firing conditions, however, the Dammam and Asmari limestones need more advanced calcination conditions than the applied ones. The Ghalilah limestone was found to be unsuitable for the production of lime.

  13. Limestone dissolution in flue gas scrubbing: Effect of sulfite

    SciTech Connect

    Gage, C.L.; Rochelle, G.T. )

    1992-07-01

    Batch limestone dissolution experiments were carried out in a pH stat apparatus at 55 C with CO{sub 2} sparging and dissolved sulfite. Particle size distribution, utilization, sulfite in solution, limestone type, and the approach to calcite equilibrium were all found to contribute to the limestone reactivity. In the absence of sulfite, limestone dissolution was controlled solely by mass transfer. For a given stone under mass transfer control, film thickness was found to be independent of pH. The dissolution rate in the presence of sulfite was controlled by a combined surface kinetics/mass transfer regime. SEM micrographs supported this conclusion. A surface rate correlation was developed which accounted for observed inhibition by an inverse dependence on calcium sulfite concentration at the limestone dependence on calcium sulfite concentration at the limestone surface. While the form of the rate expression was applicable to all stones, the surface rate constant was stone dependent. A computer code which accounted for mass transfer with surface kinetics was tested against experimental observations of four limestone types. Changes in pH and the concentrations of calcium, carbonate, sulfite, sulfate, and adipic acid were accurately modeled.

  14. Biocalcifying Bacillus subtilis cells effectively consolidate deteriorated Globigerina limestone.

    PubMed

    Micallef, Roderick; Vella, Daniel; Sinagra, Emmanuel; Zammit, Gabrielle

    2016-07-01

    Microbially induced calcite precipitation occurs naturally on ancient limestone surfaces in Maltese hypogea. We exploited this phenomenon and treated deteriorated limestone with biocalcifying bacteria. The limestone was subjected to various mechanical and physical tests to present a statistically robust data set to prove that treatment was indeed effective. Bacillus subtilis conferred uniform bioconsolidation to a depth of 30 mm. Drilling resistance values were similar to those obtained for freshly quarried limestone (9 N) and increased up to 15 N. Treatment resulted in a high resistance to salt deterioration and a slow rate of water absorption. The overall percentage porosity of treated limestone varied by ±6 %, thus the pore network was preserved. We report an eco-friendly treatment that closely resembles the mineral composition of limestone and that penetrates into the porous structure without affecting the limestones' natural properties. The treatment is of industrial relevance since it compares well with stone consolidants available commercially. PMID:27072564

  15. EXTERIOR OVERVIEW, LOOKING NORTH, OF THIS 400' DEEP LIMESTONE QUARRY ...

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

    EXTERIOR OVERVIEW, LOOKING NORTH, OF THIS 400' DEEP LIMESTONE QUARRY PIT ("THE OLD PIT") WITH LEDGE PREPARED FOR LIMESTONE EXTRACTION. AN ELEVEN-HOLE SHOT WILL DISLODGE APPROXIMATELY 25,000 TONS OF LIMESTONE WHICH, AFTER LOADING AND CRUSHING, WILL BE USED FOR ROAD CONSTRUCTION. THE CALERA QUARRY IS ONE OF FOUR ACTIVE VULCAN MATERIALS COMPANY QUARRIES IN THE DISTRICT. VULCAN MATERIALS, A FORTUNE 500 FIRM, ESTABLISHED IN BIRMINGHAM IN 1906 AS BIRMINGHAM SLAG COMPANY, VULCAN MATERIALS IS THE NATION'S FOREMOST PRODUCER OF CONSTRUCTION AGGREGATE AND A LEADING CHEMICALS MANUFACTURER - Vulcan Material Company, Calera Quarry, 1614 Highway 84, Calera, Shelby County, AL

  16. EXTERIOR OVERVIEW, LOOKING NORTH, OF THIS 400' DEEP LIMESTONE QUARRY ...

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

    EXTERIOR OVERVIEW, LOOKING NORTH, OF THIS 400' DEEP LIMESTONE QUARRY PIT ('THE OLD PIT') WITH LEDGE PREPARED FOR LIMESTONE EXTRACTION. AN ELEVEN-HOLE SHOT WILL DISLODGE APPROXIMATELY 25,000 TONS OF LIMESTONE WHICH, AFTER LOADING AND CRUSHING, WILL BE USED FOR ROAD CONSTRUCTION. THE CALERA QUARRY IS ONE OF FOUR ACTIVE VULCAN MATERIALS COMPANY QUARRIES IN THE DISTRICT. VULCAN MATERIALS, A FORTUNE 500 FIRM, ESTABLISHED IN BIRMINGHAM IN 1906 AS BIRMINGHAM SLAG COMPANY, VULCAN MATERIALS IS THE NATION'S FOREMOST PRODUCER OF CONSTRUCTION AGGREGATE AND A LEADING CHEMICALS MANUFACTURER. - Vulcan Material Company, Calera Quarry, 1614 Highway 84, Calera, Shelby County, AL

  17. Downflow limestone beds for treatment of net-acidic, oxic, iron-laden drainage from a flooded anthracite mine, Pennsylvania, USA: 2. Laboratory evaluation

    USGS Publications Warehouse

    Cravotta, C.A., III; Ward, S.J.; Hammarstrom, J.M.

    2008-01-01

    Acidic mine drainage (AMD) containing elevated concentrations of dissolved iron and other metals can be neutralized to varying degrees by reactions with limestone in passive treatment systems. We evaluated the chemical and mineralogical characteristics and the effectiveness of calcitic and dolomitic limestone for the neutralization of net-acidic, oxic, iron-laden AMD from a flooded anthracite mine. The calcitic limestone, with CaCO3 and MgCO3 contents of 99.8 and <0.1 wt%, respectively, and the dolomitic limestone, with CaCO3 and MgCO3 contents of 60.3 and 40.2 wt%, were used to construct a downflow treatment system in 2003 at the Bell Mine, a large source of AMD and baseflow to the Schuylkill River in the Southern Anthracite Coalfield, in east-central Pennsylvania. In the winter of 2002-2003, laboratory neutralization-rate experiments evaluated the evolution of effluent quality during 2 weeks of continuous contact between AMD from the Bell Mine and the crushed calcitic or dolomitic limestone in closed, collapsible containers (cubitainers). The cubitainer tests showed that: (1) net-alkaline effluent could be achieved with detention times greater than 3 h, (2) effluent alkalinities and associated dissolution rates were equivalent for uncoated and Fe(OH)3-coated calcitic limestone, and (3) effluent alkalinities and associated dissolution rates for dolomitic limestone were about half those for calcitic limestone. The dissolution rate data for the cubitainer tests were used with data on the volume of effuent and surface area of limestone in the treatment system at the Bell Mine to evaluate the water-quality data for the first 1.5 years of operation of the treatment system. These rate models supported the interpretation of field results and indicated that treatment benefits were derived mainly from the dissolution of calcitic limestone, despite a greater quantity of dolomitic limestone within the treatment system. The dissolution-rate models were extrapolated on a

  18. The conservation of Britain's limestone cave resource

    NASA Astrophysics Data System (ADS)

    Hardwick, P.; Gunn, J.

    1996-10-01

    Limestone caves are an important scientific and recreational resource in Britain. During the mid- to late 1970s, cavers and statutory conservation bodies cooperated in a review of cave resources which resulted in the designation of 48 caves or cave areas as Sites of Special Scientific Interest (SSSI). During the same period, the Wildlife and Countryside Act 1981 was introduced to provide more effective planning controls on activities such as agriculture carried out within SSSI boundaries. In one case, at Priddy in the Mendip Hills of Somerset, landowners prevented access to a number of caves in protest over the new, tougher restrictions on agriculture. Faced with the closure, and perceiving that their recreational use of caves might also be controlled, local cavers joined the landowners in opposing the proposals for SSSI designation. As a result the proposals were reviewed, three caves were excluded from the site and controls on the remaining area were relaxed. The case emphasized a need for an effective system to take account of all factors affecting cave conservation, a need which has led to a more constructive dialogue between nature conservation bodies, caver organizations and other interested parties.

  19. Residual CO2 trapping in Indiana limestone.

    PubMed

    El-Maghraby, Rehab M; Blunt, Martin J

    2013-01-01

    We performed core flooding experiments on Indiana limestone using the porous plate method to measure the amount of trapped CO(2) at a temperature of 50 °C and two pressures: 4.2 and 9 MPa. Brine was mixed with CO(2) for equilibration, then the mixture was circulated through a sacrificial core. Porosity and permeability tests conducted before and after 884 h of continuous core flooding confirmed negligible dissolution. A trapping curve for supercritical (sc)CO(2) in Indiana showing the relationship between the initial and residual CO(2) saturations was measured and compared with that of gaseous CO(2). The results were also compared with scCO(2) trapping in Berea sandstone at the same conditions. A scCO(2) residual trapping end point of 23.7% was observed, indicating slightly less trapping of scCO(2) in Indiana carbonates than in Berea sandstone. There is less trapping for gaseous CO(2) (end point of 18.8%). The system appears to be more water-wet under scCO(2) conditions, which is different from the trend observed in Berea; we hypothesize that this is due to the greater concentration of Ca(2+) in brine at higher pressure. Our work indicates that capillary trapping could contribute to the immobilization of CO(2) in carbonate aquifers. PMID:23167314

  20. LIMESTONE FGD (FLUE GAS DESULFURIZATION) SCRUBBERS: USER'S HANDBOOK

    EPA Science Inventory

    The handbook, intended for use of utility project managers and project engineers, provides guidance in selection, installation, and operation of a limestone FGD system, covering all phases from inception of the project through design, procurement, operation, and maintenance of th...

  1. Limestone - A Crucial and Versatile Industrial Mineral Commodity

    USGS Publications Warehouse

    Bliss, James D.; Hayes, Timothy S.; Orris, Greta J.

    2008-01-01

    Limestone, as used by the minerals industry, is any rock composed mostly of calcium carbonate (CaCO3). Although limestone is common in many parts of the United States, it is critically absent from some. Limestone is used to produce Portland cement, as aggregate in concrete and asphalt, and in an enormous array of other products, making it a truly versatile commodity. Portland cement is essential to the building industry, but despite our Nation's abundance of limestone, there have been cement shortages in recent years. These have been caused in part by a need to find new areas suitable for quarrying operations. To help manage our Nation's resources of such essential mineral commodities, the U.S. Geological Survey (USGS) provides crucial data and scientific information to industry, policymakers, and the public.

  2. High temperature H{sub 2}S removal using limestones

    SciTech Connect

    Cairns, E.J.; Lynn, S.

    1995-12-31

    This project is exploring the technical and economic feasibility of using limestone in a high determine process for cleaning coal gas prior to combustion in a gas turbine. In one version of the process the coal gas would pass counter-currently through a nearly-isothermal, moving bed of limestone that would serve to remove particulates (by filtration), and hydrogen sulfide (by chemisorption), and ammonia (by catalysis). Alternative process configurations include the use of limestone in a cocurrently moving bed, in a fluidized bed, or in an entrained flow sorption system. The objectives of this research have been to define the range of temperatures at which these goals can best be realized at a given pressure, to determine the effect of the magnesium content of the limestone on sulfidation kinetics and calcium utilization, to use the kinetic data to model the various types of sorption systems, and to develop a process for converting calcium sulfide to elemental sulfur and calcium carbonate.

  3. Micromechanics of inelastic compaction in micritic and allochemical limestones

    NASA Astrophysics Data System (ADS)

    Vajdova, Veronika; Baud, Patrick; Zhu, Wei; Wu, Lily; Wong, Teng-Fong

    2010-05-01

    Previous studies on the transition from brittle faulting to cataclastic flow in carbonate rocks revealed that while compact carbonate rocks display appreciable dilatancy when undergoing cataclastic flow, inelastic compaction was observed in their more porous counterparts. In their compactive behavior the porous carbonate rocks are more akin to porous siliciclastic rocks such as sandstone. Whilst for sandstone the micromechanics of inelastic compaction and cataclastic flow have been studied extensively, little is known about these processes in porous limestone. To fill this gap we performed experiments on Tavel, Indiana and Majella limestones with respective porosities 10-14%, 16-18% and 31%. Tavel limestone is a micritic limestone with a small number of sparry grains embedded in a microcrystalline matrix. Indiana and Majella limestones are allochemical limestones. In Indiana limestone allochems (fossils, ooids and peloids) form some 65% of bulk volume. In Majella limestone the allochems (represented by rudist fragments) have grain size somewhat smaller than that in Indiana limestone and form about half of the bulk volume. Samples of the three rocks were deformed in a conventional triaxial apparatus at confining pressures up to 150 MPa. Samples were loaded to various stages of deformation and microstructures associated with the damage evolution were investigated using optical and scanning electron microscopy. For a reference, a study on an intact sample and a sample deformed under hydrostatic conditions was also performed on each rock. Despite the phenomenological similarities between cataclastic flow in siliciclastic rocks and porous carbonate rocks, we showed that the micromechanics can be very different. In a clastic rock such as sandstone, inelastic compaction derives primarily from grain crushing initiated by stress concentrations at grain contacts that induce cracks to radiate in a conical pattern towards the interior of the impinging grains. In contrast

  4. Limestone and bronze "Mississippi River Crossing" Bridge plaque located at ...

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

    Limestone and bronze "Mississippi River Crossing" Bridge plaque located at North corner of Administration Building site - Huey P. Long Bridge, Administration Building, 5100 Jefferson Highway, Jefferson, Jefferson Parish, LA

  5. VIEW OF LIMESTONE BAS RELIEF "PROMOTE THE GENERAL WELFARE" ON ...

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

    VIEW OF LIMESTONE BAS RELIEF "PROMOTE THE GENERAL WELFARE" ON SOUTH ELEVATION. RESHOOT OF MD-979-13 AFTER REMOVAL OF RAILING. - Greenbelt Community Building, 15 Crescent Road, Greenbelt, Prince George's County, MD

  6. LUTETIAN LIMESTONES IN THE PARIS REGION: PETROGRAPHIC AND COMPOSITIONAL EXAMINATION

    SciTech Connect

    BLANC,A.; HOLMES,L.L.; HARBOTTLE,G.

    1998-06-11

    Stone for building and decorating monuments in the Paris Basin from antiquity to the present came from numerous quarries in the Lutetian limestone formations of the region. To identify specific-stone sources used for masonry and sculptures in these monuments, a team of geologists and archaeologists has investigated 300 quarries and collected 2,300 limestone samples for study in a collaborative effort by geologists and chemists. Petrographic and paleontologic examinations of thin sections enable geologists to distinguish the Tertiary Lutetian limestones from similar stone in Jurassic and Cretaceous strata. The methods of the geologist have been supplemented by those of the chemist whose compositional studies by neutron activation analysis can differentiate among the fine-grained upper Lutetian limestones extracted from specific ancient quarries.

  7. Lutetian limestones in the Paris region: Petrographic and compositional examination

    SciTech Connect

    Blanc, A.; Holmes, L.L.; Harbottle, G.

    1998-12-31

    Stone for building and decorating monuments in the Paris Basin from antiquity to the present came from numerous quarries in the Lutetian limestone formations of the region. To identify specific stone sources used for masonry and sculptures in these monuments, a team of geologists and archaeologists have investigated 300 quarries and collected 2,300 limestone samples for study in a collaborative effort by geologists and chemists. Petrographic and paleontologic examinations of thin sections enable geologists to distinguish the Tertiary Lutetian limestones from similar stone in Jurassic and Cretaceous strata. The methods of the geologist have been supplemented by those of the chemistry whose compositional studies by neutron activation analysis can differentiate among the fine-grained upper Lutetian limestones extracted from specific ancient quarries.

  8. 1. SOUTH FACADE. CONSTRUCTED (ca. 1895) OF INDIGENOUS LIMESTONE AND ...

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

    1. SOUTH FACADE. CONSTRUCTED (ca. 1895) OF INDIGENOUS LIMESTONE AND USED AS LOCKPORTS CENTRAL HIGH SCHOOL FOR MORE THAN SIXTY YEARS. - Lockport Historic District, Central High School, Lockport, Will County, IL

  9. T4-Related Bacteriophage LIMEstone Isolates for the Control of Soft Rot on Potato Caused by ‘Dickeya solani’

    PubMed Central

    Adriaenssens, Evelien M.; Van Vaerenbergh, Johan; Vandenheuvel, Dieter; Dunon, Vincent; Ceyssens, Pieter-Jan; De Proft, Maurice; Kropinski, Andrew M.; Noben, Jean-Paul; Maes, Martine; Lavigne, Rob

    2012-01-01

    The bacterium ‘Dickeya solani’, an aggressive biovar 3 variant of Dickeya dianthicola, causes rotting and blackleg in potato. To control this pathogen using bacteriophage therapy, we isolated and characterized two closely related and specific bacteriophages, vB_DsoM_LIMEstone1 and vB_DsoM_LIMEstone2. The LIMEstone phages have a T4-related genome organization and share DNA similarity with Salmonella phage ViI. Microbiological and molecular characterization of the phages deemed them suitable and promising for use in phage therapy. The phages reduced disease incidence and severity on potato tubers in laboratory assays. In addition, in a field trial of potato tubers, when infected with ‘Dickeya solani’, the experimental phage treatment resulted in a higher yield. These results form the basis for the development of a bacteriophage-based biocontrol of potato plants and tubers as an alternative for the use of antibiotics. PMID:22413005

  10. Field technique of permeability tests in highly fissured limestone strata

    NASA Astrophysics Data System (ADS)

    Al-Salihi, Adnan; Asaad, Abdulah

    2002-05-01

    Résumé.L'étude de dispositifs de dénoyage est nécessaire pour l'amélioration de sites avant la construction de certaines structures. L'étude de dispositifs de dénoyage efficaces exige d'estimer la valeur du coefficient de perméabilité in situ. Les relations disponibles pour estimer le coefficient de perméabilité ont été développées sur la base de mesures et de conditions de terrain limitées, et les prédictions varient de plusieurs ordres de grandeur. C'est pourquoi il est nécessaire de réaliser des mesures de perméabilité sur le terrain et de déterminer la relation qui permet le meilleur ajustement de ces mesures avant l'étude du dispositif de dénoyage pour des conditions locales et géologiques spécifiques. Ce papier présente des mesures de perméabilité sur le terrain dans des niveaux calcaires complexes chaotiques et diagénétisés. Il propose également une analyse comparative de plusieurs relations disponibles dans la littérature destinées à prédire le coefficient de perméabilité in situ. L'analyse est faite en conditions permanentes et non permanentes. Les résultats montrent que la valeur du coefficient de perméabilité dépend du niveau de la nappe, qui est affecté par le régime de marées. On montre que l'équation de l'US Navy donne la meilleure corrélation avec les mesures de terrain. Resumen.El diseño de sistemas de desecado es necesario para mejorar las condiciones de un emplazamiento antes de la construcción de determinadas estructuras. El diseño de un sistema eficiente de desecado requiere de la estimación del valor de la permeabilidad in-situ. Las relaciones disponibles para tal fin han sido desarrolladas bajo condiciones y medidas de campo limitadas; sus predicciones varían en algunos órdenes de magnitud. Por tanto, es necesario tomar medidas de permeabilidad en campo y determinar la relación que reproduce mejor dichas medidas como paso previo al diseño de un sistema de desecado en condiciones geológicas y de emplazamiento específicas. Este artículo presenta medidas de permeabilidad en campo para estratos de calcita caóticos y diagenéticos. También ofrece un análisis comparativo de diversas relaciones disponibles en la bibliografía con el fin de predecir el valor de la permeabilidad in-situ. El análisis se ha hecho tanto en régimen permanente como en estacionario. Los resultados demuestran que la permeabilidad depende del nivel freático, el cual está afectado por las mareas. La ecuación de la Marina estadounidense es la que proporciona una mejor correlación con las medidas de campo.

  11. Transport studies of radon in limestone underlying houses

    SciTech Connect

    Gammage, R.B.; Dudney, C.S.; Wilson, D.L.; Saultz, R.J.

    1990-01-01

    In hilly limestone terrains of the southern Appalachians, subterranean networks of solution cavities and fissures present circulatory systems facilitating convective and advective transport of radon-bearing gas. Evidence suggests that the primary driving forces for transport are aerostatic pressure differentials created by the difference between the underground and the outside air temperatures. Examples are presented of houses experiencing elevated indoor radon levels as a consequence of communicating with such subsurface transportation systems. The location of a house near the upper or lower end of a subterranean-circulatory system seems to produce amplification of indoor radon levels in winter or summer, respectively. The transport mechanism for radon-bearing air in karst and its impact on indoor radon need better understanding, both in regard to evaluating the geographical prevalence of the phenomenon and the induced spatial and temporal effects that are possible. This paper reports field studies made at houses in karst regions at Oak Ridge, Tennessee, and Huntsville, Alabama. A primary radon-transport mechanism is advocated of ascending or descending subsurface columns of air whose flows are largely driven by aerostatic pressure gradients created by the inground-outdoor air temperature differentials. 5 refs., 5 figs., 1 tab.

  12. Acid neutralization within limestone sand reactors receiving coal mine drainage

    USGS Publications Warehouse

    Watten, B.J.; Sibrell, P.L.; Schwartz, M.F.

    2005-01-01

    Pulsed bed treatment of acid mine drainage (AMD) uses CO2 to accelerate limestone dissolution and intermittent fluidization to abrade and carry away metal hydrolysis products. Tests conducted with a prototype of 60 L/min capacity showed effective removal of H+ acidity over the range 196-584 mg/L (CaCO3) while concurrently generating surplus acid neutralization capacity. Effluent alkalinity (mg/L CaCO3) rose with increases in CO2 (DC, mg/L) according to the model Alkalinity = 31.22 + 2.97(DC)0.5, where DC was varied from 11-726 mg/L. Altering fluidization and contraction periods from 30 s/30 s to 10 s/50 s did not influence alkalinity but did increase energy dissipation and bed expansion ratios. Field trials with three AMD sources demonstrated the process is capable of raising AMD pH above that required for hydrolysis and precipitation of Fe3+ and Al3+ but not Fe2+ and Mn2+. Numerical modeling showed CO2 requirements are reduced as AMD acidity increases and when DC is recycled from system effluent. ?? 2005 Elsevier Ltd. All rights reserved.

  13. A procedure to evaluate environmental rehabilitation in limestone quarries.

    PubMed

    Neri, Ana Claudia; Sánchez, Luis Enrique

    2010-11-01

    A procedure to evaluate mine rehabilitation practices during the operational phase was developed and validated. It is based on a comparison of actually observed or documented practices with internationally recommended best practices (BP). A set of 150 BP statements was derived from international guides in order to establish the benchmark. The statements are arranged in six rehabilitation programs under three categories: (1) planning (2) operational and (3) management, corresponding to the adoption of the plan-do-check-act management systems model to mine rehabilitation. The procedure consists of (i) performing technical inspections guided by a series of field forms containing BP statements; (ii) classifying evidences in five categories; and (iii) calculating conformity indexes and levels. For testing and calibration purposes, the procedure was applied to nine limestone quarries and conformity indexes were calculated for the rehabilitation programs in each quarry. Most quarries featured poor planning practices, operational practices reached high conformity levels in 50% of the cases and management practices scored moderate conformity. Despite all quarries being ISO 14001 certified, their management systems pay low attention to issues pertaining to land rehabilitation and biodiversity. The best results were achieved by a quarry whose expansion was recently submitted to the environmental impact assessment process, suggesting that public scrutiny may play a positive role in enhancing rehabilitation practices. Conformity indexes and levels can be used to chart the evolution of rehabilitation practices at regular intervals, to establish corporate goals and for communication with stakeholders. PMID:20630648

  14. Attrition of limestone by impact loading in fluidized beds

    SciTech Connect

    Fabrizio Scala; Fabio Montagnaro; Piero Salatino

    2007-09-15

    The present study addresses limestone attrition and fragmentation associated with impact loading, a process which may occur extensively in various regions of fluidized bed (FB) combustors/gasifiers, primarily the jetting region of the bottom bed, the exit region of the riser, and the cyclone. An experimental protocol for the characterization of the propensity of limestone to undergo attrition/fragmentation by impact loading is reported. The application of the protocol is demonstrated with reference to an Italian limestone whose primary fragmentation and attrition by surface wear have already been characterized in previous studies. The experimental procedure is based on the characterization of the amount and particle size distribution of the debris generated upon the impact of samples of sorbent particles against a target. Experiments were carried out at a range of particle impact velocities between 10 and 45 m/s, consistent with jet velocities corresponding to typical pressure drops across FB gas distributors. The protocol has been applied to either raw or preprocessed limestone samples. In particular, the effect of calcination, sulfation, and calcination/recarbonation cycles on the impact damage suffered by sorbent particles has been assessed. The measurement of particle voidage and pore size distribution by mercury intrusion was also accomplished to correlate fragmentation with the structural properties of the sorbent samples. Fragmentation by impact loading of the limestone is significant. Lime displays the largest propensity to undergo impact damage, followed by the sorbent sulfated to exhaustion, the recarbonated sorbent, and the raw limestone. Fragmentation of the raw limestone and of the sulfated lime follows a pattern typical of the failure of brittle materials. The fragmentation behavior of lime and recarbonated lime better conforms to a disintegration failure mode, with an extensive generation of very fine fragments. 27 refs., 9 figs. 1 tab.

  15. Genesis of Upper Cretaceous marl-limestone bedding, Alabama

    SciTech Connect

    King, D.T. Jr. )

    1990-09-01

    In Alabama, marl-limestone bedding couplets and correlative coeval prograding clastic barrier-shoreline facies occur in the upper 20 m of a high-stand systems tract within the lower Campanian Mooreville-Demopolis depositional sequence. The Mooreville-Demopolis depositional sequence is terminated by a type-2 unconformity biostratigraphically dated at about 80 million years before present. Based on estimates using long-term sedimentation rate, the average periodicity of the marl-limestone couplets is approximately 100,000 years. Taken at face value, the apparent 100,000-year periodicity would suggest a climate-forced (or Milankovitch) origin of the marl-limestone couplets owing to cycles of productivity and dilution. However, significant variations in marl-limestone couplet thickness (ranging from less than 1 m to several meters) both within and between couplets suggests that average periodicity is not a meaningful figure with respect to these couplets. Further, climate-forcing is not favored because coarse clastic material fines upward in the marl beds and the petrography of the beds shows that the primary mode of biochemical deposition switched from pelagic nannofossils (in the marl) to benthic algal calcispheres (in the limestone). In order to adequately explain the petrographic and thickness observations, changing relative sea level is suggested as a viable hypothesis. Tectonic effects related directly to early stages of the Laramide orogeny (about 80 million years before present) may have affected relative sea level as far east as the Gulf Coastal Plain, thus producing the marl-limestone sequences. Marl-limestone sequences may reflect either short-term buildup and relaxation of intraplate stresses or short-term eustatic changes that resulted from slight variations in Farallon spreading rates.

  16. Deformation by pore collapse in the Shu'aiba limestone: An experimental study

    NASA Astrophysics Data System (ADS)

    Al-Ghamdi, Mohammed A.

    The mechanical properties of the Shu'aiba limestone, the main reservoir in Shaybah field, Saudi Arabia, are investigated in this study. Stresses at failure are measured in the laboratory for cylindrical rock samples taken from the Shu'aiba reservoir. A failure envelope is constructed, from the critical stress states at failure, which shows that this reservoir material is mechanically weak. Experiments are carried out in the conventional uniaxial, triaxial, and hydrostatic compression modes to examine the different failure characteristics of this limestone. Two main hypotheses concerning the deformation behavior of the Shu'aiba limestone are tested in this study. The first hypothesis deals with failure by a mechanism known as "pore collapse" in which the rock deforms by reduction of pore space. Pore collapse is found to be the dominant mechanism of deformation in this limestone under triaxial and hydrostatic compression loading. The effect of initial porosity on the critical effective pressure at the onset of pore collapse is examined. A linear relationship exists by which the critical effective pressure at the onset of pore collapse can be predicted from initial porosities in the range 20% to 30%. The second hypothesis states that an increase in temperature should lower the critical effective pressure values that we measure in room temperature experiments for the same material. Conducting experiments at 90°C and 150°C on essentially the same samples used in room temperature experiments shows a considerable drop in critical effective pressures at the onset of pore collapse. Initial porosities are found to be linearly related to the critical effective pressures for the porosity range of 20% to 31%.

  17. Modifying the properties of finely ground limestone by tumbling granulation

    NASA Astrophysics Data System (ADS)

    Macho, Oliver; Eckert, Maroš; Tomášová, Barbora; Peciar, Peter; Ščasný, Martin; Fekete, Roman; Peciar, Marián

    2016-06-01

    Calcium carbonate in the form of finely ground limestone is a material that has found its application in a wide range of industries, in the chemical, rubber, agricultural, and paper industries, is used for desulfurization of boilers and other. In civil engineering, ground limestone is used for the production of building materials, plaster and mortar mixtures, as a filler in concrete mixtures, in road construction, and as an essential component of mastic asphalt. This paper deals with examining the modification of the properties of finely ground limestone by the tumbling agglomeration method. It has been shown that the components of concrete with a round grain have a positive effect on the pumping of concrete in comparison with an elongated grain or the rough surface of crushed stone. The experiments will be carried out on a granulation plate using a variety of granulation liquid. The agglomerates and their properties were compared with untreated finely ground limestone, with a focus on detecting changes in compressibility, density and particle size. The output of this paper is a description and graphical representation of the changes in the properties of ground limestone before and after the agglomeration process.

  18. Estimating porosity and solid dielectric permittivity in the Miami Limestone using high-frequency ground penetrating radar (GPR) measurements at the laboratory scale

    NASA Astrophysics Data System (ADS)

    Mount, Gregory J.; Comas, Xavier

    2014-10-01

    Subsurface water flow in South Florida is largely controlled by the heterogeneous nature of the karst limestone in the Biscayne aquifer and its upper formation, the Miami Limestone. These heterogeneities are amplified by dissolution structures that induce changes in the aquifer's material and physical properties (i.e., porosity and dielectric permittivity) and create preferential flow paths. Understanding such patterns are critical for the development of realistic groundwater flow models, particularly in the Everglades, where restoration of hydrological conditions is intended. In this work, we used noninvasive ground penetrating radar (GPR) to estimate the spatial variability in porosity and the dielectric permittivity of the solid phase of the limestone at centimeter-scale resolution to evaluate the potential for field-based GPR studies. A laboratory setup that included high-frequency GPR measurements under completely unsaturated and saturated conditions was used to estimate changes in electromagnetic wave velocity through Miami Limestone samples. The Complex Refractive Index Model was used to derive estimates of porosity and dielectric permittivity of the solid phase of the limestone. Porosity estimates of the samples ranged between 45.2 and 66.0% and showed good correspondence with estimates of porosity using analytical and digital image techniques. Solid dielectric permittivity values ranged between 7.0 and 13.0. This study shows the ability of GPR to image the spatial variability of porosity and dielectric permittivity in the Miami Limestone and shows potential for expanding these results to larger scales and other karst aquifers.

  19. Characterization of chlorinated solvent contamination in limestone using innovative FLUTe® technologies in combination with other methods in a line of evidence approach.

    PubMed

    Broholm, Mette M; Janniche, Gry S; Mosthaf, Klaus; Fjordbøge, Annika S; Binning, Philip J; Christensen, Anders G; Grosen, Bernt; Jørgensen, Torben H; Keller, Carl; Wealthall, Gary; Kerrn-Jespersen, Henriette

    2016-06-01

    Characterization of dense non-aqueous phase liquid (DNAPL) source zones in limestone aquifers/bedrock is essential to develop accurate site-specific conceptual models and perform risk assessment. Here innovative field methods were combined to improve determination of source zone architecture, hydrogeology and contaminant distribution. The FACT™ is a new technology and it was applied and tested at a contaminated site with a limestone aquifer, together with a number of existing methods including wire-line coring with core subsampling, FLUTe® transmissivity profiling and multilevel water sampling. Laboratory sorption studies were combined with a model of contaminant uptake on the FACT™ for data interpretation. Limestone aquifers were found particularly difficult to sample with existing methods because of core loss, particularly from soft zones in contact with chert beds. Water FLUTe™ multilevel groundwater sampling (under two flow conditions) and FACT™ sampling and analysis combined with FLUTe® transmissivity profiling and modeling were used to provide a line of evidence for the presence of DNAPL, dissolved and sorbed phase contamination in the limestone fractures and matrix. The combined methods were able to provide detailed vertical profiles of DNAPL and contaminant distributions, water flows and fracture zones in the aquifer and are therefore a powerful tool for site investigation. For the limestone aquifer the results indicate horizontal spreading in the upper crushed zone, vertical migration through fractures in the bryozoan limestone down to about 16-18m depth with some horizontal migrations along horizontal fractures within the limestone. Documentation of the DNAPL source in the limestone aquifer was significantly improved by the use of FACT™ and Water FLUTe™ data. PMID:27116640

  20. 3D mapping of water in oolithic limestone at atmospheric and vacuum saturation using X-ray micro-CT differential imaging

    SciTech Connect

    Boone, M.A.; De Kock, T.; Bultreys, T.; De Schutter, G.; Vontobel, P.; Van Hoorebeke, L.; Cnudde, V.

    2014-11-15

    Determining the distribution of fluids in porous sedimentary rocks is of great importance in many geological fields. However, this is not straightforward, especially in the case of complex sedimentary rocks like limestone, where a multidisciplinary approach is often needed to capture its broad, multimodal pore size distribution and complex pore geometries. This paper focuses on the porosity and fluid distribution in two varieties of Massangis limestone, a widely used natural building stone from the southeast part of the Paris basin (France). The Massangis limestone shows locally varying post-depositional alterations, resulting in different types of pore networks and very different water distributions within the limestone. Traditional techniques for characterizing the porosity and pore size distribution are compared with state-of-the-art neutron radiography and X-ray computed microtomography to visualize the distribution of water inside the limestone at different imbibition conditions. X-ray computed microtomography images have the great advantage to non-destructively visualize and analyze the pore space inside of a rock, but are often limited to the larger macropores in the rock due to resolution limitations. In this paper, differential imaging is successfully applied to the X-ray computed microtomography images to obtain sub-resolution information about fluid occupancy and to map the fluid distribution in three dimensions inside the scanned limestone samples. The detailed study of the pore space with differential imaging allows understanding the difference in the water uptake behavior of the limestone, a primary factor that affects the weathering of the rock. - Highlights: • The water distribution in a limestone was visualized in 3D with micro-CT. • Differential imaging allowed to map both macro and microporous zones in the rock. • The 3D study of the pore space clarified the difference in water uptake behavior. • Trapped air is visualized in the moldic

  1. Characterization of chlorinated solvent contamination in limestone using innovative FLUTe® technologies in combination with other methods in a line of evidence approach

    NASA Astrophysics Data System (ADS)

    Broholm, Mette M.; Janniche, Gry S.; Mosthaf, Klaus; Fjordbøge, Annika S.; Binning, Philip J.; Christensen, Anders G.; Grosen, Bernt; Jørgensen, Torben H.; Keller, Carl; Wealthall, Gary; Kerrn-Jespersen, Henriette

    2016-06-01

    Characterization of dense non-aqueous phase liquid (DNAPL) source zones in limestone aquifers/bedrock is essential to develop accurate site-specific conceptual models and perform risk assessment. Here innovative field methods were combined to improve determination of source zone architecture, hydrogeology and contaminant distribution. The FACT™ is a new technology and it was applied and tested at a contaminated site with a limestone aquifer, together with a number of existing methods including wire-line coring with core subsampling, FLUTe® transmissivity profiling and multilevel water sampling. Laboratory sorption studies were combined with a model of contaminant uptake on the FACT™ for data interpretation. Limestone aquifers were found particularly difficult to sample with existing methods because of core loss, particularly from soft zones in contact with chert beds. Water FLUTe™ multilevel groundwater sampling (under two flow conditions) and FACT™ sampling and analysis combined with FLUTe® transmissivity profiling and modeling were used to provide a line of evidence for the presence of DNAPL, dissolved and sorbed phase contamination in the limestone fractures and matrix. The combined methods were able to provide detailed vertical profiles of DNAPL and contaminant distributions, water flows and fracture zones in the aquifer and are therefore a powerful tool for site investigation. For the limestone aquifer the results indicate horizontal spreading in the upper crushed zone, vertical migration through fractures in the bryozoan limestone down to about 16-18 m depth with some horizontal migrations along horizontal fractures within the limestone. Documentation of the DNAPL source in the limestone aquifer was significantly improved by the use of FACT™ and Water FLUTe™ data.

  2. Leaching of clay minerals in a limestone environment

    USGS Publications Warehouse

    Carroll, D.; Starkey, H.C.

    1959-01-01

    Water saturated with CO2 at about 25??C was percolated through mixed beds of limestone or marble fragments and montmorillonite, "illite" and kaolinite in polyethylene tubes for six and fortyfive complete runs. The leachates were analysed for SiO2, A12O3 and Fe2O3, but only SiO2 was found. The minerals lost SiO2 in this order: montmorillonite > kaolinite > "illite". The differential removal of SiO2 during the short period of these experiments suggests a mechanism for the accumulation of bauxite deposits associated with limestones. ?? 1959.

  3. The Ançã limestones, Coimbra, Portugal

    NASA Astrophysics Data System (ADS)

    Quinta-Ferreira, Mário; Gil Catarino, Lídia; Delgado Rodrigues, José

    2016-04-01

    Ançã is located in the Lusitanian Basin (western Meso-Cenozoic sedimentary basin), in the municipality of Cantanhede, close to Coimbra, Portugal. This constitutes the northernmost Dogger (Bajocian) limestone sequence in Portugal. The use of the Ançã limestones is documented since the Roman occupation of the Iberian Peninsula. It was used for the construction of houses, palaces, churches, fine sculptures, carving, paving and for the production of lime. These limestones vary from white and very soft varieties, with very high porosity used for sculpture and carving to white and hard varieties used for masonry and as aggregates and to white to bluish with low porosity and high strength varieties, mainly used for paving. The softer and whiter variety is worldwide known as Ançã Stone (Pedra de Ançã) exhibiting a porosity of 26-29 %. It became famous after being largely used by Coimbra most famous Renaissance sculptors like João de Ruão and Nicolau de Chanterenne. The Pedra de Ançã was used mainly in the region of Coimbra, but also in several other places in Portugal, in Santiago de Compostela, Spain, and Brazil. Some examples of heritage in Coimbra using the Pedra de Ançã are the renaissance portal of the Saint Cross Church, the tombs of the first two Portuguese kings located in this church, the altar of the Saint Cross Church or of the Old Cathedral, or in sculptures at the University of Coimbra. It is quite prone to deteriorate when exposed to atmospheric agents and to soluble salts, mainly due to its high porosity. Deteriorated surfaces needing treatment constitute difficult conservation problems, especially when consolidation and protection treatments are required. The less porous varieties of the Ançã limestones (< 20 % porosity) were mainly used for masonry, paving and production of lime. The royal Palace of Buçaco is a remarkable masonry building constructed at the end of the XIX century with the less porous varieties of the Ançã limestones

  4. Limestone calcination with CO{sub 2} capture (III): characteristics of coal combustion during limestone decomposition

    SciTech Connect

    Yin Wang; Shiying Lin; Yoshizo Suzuki

    2009-05-15

    In this study, the combustion characteristics of coal in CO{sub 2}/O{sub 2} and steam/CO{sub 2}/O{sub 2} atmospheres were investigated during limestone decomposition in a continuously operating fluidized bed reactor for CO{sub 2} capture. The results show that the variations and concentrations of CO, CH{sub 4}, and H{sub 2} in the exhaust gas of the reactor in the steam/CO{sub 2}/O{sub 2} atmosphere were smaller than those in the CO{sub 2}/O{sub 2} atmosphere. Because of steam dilution, the CO{sub 2} concentration in the bed was lower in the steam/CO{sub 2}/O{sub 2} atmosphere than that in the CO{sub 2}/O{sub 2} atmosphere, and the effect of differential pressure variation on limestone decomposition in the fluidized bed was less pronounced in the steam/CO{sub 2}/O{sub 2} atmosphere than that in the CO{sub 2}/O{sub 2} atmosphere. Additionally, N{sub 2}O emission was detected only in the CO{sub 2}/O{sub 2} atmosphere, and the conversion of N to NO in the steam dilution atmosphere was of a smaller magnitude than that observed in the CO{sub 2}/O{sub 2} atmosphere. We also found that the conversion of S to SO{sub 2} in the steam/CO{sub 2}/O{sub 2} atmosphere was lower than that observed in the CO{sub 2}/O{sub 2} atmosphere. The contents of sulfur, SiO{sub 2}, and Al{sub 2}O{sub 3} were much higher in solid samples located in the cyclone than in the overflow holder in both steam/CO{sub 2}/O{sub 2} and CO{sub 2}/O{sub 2} atmospheres. Finally, the hydration and carbonation reactivities of CaO produced in the steam/CO{sub 2}/O{sub 2} atmosphere were better than those produced in the CO{sub 2}/O{sub 2} atmosphere. 13 refs., 14 figs., 3 tabs.

  5. Controls on atrazine leaching through a soil-unsaturated fractured limestone sequence at Brévilles, France

    NASA Astrophysics Data System (ADS)

    Roulier, Stéphanie; Baran, Nicole; Mouvet, Christophe; Stenemo, Fredrik; Morvan, Xavier; Albrechtsen, Hans-Jørgen; Clausen, Liselotte; Jarvis, Nicholas

    2006-03-01

    The objective of this study was to identify the main controls on atrazine leaching through luvisols and calcisols overlying fissured limestone using the dual-permeability model MACRO. The model parameterisation was based on a combination of direct measurements (e.g. hydraulic properties, adsorption and degradation), literature data and calibration against bromide leaching experiments in field plots. A Monte Carlo sensitivity analysis was carried out for a typical application pattern, considering two different depths of unsaturated limestone (15 and 30 m). MACRO calibrations to the field experiments demonstrated the occurrence of strong macropore flow in the luvisol, while transport in the calcisol could be described by the advection-dispersion equation. MACRO simulations of tritium and atrazine leaching qualitatively matched tritium concentration profiles measured in the limestone and atrazine concentrations measured in piezometers and in aquifer discharge via a spring. The sensitivity analysis suggested that the thickness of the limestone, as well as the transport properties and processes occurring in the unsaturated rock (e.g. matrix vs. fissure flow) will have little significant long-term effect on atrazine leaching, mainly because degradation is very slow in the limestone. No mineralization of atrazine was detected in one-year incubations and a mean half-life of 10 years was assumed in the simulations. Instead, processes occurring in the soil exerted the main control on predicted atrazine leaching, especially variations in the degradation rate and the strength of sorption and macropore flow. However, fissure flow in unsaturated rock is expected to exert a much more significant control on groundwater contamination for compounds that degrade more readily in the deep vadose zone.

  6. Correlation between the uniaxial compressive strength and the point load strength index of the Pungchon limestone, Korea

    NASA Astrophysics Data System (ADS)

    Baek, Hwanjo; Kim, Dae-Hoon; Kim, Kyoungman; Choi, Young-Sup; Kang, Sang-Soo; Kang, Jung-Seock

    2013-04-01

    Recently, the use of underground openings for various purposes is expanding, particularly for the crushing and processing facilities in open-pit limestone mines. The suitability of current rockmass classification systems for limestone or dolostone is therefore one of the major concerns for field engineers. Consequently, development of the limestone mine site characterization model(LSCM) is underway through the joint efforts of some research institutes and universities in Korea. An experimental program was undertaken to investigate the correlation between rock properties, for quick adaptation of the rockmass classification system in the field. The uniaxial compressive strength(UCS) of rock material is a key property for rockmass characterization purposes and, is reasonably included in the rock mass rating(RMR). As core samples for the uniaxial compression test are not always easily obtained, indirect tests such as the point load test can be a useful alternative, and various equations between the UCS and the point load strength index(Is50) have been reported in the literature. It is generally proposed that the relationship between the Is50 and the UCS value depends on the rock types and, also on the testing conditions. This study investigates the correlation between the UCS and the Is50 of the Pungchon limestone, with a total of 48 core samples obtained from a underground limestone mine. Both uniaxial compression and point load specimens were prepared from the same segment of NX-sized rock cores. The derived equation obtained from regression analysis of two variables is UCS=26Is50, with the root-mean-square error of 13.18.

  7. The Solnhofen Limestone: A stony heritage of many uses

    NASA Astrophysics Data System (ADS)

    Kölbl-Ebert, Martina; Kramar, Sabina; Cooper, Barry J.

    2016-04-01

    High above the valley of the River Altmühl (Bavaria, Germany), between Solnhofen to the west and Kelheim to the east, numerous quarries give access to thinly plated limestone from the Upper Jurassic, some 150 million years before the present. The main quarry areas lie around the town of Eichstätt and between the villages of Solnhofen, Langenaltheim and Mörnsheim. Here limestone slabs have been quarried for several hundred years, some even in Roman times. Solnhofen Limestone is famous worldwide; not only because it is a beautiful building stone of high quality, but also because of the exceptionally well-preserved fossils it contains -among them the early bird Archaeopteryx. The quarry industry between Solnhofen and Eichstätt has shaped a cultural landscape, with old and new quarries sunk into the plain and numerous spoil heaps rising above it, for the rock is not all economically useful. But many of the spoil heaps and the old quarries are environmentally protected as they provide a habitat for some rare plants and animals. It is not necessary to cut the Solnhofen Limestone with a saw: it is split by hand into thin and even slabs or sheets which are used for flagstones and wall covers, which since centuries are sold world-wide. Locally it also serves as roof tiles for traditional houses. Thick slabs of especially fine quality may be found near Solnhofen and Mörnsheim and are used for lithography printing.

  8. CALCINATION KINETICS AND SURFACE AREA OF DISPERSED LIMESTONE PARTICLES

    EPA Science Inventory

    The paper gives results of measurements of the rates of calcination of two types of limestones, ranging in particle size from 1 to 90 micrometers, and over the temperature range of 516 to 1000 C. A kinetic model, based on the B.E.T. (Brunauer-Emmett-Teller) surface area of the Ca...

  9. The influence of additives on rheological properties of limestone slurry

    NASA Astrophysics Data System (ADS)

    Jaworska, B.; Bartosik, A.

    2014-08-01

    Limestone slurry appears in the lime production process as the result of rinsing the processed material. It consists of particles with diameter smaller than 2 mm and the water that is a carrier of solid fraction. Slurry is directed to the settling tank, where the solid phase sediments and the excess water through the transfer system is recovered for re-circulation. Collected at the bottom of the tank sludge is deposited in a landfill located on the premises. Rheological properties of limestone slurry hinder its further free transport in the pipeline due to generated flow resistance. To improve this state of affairs, chemical treatment of drilling fluid, could be applied, of which the main task is to give the slurry properties suitable for the conditions encountered in hydrotransport. This treatment consists of applying chemical additives to slurry in sufficient quantity. Such additives are called as deflocculants or thinners or dispersants, and are chemical compounds which added to aqueous solution are intended to push away suspended particles from each other. The paper presents the results of research allowing reduction of shear stress in limestone slurry. Results demonstrate rheological properties of limestone slurry with and without the addition of modified substances which causes decrease of slurry viscosity, and as a consequence slurry shear stress for adopted shear rate. Achieving the desired effects increases the degree of dispersion of the solid phase suspended in the carrier liquid and improving its ability to smooth flow with decreased friction.

  10. DEVELOPMENTS IN LIMB (LIMESTONE INJECTION MULTISTAGE BURNER) TECHNOLOGY

    EPA Science Inventory

    The paper describes the most recent results from the Limestone Injection Multistage Burner (LIMB) program, results from the wall-fired demonstration. Tests were conducted to determine the efficacy of commercial calcium hydroxide--Ca(OH)2--supplied by Marblehead Lime Co. and of ca...

  11. GYPSUM CRYSTALLIZATION FOR LIMESTONE FGD (FLUE GAS DESULFURIZATION)

    EPA Science Inventory

    The paper gives results of pilot plant tests using a double draw-off crystallizer as the hold tank to improve the gypsum dewatering properties of a forced oxidation limestone flue gas desulfurization process. A hydroclone was used as the size classification device for solids sepa...

  12. EVALUATION OF GYPSUM CRYSTALLIZATION FOR LIMESTONE FLUE GAS DESULFURIZATION

    EPA Science Inventory

    The paper gives results of pilot plant tests using a double draw-off crystallizer as the hold tank to improve the gypsum dewatering properties of a forced oxidation limestone flue gas desulfurization process. A hydroclone was used as the size classification device for solids sepa...

  13. View of the main entrance with basrelief limestone panel designed ...

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

    View of the main entrance with bas-relief limestone panel designed by C. Paul Jennwein upon which is inscribed "Lege Atque Ordine Omnia Fiunt" (translated as by law and order all is accomplished) - United States Department of Justice, Constitution Avenue between Ninth & Tenth Streets, Northwest, Washington, District of Columbia, DC

  14. LABORATORY STUDY OF LIMESTONE REGENERATION IN DUAL ALKALI SYSTEMS

    EPA Science Inventory

    The report describes a series of open- and closed-loop laboratory bench scale experiments which were carried out to study parameters which affect the reaction of limestone with dual alkali flue gas desulfurization system process liquors. It gives details of several sets of operat...

  15. Detail view to show one of the limestone relief panels ...

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

    Detail view to show one of the limestone relief panels depicting one of the agencies of the Commerce Department, here the Lighthouse Service - United States Department of Commerce, Bounded by Fourteenth, Fifteenth, and E streets and Constitution Avenue, Washington, District of Columbia, DC

  16. Soil respiration patterns and controls in limestone cedar glades

    USGS Publications Warehouse

    Cartwright, Jennifer M.; Hui, Dafeng

    2015-01-01

    Soil depth, SOM, and vegetation cover were important drivers of Rs in limestone cedar glades. Seasonal Rs patterns reflected those for mesic temperate grasslands more than for semi-arid ecosystems, in that Rs primarily tracked temperature for most of the year.

  17. Curved limestone wall at east end of rail yard. Note ...

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

    Curved limestone wall at east end of rail yard. Note cut off valves at base of stump in right foreground, and utility tunnel in middle distance, superindent's house at right, looking NW. - Grand Canyon Village Utilities, Grand Canyon National Park, Grand Canyon Village, Coconino County, AZ

  18. Radial flow permeability testing of an argillaceous limestone.

    PubMed

    Selvadurai, A P S; Jenner, L

    2013-01-01

    Argillaceous Lindsay limestone is the geologic storage formation that will be encountered at the site for the construction of a deep ground repository in Ontario, Canada, for the storage of low to intermediate level nuclear waste. The permeability of the Lindsay limestone is a key parameter that will influence the long-term movement of radionuclides from the repository to the geosphere. This paper describes the use of both steady-state and transient radial flow laboratory tests to determine the permeability of this argillaceous limestone. The interpretation of the tests is carried out using both analytical results and computational models of flow problems that exhibit radial symmetry. The results obtained from this research investigation are compared with the data available in the literature for similar argillaceous limestones mainly found in the Lindsay (Cobourg) formation. The experiments give permeabilities in the range of 1.0 × 10(-22) to 1.68 × 10(-19) m(2) for radial flows that are oriented along bedding planes under zero axial stress. The factors influencing transient pulse tests in particular and the interpretation of the results are discussed. PMID:22489872

  19. COMPUTERIZED SHAWNEE LIME/LIMESTONE SCRUBBING MODEL USERS MANUAL

    EPA Science Inventory

    The manual gives a general description of a computerized model for estimating design and cost of lime or limestone scrubber systems for flue gas desulfurization (FGD). It supplements PB80-123037 by extending the number of scrubber options which can be evaluated. It includes spray...

  20. Influence of Precipitation and Soil on Transport of Fecal Enterococci in Fractured Limestone Aquifers

    PubMed Central

    Celico, Fulvio; Varcamonti, Mario; Guida, Marco; Naclerio, Gino

    2004-01-01

    Limestone aquifers provide the main drinking water resources of southern Italy. The groundwater is often contaminated by fecal bacteria because of the interaction between rocks having high permeability and microbial pollutants introduced into the environment by grazing and/or manure spreading. The microbial contamination of springwater in picnic areas located in high mountains can cause gastrointestinal illness. This study was carried out in order to analyze the interaction between Enterococcus faecalis and the soil of a limestone aquifer and to verify the influence of this interaction on the time dependence of groundwater contamination. E. faecalis was chosen because, in the study area involved, it represents a better indicator than Escherichia coli. The research was carried out through field (springwater monitoring) and laboratory experiments (column tests with intact soil blocks). The transport of bacterial cells through soil samples was analyzed by simulating an infiltration event that was monitored in the study area. Comparison of laboratory results with data acquired in the field showed that discontinuous precipitation caused an intermittent migration of microorganisms through the soil and produced, together with dispersion in the fractured medium (unsaturated and saturated zones), an articulated breakthrough at the spring. The short distances of bacterial transport in the study area produced a significant daily variability of bacterial contamination at the field scale. PMID:15128541

  1. APPLICATION OF LIMB TO PULVERIZED COAL BOILERS - A SYSTEMS ANALYSIS: LIMESTONE FEED AND BOILER SYSTEMS

    EPA Science Inventory

    The report gives results of a systems analysis of the application of Limestone Injection Multistaged Burner (LIMB) technology to pulverized-coal boilers. It evaluates alternative limestone handling, preparation, and injection methods and boiler system impacts associated with LIMB...

  2. Limestone: high-throughput candidate phenotype generation via tensor factorization.

    PubMed

    Ho, Joyce C; Ghosh, Joydeep; Steinhubl, Steve R; Stewart, Walter F; Denny, Joshua C; Malin, Bradley A; Sun, Jimeng

    2014-12-01

    The rapidly increasing availability of electronic health records (EHRs) from multiple heterogeneous sources has spearheaded the adoption of data-driven approaches for improved clinical research, decision making, prognosis, and patient management. Unfortunately, EHR data do not always directly and reliably map to medical concepts that clinical researchers need or use. Some recent studies have focused on EHR-derived phenotyping, which aims at mapping the EHR data to specific medical concepts; however, most of these approaches require labor intensive supervision from experienced clinical professionals. Furthermore, existing approaches are often disease-centric and specialized to the idiosyncrasies of the information technology and/or business practices of a single healthcare organization. In this paper, we propose Limestone, a nonnegative tensor factorization method to derive phenotype candidates with virtually no human supervision. Limestone represents the data source interactions naturally using tensors (a generalization of matrices). In particular, we investigate the interaction of diagnoses and medications among patients. The resulting tensor factors are reported as phenotype candidates that automatically reveal patient clusters on specific diagnoses and medications. Using the proposed method, multiple phenotypes can be identified simultaneously from data. We demonstrate the capability of Limestone on a cohort of 31,815 patient records from the Geisinger Health System. The dataset spans 7years of longitudinal patient records and was initially constructed for a heart failure onset prediction study. Our experiments demonstrate the robustness, stability, and the conciseness of Limestone-derived phenotypes. Our results show that using only 40 phenotypes, we can outperform the original 640 features (169 diagnosis categories and 471 medication types) to achieve an area under the receiver operator characteristic curve (AUC) of 0.720 (95% CI 0.715 to 0.725). Moreover, in

  3. Characterization of limestone reacted with acid-mine drainage in a pulsed limestone bed treatment system at the Friendship Hill National Historical Site, Pennsylvania, USA

    USGS Publications Warehouse

    Hammarstrom, J.M.; Sibrell, P.L.; Belkin, H.E.

    2003-01-01

    Armoring of limestone is a common cause of failure in limestone-based acid-mine drainage (AMD) treatment systems. Limestone is the least expensive material available for acid neutralization, but is not typically recommended for highly acidic, Fe-rich waters due to armoring with Fe(III) oxyhydroxide coatings. A new AMD treatment technology that uses CO2 in a pulsed limestone bed reactor minimizes armor formation and enhances limestone reaction with AMD. Limestone was characterized before and after treatment with constant flow and with the new pulsed limestone bed process using AMD from an inactive coal mine in Pennsylvania (pH = 2.9, Fe = 150 mg/l, acidity = 1000 mg/l CaCO3). In constant flow experiments, limestone is completely armored with reddish-colored ochre within 48 h of contact in a fluidized bed reactor. Effluent pH initially increased from the inflow pH of 2.9 to over 7, but then decreased to 6 during operation. Limestone removed from a pulsed bed pilot plant is a mixture of unarmored, rounded and etched limestone grains and partially armored limestone and refractory mineral grains (dolomite, pyrite). The ???30% of the residual grains in the pulsed flow reactor that are armored have thicker (50- to 100-??m), more aluminous coatings and lack the gypsum rind that develops in the constant flow experiment. Aluminium-rich zones developed in the interior parts of armor rims in both the constant flow and pulsed limestone bed experiments in response to pH changes at the solid/solution interface. ?? 2003 Elsevier Ltd. All rights reserved.

  4. Origin and Age of the Yemi Limestone Breccia, Korea

    NASA Astrophysics Data System (ADS)

    KOH, Hee Jae

    2015-04-01

    The Yemi Limestone Breccia (YLB), which has been argued for its age and depositional origin, occurs sporadically in the upper part of the Cambro-Ordovician Chosun Supergroup (CS) in Korean Peninsula. The YLB is characterized by a carbonate breccia with calcareous and carbonaceous shale matrix. Based on occurrence and composition of breccia and matrix, the YLB can be classified into Type-I and Type-II carbonate breccia. Type-I carbonate breccia comprises dark gray to light gray limestone and lime-mudstone breccia with calcareous matrix and is commonly constrained within the upper part of the CS as a lens-shaped zonal occurrence. The Type-I carbonate breccia results in syn-depositional solution-collapsed brecciation through karstification during intermittent subareal exposure of platform carbonate in Middle Ordovician. Type-II carbonate breccia mainly occurs in the uppermost part of the CS showing an irregular-shaped distribution rather than sheet-like layering parallel to bedding. Type-II carbonate breccia consists of gray to dark gray limestone and lime-mudstone breccia and shale matrix. Matrix is typically purple to reddish and gray to dark gray shale with minor amount of sandstone, and partly carbonaceous indicating organic origin. Most of Type-II carbonate breccia is morphologically classified into chaotic breccia. Matrix and breccia display considerable difference of composition and deformational structures. Breccia preserves various penetrative ductile to brittle deformation structures such as cleavage superimposing bedding, minor fold structure, minor faults crosscutting both dolomite and calcite veins, and fracture zones filled in calcite. However, these deformational structures of breccia do not continuously extended into matrix. Especially Type-II carbonate breccia is well observed in limestone of the lower part of unconformity between CS and clastic rocks of the Jurassic Bansong Group (BS). Fractured and solution zones of brecciated limestone of the CS

  5. Rock Magnetic Cyclostratigraphy of the Mid-Cretaceous Greenhorn Limestone, South-Central Colorado---Influence of Orbitally Induced Climate Variability for Chornostratigraphy

    NASA Astrophysics Data System (ADS)

    Sellers, T.; Geissman, J. W.; Jackson, J.

    2015-12-01

    We are testing the hypothesis that depositional processes of the mid-Cretaceous Greenhorn Limestone were influenced by orbitally-driven climate variations using rock magnetic data. Correlation of the data, including anhysteretic remanent magnetization (ARM), magnetic susceptibility, isothermal remanent magnetization in different DC fields to saturation, and hysteresis properties, from three continuously exposed sections of the full Greenhorn Limestone provides detailed spatial distribution for the depositional processes and magnetic mineral climate encoding. The Greenhorn Limestone includes the Lincoln Limestone, Hartland Shale, and the Bridge Creek Limestone members and consists of calcareous shales and limestones representing near maximum depths in the Cretaceous interior seaway. The sections, each about 30 m thick, extend from the upper Graneros Shale, through the Greenhorn Formation, to the lower Carlisle Shale, with samples collected at a two to five cm interval and are located at Badito, CO; north of Redwing, CO; and at the Global boundary Stratotype Section and Point (GSSP) at Lake Pueblo, CO. Our over 1000 samples were hand crushed to granule size pieces and packed into 7cc IODP boxes. Bulk magnetic susceptibility, anhysteretic remanent magnetization (ARM) intensity at different peak AF levels, and isothermal remanent magnetization (IRM) intensity record variations in magnetic mineral concentration and are proxies to determine orbital scale cycles and precise stratigraphic correlation between sections. ARM intensities in a peak field of 100 mT at both sites range between 1.2 x 10-3 and 1.3 x 10-4 A/m and better define periodic variation within the Greenhorn Limestone displaying differences in ferromagnetic mineral content of detrital origin. Magnetic susceptibility, which ranges from 3.5 x 10-2 to 2.86 x 10-3, also shows periodic variation with a strong correlation among the three sections. Saturation IRM at 100 mT ranges from 3.2 x 10-1 to 1.1x 10-2 A

  6. Performance of portland limestone cements: Cements designed to be more sustainable that include up to 15% limestone addition

    NASA Astrophysics Data System (ADS)

    Barrett, Timothy J.

    In 2009, ASTM and AASHTO permitted the use of up to 5% interground limestone in ordinary portland cement (OPC) as a part of a change to ASTM C150/AASHTO M85. When this work was initiated a new proposal was being discussed that would enable up to 15% interground limestone cement to be considered in ASTM C595/AASHTO M234. This work served to provide rapid feedback to the state department of transportation and concrete industry for use in discussions regarding these specifications. Since the time this work was initiated, ASTM C595/AASHTO M234 was passed (2012c) and PLCs are now able to be specified, however they are still not widely used. The proposal for increasing the volume of limestone that would be permitted to be interground in cement is designed to enable more sustainable construction, which may significantly reduce the CO2 that is embodied in the built infrastructure while also extending the life of cement quarries. Research regarding the performance of cements with interground limestone has been conducted by the cement industry since these cements became widely used in Europe over three decades ago, however this work focuses on North American Portland Limestone Cements (PLCs) which are specifically designed to achieve similar performance as the OPCs they replace.This thesis presents a two-phase study in which the potential for application of cements containing limestone was assessed. The first phase of this study utilized a fundamental approach to determine whether cement with up to 15% of interground or blended limestone can be used as a direct substitute to ordinary portland cement. The second phase of the study assessed the concern of early age shrinkage and cracking potential when using PLCs, as these cements are typically ground finer than their OPC counterparts. For the first phase of the study, three commercially produced PLCs were obtained and compared to three commercially produced OPCs made from the same clinker. An additional cement was tested

  7. Performance of portland limestone cements: Cements designed to be more sustainable that include up to 15% limestone addition

    NASA Astrophysics Data System (ADS)

    Barrett, Timothy J.

    In 2009, ASTM and AASHTO permitted the use of up to 5% interground limestone in ordinary portland cement (OPC) as a part of a change to ASTM C150/AASHTO M85. When this work was initiated a new proposal was being discussed that would enable up to 15% interground limestone cement to be considered in ASTM C595/AASHTO M234. This work served to provide rapid feedback to the state department of transportation and concrete industry for use in discussions regarding these specifications. Since the time this work was initiated, ASTM C595/AASHTO M234 was passed (2012c) and PLCs are now able to be specified, however they are still not widely used. The proposal for increasing the volume of limestone that would be permitted to be interground in cement is designed to enable more sustainable construction, which may significantly reduce the CO2 that is embodied in the built infrastructure while also extending the life of cement quarries. Research regarding the performance of cements with interground limestone has been conducted by the cement industry since these cements became widely used in Europe over three decades ago, however this work focuses on North American Portland Limestone Cements (PLCs) which are specifically designed to achieve similar performance as the OPCs they replace.This thesis presents a two-phase study in which the potential for application of cements containing limestone was assessed. The first phase of this study utilized a fundamental approach to determine whether cement with up to 15% of interground or blended limestone can be used as a direct substitute to ordinary portland cement. The second phase of the study assessed the concern of early age shrinkage and cracking potential when using PLCs, as these cements are typically ground finer than their OPC counterparts. For the first phase of the study, three commercially produced PLCs were obtained and compared to three commercially produced OPCs made from the same clinker. An additional cement was tested

  8. Cement substitution by a combination of metakaolin and limestone

    SciTech Connect

    Antoni, M.; Rossen, J.; Martirena, F.; Scrivener, K.

    2012-12-15

    This study investigates the coupled substitution of metakaolin and limestone in Portland cement (PC). The mechanical properties were studied in mortars and the microstructural development in pastes by X-ray diffraction, thermogravimetry analysis, mercury intrusion porosimetry and isothermal calorimetry. We show that 45% of substitution by 30% of metakaolin and 15% of limestone gives better mechanical properties at 7 and 28 days than the 100% PC reference. Our results show that calcium carbonate reacts with alumina from the metakaolin, forming supplementary AFm phases and stabilizing ettringite. Using simple mass balance calculations derived from thermogravimetry results, we also present the thermodynamic simulation for the system, which agrees fairly well with the experimental observations. It is shown that gypsum addition should be carefully balanced when using calcined clays because it considerably influences the early age strength by controlling the very rapid reaction of aluminates.

  9. Preservation of York Minster historic limestone by hydrophobic surface coatings.

    PubMed

    Walker, Rachel A; Wilson, Karen; Lee, Adam F; Woodford, Julia; Grassian, Vicki H; Baltrusaitis, Jonas; Rubasinghege, Gayan; Cibin, Giannantonio; Dent, Andrew

    2012-01-01

    Magnesian limestone is a key construction component of many historic buildings that is under constant attack from environmental pollutants notably by oxides of sulfur via acid rain, particulate matter sulfate and gaseous SO(2) emissions. Hydrophobic surface coatings offer a potential route to protect existing stonework in cultural heritage sites, however, many available coatings act by blocking the stone microstructure, preventing it from 'breathing' and promoting mould growth and salt efflorescence. Here we report on a conformal surface modification method using self-assembled monolayers of naturally sourced free fatty acids combined with sub-monolayer fluorinated alkyl silanes to generate hydrophobic (HP) and super hydrophobic (SHP) coatings on calcite. We demonstrate the efficacy of these HP and SHP surface coatings for increasing limestone resistance to sulfation, and thus retarding gypsum formation under SO(2)/H(2)O and model acid rain environments. SHP treatment of 19th century stone from York Minster suppresses sulfuric acid permeation. PMID:23198088

  10. Preservation of York Minster historic limestone by hydrophobic surface coatings

    NASA Astrophysics Data System (ADS)

    Walker, Rachel A.; Wilson, Karen; Lee, Adam F.; Woodford, Julia; Grassian, Vicki H.; Baltrusaitis, Jonas; Rubasinghege, Gayan; Cibin, Giannantonio; Dent, Andrew

    2012-11-01

    Magnesian limestone is a key construction component of many historic buildings that is under constant attack from environmental pollutants notably by oxides of sulfur via acid rain, particulate matter sulfate and gaseous SO2 emissions. Hydrophobic surface coatings offer a potential route to protect existing stonework in cultural heritage sites, however, many available coatings act by blocking the stone microstructure, preventing it from `breathing' and promoting mould growth and salt efflorescence. Here we report on a conformal surface modification method using self-assembled monolayers of naturally sourced free fatty acids combined with sub-monolayer fluorinated alkyl silanes to generate hydrophobic (HP) and super hydrophobic (SHP) coatings on calcite. We demonstrate the efficacy of these HP and SHP surface coatings for increasing limestone resistance to sulfation, and thus retarding gypsum formation under SO2/H2O and model acid rain environments. SHP treatment of 19th century stone from York Minster suppresses sulfuric acid permeation.

  11. Preservation of York Minster historic limestone by hydrophobic surface coatings

    PubMed Central

    Walker, Rachel A.; Wilson, Karen; Lee, Adam F.; Woodford, Julia; Grassian, Vicki H.; Baltrusaitis, Jonas; Rubasinghege, Gayan; Cibin, Giannantonio; Dent, Andrew

    2012-01-01

    Magnesian limestone is a key construction component of many historic buildings that is under constant attack from environmental pollutants notably by oxides of sulfur via acid rain, particulate matter sulfate and gaseous SO2 emissions. Hydrophobic surface coatings offer a potential route to protect existing stonework in cultural heritage sites, however, many available coatings act by blocking the stone microstructure, preventing it from ‘breathing' and promoting mould growth and salt efflorescence. Here we report on a conformal surface modification method using self-assembled monolayers of naturally sourced free fatty acids combined with sub-monolayer fluorinated alkyl silanes to generate hydrophobic (HP) and super hydrophobic (SHP) coatings on calcite. We demonstrate the efficacy of these HP and SHP surface coatings for increasing limestone resistance to sulfation, and thus retarding gypsum formation under SO2/H2O and model acid rain environments. SHP treatment of 19th century stone from York Minster suppresses sulfuric acid permeation. PMID:23198088

  12. EFFECT OF AN ACID RAIN ENVIRONMENT ON LIMESTONE SURFACES.

    USGS Publications Warehouse

    Mossotti, Victor G.; Lindsay, James R.; Hochella, Michael F., Jr.

    1987-01-01

    Salem limestone samples were exposed to weathering for 1 y in several urban and one rural environments. Samples exposed in the rural location were chemically indistinguishable from the freshly quarried limestone, whereas all samples collected from urban exposure sites developed gypsum stains on the ground-facing surfaces where the stones were not washed by precipitation. The gas-solid reaction of SO//2 with calcite was selected for detailed consideration. It appears from the model that under arid conditions, the quantity of stain deposited on an unwashed surface is independent of atmospheric SO//2 concentration once the surface has been saturated with gypsum. Under wet conditions, surface sulfation and weight loss are probably dominated by mechanisms involving wet stone. However, if the rain events are frequent and delimited by periods of dryness, the quantity of gypsum produced by a gas-solid reaction mechanism should correlate with both the frequency of rain events and the atmospheric SO//2 level.

  13. Remanent magnetization of a Pliensbachian limestone sequence at Bakonycsernye (Hungary)

    NASA Astrophysics Data System (ADS)

    Márton, E.; Márton, P.; Heller, F.

    1980-06-01

    Remanent coercivity spectra derived from IRM acquisition curves and thermal demagnetization of the IRM indicate that magnetite, haematite and minor amounts of goethite determine the magnetic properties of the Pliensbachian limestones at Bakonycsernye. These limestones have been sampled at approximately 7-cm intervals along a 10-m stratigraphic section which covers the whole Pliensbachian stage (Lower Jurassic) without any recognizable break in sedimentation. The primary natural remanent magnetization (NRM) is carried by detrital particles of magnetite and haematite, but it is seriously overprinted by a normal magnetization which originates from secondary haematite with a wide range of blocking temperatures. This haematite is believed to have formed diagenetically during one of the Mesozoic periods of normal polarity. However, the reversal pattern obtained after NRM thermal demagnetization at temperatures ≥450°C is thought to be characteristic of the Pliensbachian stage.

  14. Full-scale results for TAM limestone injection

    SciTech Connect

    Baer, S.

    1996-12-31

    Information is outlined on the use of thermally active marble (TAM) sorbents in boilers. Data are presented on: the comparison of TAM to limestone; NOVACON process development history; CFB test history; CFB pilot scale test; full-scale CFB trial; August, 1996 CFB demonstration; Foster Wheeler Mount Carmel sorbent feed rate comparison and Ca:S comparison; unburned carbon is ash; and advantages and savings in CFB boilers.

  15. Thickness of the Tertiary limestone aquifer system, southeastern United States

    USGS Publications Warehouse

    Miller, James A.

    1982-01-01

    The Tertiary limestone aquifer system of the southeastern United States is a thick sequence of carbonate rocks that vary in age and that are hydraulically connected in varying degrees. A map is presented that shows the thickness of the aquifer system. Several types of geologic structures have had an effect on the thickness of the system. The magnitude of this effect varies with the type and size of the structure. (USGS)

  16. Dolomitization of Quaternary reef limestones, Aitutaki, Cook Islands

    USGS Publications Warehouse

    Hein, J.R.; Gray, S.C.; Richmond, B.M.; White, L.D.

    1992-01-01

    The primary reef framework is considered to have been deposited during several highstands of sea level. Following partial to local recrystallization of the limestone, a signle episode of dolomitization occurred. Both tidal and thermal pumping drove large quantities of seawater through the porous rocks and perhaps maintained a wide mixing zone. However, the isotopic, geochemical and petrographic data do not clearly indicate the extent of seawater mixing. -from Authors

  17. National conference on agricultural limestone. Bulletin Y-166

    SciTech Connect

    Not Available

    1981-09-01

    Twenty-three papers were presented on various facets of the agricultural limestone (aglime) industry - from the quarry to the farmers. They are organized under the following section headings: introduction and overview; status of current use and need; agronomic situation; a total approach to marketing aglime, producing aglime; and a look to the future. Panel discussions were held on the topics, responding to the seasonal nature of aglime use and regional reviews of the status and opportunities for aglime use. (JGB)

  18. Modified dry limestone process for control of sulfur dioxide emissions

    DOEpatents

    Shale, Correll C.; Cross, William G.

    1976-08-24

    A method and apparatus for removing sulfur oxides from flue gas comprise cooling and conditioning the hot flue gas to increase the degree of water vapor saturation prior to passage through a bed of substantially dry carbonate chips or lumps, e.g., crushed limestone. The reaction products form as a thick layer of sulfites and sulfates on the surface of the chips which is easily removed by agitation to restore the reactive surface of the chips.

  19. Self-organized geodynamics of karst limestone landscapes and coupled terra rossa/bauxite formation

    NASA Astrophysics Data System (ADS)

    Merino, E.; Wang, Y.; Banerjee, A.

    2012-12-01

    Why do flat limestones overlain by terra rossa or bauxite systematically adopt so-called karst geomorphology, which consists of sets of roughly regularly spaced wormholes, or funnels, or sinkholes, or tower karst? The idea that the funnels and sinkholes are located at the intersections of preexisting sets of subvertical fractures is untenable. New field and petrographic evidence (Merino & Banerjee, J. Geology, 2008) revealed that, rather than 'residual' or 'detrital' (the only options that have been on the table for decades), the terra rossa/bauxite clays and Al- and Fe-oxyhydroxides grow authigenically at the base of the terra rossa, replacing the underlying limestone at a generally downward-moving reaction front several centimeters thick. The clay-for-limestone replacement, which preserves solid volume (because it takes place by clay-growth-driven pressure solution of calcite), releases H+ ions. These dissolve more calcite, generating considerable leached porosity in a narrow zone that travels with the replacement front. We proposed (Merino & Banerjee, J. Geology, 2008) that the moving leached-porosity maximum created at the front could trigger the reactive-infiltration instability (Chadam et al, IMA J. Appl. Math., 1986), causing the replacement-and-leaching reaction front to become regularly fingered, with the fingers jumping in scale to funnels, these to sinks, and these, when deep enough and merged together laterally, to tower karst. This new geodynamics would account both for the world-wide association of terra rossa and bauxite with karst limestones, and for the stunning, self-organized geomorphology of karst itself. We are testing these ideas through linear stability analysis of a simplified reaction-transport system of equations and through numerical solution of the full non-linear system of reaction-transport equations applicable, including aqueous speciation. Preliminary calculations (Banerjee & Merino, J. Geology, 2011) suggest that the replacement

  20. Mechanism of CaO sulfation in boiler limestone injection

    SciTech Connect

    Stouffer, M.R.; Yoon, H.; Burke, F.P.

    1987-01-01

    Pilot and industrial-scale tests of boiler limestone injection (BLI) have demonstrated flue gas SO/sub 2/ reductions of around 50% at sorbent utilization efficiencies of 15-20%. The objective of the laboratory research program described in this paper was to improve BLI sorbent utilization through an understanding of the limestone calcination and CaO sulfation reaction mechanisms. This paper describes the laboratory sulfation studies. The laboratory work used a differential reactor operated at 700-1000/degree/C and lab-produced calcines from limestones, dolomites, and hydrated limes, having particle sizes in a range applicable to BLI. The lab work determined the intrinsic sulfation reaction rate and rate-controlling steps over this temperature range. The intrinsic rate increased with the square of calcine surface area and was rate controlling only at temperatures below 800/degree/C. At the higher temperatures more applicable to BLI, the sulfation rate was limited by pore diffusion of SO/sub 2/ and pore plugging by the sulfate product. Therefore, the reaction rate and the saturated sorbent efficiency depended strongly on particle size and calcine pore structure. The lab data indicate that an optimum calcine pore structure can be obtained by appropriately evaluating sorbents, controlling calcination conditions and incorporating alkali additives in the sorbent.

  1. Development of gypsum alteration on marble and limestone

    USGS Publications Warehouse

    McGee, E.S.

    1996-01-01

    Blackened alteration crusts of gypsum plus particulates that form on sheltered areas on marble and limestone buildings pose a challenge for rehabilitation and cleaning. Fresh marble and limestone samples exposed at monitored exposure sites present conditions of simple geometry and well-documented exposures but have short exposure histories (one to five years). The gypsum alteration crusts that develop on these samples provide insight into the early stages and rate of alteration crust formation. Alteration crusts from buildings give a longer, but less well known exposure history and present much more complex surfaces for gypsum accumulation. Integrated observations and measurements of alteration crusts from exposure samples and from buildings identify four factors that are important in the formation and development of alteration crusts on marble and limestone: (1) pollution levels, (2) exposure to rain or washing, (3) geometry of exposure of the stone surface, and (4) permeability of the stone. The combination of these factors contributes to both the distribution and the physical characteristics of the gypsum crusts which may affect cleaning decisions.

  2. Stratigraphy of the Upper Pleistocene Miami Limestone of Florida

    SciTech Connect

    Johnson, R.A.

    1993-03-01

    The upper Pleistocene Miami Limestone is probably the most stratigraphically-complex formation in the Cenozoic of Florida. The Miami overlies and vertically/laterally grades into the upper Pleistocene Ft. Thompson Formation to the west in southeast Palm Beach County (west of I-95); to the west in Broward County (west of the Turnpike); and to the north in south Broward County (along U.S. 27). The Miami overlies and very locally vertically grades into the Ft. Thompson in all of Dade County. The Miami overlies and vertically/laterally grades into the upper Pleistocene Anastasia Formation to the north and east in southeast Palm Beach County (east of I-95), and to the northeast in east Broward County (east of the Turnpike). The Miami laterally grades into the upper Pleistocene Key Largo Limestone to the southeast in extreme southeast Dade County, and overlies and locally vertically grades into the Key Largo in the Lower Keys, south Monroe County. The Miami unconformably overlies the Pliocene Tamiami Formation and pinches out to the west in northeast mainland Monroe and southeast Collier Counties, and also pinches out to the north in east-central Palm Beach County. In all areas, the Miami Limestone is either overlain unconformably by very discontinuous undifferentiated surficial sediments or forms land surface.

  3. Thermo-poroelastic response of an argillaceous limestone

    NASA Astrophysics Data System (ADS)

    Selvadurai, Patrick; Najari, Meysam

    2016-04-01

    Argillaceous limestones are now being considered by many countries that intend to develop deep geologic storage facilities for siting both high-level and intermediate- to low-level nuclear fuel wastes. In deep geologic settings for high level nuclear wastes, the heating due to radioactive decay is transmitted through an engineered barrier, which consists of the waste container and an engineered geologic barrier, which consists of an encapsulating compacted bentonite. The heat transfer process therefore leads to heating of the rock mass where the temperature of the rock is substantially lower than the surface temperature of the waste container. This permits the use of mathematical theories of poroelastic media where phase transformations, involving conversion of water to a vapour form are absent. While the thermo-poroelastic responses of geologic media such as granite and porous tuff have been investigated in the literature, the investigation of thermo-poroelastic responses of argillaceous limestones is relatively new. Argillaceous limestones are considered to be suitable candidates for siting deep geologic repositories owing to the ability to accommodate stress states with generation of severe defects that can influence their transmissivity characteristics. Also the clay fraction in such rocks can contribute to long term healing type phenomena, which is a considerable advantage. This research presents the results of a laboratory investigation and computational modelling of the same that examines the applicability of the theory of thermo-poroelasticity, which extend Biot's classical theory of poroelasticity to include uncoupled heat conduction. The experimental configuration involves the boundary heating of a cylinder of the Cobourg Limestone from southern Ontario, Canada. The cylinder measuring 150 mm in diameter and 278 mm in length contains an axisymmetric fluid-filled cylindrical cavity measuring 26 mm in diameter and 139 mm in length. Thermo-poroelastic effects

  4. Structural characterization of a karstified limestone formation using GPR

    NASA Astrophysics Data System (ADS)

    Rousset, D.; Sénéchal, G.; Gaffet, S.

    2009-12-01

    The Laboratoire Souterrain à Bas Bruit (LSBB) at Rustrel - Pays d'Apt, France, is an Inter-disciplinary Underground Science and Technology Laboratory buried in a karstified limestone formation. A multidisciplinary program focused on water circulation monitoring is presently performed inside the tunnels. This program comprises the investigation of faults, fractures, karstification and stratigraphy ofthe limestone massif using GPR. We present the main results obtained from these data. The tunnel has been dug in lower cretaceous limestone which is characterized by a low clay content, high electrical resistivity which results in generally very low attenuation of electro-magnetic waves. 90% of the tunnels floor are made of concrete whereas other are made of bare limestone. This experimental site offers a unique opportunity of perfoming measurements within an unweathered limestone massif. The whole 3km long tunnel has been investigated using single offset shielded 250 MHz antennas in May 2009. Processing includes : DC and very low frequency removal, amplitude compensation preserving lateral variations, migration and time to depth conversion. When necessary predictive deconvolution has been applied to remove ringing effects. These data sets are characterized by good signal to noise ratio and a signal penetration down to 18 meters. These data allow us to accurately map the stratigraphy of the surrounding rocks across the concrete walls of the tunnel. Some 20 m deep vertical wells have been drilled inside the tunnel through observed reflectors. This is a strong validation of the GPR images. The estimated resolution is centimetric to decimetric and matches the required geologic accuracy. The GPR data set allows to extend previous geological results in depth, particularly in the concrete coated parts of the tunnel where conventional geological surveying is impossible. Thanks to the processing which preserves lateral amplitude variations, GPR sections exhibit prominent

  5. The role of saline solution properties on porous limestone salt weathering by magnesium and sodium sulfates

    NASA Astrophysics Data System (ADS)

    Ruiz-Agudo, E.; Mees, F.; Jacobs, P.; Rodriguez-Navarro, C.

    2007-03-01

    Saline solution properties, viscosity in particular, are shown to be critical in salt weathering associated with sodium and magnesium sulfate crystallization in porous limestone. The crystallization of sodium and magnesium sulfate within a porous limestone has been studied at a macro- and microscale using different techniques, including mercury intrusion porosimetry, environmental scanning microscopy and X-ray computed tomography. Such analysis enabled the visualization of the crystallization process in situ, and at high magnification, yielding critical information as to where and how salts crystallize. Sodium sulfate decahydrate (mirabilite) tends to crystallize in large pores as euhedral micron-sized crystals formed at low supersaturation near to the surface of the stone. In contrast, magnesium sulfate heptahydrate (epsomite) tends to precipitate as anhedral wax-like aggregates formed at high supersaturation and distributed homogeneously throughout the stone pore system filling large and small pores. While the former crystallization behavior resulted in scale formation, the latter led to crack development throughout the bulk stone. Ultimately, the contrasting weathering behavior of the two sulfates is explained by considering differences in flow dynamics of solutions within porous materials that are mainly connected with the higher viscosity of magnesium sulfate saturated solution (7.27 cP) when compared with sodium sulfate saturated solution (1.83 cP). On the basis of such results, new ways to tackle salt weathering, particularly in the field of cultural heritage conservation, are discussed.

  6. Chemical alteration of limestone and marble samples exposed to acid rain and weathering in the eastern United States, 1984--1988

    SciTech Connect

    Reimann, K.J.

    1991-06-01

    In a long-term program that began in 1984, limestone and marble briquettes have been exposed to both anthropogenic acid deposition and natural weathering of four field sites in the eastern United States. Similar tests began at an Ohio site in 1986. Effects of exposure on the briquettes and other materials at the sites are evaluated periodically by several federal agencies cooperating in the National Acid Precipitation Assessment Program (NAPAP). A primary contribution of Argonne National Laboratory to the NAPAP has been chemical analysis to determine changes in the samples caused by exposure to the environment. Wet chemical analysis was used to detect sulfates, nitrates, fluorides, chlorides, and a series of metal cations in sequential layers of stone removed from the briquettes after field exposure. Results from the first four years of the program indicate that rinsing by rain keeps skyward-facing stone relatively clean of reaction products, especially sulfate, the most abundant product. On groundward-facing samples, sulfate concentrations increased linearly with exposure time, and values were proportional to atmospheric SO{sub 2} concentrations at the site. Sulfate concentrations in groundward samples were much higher in limestone than in marble, because of the greater porosity of the limestone. A steep sulfate gradient was seen in both sample types from the surface to the interior. On skyward surfaces, material losses per rain event due to complete dissolution of accumulated sulfates were approximately equal to concentrations measured in runoff. Preexposed limestone samples had sulfate accumulations deep in their interiors, while fresh, unexposed limestone did not. No substantial changes in cation accumulations wee detected in either limestone or marble.

  7. Attachment and Detachment Behaviour of Adenovirus and Surrogates in Fine Granular Limestone Aquifer Material

    NASA Astrophysics Data System (ADS)

    Stevenson, Margaret; Blaschke, Alfred Paul; Kirschner, Alexander; Farnleitner, Andreas; Sommer, Regina; Sidhu, Jatinder

    2015-04-01

    Comparison of transport of virus surrogates to the pathogenic virus is necessary to understand the differences between the virus and surrogate. Since experiments using pathogenic viruses cannot be done in the field, laboratory tests using flow through soil columns are used. Adenovirus, nanoparticles, PRD1 and MS2 bacteriophages were tested in fine granular limestone aquifer material taken from a borehole at a managed aquifer recharge site in Adelaide, Southern Australia. Results show that PRD1 is the most appropriate surrogate for adenovirus in an aquifer dominated by calcite material, although PRD1 did not mimic the detachment behaviour of adenovirus successfully under high pH conditions. It was also found that the charge of the colloid is not a dominant removal mechanism in this system. Implications from this study could influence how field tests using bacteriophages and nanoparticles are interpreted.

  8. Facies development and porosity relationships in Dundee Limestone of Gladwin County, Michigan

    SciTech Connect

    Montgomery, E.L.

    1986-08-01

    The Devonian of the Michigan basin was a time of transgressive seas and extensive carbonate deposition, including coral and stromatoporoid buildups. Deposited during the Middle Devonian, the Dundee Limestone represents deposition in subtidal, intertidal, and restricted environments. The Buckeye oil field, located in south-central Gladwin County, is a combined stratigraphic and structural carbonate trap that produces from a series of intertonguing patch reefs, fringing sand bodies, and intertidal island fenestral zones. The major reef-building organisms include stromatoporoids, corals, calcareous algae, brachiopods, and crinoids, with the stromatoporoids providing the major framework. The patch-reef facies is composed of massive stromatoporoid boundstones that contain primary intraparticle porosity. The fringing grainstone sands are composed of coarse crinoid and brachiopod skeletal debris that have interparticle porosity. The intertidal island zone found in the North Buckeye field is represented by a pelletal packstone that has abundant fenestral porosity.

  9. Lower prices wreak havoc on Alaska oil patch

    SciTech Connect

    Bradner, T.

    1986-07-01

    The decline in oil prices has slowed drilling activity at Prudhoe Bay even while offshore field construction work continues. By winter, the layoff of about 14 drilling rigs will mean unemployment for an estimated 1400 workers at one field. New construction projects include a plant to process natural gas liquids for the trans-Alaska pipeline and a miscible injection project. The potential of the limestone reservoir at the Lisburne field will remain an unknown until information is available on the effects of gas injection and waterflooding. The author describes work in progress at Lisburne, Kuparuk River, Endicott, and Milne Point Fields to illustrate the bleak prospects for North Slope development. Higher prices in the future, however, will leave the US with large reserves to develop if the companies can weather the lean years. 1 figure.

  10. Effect of acidity and elevated PCO2 on acid. Neutralization within pulsed limestone bed reactors receiving coal mine drainage

    USGS Publications Warehouse

    Watten, B.J.; Sibrell, P.L.; Schwartz, M.F.

    2004-01-01

    Limestone has potential for reducing reagent costs and sludge volume associated with the treatment of acid mine drainage (AMD), but its use has been restricted by slow dissolution rates and sensitivity to scale forming reactions that retard transport of H+ at the solid-liquid interface. We evaluated a pulsed limestone bed (PLB) remediation process designed to circumvent these problems through use of intermittently fluidized beds of granular limestone and elevated carbon dioxide pressure. PLB limestone dissolution (LD, mg/L), and effluent alkalinity (Alk, mg/L) were correlated with reactor pressure (PCO2, kPa), influent acidity (Acy, mg/L) and reactor bed height (H, cm) using a prototype capable of processing 10 L/min. The PLB process effectively neutralized sulfuric acid acidity over the range of 6-1033 mg/L (as CaCO3) while generating high concentrations of alkalinity (36-1086 mg/L) despite a hydraulic residence time of just 4.2-5.0 min. Alk and LD (mg/L CaCO3) rose with increases in influent acidity and PCO2 (p < 0.001) according to the models: Alk = 58 + 38.4 (PCO2)0.5 + 0.080 (Acy) - 0.0059(PCO2) 0.5 (Acy); LD = 55 + 38.3 (PCO2)0.5 + 1.08 (Acy) - 0.0059 (PCO2)0.5 (Acy). Alkalinity decreased at an increasing rate with reductions in H over the range of 27.3-77.5 cm (p < 0.001). Carbon dioxide requirements (Q(avg)CO2, L/min) increased with PCO2 (p < 0.001) following the model Q(avg)CO2 = 0.858 (PCO2)0.620, resulting in a greater degree of pH buffering (depression) within the reactors, a rise in limestone solubility and an increase in limestone dissolution related to carbonic acid attack. Corresponding elevated concentrations of effluent alkalinity allow for sidestream treatment with blending. Numerical modeling demonstrated that carbon dioxide requirements are reduced as influent acidity rises and when carbon dioxide is recovered from system effluent and recycled. Field trials demonstrated that the PLB process is capable of raising the pH of AMD above that

  11. Middle Triassic shallow-water limestones from the Upper Muschelkalk of eastern France: the origin and depositional environment of some early Mesozoic fine-grained limestones

    NASA Astrophysics Data System (ADS)

    Duringer, Philippe; Vecsei, Adam

    1998-10-01

    We have analyzed the sedimentary structures, depositional geometries, and petrography of a Middle Triassic fine-grained limestone succession from the Upper Muschelkalk in the intracratonic Germanic Basin. The limestones occur in a unit, several metres thick, that extends over an area of at least 2500 km 2 in eastern France. The geometry of specific wave ripples and small channels filled by lateral-accretion bedded limestones, and the cyclic sedimentation of the Upper Muschelkalk in eastern France indicate deposition on a very shallow subtidal shelf, commonly under the influence of relatively strong currents. The limestones mostly consist of microspar with a few skeletal grains. The formation of current ripples in the fine-grained limestones appear to be incompatible with an originally muddy grain size. The major part of the microsparite may thus have originated from the recrystallization of silt-size carbonate grains, e.g., calcispheres or peloids.

  12. Inelastic compaction of a quartz-rich limestone (Invited)

    NASA Astrophysics Data System (ADS)

    Baud, P.; Schubnel, A.; rolland, A.; Heap, M. J.

    2013-12-01

    The analysis of deformation and failure in many sedimentary settings hinges upon a fundamental understanding of inelastic behavior and failure mode of porous carbonate rocks. Previous studies on porous carbonate focused primarily on relatively pure limestone (composed in majority of calcite). Inelastic compaction in these carbonates was reported to be associated to cataclastic pore collapse and in most cases homogeneous cataclastic flow. Recent experimental results however revealed the development of compaction localization in the more porous end-members. The analysis of strain localization and complex failure modes in limestone has proved to be significantly more challenging than in sandstone because acoustic emissions (AE) cannot usually be used to guide systematic microstructural analysis. Recent studies have therefore relied on X-ray Computed Tomography, a technique that can to date only be used in situ in relatively limited systems. In this study we investigated the development of inelastic damage in a quartz-rich limestone with two main objectives: (1) quantify the impact of a secondary mineral such as quartz on the strength and strain localization in porous carbonate, (2) try to follow the development of inelastic damage using AE in such a quartz-rich rock. Saint-Maximin limestone of 37% porosity and composed of 80% calcite and 20% quartz was selected for this study. Two series of conventional triaxial experiments were performed in parallel at room temperature, constant strain rate in both nominally dry and wet conditions at confining pressures between 3 and 50 MPa. Wet experiments were carried out with water in drained conditions at 10 MPa of pore pressure. The first series of experiments were performed at IPG Strasbourg on relatively small samples. The failure modes and spatial distribution of damage were studied systematically in these samples. The second series of experiments were performed on larger samples at ENS Paris. Acoustic emission activity was

  13. Coincident exposure/drowning surfaces within Middle Cambrian Grand Cycles, East Tennessee: A model for abrupt limestone/shale transitions/sequence boundaries

    SciTech Connect

    Rankey, E.C.; Srinivasan, K.; Walker, K.R. . Dept. of Geological Science)

    1992-01-01

    Vertical transition from limestones to shales mark the boundaries of Cambrian Grand Cycles in Passive Margin Sequences over a wide geographic area. Field, petrographic, and geochemical evidence from near platform-edge mudstones and boundstones and platform-edge boundstones at the tops of the Craig Limestone and Maryville Limestone of the Conasauga Group in the southern Appalachians indicate platform death by subaerial exposure, followed by platform drowning and subsequent onlap of siliciclastic deposits. Physical evidence, in the form of scalloped truncation surfaces, as well as petrographic evidence consisting of wholesale and fabric-selective dissolution, internal brecciation, and vadose silt deposition indicate meteoric diagenesis following exposure. Depleted stable oxygen isotope compositions of inter- and intragranular blocky clear calcite spar of the Maryville Limestone have a mean delta O-18 composition of [minus]9.3[per thousand] (PDB) and a mean delta C-13 composition of +0.01[per thousand](PDB). Preliminary data from the Craig Limestone indicate similar delta C-13 values, but more depleted. Thus, the authors propose a common origin for the limestone-shale transitions at the top of these two units. Subaerial exposure during a sea-level fall at the top of these carbonate units terminated carbonate deposition. During exposure, a meteoric-water lens developed in the platform sediments leading to early diagenetic alteration. A rapid relative sea-level rise then drowned the platform, followed by subsidence and deepening during the lag-time before the onset of carbonate deposition. The deepening suppressed carbonate production and allowed fine siliciclastics characteristic of the adjacent basin to onlap the drowned platform.

  14. Penetration into limestone targets with ogive-nose steel projectiles

    SciTech Connect

    Frew, D.J.; Green, M.L.; Forrestal, M.J.; Hanchak, S.J.

    1996-12-01

    We conducted depth of penetration experiments into limestone targets with 3.0 caliber-radius-head, 4340 Rc 45 steel projectiles. Powder guns launched two projectiles with length-to-diameter ratios of ten to striking velocities between 0.4 and 1.5 km/s. Projectiles had diameters and masses of 12.7 mm, 0. 117 kg and 25.4 mm, 0.610 kg. Based on data sets with these two projectile scales, we proposed an empirical penetration equation that described the target by its density and an empirical strength constant determined from penetration depth versus striking velocity data.

  15. Elucidation of denitrification mechanism in karstic Ryukyu limestone aquifer

    NASA Astrophysics Data System (ADS)

    Hijikawa, K.

    2014-12-01

    Nitrate (NO3-) concentrations in public water supplies have risen above acceptable levels in many areas of the world including Japan, largely as a result of contamination by human and animal waste and overuse of fertilizers. A previous study has characterized nitrate concentrations in groundwater in this area is a higher than the upper value (44mgL-1) of environmental quality criteria on one hands. On the other hand, there exists points where the concentration of nitric acid is not detected, which suggests the possibility of denitrification. During early 2000, a new analytical procedure for nitrate isotopic measurement, termed the "denitrifier method", was established. With the development of the nitrate isotope tracer method, much research has been reported detailing sources of groundwater nitrate and denitrification mechanisms. This study presents a pilot case study (in the southern part of Okinawa Main Island, Japan, where Ryukyu limestone is extensively distributed) using the combined stable isotope ratios of major elements (C, N and S) as net recorders of the biogeochemical reactions with the aim of elucidation of denitrification mechanism in Ryukyu limestone aquifer. As a result, significant decreases in nitrate concentrations due to denitrification were observed in groundwater at some locations, which induced increases in isotope ratios up to 59.7‰ for δ15NNO3. These points of groundwater were located above the cutoff wall of the underground dam and near the fault. It is considered that the residence time of the groundwater is longer than the other points at these denitrification points, and that reduction condition tends to be formed in the groundwater. However, the rapid rise of the groundwater level due to rainfall is likely to occur in the Ryukyu limestone aquifer, where the ground water was found to have changed dynamically from the reduction condition to the oxidation condition which a denitrification (has not occured)does not occur. Moreover, the

  16. Water transport in limestone by X-ray CAT scanning

    USGS Publications Warehouse

    Mossoti, Victor G.; Castanier, Louis M.

    1989-01-01

    The transport of water through the interior of Salem limestone test briquettes can be dynamically monitored by computer aided tomography (commonly called CAT scanning in medical diagnostics). Most significantly, unless evaporation from a particular face of the briquette is accelerated by forced air flow (wind simulation), the distribution of water in the interior of the briquette remains more or less uniform throughout the complete drying cycle. Moreover, simulated solar illumination of the test briquette does not result in the production of significant water gradients in the briquette under steady-state drying conditions.

  17. Southern hemisphere origin of the Cretaceous Laytonville Limestone of California

    USGS Publications Warehouse

    Tarduno, J.A.; McWilliams, M.; Sliter, W.V.; Cook, H.E.; Blake, M.C., Jr.; Premoli-Silva, I.

    1986-01-01

    New paleomagnetic, paleontologic, and stratigraphic data from outcrops of the Laytonville Limestone (101 to 88 million years old) support a Southern Hemisphere orgin. A paleomagnetic megaconglomerate test is statistically significant and suggests magnetization at 14?? ?? 5?? south, predating Late Cretaceous to Eocene (70 to 50 million years ago) accretion. Rapid Kula plate movement or the existence and demise of a now vanished oceanic plate (or both) are required to accommodate the greater than 50?? of poleward displacement implied by the paleomagnetic data. This rapid motion brings into question the validity of a "speed limit" for absolute plate velocity based on present-day plate motions.

  18. Effect of water treatment chemicals on limestone/sulfur dioxide reaction in flue gas desulfurization systems

    SciTech Connect

    Dille, E.R.; Gaikwad, R.P.

    1994-12-31

    A simple laboratory test has been developed which simulates the reaction between limestone/water and sulfur dioxide in flue gas desulfurization systems. By adding various chemicals, in differing concentrations, to the limestone/water mixture, the quantitative impact on the sulfur dioxide/limestone reaction can be qualified and quantified. This paper will present the impact of several water treatment chemicals on the reaction of limestone and sulfur dioxide. An attempt has been made to predict the effect through mathematical correlations. All of the additive chemicals tend to decrease the rate of dissolution of limestone to various degrees. Some of the chemicals retard crystal growth thus adversely impacting solids separation in the thickener. The physical appearance of the crystal growth retarded limestone absorber slurry approaches a colloidal suspension.

  19. Simultaneous removal of heavy metals from aqueous solution by natural limestones

    NASA Astrophysics Data System (ADS)

    Sdiri, Ali; Higashi, Teruo

    2013-03-01

    Two natural limestone samples, collected from the Campanian-Maastrichtian limestones, Tunisia, were used as adsorbents for the removal of toxic metals in aqueous systems. The results indicated that high removal efficiency could be achieved by the present natural limestones. Among the metal ions studied, Pb2+ was the most preferably removed cation because of its high affinity to calcite surface. In binary system, the presence of Cu2+ effectively depressed the sorption of Cd2+ and Zn2+. Similarly Cu2+ strongly competed with Pb2+ to limestone surface. In ternary system, the removal further decreased, but considerable amount of Pb2+ and Cu2+ still occurred regardless of the limestone sample. The same behavior was observed in quadruple system, where the selectivity sequence was Pb2+ > Cu2+ > Cd2+ > Zn2+. From these results, it was concluded that the studied limestones have the required technical specifications to be used for the removal of toxic metals from wastewaters.

  20. Comparison of deformation mechanics for two different carbonates: oolitic limestone and laminites

    NASA Astrophysics Data System (ADS)

    Zihms, Stephanie; Lewis, Helen; Couples, Gary; Hall, Stephen; Somerville, Jim

    2016-04-01

    two higher confining pressures both show highly complex fracture networks comprising open fractures and fracture propagation. This suggests that the laminate changes from compactive to dilational responses over the selected confining conditions. The XRT analysis indicates that a more complex fracture distribution could be linked to rock component properties e.g. grain size and composition. For the laminite these are variable with the layers. This is in agreement with field observations of laminite microfabrics (Calvo, Rodriguez-Pascua et al. 1998). Additionally, the typical grain size of the laminate (μm) is much smaller than the oolitic limestone (mm), which suggests that fracture network complexity can also be linked to bulk system complexity i.e. pore & grain network. These deformation experiments show that, as previously observed, oolitic limestones seem to behave similarly to sandstones. However this observation is not true for laminites and it is very likely that more complex carbonates will develop even more complicated deformation behaviour. It is therefore necessary to systematically test different carbonate rocks to understand the impact of geometry and composition, as well as the interplay with the pore network. Brantut, N., et al. (2014). Journal of Geophysical Research: Solid Earth 119(7): 5444-5463. Calvo, J. P., et al. (1998). Sedimentology 45: 279-292. Vajdova, V. (2004). Journal of Geophysical Research 109(B5).

  1. Discrimination between marls and limestones using intensity data from terrestrial laser scanner

    NASA Astrophysics Data System (ADS)

    Franceschi, Marco; Teza, Giordano; Preto, Nereo; Pesci, Arianna; Galgaro, Antonio; Girardi, Stefano

    Terrestrial Laser Scanner (TLS) is an active instrument widely used for physical surface acquisition and data modeling. TLS provides both the geometry and the intensity information of scanned objects depending on their physical and chemical properties. The intensity data can be used to discriminate different materials, since intensity is proportional, among other parameters, to the reflectance of the target at the specific wavelength of the laser beam. This article focuses on the TLS-based recognition of rocks in simple sedimentary successions mainly constituted by limestones and marls. In particular, a series of experiments with an Optech ILRIS 3D TLS was carried out to verify the feasibility of this application, as well as to solve problems in data acquisition protocol and data processing. Results indicate that a TLS intensity-based discrimination can provide reliable information about the clay content of rocks in clean outcrop conditions if the geometrical aspects of the acquisition (i.e. distance) are taken into account. Reflectance values of limestones, marls and clays show, both in controlled conditions and in the field, clear differences due to the interaction of the laser beam (having a 1535 nm wavelength) with H 2O-bearing minerals and materials. Information about lithology can be therefore obtained also from real outcrops, at least if simple alternation of limestones and marls are considered. Comparison between reflectance values derived from TLS acquisition of an outcrop and the clay abundance curves obtained by gas chromatography on rock samples taken from the same stratigraphic section shows that reflectance is linked by an inverse linear relationship (correlation coefficient r=-0.85) to the abundance of clay minerals in the rocks. Reflectance series obtained from TLS data are proposed as a tool to evaluate the variation of clay content along a stratigraphic section. The possibility of linking reflectance values to lithological parameters (i.e. clay

  2. Evaluation of a portable photometer for estimating diesel particulate matter concentrations in an underground limestone mine.

    PubMed

    Watts, Winthrop F; Gladis, David D; Schumacher, Matthew F; Ragatz, Adam C; Kittelson, David B

    2010-07-01

    A low cost, battery-operated, portable, real-time aerosol analyzer is not available for monitoring diesel particulate matter (DPM) concentrations in underground mines. This study summarizes a field evaluation conducted at an underground limestone mine to evaluate the potential of the TSI AM 510 portable photometer (equipped with a Dorr-Oliver cyclone and 1.0-mum impactor) to qualitatively track time-weighted average mass and elemental, organic, and total carbon (TC) measurements associated with diesel emissions. The calibration factor corrected correlation coefficient (R2) between the underground TC and photometer measurements was 0.93. The main issues holding back the use of a photometer for real-time estimation of DPM in an underground mine are the removal of non-DPM-associated particulate matter from the aerosol stream using devices, such as a cyclone and/or impactor and calibration of the photometer to mine-specific aerosol. PMID:20410071

  3. Evaluation of a Portable Photometer for Estimating Diesel Particulate Matter Concentrations in an Underground Limestone Mine

    PubMed Central

    Watts, Winthrop F.; Gladis, David D.; Schumacher, Matthew F.; Ragatz, Adam C.; Kittelson, David B.

    2010-01-01

    A low cost, battery-operated, portable, real-time aerosol analyzer is not available for monitoring diesel particulate matter (DPM) concentrations in underground mines. This study summarizes a field evaluation conducted at an underground limestone mine to evaluate the potential of the TSI AM 510 portable photometer (equipped with a Dorr-Oliver cyclone and 1.0-μm impactor) to qualitatively track time-weighted average mass and elemental, organic, and total carbon (TC) measurements associated with diesel emissions. The calibration factor corrected correlation coefficient (R2) between the underground TC and photometer measurements was 0.93. The main issues holding back the use of a photometer for real-time estimation of DPM in an underground mine are the removal of non-DPM-associated particulate matter from the aerosol stream using devices, such as a cyclone and/or impactor and calibration of the photometer to mine-specific aerosol. PMID:20410071

  4. Limestones of western Newfoundland that magnetized before Devonian folding but after Middle Ordovician lithification

    SciTech Connect

    Hodych, J.P. )

    1989-01-01

    A positive fold test and a negative conglomerate test help determine when and how stable remanence was acquired in the Middle Ordovician Table Head Group limestones of the Port au Port Peninsula of Newfoundland. The limestones magnetized after lithification and incorporation as clasts into a Middle Ordovician breccia. Hence, the limestones do not carry a detrital or other primary remanence despite their very low conodont color alteration index. The remanence may be thermoviscous or diagenetic and was acquired before Devonian folding. This suggests the need for caution in interpreting paleomagnetic results from other early Paleozoic limestones whose remanence resides in magnetite of blocking temperature lower than 400C.

  5. Analysis of medieval limestone sculpture from southwestern France and the Paris Basin by NAA

    SciTech Connect

    Holmes, L.; Harbottle, G.

    1994-12-31

    Compositional characterization of limestone from sources known to medieval craftsmen and from the monuments they built can be used in conjunction with stylistic and iconographic criteria to infer geographic origin of sculptures that have lost their histories. Limestone from 47 quarrying locations in France and from numerous medieval monuments have been subjected to neutron activation analysis (NAA) to form the nucleus of the Brookhaven Limestone Database. Even though the method and techniques of NAA are well established, this paper briefly summarizes the parameters and experimental conditions useful for determining those concentration variables for which limestone from different sources exhibits significant and reproducible differences.

  6. Enhancement of indirect sulphation of limestone by steam addition.

    PubMed

    Stewart, Michael C; Manovic, Vasilije; Anthony, Edward J; Macchi, Arturo

    2010-11-15

    The effect of water (H₂O(g)) on in situ SO₂ capture using limestone injection under (FBC) conditions was studied using a thermobalance and tube furnace. The indirect sulphation reaction was found to be greatly enhanced in the presence of H₂O(g). Stoichiometric conversion of samples occurred when sulphated with a synthetic flue gas containing 15% H₂O(g) in under 10 h, which is equivalent to a 45% increase in conversion as compared to sulphation without H₂O(g). Using gas pycnometry and nitrogen adsorption methods, it was shown that limestone samples sulphated in the presence of H₂O(g) undergo increased particle densification without any significant changes to pore area or volume. The microstructural changes and observed increase in conversion were attributed to enhanced solid-state diffusion in CaO/CaSO₄ in the presence of H₂O(g). Given steam has been shown to have such a strong influence on sulphation, whereas it had been previously regarded as inert, may prompt a revisiting of the classically accepted sulphation models and phenomena. These findings also suggest that steam injection may be used to enhance sulfur capture performance in fluidized beds firing low-moisture fuels such as petroleum coke. PMID:20958025

  7. Characterizing and modelling 'ghost-rock' weathered limestones

    NASA Astrophysics Data System (ADS)

    Dubois, Caroline; Goderniaux, Pascal; Deceuster, John; Poulain, Angélique; Kaufmann, Olivier

    2016-04-01

    'Ghost-rock' karst aquifer has recently been highlighted. In this particular type of aquifer, the karst is not expressed as open conduits but consists in zones where the limestone is weathered. The in-situ weathering of limestone leaves a soft porous material called 'alterite'. The hydro-mechanical properties of this material differs significantly from those of the host rock: the weathering enhances the storage capacity and the conductivity of the rock. This type of weathered karst aquifer has never been studied from a hydrogeological point of view. In this study, we present the hydraulic characterization of such weathered zones. We also present a modelling approach derived from the common Equivalent Porous Medium (EPM) approach, but including the spatial distribution of hydrogeological properties through the weathered features, from the hard rock to the alterite, according to a weathering index. Unlike the Discrete Fracture Network (DFN) approaches, which enable to take into account a limited number of fractures, this new approach allows creating models including thousands of weathered features. As the properties of the alterite have to be considered at a centimeter scale, it is necessary to upscale these properties to carry out simulations over large areas. Therefore, an upscaling method was developed, taking into account the anisotropy of the weathered features. Synthetic models are built, upscaled and different hydrogeological simulations are run to validate the method. This methodology is finally tested on a real case study: the modelling of the dewatering drainage flow of an exploited quarry in a weathered karst aquifer in Belgium.

  8. Hydrogeology of the gray limestone aquifer in southern Florida

    USGS Publications Warehouse

    Reese, Ronald S.; Cunningham, Kevin J.

    2000-01-01

    Results from 35 new test coreholes and aquifer-test, water-level, and water-quality data were combined with existing hydrogeologic data to define the extent, thickness, hydraulic properties, and degree of confinement of the gray limestone aquifer in southern Florida. This aquifer, previously known to be present only in southeastern Florida (Miami-Dade, Broward, and Palm Beach Counties) below, and to the west of, the Biscayne aquifer, extends over most of central-south Florida, including eastern and central Collier County and southern Hendry County; it is the same as the lower Tamiami aquifer to the north, and it becomes the water-table aquifer and the upper limestone part of the lower Tamiami aquifer to the west. The aquifer generally is composed of gray, shelly, lightly to moderately cemented limestone with abundant shell fragments or carbonate sand, abundant skeletal moldic porosity, and minor quartz sand. The gray limestone aquifer comprises the Ochopee Limestone of the Tamiami Formation, and, in some areas, the uppermost permeable part of an unnamed formation principally composed of quartz sand. Underlying the unnamed formation is the Peace River Formation of the upper Hawthorn Group, the top of which is the base of the surficial aquifer system. Overlying the aquifer and providing confinement in much of the area is the Pinecrest Sand Member of the Tamiami Formation. The thickness of the aquifer is comparatively uniform, generally ranging from 30 to 100 feet. The unnamed formation part of the aquifer is up to 20 feet thick. The Ochopee Limestone accumulated in a carbonate ramp depositional system and contains a heterozoan carbonate-particle association. The principal rock types of the aquifer are pelecypod lime rudstones and floatstones and permeable quartz sands and sandstones. The pore types are mainly intergrain and separate vug (skeletal-moldic) pore spaces. The rock fabric and associated primary and secondary pore spaces combine to form a dual diffuse

  9. Bird species diversity in the padawan limestone area, sarawak.

    PubMed

    Mansor, Mohammad Saiful; Sah, Shahrul Anuar Mohd; Koon, Lim Chan; Rahman, Mustafa Abdul

    2011-12-01

    Bird surveys were conducted in the Padawan Limestone Area for seven days at each of two study sites, Giam and Danu, from August to December 2008. The purpose of the study was to compare the area's bird species richness and abundance of bird species in other limestone areas and in other forest types. The study also compared the species richness and relative abundance of birds in undisturbed and disturbed areas at both study sites. Twenty mist nets were deployed for 12 hours daily. During this study period, direct observations of birds were also made. In all, 80 species from 34 families were recorded at both sites. At Giam, 120 birds were mist-netted. These birds represented 31 species from 16 families. The direct observations at Giam recorded 13 species from 11 families. In the undisturbed area, 21 species from 13 families were mist-netted, whereas in the disturbed area, 21 species from 10 families were mist-netted. In Danu, a total of 48 birds, representing 25 species from 12 families, were mist-netted. The observations at Danu recorded 34 species from 19 families. Twelve species from 7 families were mist-netted in the undisturbed area, whereas 18 species from 11 families were mist-netted in the disturbed area. Statistical analysis showed that the species diversity index differed significantly between undisturbed and disturbed areas. PMID:24575218

  10. Bird Species Diversity in the Padawan Limestone Area, Sarawak

    PubMed Central

    Mansor, Mohammad Saiful; Sah, Shahrul Anuar Mohd; Koon, Lim Chan; Rahman, Mustafa Abdul

    2011-01-01

    Bird surveys were conducted in the Padawan Limestone Area for seven days at each of two study sites, Giam and Danu, from August to December 2008. The purpose of the study was to compare the area’s bird species richness and abundance of bird species in other limestone areas and in other forest types. The study also compared the species richness and relative abundance of birds in undisturbed and disturbed areas at both study sites. Twenty mist nets were deployed for 12 hours daily. During this study period, direct observations of birds were also made. In all, 80 species from 34 families were recorded at both sites. At Giam, 120 birds were mist-netted. These birds represented 31 species from 16 families. The direct observations at Giam recorded 13 species from 11 families. In the undisturbed area, 21 species from 13 families were mist-netted, whereas in the disturbed area, 21 species from 10 families were mist-netted. In Danu, a total of 48 birds, representing 25 species from 12 families, were mist-netted. The observations at Danu recorded 34 species from 19 families. Twelve species from 7 families were mist-netted in the undisturbed area, whereas 18 species from 11 families were mist-netted in the disturbed area. Statistical analysis showed that the species diversity index differed significantly between undisturbed and disturbed areas. PMID:24575218

  11. Treatment of mining acidic leachates with indigenous limestone, Zimapan Mexico.

    PubMed

    Labastida, I; Armienta, M A; Lara-Castro, R H; Aguayo, A; Cruz, O; Ceniceros, N

    2013-11-15

    An experimental study to evaluate the potential of using indigenous limestones in a passive system to treat acid mine drainage, at a mining zone of Mexico was carried out. Chemical and mineralogical characteristics of four types of native rocks (KIT1, KIT2, KSS, QZ) showed distinct CaCO3 contents. Synthetic aqueous leachates from an old tailings impoundment had a pH of 2.18, 34 mg/L As, 705 mg/L Fetotal, and 3975 mg/L SO4(2-). To evaluate dissolution behavior of rocks, kinetic batch experiments with an acid Fe-rich solution were performed. Decaying kinetic constants adjusting H(+) concentration to a first order exponential process were: KIT1 (k = 2.89), KIT2 (k = 0.89) and KSS (k = 0.47). Infrared spectrum and XRD of precipitates showed schwertmannite formation. To determine As and heavy metals (Fe, Cd, Zn, Al) removal from the synthetic leachates, batch experiments using KIT1 were developed. Arsenic decreased from 34.00 mg/L to 0.04 mg/L, Fe and Al were totally removed, and concentrations of Zn and Cd decreased 88% and 91% respectively. Analyses by IR and SEM-EDS indicate that co-precipitation with Fe-Hydroxides formed upon leachate interaction with limestone is the main As removal process. Chamosite, identified by XRD may participate in the removal of Al, SiO2 and a fraction of Fe. PMID:22819958

  12. Colmenar limestone as a resource for built heritage

    NASA Astrophysics Data System (ADS)

    Fort, Rafael; Álvarez de Buergo, Mónica; Varas-Muriel, MªJosé; Mercedes Pérez-Monserrat, Elena

    2013-04-01

    The Colmenar stone (or Colmenar limestone) has been used in the construction of significant builidings of the Central area of Spain, such as the Royal Palace of Aranjuez (16th -18th centuries) or the Royal Palace of Madrid (18th century). Nowadays this building stone is still widely used, both for new construction and restoration works, as well as for the indoor ornamentation of emblematic buildings such as the Royal Theater of Madrid (20th century). There are many quarries from where this stone was exploited, being the most prestigious ones those located in Colmenar de Oreja, at 50 km Southeast the city of Madrid. The high quality of the stone in these quarries, its whiteness and pureness, made this locality the most relevant in these stonés extractive activities, concentrating the most relevant exploitations and providing the stone the denomination of the municipality (Colmenar). It was an underground mining extraction until the 20th century in order to reach the highest quality level of the mine, the so called "Banco Gordo" (Thick Bank). Generically known as moorland limestone, this rock belongs to the fluvial-lacustrine carbonates of the Upper Miocene Unit of the Tertiary Madrid's Basin. Its tonality mainly ranges from white to cream and even light grey. Under a petrographic point of view, this limestone is constituted by 40% of bioclasts (characea, ostracods and gasteropods), 20-30% of micritic matrix and 30-40% of sparitic cement. Therefore, it can be classified as a biomicrite/biosparite limestone or as a bioclastic packstone. Some particularities of these limestones regarding their appearance are related to some karstic processes they underwent linked to some dissolution phenomena during the Pliocene. All of this resulted on an abundance of cavities with terra rossa fillings, a non-soluble clayey residue, iron enriched, which is the responsible for the reddish and pinkish color that the Colmenar stone sometimes shows. These petrographic characteristics

  13. GPR investigations in galleries buried inside a karstified limestone formation

    NASA Astrophysics Data System (ADS)

    Rousset, D.; Sénéchal, G.; Gaffet, S.

    2009-04-01

    A large scientific program of geophysical investigations is presently performed inside the Low-Noise Underground Laboratory (Laboratoire Souterrain à Bas Bruit / LSBB, Rustrel, France) which is an decomissioned underground missile control center, buried in a karstified limestone formation. One of the goals of this project is the understanding of the water circulation inside the structure. This experimental site offers a unique opportunity of perfoming measurements within an unweathered limestone massif. The tunnel has been dug in lower cretaceous limestone which is characterized by a low clay content, high electrical resistivity. The dip is around 25 degrees and vertical faults locally affect the structure. The studied zone is located in south-eastern France (Provence) and is characterized by a mediterranean climate with long dry periods and strong, short events of rain. This phenomenon induces large variations of water content within the karstified limestone from dry to saturated conditions. Analysis of the spatial and temporal variations of the water flow in a karstified limestones needs to define the geological context and the adequate geophysical methods. GPR offers a good tradeoff between resolution and ease of use on one hand and investigation depth on the other hand. We present some GPR profiles which have been acquired in April 2008 after a quite long and strong period of rain, inducing a complete water saturation inside the karstified massif. We used several RAMAC shielded antennas from 100 to 500 MHz. The longest profile is around 600 m long, with a 20 cm spacing, running from a raw to a concrete gallery. These data sets are characterized by a very good signal to noise ratio and a signal penetration, up to 18 meters. Signal processing includes very low frequency filtering, amplitude compensation, keeping lateral relative attenuation and ringing suppression. Final sections includes migration and time to depth conversion or depth migration. The estimated

  14. Arun field

    SciTech Connect

    Jordan, C.F. Jr.; Abdullah, M.

    1988-01-01

    The Arun field is a giant gas-condensate field operated by Mobil and Pertamina with over 20,000 acres of closure at the top of the Arun reservoir. A middle-shelf patch reef complex of early to middle Miocene age is the producing facies at the Arun field. About 1,100 ft of porous limestones, encased in shales, create a stratigraphic trap for overpressure hydrocarbons. Three main carbonate lithologies were encountered during the examination of over 4,300 ft of core; (1) a reef facies consisting of vuggy, coral encrusting, red-algal boundstones, (2) a near-reef facies consisting of foraminiferal, mixed-skeletal packstones with gravel-size coral fragments, and (3) an interreef lagoonal facies consisting of benthonic-foram packstones. Twenty-two species of corals have been identified from Arun reef facies; major reef-forming coals, listed in order of decreasing abundance, are Porites cf P. Lutes, Cyphastrea microphthalma, Astreopora myriophthalma, Styloconiella gunetheri, Porites solida, and Acropora ssp. The Arun reef is comprised of limestones (with minor amounts of dolomite). No shale beds occur in the sequence, and all carbonate facies are in communication. A pervasive microporosity, occurring throughout the Arun Limestone, results from meteoric alteration of original carbonate mud to form a microrhombic porosity that accounts for about three-fourths of the field's total porosity.

  15. Crystallographic transformation of limestone during calcination under CO2.

    PubMed

    Valverde, Jose Manuel; Medina, Santiago

    2015-09-14

    The calcination reaction of limestone (CaCO3) to yield lime (CaO) is at the heart of many industrial applications as well as natural processes. In the recently emerged calcium-looping technology, CO2 capture is accomplished by the carbonation of CaO in a gas-solid reactor (carbonator). CaO is derived by the calcination of limestone in a calciner reactor under necessarily high CO2 partial pressure and high temperature. In situ X-ray diffraction (XRD) has been employed in this work to gain further insight into the crystallographic transformation that takes place during the calcination of limestone under CO2, at partial pressures (P) close to the equilibrium pressure (Peq) and at high temperature. Calcination under these conditions becomes extremely slow. The in situ XRD analysis presented here suggests the presence of an intermediate metastable CaO* phase stemming from the parent CaCO3 structure. According to the reaction mechanism proposed elsewhere, the exothermicity of the CaO* → CaO transformation and high values of P/Peq inhibit the nucleation of CaO at high temperatures. The wt% of CaO* remains at a relatively high level during slow calcination. Two diverse stages have been identified in the evolution of CaO crystallite size, L. Initially, L increases with CaCO3 conversion, following a logarithmic law. Slow calcination allows the crystallite size to grow up from a few nanometers at nucleation up to around 100 nm near the end of conversion. Otherwise, quick calcination at relatively lower CO2 concentrations limits CaO crystallite growth. Once calcination reaches an advanced state, the presence of CaO* drops to zero and the rate of increase of the CaO crystallite size is significantly hindered. Arguably, the first stage in CaO crystallite growth is driven by aggregation of the metastable CaO* nanocrystals, due to surface attractive forces, whereas the second one is consistent with sintering of the aggregated CaO crystals, and persists with time after full

  16. Determining the distribution of hydraulic conductivity in a fractured limestone aquifer by simultaneous injection and geophysical logging

    USGS Publications Warehouse

    Morin, R.H.; Hess, A.E.; Paillet, Frederick L.

    1988-01-01

    A field technique for assessing the vertical distribution of hydraulic conductivity in an aquifer was applied to a fractured carbonate formation in southeastern Nevada. The technique combines the simultaneous use of fluid injection and geophysical logging to measure in situ vertical distributions of fluid velocity and hydraulic head down the borehole; these data subsequently are analyzed to arrive at quantitative estimates of hydraulic conductivity across discrete intervals in the aquifer. The results of this analysis identified the contact margin between the Anchor and Dawn Members of the Monte Cristo Limestone as being the dominant transmissive unit. -from Authors

  17. Seismic Characterization of Fractured Reservoirs - Rock Physics Analysis and Modeling of James Limestone Reservoir

    NASA Astrophysics Data System (ADS)

    Sava, D. C.; Florez, J. M.; Mukerji, T.; Mavko, G.

    2002-12-01

    We present the rock physics analysis from well logs of the fractured James Limestone reservoir in the Neuville Field and also the results of our stochastic simulations of various seismic attributes for different models of fractures in the reservoir. Our goal is to determine the optimal combination of seismic attributes, and the uncertainty due to natural variability for delineating the gas filled fractured zones. Geological model based on the logs from horizontal wells suggests that the fractures are controlled by subseismic normal faults. These small faults can generate narrow zones with high fracture density. Between these fracture swarms, the background fracture density may correspond to regularly spaced, vertical joints. Therefore, for fracture modeling we consider both isotropic and anisotropic distributions of fractures. The isotropic distribution corresponds to the fracture swarms in the vicinity of faults, where the cracks are more or less randomly orientated, such as in brecciated zones. The anisotropic distribution corresponds to a single set of vertical joints that generates an azimuthally anisotropic medium with HTI symmetry. For each hypotheses of fracture distribution we stochastically model seismic interval and interface properties such as interval velocities, Poisson's Ratio, impedances, travel time, scattering attenuation, PP reflectivity as a function of angle of incidence and azimuth. The modeling shows that some of these attributes, such as Poisson's Ratio and P Impedance, are more sensitive to the presence of fractures than others. Rock physics analysis of the cross-dipole and FMI logs shows that the fractures are present especially in the clean limestone intervals, characterized by high velocity and small porosity. This observation can be used in fracture delineation from seismic measurements. In summary, rock physics fracture modeling and stochastic simulations for seismic attributes of James Lime reservoir provide a framework for delineating

  18. Chemical and isotopic evidence for hydrogeochemical processes occurring in the Lincolnshire Limestone

    NASA Astrophysics Data System (ADS)

    Bishop, Philip K.; Lloyd, John W.

    1990-12-01

    Over 150 groundwater samples from the Lincolnshire Limestone have been analysed for pH, major ions and δ 13C ratios. Where possible, field E h and iodide concentrations were measured and methane concentrations were determined for 12 samples. Stable isotope ratios were determined for soil and rock carbonate samples. A system of zonation allows the division of hydrogeochemical processes occurring in the aquifer. The use of hydrochemical and isotope data in modelling exercises enables the re-evaluation and possible enhancement of the understanding of hydrogeochemical processes. The carbonate chemistry of outcrop groundwaters is explained by calcite saturation being achieved under open-system conditions in the soil zone. δ 13C ratios in the range - 15.99 to - 10.57‰ may be generated from a stoichiometric reaction with possible additional partial and/or simultaneous exchange with soil CO 2 or carbonate. The isotopic composition of soil carbonate shows the effects of precipitation from soil waters. The incongruent dissolution of primary depositional limestone carbonate results in increasing magnesium and strontium concentrations and increasing δ 13C ratios for the groundwaters with flow down the hydraulic gradient. As a result of incongruent dissolution, secondary calcite may be precipitated onto fissure surfaces. Significant nitrate and sulphate reduction in non-saline groundwaters is not supported by the results of hydrochemical and isotope modelling exercises. However, sulphate reduction and methane fermentation may be affecting the isotopic and chemical compositions of saline groundwaters. Sodium-calcium ion exchange leads to limited calcite dissolution deep in the aquifer, but the evolution of these groundwaters is confused by the uncertain effects of oxidation of organic carbon and mixing with a saline end-member solution.

  19. In situ vitrification of Oak Ridge National Laboratory soil and limestone

    SciTech Connect

    Carter, J.G.; Bates, S.O.; Maupin, G.D.

    1987-03-01

    Process feasibility studies were successfully performed on two different developmental scales to determine the technical application of in situ vitrification (ISV) to Oak Ridge National Laboratory (ORNL) intermediate-level waste. In the laboratory, testing was performed on crucibles containing quantities of 50% ORNL soil and 50% ORNL limestone. In the engineering-scale testing, a 1/12-scaled simulation of ORNL Trench 7 was constructed and vitrified, resulting in waste product soil and limestone concentrations of 68% and 32%, respectively. Results from the two scales of testing indicate that the ORNL intermediate-level waste sites may be successfully processed by ISV; the waste form will retain significant quantities of the cesium and strontium. Because /sup 137/Cs is the major component of the radionuclide inventory in the ORNL seepage pits and trenches, final field process decontamination factors (i.e., off gas at the ground surface relative to the waste inventory) of 10/sup 4/ are desired to minimize activity buildup in the off-gas system. These values were realized during the engineering-scale test for both cesium and strontium. The vitrified material effectively contained 99.996% of the cesium and strontium placed in the engineering-scale test. This is equivalent to decontamination factors of greater than 10/sup 4/. Volume reduction for the engineering-scale test was 60%. No migration of the cesium to the uncontaminated surrounding soil was detected. These favorable results indicate that, once verified in a pilot-scale test, an adequately designed ISV system could be produced to treat the ORNL seepage pits and trenches without excessive activity accumulation in the off-gas treatment system.

  20. Geostatistical three-dimensional modeling of oolite shoals, St. Louis Limestone, southwest Kansas

    USGS Publications Warehouse

    Qi, L.; Carr, T.R.; Goldstein, R.H.

    2007-01-01

    In the Hugoton embayment of southwestern Kansas, reservoirs composed of relatively thin (<4 m; <13.1 ft) oolitic deposits within the St. Louis Limestone have produced more than 300 million bbl of oil. The geometry and distribution of oolitic deposits control the heterogeneity of the reservoirs, resulting in exploration challenges and relatively low recovery. Geostatistical three-dimensional (3-D) models were constructed to quantify the geometry and spatial distribution of oolitic reservoirs, and the continuity of flow units within Big Bow and Sand Arroyo Creek fields. Lithofacies in uncored wells were predicted from digital logs using a neural network. The tilting effect from the Laramide orogeny was removed to construct restored structural surfaces at the time of deposition. Well data and structural maps were integrated to build 3-D models of oolitic reservoirs using stochastic simulations with geometry data. Three-dimensional models provide insights into the distribution, the external and internal geometry of oolitic deposits, and the sedimentologic processes that generated reservoir intervals. The structural highs and general structural trend had a significant impact on the distribution and orientation of the oolitic complexes. The depositional pattern and connectivity analysis suggest an overall aggradation of shallow-marine deposits during pulses of relative sea level rise followed by deepening near the top of the St. Louis Limestone. Cemented oolitic deposits were modeled as barriers and baffles and tend to concentrate at the edge of oolitic complexes. Spatial distribution of porous oolitic deposits controls the internal geometry of rock properties. Integrated geostatistical modeling methods can be applicable to other complex carbonate or siliciclastic reservoirs in shallow-marine settings. Copyright ?? 2007. The American Association of Petroleum Geologists. All rights reserved.

  1. EVALUATION OF THE LIMESTONE DUAL ALKALI PROTOTYPE SYSTEM PLANT SCHOLZ: SYSTEM DESIGN AND PROGRAM PLAN

    EPA Science Inventory

    The report describes the (Phase I) design of both a limestone dual alkali system at Gulf Power Co.'s Scholz steam plant and a related test program. The limestone dual alkali process will be tested at an existing 20 MWe prototype facility at the Scholz plant. The intent of the pro...

  2. STEAM ENHANCED REMEDIATION RESEARCH FOR DNAPL IN FRACTURED ROCK, LORING AIR FORCE BASE, LIMESTONE, MAINE

    EPA Science Inventory

    This report details a research project on Steam Enhanced Remediation (SER) for the recovery of volatile organic compounds from fractured limestone that was carried out at the Quarry at the former Loring Air Force Base in Limestone, Maine. This project was carried out by USEPA, Ma...

  3. Adsorption and desorption of phosphate on limestone in experiments simulating seawater intrusion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The absorption and desorption of phosphorus on a large block of limestone was investigated using deionized water (DIW) and seawater. The limestone had a high affinity to adsorb phosphorus in DIW. Phosphate adsorption was significantly less in seawater, and more phosphorus was desorbed in the seawate...

  4. 76 FR 35396 - Black Hills National Forest, Mystic Ranger District, South Dakota, Section 30 Limestone Mining...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-17

    ... Mining Project AGENCY: Forest Service, USDA. ACTION: Corrected Notice of intent to prepare an... the purpose of mining for chemical grade limestone within mining claims on National Forest System land... publication dates. A Notice of Availability for the Section 30 Limestone Mining Project Draft EIS...

  5. EFFECT OF LIMESTONE TYPE AND GRIND ON S02 SCRUBBER PERFORMANCE

    EPA Science Inventory

    The paper describes the effect of limestone type and grind on SO2 scrubber performance. It gives results of a comparison of the amount of limestone feed required as a function of particle size, to obtain a given SO2 removal efficiency and, thus, to verify the relative magnitude o...

  6. OPTIMIZATION OF A PULSED LIMESTONE BED REACTOR AT THE ARGO TUNNEL IN IDAHO SPRINGS, COLORADO

    EPA Science Inventory

    Acid Mine Drainage (AMD) is an unintended consequence of coal and metal mining that adversely affects thousands of miles of streams both in the eastern and western regions of the U.S. A novel AMD treatment process based on limestone based on limestone neutralization has been dev...

  7. ECONOMIC EVALUATION OF A SODIUM/LIMESTONE DOUBLE-ALKALI FGD (FLUE GAS DESULFURIZATION) PROCESS

    EPA Science Inventory

    The report gives results of a comparison of results from a recent forced-oxidation limestone flue gas desulfurization (FGD) process evaluation and those from a conceptual design and economic evaluation of a sodium/limestone double-alkali FGD process, based on recent EPA-sponsored...

  8. Identification of Calcium Sulphoaluminate Formation between Alunite and Limestone

    PubMed Central

    Kim, Hyung-Seok; Han, Gi-Chun; Ahn, Ji-Whan; Cho, Kye-Hong; Cho, Hee-Chan

    2009-01-01

    This study was carried out to identify the conditions of formation of calcium sulphoaluminate (3CaO·3Al2O3·CaSO4) by the sintering of a limestone (CaCO3) and alunite [K2SO4·Al2(SO4)3·4Al(OH)3] mixture with the following reagents: K2SO4, CaCO3, Al(OH)3, CaSO4·2H2O, and SiO2. When K2SO4, CaCO3, Al(OH)3, CaSO4·2H2O were mixed in molar ratios of 1:3:6:3 and sintered at 1,200∼1,300 °C, only 3CaO·3Al2O3·CaSO4 and calcium langbeinite (2CaSO4·K2SO4) were generated. With an amount of CaO that is less than the stoichiometric molar ratio, 3CaO·3Al2O3·CaSO4 was formed and anhydrite (CaSO4) did not react and remained behind. With the amount of CaSO4 that is less than the stoichiometric molar ratio, the amounts of 3CaO·3Al2O3·CaSO4 and 2CaSO4·K2SO4 decreased, and that of CaO·Al2O3 increased. In the K2SO4-CaO-Al2O3-CaSO4-SiO2 system, to stabilize the formation of 3CaO·3Al2O3·CaSO4, 2CaSO4·K2SO4, and β-2CaO·SiO2, the molar ratios of CaO: Al2O3: CaSO4 must be kept at 3:3:1 and that of CaO/SiO2, over 2.0; otherwise, the generated amount of 3CaO·3Al2O3·CaSO4 decreased and that of gehlenite (2CaO·Al2O3·SiO2) with no hydration increased quantitatively. Therefore, if all SO3(g) generated by the thermal decomposition of alunite reacts with CaCO3 (or CaO, the thermal decomposition product of limestone) to form CaSO4 in an alunite- limestone system, 1 mol of pure alunite reacts with 6 mol of limestone to form 1 mol of 3CaO·3Al2O3·CaSO4 and 1 mol of 2CaSO4·K2SO4. PMID:22346687

  9. Toxicity of acid mine pit lake water remediated with limestone and phosphorus

    SciTech Connect

    Neil, L.L.; McCullough, C.D.; Lund, M.A.; Evans, L.H.; Tsvetnenko, Y.

    2009-11-15

    Pit lakes are increasingly common worldwide and have potential to provide many benefits. However, lake water toxicity may require remediation before beneficial end uses can be realised. Three treatments to remediate AMD (pH similar to 4.8) pit lake water containing elevated concentrations of Al and Zn from Collie, Western Australia were tested in mesocosms. Treatments were: (a) limestone neutralisation (L), (b) phosphorus amendment (P), and c) combined limestone neutralisation and phosphorus amendment (L+P). Laboratory bioassays with Ceriodaphnia cf. dubia, Chlorella protothecoides and Tetrahymena thermophila assessed remediation. Limestone neutralisation increased pH and reduced heavy metal concentrations by 98% (Al) to 14% (Mg), removing toxicity to the three test species within 2 months. Phosphorus amendment removed toxicity after 6 months of treatment. However, phosphorus amendment to prior limestone neutralisation failed to reduce toxicity more than limestone neutralisation alone. Low concentrations of both phosphorus and nitrogen appear to limit phytoplankton population growth in all treatments.

  10. Hydration mechanisms of ternary Portland cements containing limestone powder and fly ash

    SciTech Connect

    De Weerdt, K.; Haha, M. Ben; Le Saout, G.; Kjellsen, K.O.; Justnes, H.; Lothenbach, B.

    2011-03-15

    The effect of minor additions of limestone powder on the properties of fly ash blended cements was investigated in this study using isothermal calorimetry, thermogravimetry (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM) techniques, and pore solution analysis. The presence of limestone powder led to the formation of hemi- and monocarbonate and to a stabilisation of ettringite compared to the limestone-free cements, where a part of the ettringite converted to monosulphate. Thus, the presence of 5% of limestone led to an increase of the volume of the hydrates, as visible in the increase in chemical shrinkage, and an increase in compressive strength. This effect was amplified for the fly ash/limestone blended cements due to the additional alumina provided by the fly ash reaction.

  11. Thermal strengthening of limestone: monument preservation during fire

    NASA Astrophysics Data System (ADS)

    Heap, Michael; Lavallee, Yan; Benson, Philip; Hess, Kai-Uwe; Dingwell, Donald

    2010-05-01

    The use of natural rocks in the construction of buildings and monuments predates the use of commercially engineered materials such as concrete. Such building material can be subject to elevated temperatures in the misfortunate event of a fire. In civil engineering, it is generally appreciated that the strength of rock is decreased when it is or has been exposed to elevated temperatures. This is due the formation of thermal microcracks, a result of the thermal expansion mismatch between different minerals in the rock. Even today, fire is by no means an uncommon occurrence and approximately one historic building is lost to fire in the European Union every day (COST C17 2001). A large number of historically significant buildings and monuments are constructed from carbonate material. However, could the paradigm of thermal weakening of limestone construction material be in part, a paradox? We report new findings on the thermal strengthening of the Solnhofen limestone (Solnhofen, Germany), a carbonate rock traditionally used in construction of building and statues in central Europe. Two types of deformation experiments were performed to investigate: (1) the strength of samples at elevated temperatures (i.e. during fire) and (2) the strength of samples at room temperature after heat-treatment (i.e. after fire). During experimentation, microcracking was monitored by the output of acoustic emissions (AE). Thermo-gravimetric (TG) analysis was also undertaken to measure the mass loss during heating. For the experiments ‘during fire', samples were heated to temperatures of 25°, 200°, 400°, 500°, 600°, 650° and 800°C at a controlled rate of 5°C/min and deformed until failure in a uniaxial press at a constant strain rate of 10-5 s-1. For the experiments ‘after fire', samples were heat-treated to each 100°C increment up to 800°C, they were then cooled at the same rate and their strength tested at room temperature. The mechanical data demonstrate that, during fire

  12. Shallow-water limestones within the Paleogene forearc basin of California: Unique paleogeographic indicators

    SciTech Connect

    Whidden, K.J.; Bottjer, D.J.; Lund, S.P. . Dept. of Geological Sciences)

    1992-01-01

    A number of shallow-water limestones have recently been documented in late Mesozoic/Paleogene forearc strata of the Cordilleran continental arc. These limestones occur on two different tectonic blocks which were both developed within the forearc basin and subsequently moved relative to one another due to oblique convergence since Late Cretaceous time. Faunal evidence suggests that these limestones were deposited within the photic zone, at shelfal depths. Each limestone represents part or all of the basal Paleogene sequence; they are intercalated with or overlain by deeper-water strata. One region of outcrops in the western Santa Monica Mountains is latest Paleocene in age, while the other region, in the eastern Santa Ynez Mountains and Wheeler Gorge area, is early Eocene in age. These shallow-water limestones may be used as paleogeographic indicators, as they represent relative topographic highs within the basin. The microplate tectonic reconstruction of Hornafius (1985) suggests that the limestones occur on opposite sides of a north-south trending trough within the overall forearc basin. The Paleocene limestones, which occur along the eastern margin of the trough, are intercalated with marine shales and may represent small fluctuations in relative sea level and/or sediment supply on a topographic high. The Eocene limestones, which occur along the western side of the trough, are always the basal Paleogene unit deposited on tilted Cretaceous strata or Franciscan rocks and overlain by deeper-water shales. The occurrence of Franciscan as basement for limestone deposition implies localized tectonic uplift within the forearc. Each of these limestones probably represents initiation of a single period of relative sea level rise, as the basal shallow-water carbonates were eventually overwhelmed by deeper-water shales. Thus two episodes of carbonate deposition allow for the delineation of two topographic highs within the Paleogene forearc basin.

  13. Pathogen and chemical transport in the karst limestone of the Biscayne aquifer: 3. Use of microspheres to estimate the transport potential of Cryptosporidium parvum oocysts

    USGS Publications Warehouse

    Harvey, R.W.; Metge, D.W.; Shapiro, A.M.; Renken, R.A.; Osborn, C.L.; Ryan, J.N.; Cunningham, K.J.; Landkamer, L.

    2008-01-01

    The vulnerability of a municipal well in the Northwest well field in southeastern Florida to potential contamination by Cryptosporidium parvum oocysts was assessed in a large-scale, forced-gradient (convergent) injection and recovery test. The field study involved a simultaneous pulse introduction of a nonreactive tracer (SF6, an inert gas) and oocyst-sized (1.6, 2.9, and 4.9 ??m diameter) carboxylated polystyrene microspheres into karst limestone of the Biscayne aquifer characterized by a complex triple (matrix, touching-vug, and conduit) porosity. Fractional recoveries 97 m down gradient were inversely related to diameter and ranged from 2.9% for the 4.9 ??m microspheres to 5.8% for 1.6 ??m microspheres. Their centers of mass arrived at the pumping well approximately threefold earlier than that of the nonreactive tracer SF6 (gas), underscoring the need for use of colloid tracers and field-scale tracer tests for these kinds of evaluations. In a modified triaxial cell using near in situ chemical conditions, 2.9 and 4.9 ??m microspheres underestimated by fourfold to sixfold the attachment potential of the less electronegative 2.9-4.1 ??m oocysts in the matrix porosity of limestone core samples. The field and laboratory results collectively suggested that it may take 200-300 m of transport to ensure even a 1-log unit removal of oocysts, even though the limestone surfaces exhibited a substantive capability for their sorptive removal. The study further demonstrated the utility of microspheres as oocyst surrogates in field-scale assessments of well vulnerability in limestone, provided that differences in attachment behaviors between oocysts and microspheres are taken into account. Copyright 2008 by the American Geophysical Union.

  14. SRL in-situ tests in the United Kingdom: Part 2, Surface analyses of SRS waste glass buried for one and two years in limestone at Ballidon, UK

    SciTech Connect

    Namboodri, C.G. Jr.; Wicks, G.G.

    1991-02-26

    A multiphase experimental program to assess and understand waste glass behavior under a wide range of conditions has been in progress at the Savannah River Laboratory (SRL) for over a decade. An important part of this experimental effort is to assess the effects of repository relevant conditions on performance of SRS waste glass, in both controlled laboratory tests, as well as in actual field experiments. In laboratory test, SRS waste glass, simulated and in many cases also fully radioactive, has been tested in environments of salt, basalt, shale, granite, clay and tuff. In field experiments, there are four joint international programs being conducted in four different countries, involving burial of SRS simulated waste glass in granite, limestone, clay and salt geologies. This report discusses the SRS waste glass studies in limestone at Ballidon, UK..

  15. Landing and Oviposition Responses of Rhagoletis indifferens (Dipt., Tephritidae) on Sweet Cherry Treated with Kaolin- and Limestone-Based Products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Kaolin- and limestone-based products were compared for their effects on landing and oviposition on sweet cherry by Rhagoletis indifferens Curran (Dipt., Tephritidae). Surround (95% calcined kaolin), Cocoon (100% hydrous kaolin), Eclipse (>97% limestone), and Purshade (62.5% limestone) were studied....

  16. The Mississippian Leadville Limestone Exploration Play, Utah and Colorado-Exploration Techniques and Studies for Independents

    SciTech Connect

    Thomas Chidsey

    2008-09-30

    The Mississippian (late Kinderhookian to early Meramecian) Leadville Limestone is a shallow, open-marine, carbonate-shelf deposit. The Leadville has produced over 53 million barrels (8.4 million m{sup 3}) of oil/condensate from seven fields in the Paradox fold and fault belt of the Paradox Basin, Utah and Colorado. The environmentally sensitive, 7500-square-mile (19,400 km{sup 2}) area that makes up the fold and fault belt is relatively unexplored. Only independent producers operate and continue to hunt for Leadville oil targets in the region. The overall goal of this study is to assist these independents by (1) developing and demonstrating techniques and exploration methods never tried on the Leadville Limestone, (2) targeting areas for exploration, (3) increasing deliverability from new and old Leadville fields through detailed reservoir characterization, (4) reducing exploration costs and risk especially in environmentally sensitive areas, and (5) adding new oil discoveries and reserves. The final results will hopefully reduce exploration costs and risks, especially in environmentally sensitive areas, and add new oil discoveries and reserves. The study consists of three sections: (1) description of lithofacies and diagenetic history of the Leadville at Lisbon field, San Juan County, Utah, (2) methodology and results of a surface geochemical survey conducted over the Lisbon and Lightning Draw Southeast fields (and areas in between) and identification of oil-prone areas using epifluorescence in well cuttings from regional wells, and (3) determination of regional lithofacies, description of modern and outcrop depositional analogs, and estimation of potential oil migration directions (evaluating the middle Paleozoic hydrodynamic pressure regime and water chemistry). Leadville lithofacies at Libon field include open marine (crinoidal banks or shoals and Waulsortian-type buildups), oolitic and peloid shoals, and middle shelf. Rock units with open-marine and restricted

  17. A novel application of the ESR method: dating of insular phosphorites and reef limestone

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Brumby, S.; Jacobson, G.; Beckwith, A. L. J.; Polach, H. A.

    Samples composed of cemented coral conglomerate, reef limestone, and phosphorite have been obtained from outcrops and two drillholes on Nauru Island, central Pacific Ocean. They have been used to test the ESR dating method as applied to insular phosphorite and reef limestone, up to several million years in age. The following time framework for the diagenesis and recrystallisation of the deposits was obtained: 0.08-0.10 Ma for superficial phosphatic crust; 0.18-0.22 Ma for massive phosphorite with nodules and replaced coral; 0.50-0.60 Ma for uppermost reef limestone; 1.00-2.00 Ma for reef limestone at a depth of about 15 m; 3.00-5.00 Ma for reef limestone under the modern reef flat, perhaps extending to the interior upland at a depth of about 70-80 m. These ages are consistent with the stratigraphic positions and geological estimations, thus demonstrating that both phosphatic deposits and reef limestone are suitable for ESR dating. The age limination for reef limestone specimens may be more than 3-4 million years.

  18. Chemico-Mechanical Coupling during Reactive Flow in Oolitic Limestone

    NASA Astrophysics Data System (ADS)

    Odling, N. W.; Elphick, S. C.; Ngwenya, B. T.; Main, I.

    2002-12-01

    Hydrous fluids migrating on fault planes undergo decompression and thus local disequilibrium, reacting with their wallrocks and depositing or dissolving species. This physico-chemical interaction will affect local fluid flow, permeability and effective stress in the region of the fault, and may lead to fault valving. For a geologically meaningful system we have studied the reaction between dilute sulphuric acid and oolitic limestone under constant volume flow. The carbonate-gypsum reaction doubles the solid molar volume, and is capable of blocking the pore space, leading to large increases in the pore fluid pressure under constant volume flow conditions. 0.1M acid was circulated through 38mm diameter core plugs of Indiana limestone in a heated Hassler cell at 90°C, at which conditions gypsum precipitates as `blocky'prisms. Confining and end loads were 20Mpa and 10Mpa respectively, pore fluid pressure was measured at the in-flow and out-flow pistons. The out-flow pore fluid pressure was controlled at 3.5 MPa by a back pressure regulator and the flow rate through the plug was 15cm3.day-1. After some 24 hours the in-flow pore fluid pressure began to oscillate, showing repeated cycles of gradual rise to a differential pressure of 1.2MPa, followed by a sudden drop, giving a `saw-tooth' appearance in the fluid P/time relationship. At the experiments end the up-stream face of the core had been entirely converted to solid gypsum except where penetrated by a small number of holes ~1.5mm in diameter. X-ray tomography showed that these holes are the terminations of narrow dissolution channels (`wormholes') that penetrate approximately parallel to the core axis. The pressure oscilations are interpreted as resulting from chemico-mechanical coupling at the wormhole tip as it sequentially reacts to blocks the pore space, then breaks through as the pore fluid pressure rises. The maximum 1.2MPa thus gives the tensile strength of the gypsum reaction lining to the wormhole tip

  19. ARD remediation with limestone in a CO2 pressurized reactor

    USGS Publications Warehouse

    Sibrell, Philip L.; Watten, Barnaby J.; Friedrich, Andrew E.; Vinci, Brian J.

    2000-01-01

    We evaluated a new process for remediation of acid rock drainage (ARD). The process treats ARD with intermittently fluidized beds of granular limestone maintained within a continuous flow reactor pressurized with CO2. Tests were performed over a thirty day period at the Toby Creek mine drainage treatment plant, Elk County, Pennsylvania in cooperation with the Pennsylvania Department of Environmental Protection. Equipment performance was established at operating pressures of 0, 34, 82, and 117 kPa using an ARD flow of 227 L/min. The ARD had the following characteristics: pH, 3.1; temperature, 10 °C; dissolved oxygen, 6.4 mg/L; acidity, 260 mg/L; total iron, 21 mg/L; aluminum, 22 mg/L; manganese, 7.5 mg/L; and conductivity, 1400 μS/cm. In all cases tested, processed ARD was net alkaline with mean pH and alkalinities of 6.7 and 59 mg/L at a CO2 pressure of 0 kPa, 6.6 and 158 mg/L at 34 kPa, 7.4 and 240 mg/L at 82 kPa, and 7.4 and 290 mg/L at 117 kPa. Processed ARD alkalinities were correlated to the settled bed depth (p<0.001) and CO2 pressure (p<0.001). Iron, aluminum, and manganese removal efficiencies of 96%, 99%, and 5%, respectively, were achieved with filtration following treatment. No indications of metal hydroxide precipitation or armoring of the limestone were observed. The surplus alkalinity established at 82 kPa was successful in treating an equivalent of 1136 L/min (five-fold dilution) of the combined three ARD streams entering the Toby Creek Plant. This side-stream capability provides savings in treatment unit scale as well as flexibility in treatment effect. The capability of the system to handle higher influent acidity was tested by elevating the acidity to 5000 mg/L with sulfuric acid. Net alkaline effluent was produced, indicating applicability of the process to highly acidic ARD.

  20. Rehabilitation of lands mined for limestone in the Indian desert

    USGS Publications Warehouse

    Sharma, K.D.; Kumar, S.; Gough, L.P.

    2000-01-01

    In the Indian desert, the economics of mining is second only to agriculture in importance. However, research on the rehabilitation of land disturbed by mining has only recently received serious attention. An attempt has been made to determine both the qualitative and quantitative success of rehabilitation plans used to revegetate limestone mine spoils in an area near Barna, northwest arid India. Rehabilitation success was achieved using a combination of rainwater harvesting techniques, soil amendment application approaches, plant establishment methods and the selection of appropriate germplasm material (trees, shrubs and grasses). It is expected that the resulting vegetative cover will be capable of self-perpetuation under natural conditions while at the same time meeting the land-use needs of the local people. The minespoils have adequate levels of the major nutrients (except P, Mo and Se) for proper plant and grazing animal health. Levels of organic matter are low whereas total B concentrations are exceptionally high. Also, the population of soil fungi, Azotobactor, and nitrifying bacteria is negligible. Enhanced plant growth was achieved in treated plots, compared to control plots, where spoil moisture storage was improved by 5-45 per cent. Due to the decomposition of farmyard manure and nitrogen fixation by planted leguminous plant species, the electrical conductance of treated mine spoils increased threefold, CaCO3 content decreased from 20??0 to 5??2 per cent, and organic carbon, P, K, and biological activity increased significantly. The rehabilitation protocol used at the site appears to have been successful because plant self-regeneration is occurring. The increased diversity of woody perennials resulted in 'dominance' being better shared among species and 'evenness' being increased within the plant community elements. The early to mid-successional trends are continuing for six years following initial rehabilitation. This study developed methods for the

  1. Marl-limestone bedding and sea level change, Upper Cretaceous of Alabama coastal plain

    SciTech Connect

    King, D.T. Jr. )

    1990-05-01

    Primary Upper Cretaceous marl-limestone sequences in Alabama are superficially similar to sequences interpreted as orbitally forced (Milankovitch) cycles with apparent 100,000 yr periodicity. However, key petrographic and stratigraphic observations cast doubt on a Milankovitch interpretation of the Alabama sequences. These observations include (1) varying thickness from less than 1 m to several meters within marl-limestone sequences, (2) fining upward among the coarse clastic grain sizes within each marl-limestone sequence, and (3) switching the primary mode of biochemical deposition between the marl and limestone beds (e.g., the limestone bed in each marl-limestone sequence contains abundant benthic algal grains (over 50%), whereas the marl contains only pelagic nannofossils). Periodicity is not supported by observed thickness variations and the other petrographic and stratigraphic observations previously noted are inconsistent with cyclic (Milankovitch) productivity/dilution genesis of bedding. In Alabama, marl-limestone sequences and correlative coeval prograding clastic barrier-shoreline facies comprise the upper 20 m of a highstand systems tract within the lower Campanian Mooreville-Demopolis depositional sequence. A sequence-bounding (type 2) stratigraphic break, which has been biostratigraphically correlated with the global sea level drop at 80 Ma occurs at the top of the 20 m marl-limestone interval. Tectonic effects related to the early stages of the Laramide orogeny (about 80 Ma) affected short-term relative sea level thus producing the marlstone sequences. In this hypothesis, the marl-limestone sequences reflect either short-term buildup and relaxation of intraplate stresses or short-term eustatic changes that resulted from slight variations in Farallon spreading rates.

  2. Meteoric stabilization and preservation of limestone within late Proterozoic Beck Spring Dolomite of eastern California

    SciTech Connect

    Zempolich, W.G.; Wilkinson, B.H.; Lohmann, K.C.

    1989-04-01

    Petrographic and geochemical study of limestone, silicified carbonate, and dolostone indicates that meteoric diagenetic processes and paleogeographic position played important roles in the stabilization and preservation of limestone within the pervasively dolomitized Beck Spring Dolomite. The authors conclude that Beck Spring marine cement allochems precipitated as aragonite and high-magnesium calcite. In the vicinity of Saratoga Spring, these metastable mineralogies were dissolved, eroded, stabilized to calcite, and replaced by silica through interaction with meteoric waters. Early stabilization of limestone components along the margin of the Amargosa basin apparently decreased susceptibility to subsequent dolomitization.

  3. Desulfurization with a modified limestone formulation in an industrial CFBC boiler

    SciTech Connect

    Young Goo Park; Seung Ho Kim

    2006-02-01

    This work presents a practical result of experimental investigation of the limestone particle size effect on de-SOx from a circulating fluidized bed combustion (CFBC) boiler that burns domestic anthracite and is the first industrial scale in Korea. Because of combustion problems such as clinker formation, fine limestone has not been used as a desulfurization agent. The present test, however, showed that higher content (up to 50%) of the particles under 0.1 mm did not entail any malfunction in a modern CFBC system. In addition, the desulfurization efficiency was found to be comparable to the old mode of limestone sorbents. 17 refs., 4 figs., 3 tabs.

  4. Diagenetic features of Trenton Limestone in northern Indiana: petrographic evidence for Late (Mesogenetic) Dolostone

    SciTech Connect

    Fara, D.R.

    1986-08-01

    Three conventional cores of the entire Trenton section were examined in detail by in-depth visual description, analysis of more than 250 thin sections, scanning electron microscopy, and x-ray diffraction. The cores are located in the northern half of Indiana where they span the major dolostone pinch-out that is the trap for the prolific Trenton oil and gas field. The Trenton Limestone is completely dolomitized in northern Indiana. Dolostone abundance decreases to the south where the dolostone is restricted to the upper few feet of the formation. Two major types of dolostone are recognized. The top 5-20 ft of the Trenton cores consists of medium crystalline nonporous xenotopic ferroan dolostone. Mesogenetic dewatering of the overlying Maquoketa shale is the proposed dolomitizing mechanisms for this ferroan dolostone cap. Below the ferroan dolostone cap in northern Indiana is coarsely crystalline dolostone, which consists of thin intercalated subfacies of porous idiotopic and nonporous xenotopic dolostone. This is the dominant dolostone type and is the reservoir in the Trenton field. The coarsely crystalline dolostone postdates the ferroan dolostone cap, chert nodule formation, and initial pressure solution. Therefore, this dolostone is considered to have formed relatively late in the diagenetic history of the Trenton under mesogenetic conditions. In the northernmost core, nearly all of the secondary dolomitic porosity is plugged by poikilotopic gypsum and minor amounts of calcite and celestite. Other diagenetic features observed in Trenton are also discussed, including silicification, ferroan calcite cement, upper Trenton contact formation, hardgrounds, and pressure solution.

  5. Styles of trap development in Caddo limestone in Bend Arch area, north-central Texas

    SciTech Connect

    Crabtree, J.L. )

    1987-02-01

    The Lower Pennsylvanian Caddo limestone has been a prolific hydrocarbon producer in the Bend arch area of north-central Texas since the early 1900s and continues to be a major exploration target although it is in a mature province. Early explorationists understood the Caddo's large potential when the James pool was discovered in Young County in 1917. Initial flows were greater than 1,000 BOPD in some wells, and field development with additional infill drilling and waterfloods continued into the early 1980s. James pool has produced more than 2 million bbl of oil as of December 1985. Fields in jack, Throckmorton, and Archer Counties had recorded similar successes by the 1940s. The early caddo discoveries were made before singlefold seismic mapping was available, and were based on sparse subsurface control. By the 1950s and 1960s, seismic and subsurface data were more commonly used in the hunt for Caddo reservoirs. Most exploration concepts held that all Caddo traps were structural. Recent studies showed that structural, stratigraphic, and combination traps are common in the Caddo. This study presents examples of each trap type in the Bend arch area, where 49 million bbl of oil has been discovered in the Caddo, and focuses on the current exploration methods.

  6. pp iii Lichen hotspots: raised rock temperatures beneath Verrucaria nigrescens on limestone

    NASA Astrophysics Data System (ADS)

    Carter, N. E. A.; Viles, H. A.

    2004-09-01

    Field exposure trials and laboratory experiments are integrated to compare surface and internal temperature changes of limestone with an epilithic ( Verrucaria nigrescens) and endolithic ( Verrucaria baldensis) covering of lichens, and with no lichen cover (control). Blocks with covering of V. nigrescens experience both the highest surface and internal temperatures under a direct heating source during daytime and in laboratory experiments. Spectrophotometer data suggest that the black colour of the V. nigrescens thallus plays a significant role in determining the thermal response of the rock surface. When direct heating (by sun or lamp) is absent (at nighttime and for a diurnal cycle programmed in an environmental chamber), little differentiation occurs between surface and internal temperatures for all surface types compared. For all blocks exposed, maximum rates of daytime surface temperature change ranged from 1.47 to 3.04 °C min -1 and for two of the exposure periods, the highest rates of daytime surface temperature change were experienced by blocks with V. nigrescens cover. The blocks with V. nigrescens cover also experience the greatest thermal gradients in both field and laboratory experiments. The rates of surface temperature change and thermal gradients experienced beneath V. nigrescens in this study could be significant in increasing rock susceptibility to breakdown.

  7. The Surface of a Limestone-Rich World?

    NASA Astrophysics Data System (ADS)

    Melis, Carl; Dufour, Patrick

    2016-06-01

    We present spectroscopic observations of the dust- and gas-enshrouded, polluted white dwarf star SDSSJ104341.53+085558.2 (hereafter SDSSJ1043). Hubble Space Telescope Cosmic Origins Spectrograph far-ultraviolet spectra combined with deep Keck HIRES optical spectroscopy reveal the elements C, O, Mg, Al, Si, P, S, Ca, Fe, and Ni and enable useful limits for Sc, Ti, V, Cr, and Mn in the photosphere of SDSSJ1043. From this suite of elements we determine that the parent body being accreted by SDSSJ1043 is dry, rocky, and iron-poor. Synthesizing all available heavily-polluted white dwarf measurements, we find a trend in the Fe/Mg vs Fe/Si abundance ratio-space suggestive of whether accreted material originates from the inner or outer regions of a rocky body; we use this trend to identify the material being accreted by SDSSJ1043 as likely to have come from the outermost layers of a differentiated object. Enhanced levels of Ca and C in this object can be explained by the presence of significant amounts of calcium-carbonate and, if definitive, could be suggestive of a world with a crust rich in limestone.

  8. Cyclicity in Upper Mississippian Bangor Limestone, Blount County, Alabama

    SciTech Connect

    Bronner, R.L.

    1988-01-01

    The Upper Mississippian (Chesterian) Bangor Limestone in Alabama consists of a thick, complex sequence of carbonate platform deposits. A continuous core through the Bangor on Blount Mountain in north-central Alabama provides the opportunity to analyze the unit for cyclicity and to identify controls on vertical facies sequence. Lithologies from the core represent four general environments of deposition: (1) subwave-base, open marine, (2) shoal, (3) lagoon, and (4) peritidal. Analysis of the vertical sequence of lithologies in the core indicates the presence of eight large-scale cycles dominated by subtidal deposits, but defined on the basis of peritidal caps. These large-scale cycles can be subdivided into 16 small-scale cycles that may be entirely subtidal but illustrate upward shallowing followed by rapid deepening. Large-scale cycles range from 33 to 136 ft thick, averaging 68 ft; small-scale cycles range from 5 to 80 ft thick and average 34 ft. Small-scale cycles have an average duration of approximately 125,000 years, which is compatible with Milankovitch periodicity. The large-scale cycles have an average duration of approximately 250,000 years, which may simply reflect variations in amplitude of sea level fluctuation or the influence of tectonic subsidence along the southeastern margin of the North American craton.

  9. Estimating mass of crushed limestone particles from 2D images

    NASA Astrophysics Data System (ADS)

    Banta, Larry E.; Cheng, Ken; Zaniewski, John P.

    2002-02-01

    In the construction of asphalt pavements, the stability of the asphalt is determined in large part by the gradation, or size distribution of the mineral aggregates that make up the matrix. Gradation is specified on the basis of sieve sizes and percent passing, where the latter is a cumulative measure of the mass of the aggregate passing the sieve as fraction of the total mass in the batch. In this paper, an approach for predicting particle mass based on 2D electronic images is explored. Images of crushed limestone aggregates were acquired using backlighting to create silhouettes. A morphological erosion process was used to separate touching and overlapping particles. Useful features of the particle silhouettes, such as area, centroid and shape descriptors were collected. Several dimensionless parameters were defined and were used as regressor variables in a multiple linear regression model to predict particle mass. Regressor coefficients were found by fitting to a sample of 501 particles ranging in size from 4.75 mm < particle sieve size < 25 mm. When tested against a different aggregate sample, the model predicted the mass of the batch to within +/- 2%.

  10. Nitrate removal with sulfur-limestone autotrophic denitrification processes

    SciTech Connect

    Flere, J.M.; Zhang, T.C.

    1999-08-01

    Nitrate removal using sulfur and limestone autotrophic denitrification (SLAD) processes was evaluated with four laboratory-scale fixed-bed column reactors. The research objectives were (1) to determine the optimum design criteria of the fixed-bed SLAD columns; and (2) to evaluate the effects of biofouling on the SLAD column performance. A maximum denitrification rate of 384 g NO{sub 3}{sup {minus}}-N(m{sup 3}{center_dot}day) was achieved at a loading rate between 600 and 700 g NO{sub 3}{sup {minus}}-N(m{sup 3}{center_dot}day). The effluent nitrite concentration started to rise gradually once the loading rate was above 600 g NO{sub 3}{sup {minus}}-N(m{sup 3}{center_dot}day). A loading rate between 175 and 225 g NO{sub 3}{sup {minus}}-N(m{sup 3}{center_dot}day) achieved the maximum nitrate-N removal efficiency ({approximately}95%). Biofouling was evaluated based on tracer studies, the measured biofilm thickness, and modeling. The porosities of the columns fluctuated with time, and the elongation of the filter media was observed. Biofouling caused short-circuiting and decreased nitrate removal efficiency. A SLAD column will require backwashing after 6 months of operation when the influent is synthetic ground water but will foul and require backwashing within 1--2 months when the influent is real ground water.

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

    NASA Technical Reports Server (NTRS)

    Rowan, L. C.; Watson, K.

    1970-01-01

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

  12. PROCEEDINGS: INDUSTRY BRIEFING ON EPA LIME/LIMESTONE WET SCRUBBING TEST PROGRAMS AUGUST 1978

    EPA Science Inventory

    The proceedings document presentations made during the August 29, 1978 industry briefing conference which dealt with the status of EPA/IERL-RTP's flue gas desulfurization (FGD) research, development, and application programs. Subjects considered included: lime/limestone scrubbing...

  13. SELECTED CHARACTERISTICS OF LIMESTONE AND DOLOMITE RESERVOIRS IN THE UNITED STATES.

    USGS Publications Warehouse

    Schmoker, James W.; Krystinik, Katherine B.; Halley, Robert B.

    1985-01-01

    Limestone reservoirs are more numerous in the United States than dolomite reservoirs (by a ratio of about 3 to 1) because limestones are more abundant than dolomite. However, in the eight states that account for over 90% of United States carbonate reservoirs, there is a statistical tendency for carbonate reservoirs to occur preferentially in dolomites. Dolomite reservoirs, on the average, are larger and deeper than those of limestone, yet they often have lower matrix porosities and permeabilities. This line of investigation offers supplemental evidence that dolomitization tends to improve the reservoir properties of a given formation, and that effective fracture systems at reservoir depths are more likely to occur in dolomites than in limestones. Refs.

  14. Primary deforestation and regrowth on limestone slopes on Vancouver Island, British Columbia

    SciTech Connect

    Harding, K.A.; Ford, D.C. . Dept. of Geography)

    1992-01-01

    Limestones, well bedded and steeply dipping, are common in northern Vancouver Island. They have been glaciated and host a high density of postglacial karren (dissolution pits, grooves and troughs linked to underlying caves). There is rich, mature forest cover of western hemlock, silver fir and red cedar that is rooted in the karren or in overlying glacial deposits. Logging commenced around 1900 AD, intensifying after 1960 with clear cutting and (often) burning of slash. Impacts were investigated quantitatively by comparing sixteen limestone sites with eight on adjoining volcanic rocks. Some sites on each retained original forest, other were cleared. It was found that soil losses following logging are significantly greater on the limestones because of wash into karren (the epikarst zone). Regrowth is retarded on the limestones also; one site cleared in 1911 had regained approximately 17% of its original volume of timber 75 years later.

  15. Influence of limestone fillers on combustion characteristics of asphalt mortar for pavements

    NASA Astrophysics Data System (ADS)

    Wu, Ke; Zhu, Kai; Wu, Hao; Han, Jun; Wang, Jin-Chang; Huang, Zhi-Yi; Liang, Pei

    2014-07-01

    Asphalt materials will be ignited and release significant toxic fumes within tunnel fires. Thus, combustion characteristics of asphalt materials used in road tunnel should be studied in order to limit such an adverse effect. In the present work we study the influence of limestone fillers on combustion characteristics of asphalt mortar by thermogravimetric and kinetic analysis. It is shown that the combustion of asphalt mortar is not just a linear superposition of asphalt and limestone. The limestone will increase the ignition point and the activation energy of the primary volatile release, and will catalyze the char formation from the primary volatile release. Kinetic analysis shows that the primary volatile release stage of asphalt mortar combustion can be explained by a three-dimensional diffusion model, the secondary volatile release and char combustion stage can be explained by a model under the assumption of random nucleation and nuclei growth, whereas the limestone decomposition stage appears to follow the one-dimensional phase boundary model.

  16. Lime and limestone market for sulfur removal: potential for 1992. Illinois mineral notes

    SciTech Connect

    Bhagwat, S.B.

    1985-01-01

    In the United States, the market for lime and limestone declined in the 1970s and early 1980s; however, following the passage of clean air regulations, a small niche in the market developed when lime and limestone became important components of processes used to reduce the sulfur dioxide emissions that result from burning coal. No demand for lime and limestone for sulfur removal existed in 1974, and tremendous growth was predicted. However, by 1983 sales of lime and limestone only achieved 8% of the predicted potential. The demand did not reach the projected level partly because of the availability of low-sulfur fuels, the differences in industrial growth rates from state to state, the flexibility in implementation of the Clean Air Act, and the demographics of the country.

  17. EPA'S LIMB (ENVIRONMENTAL PROTECTION AGENCY'S LIMESTONE INJECTION MULTISTAGE BURNER) RESEARCH, DEVELOPMENT, AND DEMONSTRATION PROGRAM

    EPA Science Inventory

    The paper describes and discusses key design features of the retrofit of EPA's Limestone Injection Multistage Burner (LIMB) system to an operating, wallfired utility boiler at Ohio Edison's Edgewater Station, based on the preliminary engineering design. It further describes resul...

  18. DEFINITIVE SOX CONTROL PROCESS EVALUATIONS: LIMESTONE, DOUBLE ALKALI, AND CITRATE FGD PROCESSES

    EPA Science Inventory

    The report gives results of a detailed comparative technical and economic evaluation of limestone slurry, generic double alkali, and citrate flue gas desulfurization (FGD) processes, assuming proven technology and using representative power plant, process design, and economic pre...

  19. The minimal response to contact metamorphism by the Devonian Buchan Caves Limestone, Buchan Rift, Victoria, Australia

    USGS Publications Warehouse

    Barker, C.E.; Bone, Y.

    1995-01-01

    A 2.2 m thick, Late Eocene (?) dike that intruded the Devonian Buchan Caves Limestone, near Murrindal, Victoria, has produced a narrow contact aureole only centimeters wide in the adjacent host rock. The lack of response of the Buchan Caves Limestone to contact metamorphism is attributed to: 1) prior heating to near 200??C; and 2) the fact that the dike intruded into cool, near surface, low-porosity rocks which may have been in the vadose zone. -from Authors

  20. Structure, stratigraphy, and depositional environment of the heterostegina limestone and overlying sandstones in the Lake Pontchartrain area of southeast Louisiana

    SciTech Connect

    Street, S.B. III; Lock, B.E.

    1994-12-31

    The Heterostegina zone of the Oligocene Anahuac Formation in southwestern Louisiana occurs in the subsurface as an extensive shelf reef complex. The Heterostegina limestone is overlain by strata associated with the Oligocene Discorbis and lower Miocene Robulus (43) biostratigraphic zones. Examination of electric logs and drill cuttings from wells in the Lake Pontchartrain area of southeastern Louisiana reveals the importance of the Heterostegina reef as a paleoenvironmental punctuation marking a significant shift in regional depositional patterns that occurred between the generally transgressive Oligocene seas and the generally regressive Miocene seas. Fauna identified in thin section from the Heterostegina reef interval suggest deposition in a warm, shallow-marine environment relatively free of significant clastic influx. An eastward migration of late Oligocene-early Miocene stream systems introduced an influx of clastic sediments onto the ancient shelf of the Lake Pontchartrain area, which influenced the termination of favorable conditions for Heterostegina reef growth. Lithofacies I is characterized by thick, shore-parallel sandstone deposits and is interpreted to have been deposited in association with a barrier-beach/tidal-inlet channel environment. Lithofacies II is characterized by shale-prone sandstone intervals, which are immediately overlain by calcareous mudstones and limestones deposited in the offshore inner-middle neritic environment. Five oil and gas fields in the study area have produced hydrocarbons from the interval of interest. The occurrence of hydrocarbons at these locations with respect to mechanisms of entrapment and areal extent of the reservoirs was characterized through detailed subsurface mapping.

  1. Effect of the specimen length on ultrasonic P-wave velocity in some volcanic rocks and limestones

    NASA Astrophysics Data System (ADS)

    Karaman, Kadir; Kaya, Ayberk; Kesimal, Ayhan

    2015-12-01

    Ultrasonic P-wave velocity (UPV) is commonly used in different fields such as civil, mining, geotechnical, and rock engineering. One of the significant parameters which affect the UPV of rock materials is likely to be the length of test cores although it is not mentioned in the literature. In this study, in order to explore the influence of the specimen length on the UPV, rock samples were collected from eight different locations in Turkey. The NX-sized core specimens having different length of 50, 75, 100, 125, and 150 mm were prepared. Before the analyses, rocks were divided into two groups in terms of their geological origins such as volcanic and chemical sedimentary (limestone) rocks. The UPV tests were carried out under dry and saturated conditions for each 200 core specimens. By evaluating the test results, it was shown that the length of the specimens significantly affects the UPV values. Based on the regression analyses, a method was developed to determine the threshold specimen length of studied rocks. Fluctuations in UPVdry and UPVsat values were generally observed for cores smaller than the threshold specimen length. In this study, the threshold specimen length was determined as 79 mm for volcanic rocks and 109 mm for limestones.

  2. Novel preparation method of macroporous lime from limestone for high-temperature desulfurization

    SciTech Connect

    Sasaoka, Eiji; Uddin, M.A.; Nojima, Shigeru

    1997-09-01

    Limestone is a very important material as a high temperature desulfurization sorbent: limestone is used for in-bed SO{sub 2} capture in fluidized bed combustors of coal and can be used in coal gasifiers for the in-bed removal of H{sub 2}S. In order to develop a highly active calcium oxide high-temperature desulfurization sorbent, macroporous calcium oxides were directly prepared from limestone. This method is composed of two steps: swelling of the limestone in the gas phase followed by drying and calcination of the swelled samples. The swelling was found when limestone was exposed to a vapor of aqueous acetic acid. The swelling of the sample resulted from an increase of calcium acetate formation in the sample. It was then converted to macroporous calcium oxides by heating the sample to 850 C. The reactivity of the macroporous calcium oxide for the removal of SO{sub 2} or H{sub 2}S under coexisting H{sub 2}O vapor was higher than that of the calcined raw limestone. In particular, its SO{sub 2} removal capacity and oxidative character of CaS to CaSO{sub 4} and CaO were greatly improved by the swelling method.

  3. Direct sulfation of limestone based on oxy-fuel combustion technology

    SciTech Connect

    Chen, C.M.; Zhao, C.S.; Liu, S.T.; Wang, C.B.

    2009-10-15

    With limestone as the sorbent, the sulfation reaction can proceed via two different routes depending on whether calcination of the limestone takes place under the given reaction conditions. The direct sulfation reaction is defined as the sulfation reaction between sulfur dioxide (SO{sub 2}) and limestone in an uncalcined state. This reaction, based on oxyfuel combustion technology, was studied by thermogravimetric analysis. Surface morphologies of the limestone particles after sulfation were examined by a scanning electron microscope. Results show that there are more pores or gaps in the product layer formed by direct sulfation of limestone than by indirect sulfation, which can be attributed to the generation of carbon dioxide (CO{sub 2}) at a reaction interface. Compared with indirect sulfation, direct sulfation of limestone can yield much higher conversion and has a much higher reaction rate. For direct sulfation, the greater porosity in the product layer greatly reduces the solid-state ion diffusion distance, resulting in a higher reaction rate and higher conversion.

  4. Interpretation of well hydrographs in the karstic Maynardville Limestone at the Oak Ridge Y-12 Plant

    SciTech Connect

    Shevenell, L.A.; McMaster, B.W.

    1996-06-01

    The Maynardville Limestone in Oak Ridge, Tennessee underlies the southern portion of Bear Creek Valley (BCV), and is considered to be the primary pathway for groundwater leaving the Y-12 Plant boundaries. Sixty-seven percent of all wells drilled into the Maynardville Limestone have intersected at least one cavity, suggesting karst features may be encountered throughout the shallow (< 200 ft) portions of the Limestone. Because waste facilities at the Y-12 Plant are located adjacent to the Maynardville Limestone, contaminants could enter the karst aquifer and be transported in the conduit system. As part of an overall hydrologic characterization effort of this karst aquifer, 41 wells in the Maynardville Limestone were instrumented with pressure transducers to monitor water level changes (hydrographs) associated with rain events. Wells at depths between approximately 20 and 750 ft were monitored over the course of at least two storms in order that variations with depth could be identified. The wells selected were not exclusively completed in cavities but were selected to include the broad range of hydrologic conditions present in the Maynardville Limestone. Cavities, fractures and diffuse flow zones were measured at a variety of depths. The water level data from the storms are used to identify areas of quickflow versus slower flowing water zones. The data are also used to estimate specific yields and continuum transmissitives in different portions of the aquifer.

  5. Accelerated weathering of limestone for CO2 mitigation opportunities for the stone and cement industries

    USGS Publications Warehouse

    Langer, W.H.; Juan, C.A.S.; Rau, G.H.; Caldeira, K.

    2009-01-01

    Large amounts of limestone fines coproduced during the processing of crushed limestone may be useful in the sequestration of carbon dioxide (CO 2). Accelerated weathering of limestone (AWL) is proposed as a low-tech method to capture and sequester CO2 from fossil fuel-fired power plants and other point-sources such as cement manufacturing. AWL reactants are readily available, inexpensive, and environmentally benign. Waste CO 2 is hydrated with water to produce carbonic acid, which then reacts with and is neutralized by limestone fines, thus converting CO2 gas to dissolved calcium bicarbonate. AWL waste products can be disposed of in the ocean. Feasibility requires access to an inexpensive source of limestone and to seawater, thus limiting AWL facilities within about 10 km of the coastline. The majority of U.S. coastal power generating facilities are within economical transport distance of limestone resources. AWL presents opportunities for collaborative efforts among the crushed stone industry, electrical utilities, cement manufactures, and research scientists.

  6. Sedimentology and diagenesis of Miocene Lirio Limestone, Isla de Mona, Puerto Rico

    SciTech Connect

    Ruiz, H.; Gonzalez, L.A.; Budd, A.F. )

    1991-03-01

    Isla de Mona is a carbonate plateau, 50 mi west of Puerto Rico. The island lies on the southern portion of the Mona Platform. It is composed mostly of two Miocene carbonate units: Isla de Mona Dolomite overlain by Lirio Limestone. The Lirio Limestone was deposited on a sloping erosional surface over the Isla de Mona Dolomite. The Miocene Lirio Limestone consists mostly of backreef sands (packstones) with a reefal sequence (boundstones and grainstones) present in the southwestern portion of the island. The reefal sequence is made up mostly of Stylophora, Porites, and Millepora. Thin, discreet pockets of carbonate mud, rich in planktonic foraminifera and radiolarians and mixed with shallow benthic fauna/flora (foraminifera, echinoderms, red algae, and corals) interpreted as storm deposits, are found throughout the unit. An extensive reefal zone can be inferred to be present throughout the southwestern to southern portions of the Mona Platform. The Lirio Limestone is heavily karstified and is riddled with sinkholes on the plateau surfaces and caves around the periphery of the island. Caves are exposed around the periphery of the island, radiating from a depression in the central portions of the Lirio Limestone, near contacts with the Isla de Mona Dolomite, are partially dolomitized. The southwestern outcrops exhibit partial dolomitization throughout. The distribution of sinkholes, seaward caverns, and partial dolomitization of the lowermost Lirio Limestone suggests diagenetic modifications by meteoric fluids in central exposed portions of the island and by marine-meteoric fluids in the lowermost portions of the phreatic lens.

  7. Diagenetic history of the Stanton Limestone (Missourian, Upper Pennsylvanian) in northern midcontinent

    SciTech Connect

    Xiong, B.; Heckel, P.H. . Dept. of Geology)

    1993-03-01

    The Stanton Limestone in the northern midcontinent represents a complete cyclothem deposited during eustatic sea level change. The transgressive and regressive limestone members of the Stanton Limestone experienced initially different but later similar diagenetic patterns. Three phases of diagenesis are recognized. Early phase in the transgressive limestone took place during shallow burial probably up through maximum transgression. It is characterized by aragonite botryoids in skeletal cavities and in sheltered pore space beneath algal blades. Pervasive pyrite cement near the upper part resulted from sulfate reduction under the anoxic environment established at maximum transgression. Early diagenesis of the regressive limestone, however, is characterized by a great abundance of isopachous rims of fibrous to bladed calcite and inclusion-rich syntaxial overgrowths. The second phase of diagenesis involved meteoric water, which caused leaching of unstable grains and subsequent collapse and micro-brecciation in both limestones. Cements precipitated during early diagenesis were geochemically overprinted during meteoric diagenesis, giving rise to bright luminescence (higher Mn[sup 2+] ) under CL for all the early marine cements. The late diagenetic phase occurred during deeper burial when higher cyclothems were at their early to second phases of diagenesis. Much iron (Fe[sup 2+]) was incorporated into carbonate cements dominated by ankerite and Fe-dolomite, because of the reducing nature of deep burial environments. In some cases, silica void-filling and replacement of earlier cements represent the latest generation of cements.

  8. A reconnaissance in northern Alaska across the Rocky Mountains, along Koyukuk, John, Anaktuvuk, and Colville rivers and the Arctic coast to Cape Lisburne, in 1901, with notes

    USGS Publications Warehouse

    Schrader, F.C.; Peters, W.J.

    1904-01-01

    Since 1898 the United States Geological Survey has been carrying on systematic topographic and geologic surveys in Alaska under an appropriation made for the investigation of the mineral resources of the Territory. This work has included not only areal surveys of regions already being developed by the miner and prospector, but also explorations and investigations of regions that are little known or entirely unexplored. As a result of these explorations a network of reconnaissance traverses has been extended over a large part of Alaska, where route surveys of this character must necessarily precede more detailed topographic and geologic mapping. They serve to outline the main geographic features of the country and afford the pioneer or prospector a guide for his journeys as well as help him to select his field of operations. The present report and maps are the results of such an investigation.

  9. Mangrove plantation over a limestone reef - Good for the ecology?

    NASA Astrophysics Data System (ADS)

    Asaeda, Takashi; Barnuevo, Abner; Sanjaya, Kelum; Fortes, Miguel D.; Kanesaka, Yoshikazu; Wolanski, Eric

    2016-05-01

    There have been efforts to restore degraded tropical and subtropical mangrove forests. While there have been many failures, there have been some successes but these were seldom evaluated to test to what level the created mangrove wetlands reproduce the characteristics of the natural ecosystem and thus what ecosystem services they can deliver. We provide such a detailed assessment for the case of Olango and Banacon Islands in the Philippines where the forest was created over a limestone reef where mangroves did not exist in one island but they covered most of the other island before deforestation in the 1940s and 1950s. The created forest appears to have reached a steady state after 60 years. As is typical of mangrove rehabilitation efforts worldwide, planting was limited to a single Rhizophora species. While a forest has been created, it does not mimic a natural forest. There is a large difference between the natural and planted forests in terms of forest structure and species diversity, and tree density. The high density of planted trees excludes importing other species from nearby natural forests; therefore the planted forest remains mono-specific even after several decades and shows no sign of mimicking the characteristics of a natural forest. The planted forests provided mangrove propagules that invaded nearby natural forests. The planted forest has also changed the substratum from sandy to muddy. The outline of the crown of the planted forest has become smooth and horizontal, contrary to that of a natural forest, and this changes the local landscape. Thus we recommend that future mangrove restoration schemes should modify their methodology in order to plant several species, maintain sufficient space between trees for growth, include the naturally dominant species, and create tidal creeks, in order to reproduce in the rehabilitated areas some of the key ecosystem characteristics of natural mangrove forests.

  10. Techniques to improve the economics of limestone FGDS

    SciTech Connect

    Bresowar, G.E.; Klingspor, J.

    1995-12-31

    Many utilities have evaluated the cost of scrubbing versus fuel switching in various plans and scenarios to determine the most economical means for meeting the requirements of the new law. Presently, the future cost of removing a ton of SO{sub 2} is based on fuel switching, and the market values are in the range of $150 - $250 per ton. The perceived cost of FGDS retrofits is $250 - $400 per ton for eastern medium to high sulfur coal. ABB has studied the overall costs of FGDS and has developed a series of cost reducing improvements. and innovations. The improvements are manifested in ABBs new limestone FGDS technology known by the code phrase {open_quote}Stealth FGDS{close_quotes}. Stealth promises low capital and operating cost, high removal efficiencies for SO{sub 2} and other pollutants, little or positive environmental and economic impact on the local community, salable or non-hazardous by-products, ease of retrofit, and exceptionally short installation schedules. The concepts are being demonstrated in one system at the Miles Generating Station of Ohio Edison Company. Bearing the name {open_quote}LS-2 Advanced SO, Scrubbing{close_quotes}, the Stealth scrubber at Niles is a 110 MWe turnkey, retrofit unit to be completed 20 months after the release of engineering. It will remove 20,000 or more tons per year of SO{sub 2} from the flue gases generated by both Unit 1 and Unit 2 boilers, producing wallboard-grade gypsum. Upon completion of a four month test program, the plant will be operated by Ohio Edison for a four to five year reliability demonstration period. The performance and economic projections for LS-2 scrubbers show the technology to be quite attractive relative to projections for fuel switching when installed in a manner similar to the installation plan for Niles. The description and basis for these economic projections are described in this paper.

  11. An Unusual Process of Accelerated Weathering of a Marly Limestone

    NASA Astrophysics Data System (ADS)

    Ercoli, L.; Rizzo, G.; Algozzini, G.

    2003-04-01

    This work deals with a singular case of stone deterioration, which occurred during the restoration of the Cathedral of Cefalù. In particular, a significant process of stone decohesion started after a consolidation treatment on ashlars of the external face of the cloister portico. A study was carried out to characterize the stone and to investigate the deterioration process. Petrographical, chemical and physical analyses were performed on samples taken from the wall. The results indicate that the medieval monument was built using a Pliocene marly limestone, called "trubo", quarried from outcrops of the environs of Cefalù. The rock is soft and uniformely cemented. The carbonatic fraction of the rock is due to foraminifera shells; the rock also contains detritic quartz, feldspate and glauconite. The clay minerals, mainly illite and montmorillonite, are widespread in the rock in the form of thin layers. The use of such a stone in a building of relevant artistic value is definitely unusual. In fact, the "trubo" is a rock subjected to natural decay because of its mineralogical composition and fabric; as effect of natural weathering, in the outcrops the rock disaggregates uniformely, producing silt. In the cloister this effect was magnified by extreme environmental conditions (marine spray, severe excursions of both relative humidity and temperature). Furthermore, after soluble salts removing and subsequent consolidation with ethyl silicate, a significant acceleration of the decay process was observed, producing friable scales detach for a depth of about 3 cm into the ashlars. The stone appeared corroded and uneven. Experimental tests were performed in laboratory in order to evidence any origin of incompatibility between such stone composition and the treatments carried out, which on the other hand are the most generally adopted in restoration interventions.

  12. Underground dams for irrigation supplies in coastal limestone aquifer, Okinawa, Japan

    NASA Astrophysics Data System (ADS)

    Yasumoto, J.; Nakano, T.; Nawa, N.

    2011-12-01

    were a few differences between the calculation and observation. The numerical model introducing non-darcian flow could be carried out to improve the model by inputting various data of geological structure of Ryukyu limestone. It was found that the NO3-N concentrations in springs ranged from 6.2 mg/L to 16.6mg/L during 17 years in this area. The NO3-N concentrations had decreased from the mid-1990s to early 2000s. And The NO3-N concentrations have not decreased or increased since early 2000s. Distribution of NO3-N concentrations shows variations according to location and they are roughly classified into two types (stable type and unstable type). It was considered that NO3-N concentrations were influenced by the rainfall, geological structure and land use of upland fields. The results show that the underground dams are a contribution in sustainable development of irrigation in Okinawa islands. The results also demonstrate that underground dam may be a very useful instrument of sustainable increase in the available storage in the tropical and subtropical coastal aquifers. The future challenge is how to decrease the high NO3-N concentrations in underground dam areas.

  13. Detailed characterization of a fractured limestone formation using stochastic inverse approaches

    SciTech Connect

    Gupta, A.D.; Vasco, D.W.; Long, J.C.S.

    1994-07-01

    We discuss here two inverse approaches to construction of fracture flow models and their application in characterizing a fractured limestone formation. The first approach creates ``equivalent discontinuum`` models that conceptualize the fracture system as a partially filled lattice of conductors which are locally connected or disconnected to reproduce the observed hydrologic behavior. An alternative approach viz. ``variable aperture lattice`` models represent the fracture system as a fully filled network composed of conductors of varying apertures. The fracture apertures are sampled from a specified distribution, usually log-normal consistent with field data. The spatial arrangement of apertures is altered through inverse modeling so as to fit the available hydrologic data. Unlike traditional fracture network approaches which rely on fracture geometry to reproduce flow and transport behavior, the inverse methods directly incorporate hydrologic data in deriving the fracture networks and thus naturally emphasize the underlying features that impact the fluid flow and transport. However, hydrologic models derived by inversion are non-unique in general. We have addressed such non-uniqueness by examining an ensemble of models that satisfy the observational data within acceptable limits. We then determine properties which are shared by the ensemble of models as well as their associated uncertainties to create a conceptual model of the fracture system.

  14. Attachment and Detachment Behavior of Human Adenovirus and Surrogates in Fine Granular Limestone Aquifer Material.

    PubMed

    Stevenson, Margaret E; Sommer, Regina; Lindner, Gerhard; Farnleitner, Andreas H; Toze, Simon; Kirschner, Alexander K T; Blaschke, Alfred P; Sidhu, Jatinder P S

    2015-09-01

    The transport of human adenovirus, nanoparticles, and PRD1 and MS2 bacteriophages was tested in fine granular limestone aquifer material taken from a borehole at a managed aquifer recharge site in Adelaide, South Australia. Comparison of transport and removal of virus surrogates with the pathogenic virus is necessary to understand the differences between the virus and surrogate. Because experiments using pathogenic viruses cannot be done in the field, laboratory tests using flow-through soil columns were used. Results show that PRD1 is the most appropriate surrogate for adenovirus in an aquifer dominated by calcite material but not under high ionic strength or high pH conditions. It was also found that straining due to size and the charge of the colloid were not dominant removal mechanisms in this system. Implications of this study indicate that a certain surrogate may not represent a specific pathogen solely based on similar size, morphology, and/or surface charge. Moreover, if a particular surrogate is representative of a pathogen in one aquifer system, it may not be the most appropriate surrogate in another porous media system. This was apparent in the inferior performance of MS2 as a surrogate, which is commonly used in virus transport studies. PMID:26436257

  15. A new type of solar-system material recovered from Ordovician marine limestone

    PubMed Central

    Schmitz, B.; Yin, Q. -Z.; Sanborn, M. E.; Tassinari, M.; Caplan, C. E.; Huss, G. R.

    2016-01-01

    From mid-Ordovician ∼470 Myr-old limestone >100 fossil L-chondritic meteorites have been recovered, representing the markedly enhanced flux of meteorites to Earth following the breakup of the L-chondrite parent body. Recently one anomalous meteorite, Österplana 065 (Öst 65), was found in the same beds that yield L chondrites. The cosmic-ray exposure age of Öst 65 shows that it may be a fragment of the impactor that broke up the L-chondrite parent body. Here we show that in a chromium versus oxygen-isotope plot Öst 65 falls outside all fields encompassing the known meteorite types. This may be the first documented example of an ‘extinct' meteorite, that is, a meteorite type that does not fall on Earth today because its parent body has been consumed by collisions. The meteorites found on Earth today apparently do not give a full representation of the kind of bodies in the asteroid belt ∼500 Myr ago. PMID:27299793

  16. The role of land use and environmental factors on microbial pollution of mountainous limestone aquifers

    NASA Astrophysics Data System (ADS)

    Allocca, V.; Celico, F.; Petrella, E.; Marzullo, G.; Naclerio, G.

    2008-07-01

    Limestone aquifers in Southern Italy are often affected by bacterial contamination produced by pasture and agriculture. The main goals of this study were (1) to analyze the role of land use and environmental factors on microbial contamination and, (2) to identify, at field scale, the most suitable indicator of fecal pollution, by comparing fecal coliforms and fecal enterococci. Analyzing surface and spring water, it was noted that both fecal indicators showed a significant decrease during the period characterized by freezing and/or freeze-thaw intervals. The data analysis shows that fecal coliforms are characterized by a significant decrease in population (3 orders of magnitude, at least) during the freezing period, while fecal enterococci are temporarily inhibited. A taxonomic classification of fecal enterococci detected in spring water samples was performed by the API 20 Strep system and by sequencing of the ribosomal 16S DNA genes. The results showed that freezing conditions did not cause any significant change on the set of enterococcal species.

  17. A new type of solar-system material recovered from Ordovician marine limestone.

    PubMed

    Schmitz, B; Yin, Q-Z; Sanborn, M E; Tassinari, M; Caplan, C E; Huss, G R

    2016-01-01

    From mid-Ordovician ∼470 Myr-old limestone >100 fossil L-chondritic meteorites have been recovered, representing the markedly enhanced flux of meteorites to Earth following the breakup of the L-chondrite parent body. Recently one anomalous meteorite, Österplana 065 (Öst 65), was found in the same beds that yield L chondrites. The cosmic-ray exposure age of Öst 65 shows that it may be a fragment of the impactor that broke up the L-chondrite parent body. Here we show that in a chromium versus oxygen-isotope plot Öst 65 falls outside all fields encompassing the known meteorite types. This may be the first documented example of an 'extinct' meteorite, that is, a meteorite type that does not fall on Earth today because its parent body has been consumed by collisions. The meteorites found on Earth today apparently do not give a full representation of the kind of bodies in the asteroid belt ∼500 Myr ago. PMID:27299793

  18. Mechanisms for high-frequency cyclicity in the Upper Jurassic limestone of northeastern Mexico

    SciTech Connect

    Johnson, C.R.; Ward, W.C. ); Goldhammer, R.K. )

    1991-03-01

    The 520 m of Upper Jurassic Zuloaga Limestone exposed in the Sierra de Bunuelos in southern Coahuila comprise 118 cycles of peritidal carbonate rock deposited on a gently dipping ramp. Field studies with Fischer plots and time-series analysis suggest that a Milankovitchian glacioeustasy mechanism is inadequate to describe the Zuloaga cycles. Autocyclic progradation may have been the major influence on depositional cyclicity. Depositional cycles in the Zuloaga Formation typically are a few meters thick and asymmetric with subtidal wackestone and packstone grading upward into subtidal grainstone or into intertidal stromatolites. Width of the carbonate ramp is estimated to have been about 150 km. Sedimentation rates for these peritidal carbonate environments apparently exceeded subsidence rates inasmuch as most of the carbonate platform remained near sea level during Zuloaga deposition. The area was tectonically quiescent during the late Jurassic. Autocyclic shoreline progradation is a feasible mechanism for producing the high-frequency cycles, as suggested by (1) poor correlation with predicted Milankovitch periodicity shown by time-series analysis, (2) little evidence of subaerial exposure, (3) development of complete peritidal cycles, (4) general progradational sequences within each third-order unit, and (5) absence of polar glaciation during Late Jurassic.

  19. GIS-based detachment susceptibility analyses of a cut slope in limestone, Ankara—Turkey

    NASA Astrophysics Data System (ADS)

    Oztekin, B.; Topal, T.

    2005-11-01

    Due to the rapidly growing population of the city of Ankara (Turkey) and increased traffic congestion, it has become necessary to widen the Ankara-Eskişehir (E-90) highway connecting the newly built areas west of the city to the city center. During widening, several cut slopes were formed along the highway route. As a result, some instability problems (small-sized rock falls/sliding, sloughing, raveling) produced detachment zones along a cut slope in highly jointed, folded and sheared limestone, causing local degradation of the cut slope. Identification of the areas that are likely to detach from the cut slope in the future is considered to be very important for the application of remedial measures. For this purpose, the relationships between the existing detachment zones and various parameters (e.g., point load strength index, weathering, block size, daylighting, shear zone) were investigated using GIS-based statistical detachment susceptibility analyses in order to predict the further aerial extension of the detachment zones with time. During the overlay analyses, statistical index and weighting factor methods were used. The outcomes of the analyses were compared and evaluated with the field observations to check the reliability of the methods and to assess the detachment zones that may develop in the future. The detachment susceptibility map without the block-size layer gives the best result and indicates some risky zones where detachments are likely to occur in the future. Recommendations on remedial measures of the cut slope should consider these risky zones.

  20. Bioconstruction, bioerosion and disturbance on tropical coasts: coral reefs and rocky limestone shores

    NASA Astrophysics Data System (ADS)

    Spencer, Tom; Viles, Heather

    2002-11-01

    The ecology of tropical carbonate coasts, including coral reefs and rocky limestone shores, is susceptible to disturbance that may have linked effects on geomorphology. Biogeomorphology, which considers the interrelations between biological and geomorphological processes, is particularly well-suited toward the understanding of such carbonate systems. Field observations and experimentation on tropical and temperate coasts by both biologists and geomorphologists, and the development of ecological theory, have come to stress the importance not of stable, successional littoral communities but rather of nonequilibrial, multistate systems. These ideas now need to be incorporated into improved models of coastal dynamics. Case studies from the Central Pacific, the Caribbean and the western Indian Ocean illustrate the interactions between external environmental variability and internal biological processes. These studies show how changing the balance between bioconstructional and bioerosional processes can interrupt a system's development and, in some cases, shift carbonate-based systems between healthy and degradational states. A better understanding of the spatial and temporal complexities present in carbonate coastal and shallow marine environments is an important precursor to effective coastal zone management on these prevalent tropical shorelines.

  1. Joints and Mineral Veins in Limestone-Marl Alternations: Arrest and Fracture Frequencies

    NASA Astrophysics Data System (ADS)

    Philipp, S. L.; Reyer, D.

    2009-05-01

    Layering is a common feature of many rock masses. In particular, many sedimentary rocks are layered because of depositional changes (stratification), and diagenetic processes. Mechanical layering, where the mechanical properties, particularly the Young's moduli (stiffness), change between layers, may coincide with changes in grain size, mineral content or facies. The mechanical layering of the rock is important because layering commonly results in abrupt changes in local stress fields that may lead to fracture arrest. However, if all the beds in a rock mass have essentially the same Young's modulus and their contacts are welded together (sealed or healed) the beds may function mechanically as a single layer. Here we explore how mechanical layers relate to sedimentary layers in limestone-marl alternations. This we do by investigating the effects of sedimentary layering of the host rock, on the emplacement and geometries of extension fractures such as joints and mineral veins. Detailed field studies were carried out at two localities of well-exposed limestone-marl alternations: (1) the Jurassic Blue Lias at the Glamorgan Coast of South Wales, UK, and (2) the Triassic Muschelkalk in the Kraichgau area, Southwest Germany. In both study areas, calcite veins occur almost exclusively in the cores and damage zones of faults, whereas jointing is pervasive. Fracture arrest, common in mechanically layered host rocks, is primarily controlled by local variations in the stress field, mainly due to three factors: discontinuities (fractures and contacts), changes in host rock mechanical properties, and stress barriers, where the local stress field is unfavorable to fracture propagation. These factors are related in that changes in stiffness and stress barriers are common at contacts between different rock types. A fourth mechanism, namely the material toughness (critical strain energy release rate) of the contact in relation to that of the adjacent layers has been much studied in

  2. Nomination of the Globigerina Limestone of the Maltese Islands as a "Global Heritage Stone Resource"

    NASA Astrophysics Data System (ADS)

    Cassar, JoAnn

    2016-04-01

    The Maltese Islands consist of two main islands, Malta and Gozo, as well as a small number of islets, and lie in the central Mediterranean Sea approximately 90 km south of Sicily. Although only 316 square kilometres in size, the Islands contain a rich concentration of archaeological sites and historic buildings, as well as vernacular architecture and modern buildings, for the most part built of the local Globigerina Limestone, which is one of the few natural resources of the Islands. This stone can be described as a typical "soft limestone", very easy to carve and shape. It forms part of the large family of Oligo-Miocene "soft limestones" widely diffused in the Mediterranean Basin. The Maltese Globigerina Limestone Formation is one of five main Formations, and varies in thickness from 20 to over 200 m. The material used for building is located stratigraphically in the lower part of the Globigerina Limestone Formation, called the Lower Globigerina Limestone. This Formation is stratified into thick beds at outcrop. Sections where bioturbation is concentrated often also occur. This limestone is fine-grained, yellow to pale grey in colour, almost wholly composed of the tests of globigerinid planktonic foraminifera. Petrographically, Globigerina Limestone can be described as a bioclastic packstone, with bioclastic wackestones also occurring. This limestone has always been used as the predominant building material in the Islands. The Maltese prehistoric Temples, which were constructed approximately 6000 years ago, bear testimony to this. Between 1530 and 1798 the Order of the Knights of St John built kilometres of fortifications in this same material to protect the Island from the expanding Ottoman Empire. Fortifications, impressive churches, auberges and palaces were built of this stone during this period. The capital city of Valletta, a rich and dense manifestation of Baroque architecture in Globigerina Limestone, is included on the UNESCO World Heritage List, as are

  3. Comparative study of porous limestones used in heritage structures in Cyprus and in Hungary

    NASA Astrophysics Data System (ADS)

    Theodoridou, Magdalini; Ioannou, Ioannis; Rozgonyi-Boissinot, Nikoletta; Török, Ákos

    2015-04-01

    Porous limestone is widely used as construction material in the monuments of Cyprus and Hungary. The present study compares the physical properties of a bioclastic limestone from Cyprus and an oolitic limestone from Hungary. Petra Gerolakkou is a Pliocene limestone from Cyprus that originates from the district of Nicosia, the island's capital. It has been extensively used throughout the years in construction and restoration projects, particularly in the Nicosia area. Distinctive examples of its use can be found in the majority of the most important historic monuments in Nicosia, such as the Venetian walls and fortifications, churches (e.g. the Agia Sofia Cathedral), the archbishop and presidential palaces and a high number of other traditional buildings. The studied Miocene limestone from Hungary was exploited from Sóskút quarry (15-20 km W-SW to Budapest). The quarry provided stone for emblematic monuments of the capital of Hungary such as the Parliament building, Mathias Church, the Opera House and Citadella. In this study, mechanical parameters for both aforementioned stones, such as uniaxial compressive and tensile strengths, were tested under laboratory conditions. Their density, porosity and water absorption were also compared. The studied limestone from Cyprus exhibits porosity values within the range of 48-51%, apparent density between 1340 and 1400 kg/m3 and strength values under uniaxial compressive load between 1.2 and 2.8 MPa. This lithotype is also considered susceptible to salt decay, since an approximate mass loss of 12.5% is noted after 15 salt crystallization artificial weathering cycles. The porosity of the Hungarian limestone is in the order of 16-35%, the bulk density is 1600-1950 kg/m3, while the compressive strength is 2.5-15 MPa. Durability tests indicate that even after 10 freeze-thaw cycles the loss in strength is dramatic. Test results indicate that use of porous limestone in both countries is common and fabric strongly controls the

  4. Cohesive model applied to fracture propagation in Indiana Limestone

    NASA Astrophysics Data System (ADS)

    Dewers, T. A.; Rinehart, A. J.; Bishop, J. E.

    2014-12-01

    We apply a cohesive fracture (CF) model to results of short-rod (SR), notched 3-point-bend (N3PB) tests, and Brazil tests in Indiana Limestone. Calibration and validation of the model are performed within a commercial finite element modeling platform. By using a linear traction-displacement softening response for a defined fracture-opening displacement (w1) following peak tensile stress (σcrit), the CF model numerically lumps different spatially distributed inelastic processes occurring at and around fracture tips into a thin zone within an elastic domain. Both the SR and the N3PB test specimen geometries use a notch partway through the sample to control the location of fracture propagation. We develop a mesh for both the SR and N3PB geometries with a narrow cohesive zone in the center of notches. From the Brazil tests, we find a tensile splitting stress (σsplit) of 5.9 MPa. We use a σsplit as the peak tensile stress (σcrit) for all simulations. The Young's modulus (E) and the critical crack opening distance (w1) of the CF model are calibrated against the SR data. The model successfully captures the elastic, yield, peak, and initial and late failure behavior and compares favorably against the N3PB tests. Differences in force-displacement and crack propagation are primarily caused by: more mixed-mode (shear and opening) crack propagation in N3PB than in SR tests, causing a higher peak; and transition from compression (high E) to tension (low E) in a larger volume of the N3PB sample than in the SR geometry. This material is based upon work supported as part of the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001114. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy

  5. Evolution of flow properties in homogeneously altered limestone specimens

    NASA Astrophysics Data System (ADS)

    Zinsmeister, L.; Dautriat, J.; Dimanov, A.; Raphanel, J.; Bornert, M.; Gland, N.

    2012-04-01

    CO2 storage in deep saline aquifers is a way to limit the anthropogenic part of the greenhouse effect. The injection of supercritical CO2 in aquifer leads to geochemical reactions with the host rock, resulting for instance in dissolution and precipitation processes. These phenomena impact the flow properties of the porous network. To study this impact, we make use of thermally activated retarded acid. This treatment allows us to realize an homogeneous alteration. The materiel is an oolitic limestone from the Lavoux quarry in the Paris basin. We analyse the evolution of flow properties using porosity and permeability measurements in connection with the micro-structural evolution, studied with mercury porosimetry, NMR, medical scanner, laser diffraction, SEM and thin section analyses. A particular attention has been paid to the permeability evolution and the distribution of fines. Intact samples show a bimodal porosity distribution, with a micro-porosity ranging from 0.5µm to 3µm, a macro-porosity ranging from 10µm to 100µm, and a total porosity exceeding 20%. Permeability is about 100mD. Porosity increases by 0.4% per alteration cycle together with the proportion of micro pore throats and the size of the macro pore throat, as evidenced by mercury porosimetry. The permeability is measured using a differential pressure sensor before and after alteration, back and forth in the axis direction of the plug. The results show that while the alteration in general results in an increase of the permeability, some complex non monotoneous behaviour can be observed. We infer that fines are mobilized in the porous network, clogging some pore throats. We also analyse the outgoing fluids after alteration with laser diffraction. A familly of particles ranging from 3µm to 10µm is detected, suggesting that bigger fines remain stuck in the porosity. These larger particles can be observed using comparative µ-CT imaging. Thin sections and SEM analyses do not show any evidence of

  6. Optimization of Trona/Limestone Injection for SO2 Control in Coal-Fired Boilers

    SciTech Connect

    2005-09-01

    Mobotec USA develops and markets air pollution control systems for utility boilers and other combustion systems. They have a particular interest in technologies that can reduce NOx, SOx, and mercury emissions from coal-fired boilers, and have been investigating the injection of sorbents such as limestone and trona into a boiler to reduce SOx and Hg emissions. WRI proposed to use the Combustion Test Facility (CTF) to enable Mobotec to conduct a thorough evaluation of limestone and trona injection for SO{sub 2} control. The overall goal of the project was to characterize the SO{sub 2} reductions resulting from the injection of limestone and trona into the CTF when fired with a high-sulfur eastern bituminous coal used in one of Mobotec's Midwest installations. Results revealed that when limestone was injected at Ca:S molar ratios of 1.5 to 3.0, the resulting SO{sub 2} reductions were 35-55%. It is believed that further reductions can be attained with improved mixing of the sorbent with the combustion gases. When limestone was added to the coal, at Ca:S molar ratios of 0.5 to 1.5, the SO{sub 2} reductions were 13-21%. The lower reductions were attributed to dead-burning of the sorbent in the high temperature flame zone. In cases where limestone was both injected into the furnace and added to the coal, the total SO{sub 2} reductions for a given Ca:S molar ratio were similar to the reductions for furnace injection only. The injection of trona into the mid-furnace zone, for Na:S molar ratios of 1.4 to 2.4, resulted in SO{sub 2} reductions of 29-43%. Limestone injection did not produce any slag deposits on an ash deposition probe while trona injection resulted in noticeable slag deposition.

  7. Color measurements on marble and limestone briquettes exposed to outdoor environment in the Eastern United States. Volume I: Results of exposure 1984-1990

    SciTech Connect

    Reimann, K.J.

    1994-04-01

    In a long-term program that began in 1984, limestone and marble briquettes have been exposed to both anthropogenic acid deposition and natural weathering at four field sites in the eastern United States. Similar tests began at an Ohio site in 1986. Effects of exposure on the briquettes and other materials at the sites are evaluated periodically by several federal agencies cooperating in the National Acid Precipitation Assessment Program (NAPAP). One of the primary contributions of Argonne National Laboratory to the NAPAP has been the measurement of tristimulus color change on samples exposed to the environment. Results from the first six years indicate a yellowing of the marble and a darkening of limestone on both the skyward and groundward surfaces of fresh and preexposed briquettes. The relationship between discoloration and exposure period appears to be linear. Discoloration rates as a function of a cumulative exposure time are almost constant for marble and slightly decreasing for limestone Dark spots on groundward surfaces were measured with tristimulus color equipment prior to chemical analysis to determine if a correlation exists between darkening (change in reflectance) and SO{sub 4} concentration. Taking exposure time into consideration, and assuming that the airborne concentration of dark particles, which cause darkening, is proportional to airborne SO{sub 2} concentration, one can establish a linear relationship between exposure time, darkening, and SO{sub 2} concentration. The program is continuing so that additional data can be obtained.

  8. Mineralogical characterization of the Shelburne Marble and the Salem limestone: Test stones used to study the effects of acid rain

    SciTech Connect

    McGee, E.S.

    1989-01-01

    The Salem Limestone and the Shelburne Marble are representative of limestones and marbles commonly used in buildings and monuments. Both stones are composed predominantly of calcite. The Salem Limestone is homogeneous in composition and mineralogic characteristics throughout the test block. The Shelburne Marble has compositionally homogeneous mineral phases, but the distribution of those phases within the test block is random. The mineralogy and physical characteristics of the Shelburne Marble and Salem Limestone test blocks described in the study provide a baseline for future studies of the weathering behavior of these stones. Because the Shelburne Marble and the Salem Limestone are representative of typical commercial marbles and limestones, they are likely to be useful in a consortium study of the effects of acid precipitation on these two types of building stones.

  9. Drenov Grič black limestone as a heritage stone from Slovenia

    NASA Astrophysics Data System (ADS)

    Kramar, Sabina; Rožič, Boštjan; Žbona, Nina; Bedjanič, Mojca; Mladenović, Ana

    2016-04-01

    The limestone known as Drenov Grič black limestone is considered one of the most beautiful Slovenian natural stones due to its homogenous black colour interwoven with white veins. Over the centuries it has been exploited from three major quarries west of Ljubljana, with the main quarry at Drenov Grič playing the primary role in supplying building material for the central parts of Slovenia. All the quarries are currently not active. In the area of Drenov grič, one locality of black limestone is protected - Kuclerjev kamnolom quarry. It has the status of 'valuable natural feature of national importance' and is protected as a natural monument. This well-stratified micritic limestone of Triassic (Carnian) age occurs in 10-80 cm thick beds, with thin marl interlayers. The stone contains abundant fossil bivalves and ostracods. Apart from calcite as the main component, dolomite, quartz, illite/muscovite and pyrite are also present. The limestone is relatively rich in carbonaceous and bituminous organic matter, which is responsible for the black colour of the stone. This component does not have any adverse effect on mechanical and physical characteristics. As the lime¬stone is dense, thus facilitating a good polish, it has been commercially considered as marble. The stone has been widely used in Slovenian monuments, not only in Ljubljana but also in other regions of Slovenia. Many inner and outdoor architectural elements were made of this limestone, particularly in the baroque period, which was known for the extensive use of black limestones also in other European countries. The most significant use of this limestone has been recorded in sculptured portals and altars. Some of the important buildings decorated utilising this stone, are the Ljubljana Cathedral, the St. James's Parish Church, and the Franciscan Church of the Annunciation, all of which are located in Ljubljana, some of them having been declared as cultural monuments of local or national importance. When

  10. The Significance of Podpe limestone in the Cultural Heritage of Slovenia

    NASA Astrophysics Data System (ADS)

    Kramar, Sabina; Bedjanič, Mojca; Mirtič, Breda; Mladenović, Ana; Rožič, Boštjan; Skaberne, Dragomir; Zupančič, Nina

    2013-04-01

    Podpeč limestone is characterized by its dark grey, or nearly black colour, with white fossil shells of the Lithiotis. These beds, which have been dated as Lower Jurassic, occur in southern and south-western Slovenia, and are particularly common in areas southwest of Ljubljana. The main quarry, which is not active, is located next to the village of Podpeč near Ljubljana, and has been declared as a geological natural value of national importance; as such, it is officially protected as a natural monument. In the close vicinity of the village there are some other smaller quarries, but all of them have been abandoned. With its very low porosity (0.9%) and water absorption (0.13 - 0.30 % by mass), but relatively high compressive strength (185 MPa), this limestone is quite durable, although its colouring becomes somewhat bleached when situated outdoors. The use of Podpeč limestone was first documented in the case of the Roman period in Slovenia, when it was used for funerary stelae, votive altars, boundary stones, and other artefacts. At the end of the 5th Century AD, with the fall of the Roman Empire, stone-cutting ceased at Podpeč for the next few centuries. Before 1850 Podpeč limestone had no special value. Only very few portals or pilasters made of this stone are known, and no evidence has been found in churches. However, towards the end of the 19th Century Podpeč limestone became better-known, although before the first half of the 20th Century there were no significant stonecutting workshops in Podpeč. After this, stone was supplied progressively from the main quarry. Large numbers of buildings in Ljubljana and central Slovenia have sills, lintels and jambs made of Podpeč limestone. Production stopped in 1967. The internationally renowned Slovenian architect Jože Plečnik (1872-1957) used Podpeč limestone in various Slovenian buildings - the central stadium in Ljubljana, the National University Library, many altars and churches (Bogojina, the Ši\\vska and

  11. Limestones as a paleobathymeter for reconstructing past seismic activities: Muroto-misaki, Shikoku, southwestern Japan

    NASA Astrophysics Data System (ADS)

    Iryu, Y.; Maemoku, H.; Yamada, T.; Maeda, Y.

    2009-03-01

    Muroto-misaki (Cape Muroto) is located at the southern tip of the eastern half of Shikoku, southwestern Japan and is ~ 100 km north of the Nankai Trough where the Philippine Sea Plate is being subducted beneath the Eurasian Plate. Therefore, the Muroto-misaki area has been seismically uplifted. Sedimentologic analyses were conducted on Holocene limestones that occur along the coast from Muroto-misaki to Meoto-iwa, located ~ 13 km north of the cape. The limestones are limited to less than 9.2 m in elevation. The limestones are up to 4.4 m in mean diameter, up to 0.5 m in thickness, and consist mainly of fossilized sessile organisms, including annelids, corals, bryozoans, encrusting foraminifers, barnacles, nongeniculate coralline algae, and, to a lesser extent, molluscs and peyssonneliacean algae. Acicular and equant cements are minor components. Acicular cements are found in semi-closed spaces between coralline algal crusts and their substrates. The modal composition of limestones was determined by a point-counting technique. Based on the biotic composition, the Holocene limestones can be classified into six types (Types I to VI). A comparison of the vertical distribution of these rock types with that of modern sessile organisms indicates that the top of Type I limestone, which is characterized by the occurrence of hermatypic corals, corresponds approximately to the mean low water springs when the limestones formed. A difference in the highest occurrence of Type I limestone between two sites may represent the variation in the total amount of uplift over the last 1000 to 1500 years, which resulted in an apparent northward decline of paleo-mean low water springs at a rate of ~ 10 cm/km. Therefore, the Holocene limestones are a good paleobathymeter to reconstruct past seismic activities in this area. This study shows that warm temperate carbonate deposits are as excellent recorders of geologic events, such as the timing and scale of repeated coseismic uplifts and

  12. The effects of lichen cover upon the rate of solutional weathering of limestone

    NASA Astrophysics Data System (ADS)

    McIlroy de la Rosa, J. P.; Warke, P. A.; Smith, B. J.

    2014-09-01

    The contribution of lichens to the biomodification of limestone surfaces is an area of conflict within bioweathering studies, with some researchers suggesting a protective effect induced by lichen coverage and others a deteriorative effect induced by the same organisms. Data are reported demonstrating the potential role of endolithic lichen, in particular of Bagliettoa baldensis, in the active protection of Carboniferous limestone surfaces from rainfall-induced solutional weathering. During a 12-month microcatchment exposure period in the west of Northern Ireland, average dissolutional losses of calcium are greater from a lichen-free limestone surface compared with a predominantly endolithic lichen-covered surface by just under 1.25 times. During colder winter months, the lichen-free surface experiences calcium loss almost 1.5 times greater than the lichen-covered surface. Using extrapolation to upscale from the micro-catchment sample scale, for the year of sample exposure, the rate of calcium loss is 1.001 g m- 2 a- 1 from lichen-covered limestone surfaces and 1.228 g m- 2 a- 1 from lichen-free bare limestone surfaces. This research has implications for our understanding of karst environments, the contribution of lichens to karren development and the conservation of lichen-colonised dimension stone within a cultural setting.

  13. Effect of magnesium salts on the sulphation capacity of limestone slurry

    SciTech Connect

    Ozyuguran, A.; Altun-Ciftcioglu, G.; Karatepe, N.; Ersoy-Mericboyu, A.

    2006-09-15

    The effect of different magnesium salts such as MgO, MgSO{sub 4}.7H{sub 2}O and Mg(OH){sub 2} on the total sulphation capacities of limestone slurries prepared from five different limestone samples was investigated. Sulphation reactions of slurries were conducted at a constant temperature of 323 K in a gaseous mixture consisting of 5% O{sub 2}, 10% CO{sub 2}, 0.5% SO{sub 2} and a balance of nitrogen by volume. It was found that the total sulphation capacities of limestone slurries increased with the addition of MgO and Mg(OH){sub 2} salts and decreased with the addition of MgSO{sub 4}.7H{sub 2}O salt. Depending on the chemical composition of the limestone samples the total sulphation capacities of limestone slurries were increased between 22.30% and 75.00% by MgO addition and between 23.70% and 69.00% by Mg(OH){sub 2} addition.

  14. Depositional facies and diagenetic history of Trenton Limestone in northern Indiana

    SciTech Connect

    Fara, D.R.; Keith, B.D.

    1984-12-01

    Subsurface cores were studied petrographically to determine the facies and diagenetic history of the Trenton Limestone on a regional scale in northern Indiana. The Trenton Limestone is a yellowish olive-gray fossiliferous limestone, which is replaced by a light-gray dolostone in northern Indiana. Facies composing the Trenton are: 1) bryozoan-echinoderm packstone, 2) bryozoan-echinoderm grainstone, 3) bryozoan packstone to wackestone, 4) lime mudstone, and 5) dolostone. The bryozoan-echinoderm packstone is the major facies. Coarse-grained (1-4 mm) grainstones are typically 1 ft (30 cm) thick, have abrupt bases, and become muddy upward. They are considered storm deposits. Hardgrounds occur throughout the limestone facies, but they are most numerous toward the base. These facies indicate deposition below wave base, interrupted by periods of high energy during storms. Fossiliferous white and gray chert nodules are scattered throughout the unit. Also found in the limestone facies are prevalent stylolites and microstylolites, an indication of chemical compaction. The dolostone facies consists of coarsely crystalline (0.4 mm) idiotopic dolomite. Pyrite is associated with the dolomite. Porosity, found only in the dolostone, is discontinuous and characterized as intercrystalline, vuggy, and moldic. Porous zones are commonly oil stained or have been plugged by poikilotopic selentic gypsum. Minor amounts of celestite are found as cavity fillings.

  15. Discrimination of reservoir dolostone within tight limestone using rock physics modeling and pre-stack parameters

    NASA Astrophysics Data System (ADS)

    Park, G.; Lee, B.; Lee, G.

    2013-12-01

    Dolostones may be differentiated from limestones based on various pre-stack seismic parameters as they are denser and faster. However, because the seismic properties of a rock are affected strongly by porosity, porous dolostones may not be significantly denser and faster than limestones. We computed various pre-stack parameters (P-impedance, S-impedance, Vp/Vs, Poisson's ratio, Lamé constants) for tight limestones using the Vp and density logs from a well that penetrated Jurassic carbonate and the Vs log, constructed from the empirical relationships of Vp and Vs. The pre-stack parameters of dolostones with 1% - 40% porosity were estimated based on the bulk and shear moduli and bulk densities computed from the formulas proposed by various workers, including Gassmann equations. Crossplots of the pre-stack parameters show that the Lamé constants (λ, μ) are most effective in differentiating dolostones from limestones. In particular, the λρ -μρ vs. μρ crossplot shows a clear-cut separation of the porous dolostones and tight limestones; the porous dolostones plot exclusively to the left of the λρ -μρ of about 25 GPa.

  16. Forest seasonality shapes diet of limestone-living rhesus macaques at Nonggang, China.

    PubMed

    Tang, Chuangbin; Huang, Libin; Huang, Zhonghao; Krzton, Ali; Lu, Changhu; Zhou, Qihai

    2016-01-01

    Limestone forests are an unusual habitat for primates, but little information is available for the genus Macaca in such habitats, making a comparative understanding of extant limestone primates' behavioral adaptation incomplete. We collected data on the diet of rhesus macaques (Macaca mulatta) in a limestone habitat at Nonggang Nature Reserve, southwestern Guangxi, China, and examined the effects of forest seasonality on their diet. Our results indicated that a total of 114 species of plants are consumed by macaques. Young leaves are a preferred food, accounting for 48.9 and 56.9% of the overall diets. One group significantly increased young leaf consumption in response to availability. Fruits contributed to only 27.3 and 28.7% of overall diet. The macaque diet varied according to season. They fed on more fruits in the rainy season. Consumption of mature leaves increased when the availability of young leaves and fruits declined in the dry season, indicating that mature leaves are a fallback food for macaques in a limestone habitat. Similar to sympatric Assamese macaques, Bonia saxatilis, a shrubby, karst-endemic bamboo was consumed by rhesus macaques throughout the year, and was the top food species through most of the year, suggesting that bamboo consumption represents a key factor in the macaque's dietary adaptation to limestone habitat. PMID:26530218

  17. Tidal rhythmites infine-grained Carboniferous limestones, U.S.A.

    USGS Publications Warehouse

    Archer, A.W.; Feldman, H.R.

    1994-01-01

    Analyses of fine-grained limestones reveals that many exhibit fine-scale laminations. Laminations can be normally graded and consist of a coarser-grained lower part and a finer-grained upper part. The upper part can also contain finely disseminated organic material. Despite the similarities of such graded laminae to yearly varves and turbidites, it can be demonstrated by use of laminae-thickness periodicities that some graded laminae are reasonably interpreted as the product of tidal processes. Within siliciclastic systems, modern analogues of such processes are available for comparisons. In fine-grained facies of the Salem Limestone (Visean; Indiana, U.S.A.), periodicities observed within sequential-laminae thicknesses indicate a dominant control by neap-spring tidal processes. Similarly, laminae within limestones of the vertebrate-bearing Hamilton paleochannel (Stephanian; Kansas, U.S.) exhibit similar features, including fine-scale tidal bundles. This limestone is noted for the abundance of articulated fish fossils. Carbonates containing articulated fish from the Wild Cow Formation (Stephanian; New Mexico, U.S.), exhibit diffuse laminations; however, closely associated siliciclastic mudstones contain laminae that exhibit tidal periodicities. There are many similarities between tidal periodicities and patterns of lamination thicknesses of these rocks. A tidal interpretation for these rocks allows for localized, very rapid rates of deposition. Such rapid deposition may, in part, help to explain how articulated fish and other vertebrates can become preserved within such fine-grained limestones. ?? 1994.

  18. Influence of clay swelling on the mechanical behaviour of Egyptian Helwan limestone

    NASA Astrophysics Data System (ADS)

    Aly, Nevin

    2016-04-01

    Clay minerals exist naturally in the majority of different Egyptian limestones types. Changes in the dimensions of clays during swelling / shrinking process induced by changes in the environmental conditions can result in acceleration the deterioration of the hosting stone. Petrographic investigation by scanning - electron microscope (SEM) of Helwan limestone (biomicritic limestone) revealed distribution of a typical smectite morphology (curled - leaf shape) beside abundance of glauconite pellets within the stone material. The clay frication extracted from Helwan reached 10% and oriented aggregates samples were analyzed by X- ray diffraction (XRD) and confirmed the identification of smectite as the main mineral in the clay frication. To study the effect of the clay content on the mechanical behavior of Helwan limestone, hygric swelling test was performed at first by using displacement sensor and then the effect of multiple wetting/ drying cycles on the stone strength was determined using unconfined compressive strength (UCS). Results revealed that there was a significant correlation between degree of swelling of the clay and strength of the limestone.

  19. Dietary adaptations of Assamese macaques (Macaca assamensis) in limestone forests in Southwest China.

    PubMed

    Huang, Zhonghao; Huang, Chengming; Tang, Chuangbin; Huang, Libin; Tang, Huaxing; Ma, Guangzhi; Zhou, Qihai

    2015-02-01

    Limestone hills are an unusual habitat for primates, prompting them to evolve specific behavioral adaptations to the component karst habitat. From September 2012 to August 2013, we collected data on the diet of one group of Assamese macaques living in limestone forests at Nonggang National Nature Reserve, Guangxi Province, China, using instantaneous scan sampling. Assamese macaques were primarily folivorous, young leaves accounting for 75.5% and mature leaves an additional 1.8% of their diet. In contrast, fruit accounted for only 20.1%. The young leaves of Bonia saxatilis, a shrubby, karst-endemic bamboo that is superabundant in limestone hills, comprised the bulk of the average monthly diet. Moreover, macaques consumed significantly more bamboo leaves during the season when the availability of fruit declined, suggesting that bamboo leaves are an important fallback food for Assamese macaques in limestone forests. In addition, diet composition varied seasonally. The monkeys consumed significantly more fruit and fewer young leaves in the fruit-rich season than in the fruit-lean season. Fruit consumption was positively correlated with fruit availability, indicating that fruit is a preferred food for Assamese macaques. Of seventy-eight food species, only nine contributed >0.5% of the annual diet, and together these nine foods accounted for 90.7% of the annual diet. Our results suggest that bamboo consumption represents a key factor in the Assamese macaque's dietary adaptation to limestone habitat. PMID:25231871

  20. Fluoride removal from groundwater by limestone treatment in presence of phosphoric acid.

    PubMed

    Gogoi, Sweety; Nath, Suresh K; Bordoloi, Shreemoyee; Dutta, Robin K

    2015-04-01

    Fluoride removal from groundwater has been studied by addition of dilute phosphoric acid (PA) to the influent water before limestone treatment through laboratory plug-flow column experiments and bench-scale plug-flow pilot tests. In this PA-enhanced limestone defluoridation (PAELD) technique, fluoride is removed from 0.526 mM to 0.50-52.60 μM in 3 h with near neutral final pH. The presence of PA increases the fluoride removal capacity of limestone to 1.10 mg/g compared to 0.39 mg/g reported in its absence. The changes in fluoride removal with variation in initial PA concentration, initial fluoride concentration and the final pH have been found to be statistically significant with p < 0.05. The estimated recurring cost is US$ ≈0.58/m(3) water. Simple scrubbing and rinsing is a preferable method for regeneration of limestone as it is almost equally effective with lime or NaOH. Sorption of fluoride by calcium phosphates produced in situ in the reactor is the dominant mechanism of fluoride removal in the PAELD. Precipitation of CaF2 and sorption of fluoride by the limestone also contribute to the fluoride removal. High efficiency, capacity, safety, environment-friendliness, low cost and simplicity of operation make the PAELD a potential technique for rural application. PMID:25621387

  1. Neogene-Eopleistocene shelly limestones in the North Caucasus and Ciscaucasia regions

    NASA Astrophysics Data System (ADS)

    Beluzhenko, E. V.

    2014-07-01

    In the North Caucasus and Ciscaucasia, seven distribution zones of Middle-Upper Miocene, Pliocene, and Eopleistocene shell-detrital limestones are defined: Lower Don, Tsimlyansk-Manych, Western Ciscaucasia, Western Caucasus, Central Ciscaucasia, Kabarda-Chechen, and Eastern Dagestan. The shell-detrital limestones are present among sandy-clayey sediments in the form of intercalations of variable thickness traceable over different distances (up to a few kilometers). The maximum thicknesses of such limestones are characteristic of the Neogene sections in the northwestern pericline of the Greater Caucasus: Taman-Adagum area, where their distribution comprises the stratigraphic interval from the Chokrakian to early Cimmerian regional stages (approximately 10 m.y. long). Their most spacious distribution area is confined to the Central Ciscaucasia zone. The shell-detrital limestones in the Neogene sections mark shallowwater shelf areas (ancient coastal bars, banks, and shoals) with intermittently forming environments favorable for accumulation of significant volumes of shelly detritus. In such paleogeographic settings, the sediments were subjected to repeated erosion with subsequent formation of limestones. Now, they represent building material widely used in the region for different purposes.

  2. Actinobacterial diversity in limestone deposit sites in Hundung, Manipur (India) and their antimicrobial activities

    PubMed Central

    Nimaichand, Salam; Devi, Asem Mipeshwaree; Tamreihao, K.; Ningthoujam, Debananda S.; Li, Wen-Jun

    2015-01-01

    Studies on actinobacterial diversity in limestone habitats are scarce. This paper reports profiling of actinobacteria isolated from Hundung limestone samples in Manipur, India using ARDRA as the molecular tool for preliminary classification. A total of 137 actinobacteria were clustered into 31 phylotypic groups based on the ARDRA pattern generated and representative of each group was subjected to 16S rRNA gene sequencing. Generic diversity of the limestone isolates consisted of Streptomyces (15 phylotypic groups), Micromonospora (4), Amycolatopsis (3), Arthrobacter (3), Kitasatospora (2), Janibacter (1), Nocardia (1), Pseudonocardia (1) and Rhodococcus (1). Considering the antimicrobial potential of these actinobacteria, 19 showed antimicrobial activities against at least one of the bacterial and candidal test pathogens, while 45 exhibit biocontrol activities against at least one of the rice fungal pathogens. Out of the 137 actinobacterial isolates, 118 were found to have at least one of the three biosynthetic gene clusters (PKS-I, PKS-II, NRPS). The results indicate that 86% of the strains isolated from Hundung limestone deposit sites possessed biosynthetic gene clusters of which 40% exhibited antimicrobial activities. It can, therefore, be concluded that limestone habitat is a promising source for search of novel secondary metabolites. PMID:25999937

  3. Burial diagenesis of upper Mississippian Greenbrier limestone in central Appalachian basin

    SciTech Connect

    Carney, C.

    1987-09-01

    As carbonate sediments undergo progressive burial under conditions of increasing temperature and pressure, they go through a variety of changes. Burial diagenesis includes processes such as mechanical and chemical compaction, mineralogic change, cementation, dolomitization, and various types of neomorphic fabric change. Identifying the products of burial diagenesis may be useful in predicting porosity and reservoir quality in the subsurface. The Upper Mississippian Greenbrier Limestone and equivalents are exposed throughout the central Appalachians. Important textural and mineralogical changes have been recognized in these shallow shelf limestones, which indicate burial to different depths. Variations in trace- and minor-element concentrations occur with increasing diagenesis. Textural alterations include increased matrix (micrite) crystal size and increased twinning of echinoderm fragments. The Greenbrier Limestone can be divided into three diagenetic provinces. Zone 1, located on the extreme western side of the basin, is characterized by little evidence of compaction, mineralogic variation, or textural change. In this area, the limestones were never buried to any great depth. Zone 3, on the eastern side of the basin, is characterized by significant mechanical and chemical compaction, and mineralogic and textural change. Limestones of this diagenetic province have been subjected to relatively high paleotemperatures during deep burial. Zone 2 is of intermediate burial depth and diagenesis and is present between zones 1 and 3.

  4. Methods of chemical analysis for selected species in marble and limestone surfaces exposed to the acidic outdoor environment

    SciTech Connect

    Jensen, K.J.; Williams, F.L.; Huff, E.A.; Youngdahl, C.A.

    1986-03-01

    There is concern for marble and limestone exposed to the acidic outdoor environment because they are widely used as the exterior structures of buildings and monuments and because the calcium carbonate stones are especially sensitive to acid. Field tests of these building materials under carefully monitored environmental conditions are being conducted to measure damage rates and ultimately to quantify the individual effects of the important damage mechanisms. The development of further quantitative understanding will provide an improved basis for control strategies. The demonstration, verification, and application of a technique to measure selected surface anionic and cationic species are important contributions to this study. These methods of stone surface chemical analysis, developed for and applied in the National Acid Precipitation Assessment Program (NAPAP), are appropriate to monitor selected species of program interest and are sufficient to determine surface sulfate and nitrate reaction products.

  5. 72. OVERALL VIEW OF WEAPONS STORAGE AREA IGLOO FIELDS. TAKEN ...

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

    72. OVERALL VIEW OF WEAPONS STORAGE AREA IGLOO FIELDS. TAKEN FROM ROOF OF BUILDING 232 (MINE SHOP) LOOKING NORTH. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

  6. Porosity development in the Copper Ridge Dolomite and Maynardville Limestone, Bear Creek Valley and Chestnut Ridge, Tennessee

    SciTech Connect

    Goldstrand, P.M.; Menefee, L.S.; Dreier, R.B.

    1995-12-01

    Matrix porosity data from deep core obtained in Bear Creek Valley indicate that porosities in the Maynardville Limestone are lithology and depth dependent. Matrix porosities are greater in the Cooper Ridge Dolomite than in the Maynardville Limestone, yet there is no apparent correlation with depth. Two interrelated diagenetic processes are the major controlling factors on porosity development in the Copper Ridge Dolomite and Maynardville Limestone; dissolution of evaporate minerals and dedolomitization. Both of these diagenetic processes produce matrix porosities between 2.1 and 1.3% in the Copper Ridge Dolomite and upper part of the Maynardville Limestone (Zone 6) to depths of approximately 600 ft bgs. Mean matrix porosities in Zones 5 through 2 of the Maynardville Limestone range from 0.8 to 0.5%. A large number of cavities have been intersected during drilling activities in nearly all zones of the Maynardville Limestone in Bear Creek Valley. Therefore, any maynardville Limestone zone within approximately 200 ft of the ground surface is likely to contain cavities that allow significant and rapid flow of groundwater. Zone 6 could be an important stratigraphic unit in the Maynardville Limestone for groundwater flow and contaminant transport because of the abundance of vuggy and moldic porosities. There are large variations in the thickness and lithology in the lower part of the Maynardville (Zones 2, 3, and 4 in the Burial Grounds region). The direction and velocity of strike-parallel groundwater flow may be altered in this area within the lower Maynardville Limestone.

  7. Exploratory and basic fluidized-bed combustion studies. Quarterly report, April-June 1980. [Limestone and dolomite; USA

    SciTech Connect

    Johnson, I.; Myles, K.M.; Swift, W.M.

    1980-12-01

    This work supports the development studies for both atmospheric and pressurized fluidized-bed coal combustion. Laboratory and process development studies are aimed at providing needed information on limestone utilization, removal of particles and alkali metal compounds from the flue gas, control of SO/sub 2/ and trace pollutant emissions, and other aspects of fluidized-bed coal combustion. This report presents information on: (1) the development of a sorbent utilization prediction methodology, (2) studies of factors which affect limestone breakup and elutriation, (3) basic studies of limestone sulfation under combustion conditions, and (4) studies of the kinetics of the hydration of spent limestone.

  8. Limestone Dissolution in Converter Slag at 1873 K (1600 °C)

    NASA Astrophysics Data System (ADS)

    Deng, Tengfei; Nortier, Patrice; Ek, Mattias; Sichen, Du

    2013-02-01

    Decomposition and dissolution of limestone in slag at 1873 K (1600 °C) were studied. The limestone samples were in the shape of cubes (11 mm × 11 mm × 11 mm approximately). The decomposition was carried out both in argon and in slag under argon atmosphere. In order to gain an insight into the phenomenon of slow decomposition, the decomposition process of CaCO3 was simulated using Comsol. The results showed evidently that the decomposition of calcium carbonate was controlled mostly by heat transfer. It was also found that the decomposition product CaO had very dense structure, whether the sample was decomposed in slag or in argon. The slow decomposition and the dense CaO layer would greatly hinder the dissolution of lime in the slag. The present results clearly indicate that the addition of limestone instead of lime would not be beneficial in the converter process.

  9. Prediction of building limestone physical and mechanical properties by means of ultrasonic P-wave velocity.

    PubMed

    Concu, Giovanna; De Nicolo, Barbara; Valdes, Monica

    2014-01-01

    The aim of this study was to evaluate ultrasonic P-wave velocity as a feature for predicting some physical and mechanical properties that describe the behavior of local building limestone. To this end, both ultrasonic testing and compressive tests were carried out on several limestone specimens and statistical correlation between ultrasonic velocity and density, compressive strength, and modulus of elasticity was studied. The effectiveness of ultrasonic velocity was evaluated by regression, with the aim of observing the coefficient of determination r(2) between ultrasonic velocity and the aforementioned parameters, and the mathematical expressions of the correlations were found and discussed. The strong relations that were established between ultrasonic velocity and limestone properties indicate that these parameters can be reasonably estimated by means of this nondestructive parameter. This may be of great value in a preliminary phase of the diagnosis and inspection of stone masonry conditions, especially when the possibility of sampling material cores is reduced. PMID:24511286

  10. Weight losses of marble and limestone briquettes exposed to outdoor environments in the eastern United States

    SciTech Connect

    Reimann, K.J.

    1991-09-01

    Gravimetric changes in marble and limestone briquettes exposed to outdoor environment at five sites in the eastern United States have been monitored since 1984. An earlier report describes procedures and results obtained in 1984--1988. This report presents the results of the exposure period 1984--1988 and reviews and summarizes those of prior years. A linear relationship was found between cumulative gravimetric losses and exposure period or rain depth. These losses resulted in an average recession rate of 14 to 24 {mu}m/yr for marble and twice that for limestone. Variations in recession among the various exposure sites can be ascribed to differences in rain depth and hydrogen ion concentration. The annual recession rates obtained from gravimetry yielded rates that were for marble twice those obtained from runoff experiments, and more than three times those for limestone; this indicates that physical erosion plays an important role. Gravimetric monitoring of exposed briquettes is continuing in a planned 10-yr program.

  11. Search for high-calcium limestone in Silurian reefs of northern Indiana.

    USGS Publications Warehouse

    Ault, C.H.; Carr, D.D.

    1981-01-01

    During Silurian time, the Indiana part of the Wabash Platform was a shallow-water area between the proto-Illinois and proto- Michigan Basins and a site of growth of hundreds, or perhaps thousands, of reefs. Today, most reefs of northern Indiana are dolomite, but some are dolomitic limestone, and a few are limestone of high purity in deposits that can be mined by openpit methods. Four of the five generations of reefs of Silurian age in the Great Lakes area have been recognized in northern Indiana. All known limestone reefs are restricted to an area of six countries in north-central Indiana, although no apparent depositional environment as revealed from study of surrounding inter-reef rocks has been found to account for any restriction. Dolomitization is more likely related to the textures and lithologies of the individual reefs.-from Authors

  12. Prediction of Building Limestone Physical and Mechanical Properties by Means of Ultrasonic P-Wave Velocity

    PubMed Central

    Concu, Giovanna; De Nicolo, Barbara; Valdes, Monica

    2014-01-01

    The aim of this study was to evaluate ultrasonic P-wave velocity as a feature for predicting some physical and mechanical properties that describe the behavior of local building limestone. To this end, both ultrasonic testing and compressive tests were carried out on several limestone specimens and statistical correlation between ultrasonic velocity and density, compressive strength, and modulus of elasticity was studied. The effectiveness of ultrasonic velocity was evaluated by regression, with the aim of observing the coefficient of determination r2 between ultrasonic velocity and the aforementioned parameters, and the mathematical expressions of the correlations were found and discussed. The strong relations that were established between ultrasonic velocity and limestone properties indicate that these parameters can be reasonably estimated by means of this nondestructive parameter. This may be of great value in a preliminary phase of the diagnosis and inspection of stone masonry conditions, especially when the possibility of sampling material cores is reduced. PMID:24511286

  13. Reduction of soil pollution by usingwaste of the limestone in the cement industry

    NASA Astrophysics Data System (ADS)

    Muñoz, M. Cecilia Soto; Robles Castillo, Marcelo; Blanco Fernandez, David; Diaz Gonzalez, Marcos; Naranjo Lamilla, Pedro; Moore Undurraga, Fernando; Pardo Fabregat, Francisco; Vidal, Manuel Miguel Jordan; Bech, Jaume; Roca, Nuria

    2016-04-01

    In the cement manufacturing process (wet) a residue is generated in the flotation process. This builds up causing contamination of soil, groundwater and agricultural land unusable type. In this study to reduce soil and water pollution 10% of the dose of cement was replaced by waste of origin limestone. Concretes were produced with 3 doses of cement and mechanical strengths of each type of concrete to 7, 28 and 90 days were determined. the results indicate that the characteristics of calcareous residue can replace up to 10% of the dose of cement without significant decreases in strength occurs. It is noted that use of the residue reduces the initial resistance, so that the dose of cement should not be less than 200 kg of cement per m3. The results allow recommends the use of limestone waste since it has been observed decrease in soil and water contamination without prejudice construction material Keywords: Soil contamination; Limestone residue; Adding concrete

  14. Epilithic and endolithic bacterial communities in limestone from a Maya archaeological site.

    PubMed

    McNamara, Christopher J; Perry, Thomas D; Bearce, Kristen A; Hernandez-Duque, Guillermo; Mitchell, Ralph

    2006-01-01

    Biodeterioration of archaeological sites and historic buildings is a major concern for conservators, archaeologists, and scientists involved in preservation of the world's cultural heritage. The Maya archaeological sites in southern Mexico, some of the most important cultural artifacts in the Western Hemisphere, are constructed of limestone. High temperature and humidity have resulted in substantial microbial growth on stone surfaces at many of the sites. Despite the porous nature of limestone and the common occurrence of endolithic microorganisms in many habitats, little is known about the microbial flora living inside the stone. We found a large endolithic bacterial community in limestone from the interior of the Maya archaeological site Ek' Balam. Analysis of 16S rDNA clones demonstrated disparate communities (endolithic: >80% Actinobacteria, Acidobacteria, and Low GC Firmicutes; epilithic: >50% Proteobacteria). The presence of differing epilithic and endolithic bacterial communities may be a significant factor for conservation of stone cultural heritage materials and quantitative prediction of carbonate weathering. PMID:16391878

  15. Franciscan complex calera limestones: Accreted remnants of farallon plate oceanic plateaus

    USGS Publications Warehouse

    Tarduno, J.A.; McWilliams, M.; Debiche, M.G.; Sliter, W.V.; Blake, M.C.

    1985-01-01

    The Calera Limestone, part of the Franciscan Complex of northern California, may have formed in a palaeoenvironment similar to Hess and Shatsky Rises of the present north-west Pacific1. We report here new palaeomagnetic results, palaeontological data and recent plate-motion models that reinforce this assertion. The Calera Limestone may have formed on Farallon Plate plateaus, north of the Pacific-Farallon spreading centre as a counterpart to Hess or Shatsky Rises. In one model2, the plateaus were formed by hotspots close to the Farallon_Pacific ridge axis. On accretion to North America, plateau dissection in the late Cretaceous to Eocene (50-70 Myr) could explain the occurrence of large volumes of pillow basalt and exotic blocks of limestone in the Franciscan Complex. Partial subduction of the plateaus could have contributed to Laramide (70-40 Myr) compressional events3. ?? 1985 Nature Publishing Group.

  16. Reducing Energy-Related CO2 Emissions Using Accelerated Limestone Weathering

    SciTech Connect

    Rau, G H; Knauss, K G; Langer, W H; Caldeira, K

    2004-04-27

    Following earlier descriptions, the use and impacts of accelerated weathering of limestone AWL; reaction: CO{sub 2} + H{sub 2}O + CaCO{sub 3} {yields} Ca{sup 2+} + 2(HCO{sub 3}{sup -}) as a CO{sub 2} capture and sequestration method is further explored. Since ready access to the ocean is likely an essential requirement for AWL, it is shown that significant limestone resources are relatively close to a majority of CO{sub 2}-emitting power plants along the coastal US. Furthermore, waste fines, representing more than 20% of current US crushed limestone production (>10{sup 9} tonnes/yr), could be used in many instances as an inexpensive or free source of AWL carbonate. With limestone transportation to coastal sites then as the dominant cost variable, CO{sub 2} sequestration (plus capture) costs of $3-$4/tonne are achievable in certain locations. While there is vastly more limestone and water on earth than that required for AWL to capture and sequester all fossil fuel CO{sub 2} production, the transportation cost of bringing limestone, seawater, and waste CO{sub 2} into contact likely limits the method's applicability to perhaps 10-20% of US point-source emissions. Using a bench-scale laboratory reactor, it is shown that CO{sub 2} sequestration rates of 10{sup -6} to 10{sup -5} moles/sec per m{sup 2} of limestone surface area are readily achievable using seawater. This translates into reaction densities as high as 2 x 10{sup -2} tonnes CO{sub 2} m{sup -3}day{sup -1}, highly dependent on limestone particle size, solution turbulence and flow, and CO{sub 2} concentration. Modeling of AWL end-solution disposal in the ocean shows significantly reduced effects on ocean pH and carbonate chemistry relative to those caused by direct CO{sub 2} disposal into the atmosphere or ocean. In fact the increase in ocean Ca{sup 2+} and bicarbonate offered by AWL should significantly enhance the growth of corals and other marine calcifiers whose health is currently being threatened by

  17. Rapid method to determine actinides and 89/90Sr in limestone and marble samples

    DOE PAGESBeta

    Maxwell, Sherrod L.; Culligan, Brian; Hutchison, Jay B.; Utsey, Robin C.; Sudowe, Ralf; McAlister, Daniel R.

    2016-04-12

    A new method for the determination of actinides and radiostrontium in limestone and marble samples has been developed that utilizes a rapid sodium hydroxide fusion to digest the sample. Following rapid pre-concentration steps to remove sample matrix interferences, the actinides and 89/90Sr are separated using extraction chromatographic resins and measured radiometrically. The advantages of sodium hydroxide fusion versus other fusion techniques will be discussed. Lastly, this approach has a sample preparation time for limestone and marble samples of <4 hours.

  18. Passive treatment of acid mine drainage in down-flow limestone systems

    SciTech Connect

    Watzlaf, G.R.

    1997-12-31

    Passive down-flow systems, consisting of compost and/or limestone layers, may be well suited for treatment of acidic mine drainage containing ferric iron and/or aluminum. Two columns were constructed and operated in the laboratory. The first column simulated a downward, vertical-flow anaerobic wetland, also referred to as successive alkalinity-producing systems (SAPS), and has received mine drainage for 97 weeks. The 0.16-m diameter column was vertically oriented and (from bottom to top) consisted of a 0.30-m thick layer of limestone, a 0.76-m thick layer of spent mushroom compost, and 0.91 m of free standing water. Water flowed vertically downward through the system. A second column, filled with only limestone, received water from the same source as the first column. This limestone column contained a 1.06-m thick layer of limestone and 0.91 m of free standing water and has received water for 55 weeks. Actual acid mine drainage (pH = 3.1, acidity = 200 mg/L (as CaCO{sub 3}), SO{sub 4}{sup 2-} = 600 mg/L, Total Fe = 10 mg/L, Mn = 14 mg/L, and Al = 18 mg/L) was collected every two weeks from a nearby abandoned deep mine and applied to these columns at a rate of 3.8 mL/min. For the compost/limestone column, effluent pH remained above 6.2 (6.2-7.9); however, pH at a depth of 0.38 m in the compost (halfway) dropped to < 4 after 28 weeks (net acidic). At the bottom of the compost pH remained > 4.5 for all 97 weeks. Alkalinity was generated by a combination of limestone dissolution and sulfate reduction. Over the 97 week period, the column generated an average of 330 mg/L of alkalinity, mostly due to limestone dissolution. Bacterial sulfate reduction displayed an ever decreasing trend, initially accounting for more than 200 mg/L of alkalinity and after 40 weeks only accounting for about 50 mg/L.

  19. Accelerated weathering of limestone for CO2 mitigation: Opportunities for the stone and cement industries

    USGS Publications Warehouse

    Langer, William H.; San, Juan A.; Rau, Greg H.; Caldeira, Ken

    2009-01-01

    Accelerated weathering of limestone appears to provide a low-tech, inexpensive, high-capacity, environmentally friendly CO2 mitigation method that could be applied to about 200 fossil fuel fired power plants and about eight cement plants located in coastal areas in the conterminous U.S. This approach could also help solve the problem of disposal of limestone waste fines in the crushed stone industry. Research and implementation of this technology will require new collaborative efforts among the crushed stone and cement industries, electric utilities, and the science and engineering communities.

  20. Discrimination of moist oil shale and limestone using laser induced breakdown spectroscopy

    NASA Astrophysics Data System (ADS)

    Paris, P.; Piip, K.; Lepp, A.; Lissovski, A.; Aints, M.; Laan, M.

    2015-05-01

    Laser-induced plasma emission spectra of Estonian oil shale and associated limestone with varying moisture content were studied. Time gated spectra excited by 1064 nm laser radiation were recorded. Spectral lines for determination of plasma parameters were selected. Moisture causes the reduction of the intensity of the total emission, and increases the intensity of the Hα line. It was found that the effect of the moisture content on the plasma temperature and electron concentration was inconsiderable. Using the ratio of intensities of Hα and Mg spectral lines, it was possible to distinguish reliably between limestone and oil shale independently of their moisture content.

  1. Impacts of fracturing patterns on the rockfall susceptibility and erosion rate of stratified limestone

    NASA Astrophysics Data System (ADS)

    Matasci, B.; Jaboyedoff, M.; Loye, A.; Pedrazzini, A.; Derron, M.-H.; Pedrozzi, G.

    2015-07-01

    The erosion of steep rock slopes is largely controlled by rockfalls, which are a relevant hazard in mountainous regions. The deposition of blocks allows us to quantify rockfall activities and analyze the fracturing pattern that is the key to understand the processes that result in rockfalls. At Monte Generoso (in southern Switzerland), we compared the calculated rockfall susceptibility with the measured rockfall activity for a thinly stratified limestone cliff area. Thus, we were able to determine the erosion rate for the past 40 years and verify the reliability of the method used to perform the rockfall susceptibility analysis. The geomorphology of the area and the fracturing pattern have been accurately analyzed and quantified in the field and using airborne laser scanning techniques. These results have been used to perform a rockfall susceptibility assessment based on the frequency of joints and the distribution of failure mechanisms. Five joint sets have been detected, and the large influence of wedge sliding is demonstrated. The emptying works carried out on a series of protective barriers and nets resulted in detailed data regarding the magnitude distribution of the blocks that fell over a period of 40 years. This information, coupled with the inventory of the present day rock slope instabilities, results in a method that can be used to correct the erosion rate. Power laws have been fit with the blocks and instability data. Then, several calibration options have been tested to consider the additional amounts of erosion due to larger and less frequent potential rockfall events. The rockfall susceptibility, calculated with the distribution of the failure mechanisms, is correlated well with the measured rockfall activity. This approach allows us to characterize the erosion processes in a steep geomorphological context to obtain new insights regarding the evolution of rock slopes.

  2. Basalt-Limestone and Andesite-Limestone Interaction in the Arc Crust - Implications for Volcanic Degassing of CO2

    NASA Astrophysics Data System (ADS)

    Carter, L. B.; Dasgupta, R.

    2014-12-01

    Volcanically emitted CO2 is generally mantle-derived, but high degassing rates at some arcs (e.g. Merapi [1] and Colli Albani Volcanic District [2]) are thought to be affected by magma-carbonate interaction in the upper plate. However, the effects of depth, temperature, and composition on this process are poorly known. We experimentally simulated magma (50%)-limestone (50%) wallrock interactions at 0.5-1.0 GPa, 1100-1200 °C using pure calcite and a hydrous (~3-5 wt.% H2O) melt (basalt, andesite, or dacite). At 1.0 GPa, 1200 °C starting melts are superliquidus, whereas in the presence of calcite, Ca-rich cpx ± Ca-scapolite are produced. With increasing T, basalt-calcite interaction causes the melt, on a volatile-free basis, to become silica-poor and Ca-rich with alumina decreasing as cpx becomes more CaTs-rich. The same trend is seen with all starting melt compositions as P decreases at a constant T (1200 °C), producing melts similar to ultracalcic (CaO/Al2O3>>1) melt inclusions found in arc settings. Shifting from basalt to andesite has little effect on SiO2 and CaO of the reacted melt (e.g. 37 wt.% SiO2, 42 wt.% CaO at 0.5 GPa, 1200 °C), whereas Al2O3 of andesite-derived reacted melt is lower, likely a result of lower alumina in the starting andesite. Wall-rock calcite consumption is observed to increase with increasing T, decreasing P, and increasing melt XSiO2. At 0.5 GPa between 1100 and 1200 °C, our basalt experiments yield carbonate assimilation from 22 to 48 wt.%. This decreases to 20 wt.% at 1.0 GPa, 1200 °C, whereas an andesitic composition assimilates 59 to 52 wt.% from 0.5 to 1.0 GPa at 1200 °C. The higher assimilation in andesite-added runs at high-T is because of lower silicate liquidus as evidenced by lower modal proportion or absence of cpx ± scapolite. Using a magma flux rate estimated for Mt. Vesuvius [3], we obtain a CO2 outflux for a single such volcano experiencing arc magma-calcite reaction [4] of at least 2-4% of the present

  3. Structure, stratigraphy, and depositional environment of the Heterostegina limestone and overlying sands in the Lake Pontchartrain Area of southeast Louisiana

    SciTech Connect

    Street, S.B. III

    1994-09-01

    The Heterostegina zone of the Oligocene Anahuac Formation in southeastern Louisiana occurs in the subsurface as an extensive shelf reef complex. The Heterostegina limestone is overlain by strata associated with the Oligocene Discorbis and lower Miocene Robulus (43) biostratigraphic zones. Examination of electric logs and drill cuttings from wells in the Lake Pontchartrain area of southeastern Louisiana reveal the importance of the Heterostegina reef as a paleoenvironmental punctuation marking a significant shift in regional depositional patterns that occurred between the generally transgressive Oligocene seas and the generally regressive Miocene seas. Fauna identified in thin section from the Heterostegina reef interval suggest deposition in a warm, shallow marine environment relatively free of significant elastic influx. An eastward migration of late Oligocene-early Miocene stream systems introduced an influx of elastic sediments onto the ancient shelf of the Lake Pontchartrain area, which influenced the termination of favorable conditions for Heterostegina reef growth. The Robulus (43) zone strata are characterized by a cyclic sequence of lime, shale, and sand. Within this interval, two general lithofacies are identified. Lithofacies I is characterized by thick, shore-parallel sand deposits, and is interpreted to have been deposited in association with a barrier-beach/tidal-inlet channel environment. Lithofacies II is characterized by shaleprone sand intervals, which are immediately overlain by calcareous shales and limestones deposited in the offshore inner-middle neritic environment. Five oil and gas fields in the study area have produced hydrocarbons from the interval of interest. The occurrence of hydrocarbons at these locations with respect to mechanisms of entrapment and areal extent of the reservoirs is characterized through detailed subsurface mapping.

  4. Structural-tectonic controls and geomorphology of the karst corridors in alpine limestone ridges: Southern Carpathians, Romania

    NASA Astrophysics Data System (ADS)

    Tîrlă, Laura; Vijulie, Iuliana

    2013-09-01

    The relationship between surface karst development and the geological frame is widely acknowledged in the study of karst landforms. It is of considerable interest especially in alpine environments (e.g. Alpine-Dinaric-Carpathian orogenic system). Karst corridors are generally known as kluftkarren or bogaz and form by solution of limestone along a lithoclase network. The Vânturariţa-Buila Massif (Carpathians, Romania) is a typical alpine karst ridge and a former carbonate platform of Upper Jurassic age in which geologically-controlled karst features have been developing over a geologic timescale. Field research and mapping were useful in extracting geologic features. Joint- and structure-controlled karst corridors are common in the upper section of the mountain, between 1600 and 1850 m. First, a complex system of lithoclases (fissures, joints and faults) occurred; then, surface runoff or meltwater solutionally enlarged them. Tension fractures strike in a northeast-southwest direction, parallel to homoclinal limestone layers. The exposed fault walls often preserve draperies and speleothem remnants. Further, statistical analysis of joint, fault and bogaz orientations has shown the close relation between the three datasets, and morphometric analysis centered only on the karst corridor system. Results derived from the statistical analysis of orientation data show that there is a strong preferred orientation of the bogaz or bogaz-like forms along the directional faults and that they commonly develop in extensional (tectonically active) environments. Additional features typical to fluviokarst are also present — subterranean connections between the karst corridors and the headwalls of the pocket valleys, generating headward recession both by continuous sapping of karst springs at the headwall base followed by collapses. An extremely poor surface drainage network developed in the upper pavement facing southeast, compared to that on the middle and lower sides.

  5. ECONOMIC EVALUATION OF ADVANCED LIMESTONE, DAVY S-H, AND DOWA GYPSUM-PRODUCING FGD (FLUE GAS DESULFURIZATION) PROCESSES

    EPA Science Inventory

    The report gives results of economic evaluations of three gypsum-producing flue gas desulfurization processes: advanced limestone (in-loop forced oxidation with adipic acid additive), Davy S-H (lime), and Dowa (aluminum sulfate, limestone). For a 500-MW power unit burning 3.5% su...

  6. Imaging strain localization in porous limestone by X-ray Computed Tomography and Digital Image Correlation

    NASA Astrophysics Data System (ADS)

    Ji, Y.; Baud, P.; Hall, S.; Wong, T.-f.

    2012-04-01

    The brittle-ductile transition in porous sandstones has now been studied extensively. Microstructural studies combining various techniques on samples deformed in the laboratory documented the development of a wide variety on strain localization patterns and failure modes in overall agreement with the field observations in various sandstone formations. In contrast, there is a paucity of mechanical and microstructural laboratory data on the brittle-ductile transition in porous carbonates, particularly for the high porosity end-members. The question of strain localization is in particular hard to tackle as conventional microstructural analyses cannot as in sandstone be guided by acoustic emission statistics. In this context, X-ray Computed Tomography (CT) imaging provides a promising technique to accurately describe the various failure modes associated with the brittle-ductile transition in porous limestone. In this study, we focused on a grainstone from the Majella Mountain, central Italy. Detailed field observations performed in this formation by Tondi et al. (2006) have revealed some complex interplay between deformation/compaction bands and stylolites. Our samples of Majella grainstone had a nominal porosity of 31% and were primarily composed of calcite. A series of hydrostatic and conventional triaxial experiments were performed in dry conditions at room temperature, constant strain rate and at confining pressures ranging from 5 to 50 MPa. Several sets of CT images at a resolution of 25 microns were acquired before and after deformation. Digital Image Correlation (DIC) was performed on images of the intact and deformed samples. The full 3D strain tensor field was derived. Results for the two strain invariants corresponding to the volumetric and shear components were obtained for grid steps of 500 and 250 microns. Our new results showed that deformation was compactant in Majella grainstone over the wide range of pressures investigated. Strain localization was

  7. Determination of paleostresses from stylolite morphologies in the limestones of Bure-sur-Meuse

    NASA Astrophysics Data System (ADS)

    Rolland, Alexandra; Toussaint, Renaud; Schmittbuhl, Jean; Baud, Patrick; Conil, Nathalie

    2010-05-01

    In order to demonstrate the feasibility of a radioactive waste repository (HLW) in clay-stone formation, the French national radioactive waste management agency (Andra) started in 2000 to build an underground research laboratory (URL) at Bure in the south of the Meuse district. The target horizon for the laboratory is a 135 m thick layer of argillaceous rock (Callovo-Oxfordian claystone) that lies between about 420 and 555 meters below the surface at the URL site. The argillite layer (COX) is surrounded by limestones from the Dogger and the Oxfordian ages (respectively 164,7 to 175,6 Ma and 161,2 to 164,7Ma). Numerous stylolites were found present in the cores of these limestones, from around 378 m depth for the Oxfordian age and 719 m depth for the Dogger age. They were sampled and their morphology was precisely quantified with different techniques. Recent studies (Schmittbuhl et al., 2004; Ebner et al., 2008, 2009) suggest that paleotresses can be determined from the stylolites morphologies. The goal of this study is to obtain estimates of the paleostress field during the appearance of these stylolites, and thus constraints on the deformation kinematics of these formations. Several stylolites were samples in the Dogger and Oxfordian formations. First, the trace of the stylolites along the core sides is investigated: high resolution photographs (at 47 microns resolution) are shot, digitalized and analyzed. From these photographs, the exact shape of the inner part of stylolites was extracted, and 1D function describing the stylolites boundaries is obtained. Next, 3D profilometry is performed to obtain a complete coverage at roughly micrometric resolution of the whole surface of the sides of opened stylolites spanning through the cores. The 1D and 2D geometries of the stylolites are analysed with correlation techniques as the Fourier Power Spectrum, the Average Wavelet Coefficient. We look for scaling laws of the elevation of the stylolite height above its mean

  8. Use of limestone obtained from waste of the mussel cannery industry for the production of mortars

    SciTech Connect

    Ballester, Paloma; Marmol, Isabel; Morales, Julian; Sanchez, Luis . E-mail: luis-sanchez@uco.es

    2007-04-15

    Various types of cement-SiO{sub 2}-CaCO{sub 3} mortar were prepared by replacing quarry limestone aggregate with limestone obtained as a by-product from waste of the mussel cannery industry. The CaCO{sub 3} aggregate consists mainly of elongated prismatic particles less than 4 {mu}m long rather than of the rounded particles of smaller size (2-6 {mu}m) obtained with quarry limestone. The mechanical and structural properties of the mortars were found to be influenced by aggregate morphology. Setting of the different types of mortar after variable curing times was evaluated by scanning electron microscopy (SEM), thermogravimetric analysis (TG) and mercury intrusion porosimetry (MIP) techniques. Mortars with a high content in mussel shell limestone exhibited a more packed microstructure, which facilitates setting of cement and results in improved mortar strength. The enhanced mechanical properties of the new mortars allow the cement content in the final mortar composition to be decreased and production costs to be reduced as a result.

  9. Early mixed-water dolomitization in the Pleistocene reef limestones, west coast of Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Durgaprasada Rao, N. V. N.; Al-Imam, O. A. O.; Behairy, A. K. A.

    1987-07-01

    Raised Pleistocene reef limestone characterizes the western coastal plain of Jeddah on the eastern margin of the Red Sea. Soon after the Mid-Pleistocene regression, the subaerially exposed limestone was subjected to meteoric processes during which Mg-calcite was converted to stable low Mg-calcite and partial or complete dissolution of aragonite occurred at various depths. Early meteoric diagenesis through dissolution-precipitation processes had produced sparry calcite in the voids formed by the dissolution of aragonite in the limestone. Following the late Pleistocene-Holocene marine transgression, dolomitization was initiated in the reef in a meteoric-marine water mixing zone. Lack of correlation between dolomite and the evaporite minerals and the low Sr concentrations argue against hypersaline solutions as agents of dolomitization. Mineralogical and chemical data suggest that most diagenetic dolomite is formed at the expense of primary aragonite. Vertical and lateral variations in the distribution of dolomite, aragonite and calcite indicate that dolomitization processes have been affected by the fluctuating mixed-water zone associated with sea-level oscillations. Holocene rise in the sea level terminated dolomitization in the lower layers and shifted the dolomitizing front to the upper sections of the limestone. Dolomite is low in the upper horizons of the reef and occurs as scattered perfect rhombs, while in the lower layers it is fine-grained and subhedral.

  10. Performance Monitoring: Evaluating an Organic Carbon-Limestone PRB for Treatment of Heavy Metals and Acidity

    EPA Science Inventory

    Since 2004, researchers from the U.S. EPA National Risk Management Research Laboratory (NRMRL) have annually evaluated performance of an organic carbon-limestone permeable reactive barrier (PRB) system installed in 2003 by EPA Region 6 at the Delatte Metals Superfund site in Ponc...

  11. PROCEEDINGS: EPA'S INDUSTRY BRIEFING ON THE ADIPIC ACID ENHANCED LIMESTONE FGD PROCESS (JULY 1981)

    EPA Science Inventory

    The proceedings document presentations made during an EPA-sponsored industry briefing, July 15, 1981, in Springfield, MO. The briefing dealt with the status of EPA's research activities on the adipic-acid-enhanced limestone flue gas desulfurization (FGD) process. Subjects covered...

  12. SHAWNEE LIME/LIMESTONE SCRUBBING COMPUTERIZED DESIGN/COST-ESTIMATE MODEL USERS MANUAL

    EPA Science Inventory

    The manual gives a general description of the Shawnee lime/limestone scrubbing computerized design/cost-estimate model and detailed procedures for using it. It describes all inputs and outputs, along with available options. The model, based on Shawnee Test Facility scrubbing data...

  13. The effect of elevated temperature on the strength parameters of silica acid ester consolidated porous limestones

    NASA Astrophysics Data System (ADS)

    Pápay, Zita; Török, Ákos

    2013-04-01

    The porous limestone is one of the most widespread construction materials of the monuments in Central Europe, with emblematic buildings in Vienna, Bratislava, Budapest and many other cities of Austria, Slovakia, Czech Republic and Hungary. The restoration of these monuments very often requires the consolidation of the porous limestone material, where various types of consolidants are used to strengthen the highly weathered stone. Our research focused on the understanding of the behaviour of consolidated porous limestone when the material is subjected to higher temperatures. Test procedure included the preparation of cylindrical test specimens from the Miocene porous limestone which was followed by consolidation by four various types of silica acid ester. The samples after consolidation were heated to 300 and 600 °C in electric oven. The material properties such as ultrasonic pulse velocity, density were tested before and after the treatment. Indirect tensile strength (Brazilian test) was used to compare the strength parameters of non treated and consolidated samples. Silica acid ester treated samples after heating were also measured in terms of strength, density and ultrasonic pulse velocity. The results show that there are significant changes in strength of various pre-treated samples after heating indicating the sensitivity of the materials to temperature changes and accidental fire.

  14. Hydrology of the cavernous limestones of the Mammoth Cave area, Kentucky

    USGS Publications Warehouse

    Brown, Richmond F.

    1966-01-01

    The Mammoth Cave National Park in central Kentucky offers a unique opportunity to study the occurrence of ground water in limestone under natural conditions. Ground water occurs as perched and semiperched bodies in alternate sandstone, shale, and limestone formations and under water-table conditions at the approximate level of the Green River in thick soluble limestone. Three continuous recorders that operated for 5 years indicate that precipitation on the Mammoth Cave plateau recharges the underlying sandstone rapidly. Ground water from the sandstone discharges horizontally to the edges of the plateau and vertically to underlying formations. Some of the precipitation recharges underlying formations almost immediately through overland flow to sinkholes and free fall through open shafts to pools at the water table. Much of the precipitation on the Pennyroyal plain flows overland into sinkholes and then through solution openings to the Green River. Water from the Green River flows into limestone solution channels under Mammoth Cave plateau at some stages, and this water discharges again to the Green River downstream. The presence of salt water, high in chloride in the Green River, makes it possible to trace the movement of the river water through the underground streams. Graphs show relationships of chloride concentration, stage of the Green River, time, precipitation, ground-water levels, and stratigraphy.

  15. UTILIZATION OF LIME/LIMESTONE WASTE IN A NEW ALUMINA EXTRACTION PROCESS

    EPA Science Inventory

    The report gives results of a preliminary process design and economic evaluation of a process for using lime/limestone scrubbing wastes as a source of calcium in the extraction of alumina (for use in aluminum production) from low grade domestic ores such as clays and coal ash. Th...

  16. Limestone characterization to model damage from acidic precipitation: Effect of pore structure on mass transfer

    USGS Publications Warehouse

    Leith, S.D.; Reddy, M.M.; Irez, W.F.; Heymans, M.J.

    1996-01-01

    The pore structure of Salem limestone is investigated, and conclusions regarding the effect of the pore geometry on modeling moisture and contaminant transport are discussed based on thin section petrography, scanning electron microscopy, mercury intrusion porosimetry, and nitrogen adsorption analyses. These investigations are compared to and shown to compliment permeability and capillary pressure measurements for this common building stone. Salem limestone exhibits a bimodal pore size distribution in which the larger pores provide routes for convective mass transfer of contaminants into the material and the smaller pores lead to high surface area adsorption and reaction sites. Relative permeability and capillary pressure measurements of the air/water system indicate that Salem limestone exhibits high capillarity end low effective permeability to water. Based on stone characterization, aqueous diffusion and convection are believed to be the primary transport mechanisms for pollutants in this stone. The extent of contaminant accumulation in the stone depends on the mechanism of partitioning between the aqueous and solid phases. The described characterization techniques and modeling approach can be applied to many systems of interest such as acidic damage to limestone, mass transfer of contaminants in concrete and other porous building materials, and modeling pollutant transport in subsurface moisture zones.

  17. LIMESTONE WET-SCRUBBING TEST RESULTS AT THE EPA ALKALI SCRUBBING TEST FACILITY. CAPSULE REPORT

    EPA Science Inventory

    This capsule report discusses the highlights of the first detailed engineering progress report. It describes the test facility and test program and presents results to date of the limestone wet-scrubbing testing. In addition, the realiability and operability of the test facility ...

  18. Oxygen and carbon isotopic composition of limestones and dolomites, bikini and eniwetok atolls

    USGS Publications Warehouse

    Grant, Gross M.; Tracey, J.I., Jr.

    1966-01-01

    Aragonitic, unconxolidated sediments from the borings on the Eniwetok and Bikini atolls are isotopically identical with unaltered skeletal fragments, whereas the recrystallized limestones exhibit isotopic variations resulting from alteration in meteoric waters during periods of emergence. Dolomites and associated calcites are enriched in O18, perhaps because of interaction with hypersaline brines.

  19. Goat Urine and Limestone Affect Nitrogen and Cation Distributions in an Acidic Grassland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Use of goats (Capra aegagrus hircus L.) to clear overgrown pastures and woodlots of unwanted vegetation may result in high rates of urine deposition where goats congregate. Surface application of limestone to dystrophic acid soils before clearing is known to augment ammonia gas volatilization from ...

  20. Adsorption/desorption of phosphorus on limestone from the Biscayne Aquifer under freshwater and seawater conditions.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Areas of seawater intrusion are known geochemically active regions particularly in limestone aquifers, where carbonate mineral dissolution and ion exchange reactions are important. Both of these processes can lead to a release of phosphorus from the aquifer matrix to the groundwater as seawater int...

  1. Sulfate Attack of Cement-Based Material with Limestone Filler Exposed to Different Environments

    NASA Astrophysics Data System (ADS)

    Gao, Xiaojian; Ma, Baoguo; Yang, Yingzi; Su, Anshuang

    2008-08-01

    Mortar prisms made with OPC cement plus 30% mass of limestone filler were stored in various sulfate solutions at different temperatures for periods of up to 1 year, the visual appearance was inspected at intervals, and the flexural and compressive strength development with immersion time was measured according to the Chinese standard GB/T17671-1999. Samples were selected from the surface of prisms after 1 year immersion and examined by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), laser-raman spectroscopy and scanning electron microscopy (SEM). The results show that MgSO4 solution is more aggressive than Na2SO4 solution, and Mg2+ ions reinforce the thaumasite sulfate attack on the limestone filler cement mortars. The increase of solution temperature accelerates both magnesium attack and sulfate attack on the limestone filler cement mortar, and leads to more deleterious products including gypsum, ettringite and brucite formed on the surface of mortars after 1 year storage in sulfate solutions. Thaumasite forms in the mortars containing limestone filler after exposure to sulfate solutions at both 5 °C and 20 °C. It reveals that the thaumasite form of sulfate attack is not limited to low-temperature conditions.

  2. EVALUATION OF THE LIMESTONE DUAL ALKALI PROTOTYPE SYSTEM AT PLANT SCHOLZ: FINAL REPORT

    EPA Science Inventory

    The report gives results of a 2-month test (February/March 1981) of the limestone dual alkali process at an existing 20 MW prototype facility at Gulf Power Company's Scholz Steam Plant. The project was intended to evaluate the technical feasibility of the process at a prototype s...

  3. ENGINEERING APPLICATION AND ECONOMICS OF LIMB (LIMESTONE INJECTION/MULTISTAGE BURNERS)

    EPA Science Inventory

    The paper describes the use of an EPA LIMB cost model, in conjunction with cost and performance models for flue gas desulfurization (FGD), to compare these two technologies under similar premises. (NOTE: The performance goals of LIMB, EPA's acronym for Limestone Injection/Multist...

  4. Demonstration of a hydration process for reactivating partially sulfated limestone sorbents

    SciTech Connect

    Smith, G.W.; Hajicek, D.R.; Myles, K.M.; Goblirsch, G.M.; Mowry, R.W.; Teats, F.G.

    1981-10-01

    The utilization of limestione sorbent for the removal of SO/sub 2/ in coal combustion in an atmospheric fluidized-bed combustor (AFBC) can be markedly increased by reactivating the partially sulfated limestone for reuse in the combustor. Such reuse would reduce costs and the environmental impact of quarrying and disposing of large quantities of limestone. The reactivation process consists of hydrating the partially sulfated limestone by treatment with water. A demonstration of the hydration process and the reuse of the reactivated limestone were carried out at Grand Forks Energy Technology Center (GFETC) in cooperation with Argonne National Laboratory (ANL). The data obtained in the GFETC 0.2-m/sup 2/ AFBC are compared with those obtained earlier in the ANL 0.02-m/sup 2/ AFBC. Marked enhancement of calcium utilization was achieved in both studies, but differences were noted in the degree of enhancement and in the Ca/S mole ratios required to maintain SO/sub 2/ in the off-gas at an acceptable level.

  5. EPA'S LIMB (ENVIRONMENTAL PROTECTION AGENCY'S LIMESTONE INJECTION MULTISTAGE BURNER) DEVELOPMENT AND DEMONSTRATION PROGRAM

    EPA Science Inventory

    The paper describes and discusses key design features of the retrofit of EPA's Limestone Injection Multistage Burner (LIMB) system to an operating, wall-fired utility boiler at Ohio Edison's Edgewater Station, based on the preliminary engineering design. The full-scale demonstrat...

  6. DEFINITIVE SOX CONTROL PROCESS EVALUATIONS: LIMESTONE, LIME, AND MAGNESIA FGD PROCESSES

    EPA Science Inventory

    The report gives economic and ground-to-ground energy evaluations of limestone slurry, lime slurry, and magnesia (producing sulfuric acid) flue gas desulfurization (FGD) processes. The lime slurry process, using purchased lime and lime calcined onsite, remains lower in capital in...

  7. ECONOMICS OF DISPOSAL OF LIME/LIMESTONE SCRUBBING WASTES: UNTREATED AND CHEMICALLY TREATED WASTES

    EPA Science Inventory

    The report gives results of a detailed, comparative economic evaluation of four alternatives available to the utility industry for the disposal of wastes from flue gas desulfurization using limestone or lime slurry scrubbing. The alternatives are untreated sludge (pond or landfil...

  8. ECONOMICS OF DISPOSAL OF LIME/LIMESTONE SCRUBBING WASTES: SURFACE MINE DISPOSAL AND DRAVO LANDFILL PROCESSES

    EPA Science Inventory

    The report gives results of economic evaluations of flyash and limestone scrubbing waste disposal in a surface mine and in a landfill after treatment with a Dravo Lime Co. chemical additive. For the base case (new 500 MW midwestern plant burning 3.5% S, 16% ash, 10,500 Btu/lb coa...

  9. Treatment Of Metal-Mine Effluents By Limestone Neutralization And Calcite Co-Precipitation (Presentation)

    EPA Science Inventory

    The U.S. Geological Survey - Leetown Science Center and the Colorado School of Mines have developed a remediation process for the treatment of metals in circumneutral mining influenced waters. The process involves treatment with a pulsed limestone bed (PLB) system, followed by c...

  10. Treatment Of Metal-Mine Effluents By Limestone Neutralization And Calcite Co-Precipitation

    EPA Science Inventory

    The U.S. Geological Survey - Leetown Science Center and the Colorado School of Mines have developed a remediation process for the treatment of metals in circumneutral mining influenced waters. The process involves treatment with a pulsed limestone bed (PLB) system, followed by c...

  11. Laboratory studies of Miocene limestone for the use of construction industry in Sri Lanka

    NASA Astrophysics Data System (ADS)

    de Silva Jayawardena, Upali

    2016-04-01

    Geologically ten percent of Sri Lanka is made up of Miocene limestone which covers northern and north-western coastal belt of the Island. It is used as a raw material for various industries but only cement and lime are being used for the construction industry. Except its chemical composition there is no available literature to study about other properties. Therefore the author carried out a series of laboratory tests to find out the mechanical properties of limestone in Sri Lanka. The objective of this paper is to make a note on the various properties of Miocene limestone and describe its suitability to use as an aggregate for the construction industry in Sri Lanka. Borehole samples (NX size) of limestone were obtained from various drilling sites in Northern Province of Sri Lanka and selected samples were prepared for different laboratory tests after visual observations. The tests were carried out according to ASTM Standards at the geotechnical and materials testing laboratories. The number of samples per each test was different. The range (and average result) for each property can be mentioned here as bulk density 2213-2643 (2452) kg/m3, water absorption 2.2-4.5 (1.91)%, porosity 1-15 (6.5)%, specific gravity 2.58-2.68(2.62), ultrasonic pulse velocity P wave 4480-6338 (5668) m/s and S wave 2688-3802 (3400) m/s, uniaxial compressive strength 11-92 (35)MPa, point load strength 1.2-7.1 (3.7)MPa, aggregate impact value, AIV 25-30 (28)%, LAAV 35-38 (36)%, and Brazilian tensile strength 2.1-4.4 (3.2)MPa. Poisson's ratio 0.12-0.68 (0.22) and modulus of elasticity 42-85 (62) GPa were obtained by using P and S ultrasonic wave velocity values. According to LAAV and AIV this limestone may be suitable as the base course material for road construction but may not be suitable for surface material of highways and rail road ballasts. Ultrasonic velocity waves indicate that limestone is highly compacted and solid. According to the compressive strength of solid limestone rock a few

  12. The Öland limestone - A Swedish stone used for more than one thousand years

    NASA Astrophysics Data System (ADS)

    Schouenborg, Björn; Wickström, Linda; Mikaelsson, Jan

    2016-04-01

    The second largest island in Sweden is the home of the "Öland limestone", a condensed and bedded limestone whose origin dates back to Lower Ordovician, i.e. about 480 M years ago. Öland is a part of the palaeocontinent Baltica that, at the time, was situated at low latitudes with deposition of the calcareous sediments in a cool water environment. The limestone on Öland represents a proximal ramp tectonic setting, with the oldest sediments deposited in the west and younger sediments deposited towards east and southeast. Fluctuating sea-levels have created erosional hard grounds such as the Flowery sheet. These hardgrounds are recognised by their vivid colours and trace fossils, and can be traced all over Baltica, but is maybe best represented on Öland. Ordovician limestones are present in many places in Sweden, but it is the occurrence on Öland that is the most renowned in a building stone perspective. One reason for this is the favourable trading location, an island off the Swedish East coast in middle of the trading routes between the Baltic countries and the continent. Other reasons are the pleasant aesthetical values with numerous orthoceratites and other fossils. The limestones on Öland differ in colour. From the red varieties (with oxidized iron) to brownish and grey. The bedding is mostly in the cm-scale which easily enables very exploitable thickness of slabs. Every mm limestone represents about 1000 years of deposition. The limestone has most likely been used in a very crude way for many thousand years, but archaeological evidence of a more industrialized usage is just a little more than 1000 years. It is known from the literature that the first official Swedish king, Gustav Vasa (16th century), desired this stone. At the time it was called "Öland marble", and the king "imported" specialists to process it further at the Royal Stone workshop on northern Öland. Remnants of tools and working sites still remain in an outdoor museum. Export of the

  13. An integrated study of limestone behavior during calcination and hydration processes

    NASA Astrophysics Data System (ADS)

    Leontakianakos, George; Baziotis, Ioannis; Kiousis, George; Giavis, Dimitrios; Tsimas, Stamatios

    2010-05-01

    One of the most important processes in industrial scale, represents the dissociation of carbonates to lime and CO2. This process, called calcination, occur at relative high temperatures (>9000C). Lime rapidly reacts with the water, liberating high amounts of heat producing Ca(OH)2. For the purpose of the present study five samples of different limestones from different quarries from Greece were collected. The aim of the study was to analyze the behavior of the limestones during calcination and test the hydraulic properties of the quick lime. Limestone particles (1.6-2 cm) were reacted in a pre-heated oven at three different temperatures (900, 1050 and 1200oC) for 30 min in order to produce quick lime. Petrographic features of studied limestones were done using secondary electron microscopy (SEM). X-ray diffractometry and Raman micro-spectroscopy were applied in order to identify the carbonate phases (calcite and dolomite) in the studied limestones. Chemical composition of limestones and limes were determined by Atomic absorption spectroscopy (AAS) method. 25 gr of the produced lime were hydrated by adding 100 ml distilled water having a room temperature (~250C) to produce Ca(OH)2 through the exothermic reaction CaO(s) + H2O(l)-Ca(OH)2(aq). We measured the temperature difference in the water until a maximum value is reached; this value represents the reactivity of the produced slaked lime. Chemical composition and reactivity estimation were done following European Standards EN-459-2. The reactivity of quick lime depends on various factors with the most important being the internal structure of the limestone, calcination temperature/duration applied to the limestone, the admixtures such as the MgO content, hard-burned phenomena etc. The treatment of the experimental results suggests the following: i) The (CaO+MgO)Lime value have similar variation for both samples calcined at temperatures of 1050oC (58-90 wt%) and 1200oC (57-94 wt%); whereas the samples calcined at

  14. A field method for the determination of calcium and magnesium in limestone and dolomite

    USGS Publications Warehouse

    Shapiro, Leonard; Brannock, Walter Wallace

    1957-01-01

    The method is an adaptation of a procedure described by Betz and Noll1 in 1950. Calcium and magnesium are determined by visual titration using Versene (disodium ethylenediamine tetraacetate) with Murexide (ammonium purpurate) as the indicator for calcium and Eriochrome Black T as the indicator for magnesium.

  15. The effect of limestone treatments on the rate of acid generation from pyritic mine gangue.

    PubMed

    Burt, R A; Caruccio, F T

    1986-09-01

    Surface water enters the Haile Gold Mine, Lancaster County, South Carolina by means of a small stream and is ponded behind a dam and in an abandoned pit. This water is affected by acidic drainage. In spite of the large exposures of potentially acid producing pyritic rock, the flux of acid to the water is relatively low. Nevertheless, the resulting pH values of the mine water are low (around 3.5) due to negligible buffering capacity. In view of the observed low release of acidity, the potential for acid drainage abatement by limestone ameliorants appears feasible.This study investigated the effects of limestone treatment on acid generation rates of the Haile mine pyritic rocks through a series of leaching experiments. Below a critical alkalinity threshold value, solutions of dissolved limestone were found consistently to accelerate the rate of pyrite oxidation by varying degrees. The oxidation rates were further accelerated by admixing solid limestone with the pyritic rock. However, after a period of about a month, the pyrite oxidation rate of the admixed samples declined to a level lower than that of untreated pyrite. Leachates produced by the pyrite and limestone mixtures contained little if any iron. Further, in the mixtures, an alteration of the pyrite surface was apparent.The observed behaviour of the treated pyrite appears to be related to the immersion of the pyrite grains within a high alkalinity/high pH environment. The high pH increases the rate of oxidation of ferrous iron which results in a higher concentration of ferric iron at the pyrite surface. This, in turn, increases the rate of pyrite oxidation. Above a threshold alkalinity value, the precipitation of hydrous iron oxides at the pyrite surface eventually outpaces acid generation and coats the pyrite surface, retarding the rate of pyrite oxidation. PMID:24214013

  16. Quantifying and timing of long-term carbonate mobilisation in a limestone aquifer

    NASA Astrophysics Data System (ADS)

    Kirstein, J.; Gaupp, R.

    2012-04-01

    Carbonate dissolution during weathering, its intermediate storage by reprecipitation, and/or final export to the sea are major components in the global carbon cycle. The Thuringian Basin in the central part of Germany exposes deposits of the German Triassic Muschelkalk sequence consisting of limestone and dolostone beds. Partial dissolution, oxidation and iron redistribution is obvious in limestones along the slopes of the middle Saale river valley. These features are most prominent close to a Mid Quaternary valley floor (Elster terrace). They decrease down-section following fractures in homogeneous micritic limestones of the Lower Muschelkalk (Jena Formation), and reach a minimum close to the present groundwater table. It implies a discontinuous vertical migration of the groundwater table close to the valley slopes, spanning >700 ka of valley incision, and a coeval increase of oxidative weathering of sulfides and organic matter in the micritic carbonate. The recharging groundwater carries dissolved and particulate organic matter from the soil into fractures and pores. Microbial community oxidizes the organic material by using O2 that diffuses in from atmosphere. Due to the dissolved CO2 the water is undersaturated concerning carbonate minerals. The fissures enlarge by the water dissolving the limestones. The working hypothesis suggests the maximum of carbonate dissolution and descendant export within the vadose zone. Material export is supposed to occur dependant on climatic variations with microbial mediation in both dissolution and transient reprecipitation. Furthermore, the study area has the important advantage that the timing of the 100 m migration of the ground water table has a good age control due to topographic dating of terrace formation. Key aspects of this study are the quantification of long-term telodiagenetic transformations of the limestones, the timing of the involved processes and the analysis of current carbon fluxes both surface and subsurface

  17. Dissolution rates of subsoil limestone in a doline on the Akiyoshi-dai Plateau, Japan: An approach from a weathering experiment, hydrological observations, and electrical resistivity tomography

    NASA Astrophysics Data System (ADS)

    Akiyama, Sanae; Hattanji, Tsuyoshi; Matsushi, Yuki; Matsukura, Yukinori

    2015-10-01

    This study aims at estimating the controlling factors for the denudation rates of limestone, which often forms solution dolines on karst tablelands. Our approaches include (1) electrical resistivity tomography (ERT) to reveal shallow subsurface structures and hydrological settings, (2) automated monitoring of volumetric water content in soil profiles and manual measurements of subsurface CO2 concentrations and soil water chemistry, and (3) a field weathering experiment using limestone tablets with the micro-weight loss technique for determining current denudation rates. The field experiment and monitoring were carried out over 768 days from 2009-2011 at four sites with varying topographic and hydrological conditions along the sideslope of a doline on the Akiyoshi-dai karst plateau in SW-Japan. The installation depths of the limestone tablets were 15 cm or 50 cm below the slope surface. The soil moisture conditions varied site by site. Water-saturated conditions continued for 40-50% of the whole experimental period at 50-cm depth of upper and middle sites, while only 0-10% of the experimental period was water-saturated at the other sites. Chemical analysis revealed that the soil water was chemically unsaturated with calcite for all the sites. Spatial differences in concentrations of CO2 in soil pore air were statistically less significant. The denudation rates of the buried limestone tablets were 17.7-21.9 mg cm- 2 a- 1 at the upper and middle slopes, where the soil was water-saturated for a long time after precipitation. The lowest denudation of 3.9 mg cm- 2 a- 1 was observed on lower slopes where soil was not capable of maintaining water at a near saturation level even after precipitation. Statistical analysis revealed that the denudation rates of the tablets were strongly controlled by the duration for which soil pores were saturated by water (the conditions defined here are degrees of water saturation greater than 97%). Electrical resistivity tomography

  18. Cretaceous planktic foraminiferal biostratigraphy of the Calera Limestone, Northern California, USA

    USGS Publications Warehouse

    Sliter, W.V.

    1999-01-01

    The Calera Limestone is the largest, most stratigraphically extensive limestone unit of oceanic character included in the Franciscan Complex of northern California. The aim of this paper is to place the Calera Limestone at its type locality (Rockaway Beach, Pacifica) in a high-resolution biostratigraphy utilizing planktic foraminifers studied in thin section. A section, about 110 m-thick, was measured from the middle thrust slice exposed by quarrying on the southwest side of Calera Hill at Pacifica Quarry. Lithologically, the section is divided in two units; a lower unit with 73 m of black to dark-grey limestone, black chert and tuff, and an upper unit with 36.8 m of light-grey limestone and medium-grey chert. Two prominent black-shale layers rich in organic carbon occur 11 m below the top of the lower black unit and at the boundary with overlying light-grey unit, yielding a total organic content (TOC) of 4.7% and 1.8% t.w., respectively. The fossiliferous Calera Limestone section measured at Pacifica Quarry, from the lower black shale, contains eleven zones and three subzones that span approximately 26 m.y. from the early Aptian to the late Cenomanian. The zones indentified range from the Globigerinelloides blowi Zone to the Dicarinella algeriana Subzone of the Rotalipora cushmani Zone. Within this biostratigraphic interval, the Ticinella bejaouaensis and Hedbergella planispira Zones at the Aptian/Albian boundary are missing as are the Rotalipora subticinensis Subzone of the Biticinella breggiensis Zone and the overlying Rotalipora ticinensis Zone in the late Albian owing both to low-angle thrust faulting and to unconformities. The abundance and preservation of planktic foraminifers are poor in the lower part and improve only within the upper G. algerianus Zone. The faunal relationship indicate that the lower black shale occurs in the upper part of the G. blowi Zone and correlates with the Selli Event recognized at global scale in the early Aptian. The upper black

  19. Investigation of elastic weakening in limestone and sandstone samples from moisture adsorption

    NASA Astrophysics Data System (ADS)

    Pimienta, L.; Fortin, J.; Guéguen, Y.

    2014-10-01

    Elastic and mechanical weakening from water saturation are widely known to occur in sedimentary rocks, and particularly in carbonate rocks. To improve our understanding of the physics underlying this phenomenon, ultrasonic (f ˜ 0.5 MHz) elastic properties are measured on a large suite of clean limestones and sandstones at very low saturations from relative humidity (RH) variations at ambient conditions. Measurements clearly highlight an elastic weakening (i.e. decrease in elastic wave velocity) from moisture adsorption. P- and S-wave velocities are similarly affected by adsorption, but in a different way for limestones and sandstone samples. While the elastic properties of limestone samples show almost no RH dependence, a large weakening is observed for samples of Fontainebleau sandstone that increases with the samples' porosity. The main elastic weakening effect is likely to result from adsorption of fluid at grain contacts. It thus affects particularly granular rocks such as sandstones while well-cemented limestones are not affected. The granular model from Murphy et al., accounting for surface energy effects, proves to be appropriate. Applying this model, it is shown that (i) P- and S-wave velocities have the same dependence on surface energy, which is consistent with the measurements and (ii) surface energy values obtained from the ultrasonic data using this model correlate with RH, and are consistent with the expected value for quartz crystals at vapour pressure. Yet, porosity, which relates to degree of cementation in the particular case of Fontainebleau sandstone, appears to be an additional parameter. A modified model is thus derived using the cementation model from Digby, accounting for a bonding radius at grain contact. It proves to apply well to the measured data. The fundamental difference between limestones' and sandstones' dependence to RH appears to be related to a microstructural difference. Saturation variations from RH increase depend on specific

  20. Drowning of algal mounds: records from the Upper Carboniferous Lower Pseudoschwagerina Limestone, Carnic Alps, Austria

    NASA Astrophysics Data System (ADS)

    Samankassou, Elias

    1999-09-01

    Anthracoporella algal mounds, up to 22 m thick, occur within the cyclic sequences of the Lower Pseudoschwagerina Limestone (uppermost Carboniferous), Carnic Alps (Austria). Their depositional environment lay between the wave base and the base of the photic zone. The algal mounds are overlain by dark, well-bedded, cherty wackestones and packstones. The cherty limestones contain cephalopods, thick-shelled brachiopods, and sponge spicules and lack Anthracoporella in growth position. They are typical deeper-water sediments, deposited below the photic zone. This sequence records drowning episodes; the shallow-water algal mounds were drowned by relative rise of sea level as sea-bottom production shut down below the photic zone. The sedimentological and paleontological evidence of drowning are supported by geochemical data of two measured sections. The mean sulfur content of the well-oxygenated algal limestones is 0.02% for both sections; the TOC values are 0.17% for the section AI and 0.10% for the section AR. The S contents of the cherty limestones are approximately twice as high with values of 0.48 and 0.05% for the respective sections. TOC values of the cherty limestones are also significantly higher, with 0.30 and 0.51% contents for the respective sections. The cherty limestones document the termination of the mounds and the demise of reef-building algae in each cycle. This interval is therefore termed `shroud facies'. The rapid sea-level rise reported is a further proof for high-magnitude sea-level fluctuations in intervals of glacio-eustasy. The documented drowning mode is novel through the definable interval of drowning, the repeated events during a short time interval, the full record of pre-, syn-, and post-drowning deposits, and the unequivocal attribution to glacio-eustatic sea-level rise. This mode seems to be characteristic of an icehouse period and clearly differs from the drowning mode in greenhouse periods which is often gradual, lacks an unequivocal

  1. Mechanical and chemical compaction in fine-grained shallow-water limestones.

    USGS Publications Warehouse

    Shinn, E.A.; Robbin, D.M.

    1983-01-01

    Significant mechanical compaction resulted from pressures simulating less than 305 m of burial. Increasing loads to an equivalent of more than 3400 m did not significantly increase compaction or reduce sediment core length. Chemical compaction (pressure dissolution) was detected only in sediment cores compacted to pressures greater than 3400 m of burial. These short-term experiments suggest that chemical compaction would begin at much shallower depths given geologic time. Compaction experiments that caused chemical compaction lend support to the well-established hypothesis; that cement required to produce a low-porosity/low-permeability fine-grained limestone is derived internally. Dissolution, ion diffusion, and reprecipitation are considered the most likely processes for creating significant thicknesses of dense limestone in the geologic record. Continuation of chemical compaction after significant porosity reduction necessitates expulsion of connate fluids, possibly including hydrocarbons. -from Authors

  2. Biological effects of long term fine limestone tailings discharge in a fjord ecosystem.

    PubMed

    Brooks, Lucy; Melsom, Fredrik; Glette, Tormod

    2015-07-15

    Benthic infaunal data collected from 1993 to 2010 were analysed to examine the effect of long term discharge of fine limestone tailings on macrofaunal species assemblages in a fjord. Relative distance from the outfall and proportion of fine tailings in the sediment were correlated with benthic community structure. Diversity decreased with increasing proportion of fine tailings. Biological Traits Analysis (BTA) was used to explore the temporal and spatial effects of the tailings gradient on macrofaunal functional attributes. BTA revealed that all stations along a pressure gradient of fine limestone tailings were dominated by free-living species. As the proportion of fine tailings in the sediment increased, there was an increase in fauna that were smaller, highly mobile, living on or nearer the surface sediment, with shorter lifespans. There was a decrease in permanent tube dwellers, those fauna with low or no mobility, that live deeper in the sediment and have longer lifespans (>5 yrs). PMID:25960275

  3. Intermediate-scale sodium-concrete reaction tests with basalt and limestone concrete

    SciTech Connect

    Hassberger, J.A.; Muhlestein, L.D.

    1981-01-01

    Ten tests were performed to investigate the chemical reactions and rate and extent of attack between sodium and basalt and limestone concretes. Test temperatures ranged from 510 to 870/sup 0/C (950 to 1600/sup 0/F) and test times from 2 to 24 hours. Sodium hydroxide was added to some of the tests to assess the impact of a sodium hydroxide-aided reaction on the overall penetration characteristics. Data suggest that the sodium penetration of concrete surfaces is limited. Penetration of basalt concrete in the presence of sodium hydroxide is shown to be less severe than attack by the metallic sodium alone. Presence of sodium hydroxide changes the characteristics of sodium penetration of limestone concrete, but no major differences in bulk penetration were observed as compared to penetration by metallic sodium.

  4. Attenuation of stormwater contaminants from highway runoff within unsaturated limestone, Dade County, Florida

    USGS Publications Warehouse

    Waller, Bradley G.; Klein, Howard; Lefkoff, Lawrence J.

    1984-01-01

    Infiltration of stormwater in heavily urbanized parts of Dade County, Florida, is a prime source of recharge to the unconfined Biscayne aquifer, the sole source of drinking water for southeast Florida. Ponded stormwater at the test site contained greater concentrations of lead, zinc, manganese, nitrogen (except nitrate), and phosphorus than the water which percolated through the unsaturated limestone. Attenuation of some stormwater contaminants in the surface soils and limestone is indicated at the test site adjacent to a busy throughfare. Lead concentrations of 610 micrograms per kilogram and zinc concentrations of 91 micrograms per kilogram were found in the thin surface soils, nearly 20 times more than the concentrations of these metals at greater depth. In contrast, soil and rock sample at a control site remote from heavy traffic contained low concentrations of metals and showed little variation in concentration with depth. (USGS)

  5. Microstructural study of sulfate attack on ordinary and limestone Portland cements at ambient temperature

    SciTech Connect

    Irassar, E.F.; Bonavetti, V.L.; Gonzalez, M

    2003-01-01

    This paper presents an investigation on the mechanism of sulfate attack on Portland cements (PCs) containing limestone filler. It is based on the analysis of microstructure and composition of mortar specimens (ASTM C 1012) stored for 2 years in sodium sulfate solution (0.352 M). Microstructure was studied using quantitative X-ray diffraction (XRD) on samples taken from the surface to the core of the specimens. The profile of compounds formed by sulfate attack was determined millimeter by millimeter at 1 and 2 years. Results show that sulfate attack in mortars containing limestone filler is characterized by an inward movement of the reaction front leading first to the formation of ettringite, later to gypsum deposition, and finally to thaumasite formation when the decalcification of mortar leads to the breakdown of C-S-H.

  6. A Homoploid Hybrid Between Wild Vigna Species Found in a Limestone Karst

    PubMed Central

    Takahashi, Yu; Iseki, Kohtaro; Kitazawa, Kumiko; Muto, Chiaki; Somta, Prakit; Irie, Kenji; Naito, Ken; Tomooka, Norihiko

    2015-01-01

    Genus Vigna comprise several domesticated species including cowpea and mungbean, and diverse wild species. We found an introgressive hybrid population derived from two wild species, Vigna umbellata and Vigna exilis, in Ratchaburi district, Thailand. The hybrid was morphologically similar to V. umbellata but habituated in a limestone rock mountain, which is usually dominated by V. exilis. Analyzing simple sequence repeat loci indicated the hybrid has undergone at least one round of backcross by V. umbellata. We found the hybrid acquired vigorous growth from V. umbellata and drought tolerance plus early flowering from V. exilis, and thus has taken over some habitats of V. exilis in limestone karsts. Given the wide crossability of V. umbellata, the hybrid can be a valuable genetic resource to improve drought tolerance of some domesticated species. PMID:26648953

  7. A Novel Treatment for Acid Mine Drainage Utilizing Reclaimed Limestone Residual

    SciTech Connect

    Horace K. Moo-Young; Charles E. Ochola

    2004-08-31

    The viability of utilizing Reclaimed Limestone Residual (RLR) to remediate Acid Mine Drainage (AMD) was investigated. Physical and chemical characterization of RLR showed that it is composed of various minerals that contain significant quantities of limestone or calcium bearing compounds that can be exploited for acid neutralization. Acid Neutralization Potential (ANP) test results showed that RLR has a neutralization potential of approximately 83% as calcium carbonate (CaCO{sub 3}). Neutralization tests with most of the heavy metals associated with AMD showed removal efficiencies of over 99%. An unexpected benefit of utilizing RLR was the removal of hexavalent chromium Cr (VI) from the aqueous phase. Due to an elevation in pH by RLR most AMD heavy metals are removed from solution by precipitation as their metal hydroxides. Cr (VI) however is not removed by pH elevation and therefore subsequent ongoing tests to elucidate the mechanism responsible for this reaction were conducted.

  8. Analysis of roof and pillar failure associated with weak floor at a limestone mine

    PubMed Central

    Murphy, Michael M.; Ellenberger, John L.; Esterhuizen, Gabriel S.; Miller, Tim

    2016-01-01

    A limestone mine in Ohio has had instability problems that have led to massive roof falls extending to the surface. This study focuses on the role that weak, moisture-sensitive floor has in the instability issues. Previous NIOSH research related to this subject did not include analysis for weak floor or weak bands and recommended that when such issues arise they should be investigated further using a more advanced analysis. Therefore, to further investigate the observed instability occurring on a large scale at the Ohio mine, FLAC3D numerical models were employed to demonstrate the effect that a weak floor has on roof and pillar stability. This case study will provide important information to limestone mine operators regarding the impact of weak floor causing the potential for roof collapse, pillar failure, and subsequent subsidence of the ground surface. PMID:27088041

  9. Contribution in support of a Global Heritage Stone designation for the Leitha Limestone s.l. of eastern Austria because of its use in Roman times

    NASA Astrophysics Data System (ADS)

    Moshammer, Beatrix; Rohatsch, Andreas

    2015-04-01

    The Leitha Limestone s.l., which has been proposed for Global Heritage Stone listing, comprises the red algae dominated sediments of shallow water carbonate platforms distributed around the Leitha Mountains, the Ruster Hills and other parts of the Vienna Basin. In our sense it comprehends the Leithakalk faciostratotype of the Badenian regional stage along with its lateral equivalents of near shore calcareous sandstones, breccias and conglomerates. It also includes the so called detrital Leithakalk, an informal name for calcareous algae sandstones of the Sarmatian regional stage that is perhaps comparable with the Skalica Formation and finally it covers the algae strata known from the Pannonian regional stage. Thus the Leitha Limestone s.l. belongs to the middle and upper part of the Miocene, i.e. ranging from about 16 to 10 my BP. The geoscientific focus of this multidisciplinary research is on deciphering the petrological types and carbonate facies of stone monuments and building stones and on comparing them with the successions of the strata outcropping in abandoned quarries. We are recording distinguishing lithological features and collecting appropriate field samples for microscopic, petrophysical, and geochemical analysis. The results of these analyses will be used to characterise the different varieties of Leitha Limestone s.l. of the investigated stone objects, with a view to setting up a catalogue based on lithological types that could be of considerable value for restoration and conservation too. Carnuntum was the regional metropolis of the Roman province Pannonia Superior and one of the legionary camps along the Danube Limes from about 40 AD to the end of the 5th century. It is situated about 40 km east of Vienna city centre, in the present-day market-town of Petronell-Carnuntum. Most of the stone objects from Carnuntum are made of the local quarried Leitha Limestone s.l. from the Hainburg Mountains and from ancient quarries in the Leitha Mountains

  10. Thickness of the upper permeable zone of the Tertiary limestone aquifer system, southeastern United States

    USGS Publications Warehouse

    Miller, James A.

    1982-01-01

    The Tertiary limestone aquifer system of the southeastern United States is a thick sequence of carbonate rocks that vary in age and that are hydraulically connected in varying degrees. A map is presented that shows the thickness of the upper permeable zone of the aquifer system. Several types of geologic structures have had an effect on the thickness of the upper permeable zone. The magnitude of this effect varies with the type and size of the structure. (USGS)

  11. The implication of the oxygen isotopic composition of lower Devonian micritic limestone, Oklahoma

    SciTech Connect

    Gao, G. . Dept. of Geological Sciences)

    1992-01-01

    The documented [delta]O-18 values of presumably well preserved lower Devonian marine carbonates are significantly lower than those of post-Devonian carbonates. These have been interpreted to have resulted from either O-18-depleted or hot oceans, relative to post-Devonian oceans. To test these hypotheses, micritic limestones were sampled for oxygen (as well carbon and strontium) isotope analysis from the lower Devonian (Lochkovian) Haragan-Bois d'Arc formations of the Hunton Group, South-Central Oklahoma. Of the 25 analyzed samples, 22 samples are characterized by high [delta]C-13 values and ranging from [minus]1.9[per thousand] to [minus]2.9[per thousand](PDB). These are the highest [delta]C-13 limestones were deposited in a shallow normal marine setting and have both [delta]C-13 values and Sr-87/Sr-86 ratios similar to other lower Devonian carbonates elsewhere, the high [delta]O-18 values of these limestones are unlikely to have originated either from any unusual depositional setting or from diagenetic alteration at low temperatures by O-18- and Sr-87-enriched basinal brines. The high [delta]O-18 values of the Haragan-Bois d'Arc limestones are thus interpreted to represent near-primary signals. The temperatures and [delta]O-18 values of early Devonian seawater can be constrained to have been 25 [+-] 7 C and 0 [+-] 1[per thousand] (SMOW), respectively. This implies that neither O-18 depletion nor high temperatures characterized early Devonian oceans.

  12. Importance of Radius of Influence and its Estimation in a Limestone Quarry

    NASA Astrophysics Data System (ADS)

    Soni, A. K.; Sahoo, L. K.; Ghosh, U. K.; Khond, M. V.

    2015-04-01

    Limestone mining at Lanjiberna limestone and dolomite quarry has created positive as well negative impacts on ground water. With further deepening of the mine, drawdown trend (negative effect) is observed and at the same time ground water recharge of the order of 4,527.48 m3/day, through mine pits (positive impact) is noticed. The aquifer present in the area is unconfined and mainly consists of weathered quartzite, phyllites, limestone and dolomite. To know the cumulative impact of mining on surroundings, the effective radius of influence (Re) for excavated mine area is calculated as 1,059 m. Here, it may be noted that three `concentric working pits' (Pit No. 2 & 6; Pit no 1 & 3 and Pit No 4 & 5) produces limestone at this mine and the pit-wise radius of influence (Ro) is estimated. Value of Ro for Pit-2 & 6 is 612.14 m; Pit-1 & 3 is 475 m and Pit-4 & 5 is 384.15 m. Its average i.e., Ro (for all three pits, cumulative) is estimated as 490 m. From this typical case study and estimation of Ro and Re values, it is concluded that the maximum and minimum value of overall impact/influence lies in between 0.49 and 1.05 km. These estimated values of `area of influence' are less compared to the whole mine lease area values. Local aquifer, which lies at shallower as well as at deeper depth had behaved consistently with respect to recharge and drawdown conditions. Thus, assessment of Ro and Re is extremely helpful for `integrated mine planning' to achieve targeted production, economically with minimum interruptions.

  13. Changes in Zn speciation during soil formation from Zn-rich limestones

    NASA Astrophysics Data System (ADS)

    Jacquat, Olivier; Voegelin, Andreas; Juillot, Farid; Kretzschmar, Ruben

    2009-10-01

    In order to better understand the long-term speciation and fractionation of Zn in soils, we investigated three soils naturally enriched in Zn (237-864 mg/kg Zn) from the weathering of Zn-rich limestones (40-207 mg/kg Zn) using extended X-ray absorption fine structure (EXAFS) spectroscopy and sequential extractions. The analysis of bulk EXAFS spectra by linear combination fitting (LCF) indicated that Zn in the oolitic limestones was mainly present as Zn-containing calcite (at site Dornach), Zn-containing goethite (Gurnigel) and Zn-containing goethite and sphalerite (Liestal). Correspondingly, extraction of the powdered rocks with 1 M NH 4-acetate at pH 6.0 mobilized only minor fractions of Zn from the Gurnigel and Liestal limestones (<30%), but most Zn from the Dornach rock (81%). In the Dornach soil, part of the Zn released from the dissolving limestone was subsequently incorporated into pedogenic hydroxy-interlayered vermiculite (Zn-HIV, ˜30%) and Zn-containing kaolinite (˜30%) and adsorbed or complexed by soil organic and inorganic components (˜40%). The Gurnigel and Liestal soils contained substantial amounts of Zn-containing goethite (˜50%) stemming from the parent rock, smaller amounts (˜20%) of Zn-containing kaolinite (and possibly Zn-HIV), as well as adsorbed or complexed Zn-species (˜30%). In the soil from Liestal, sphalerite was only found in trace amounts, indicating its dissolution during soil formation. In sequential extractions, large percentages of Zn (˜55-85%) were extracted in recalcitrant extraction steps, confirming that Zn-HIV, Zn-containing kaolinite and Zn-containing goethite are highly resistant to weathering. These Zn-bearing phases thus represent long-term hosts for Zn in soils over thousands of years. The capability of these phases to immobilize Zn in heavily contaminated soils may however be limited by their uptake capacity (especially HIV and kaolinite) or their abundance in soil.

  14. Condition assessment of a highly porous limestone fortress: damage categories and structural integrity

    NASA Astrophysics Data System (ADS)

    Török, Ákos; Czinder, Balázs; Farkas, Orsolya; Görög, Péter; Kopecskó, Katalin; Lógó, János; Rozgonyi-Boissinot, Nikoletta; Vásárhelyi, Balázs

    2016-04-01

    An emblematic monument the Citadella fortress of Budapest has been studied in details to assess the condition of stone structure. The fortress is a large stone structure of 220 m in length and 60 m in width. The height of the porous limestone walls are in between 12-16 metres. The fortress was completed in 1854 but has been partly rebuilt due to changes in function and war related structural damages. The present paper provides an overview of the lithology, weathering forms and structural condition of the fortress related to a forthcoming restoration-reconstruction project. To assess the condition of stone both on site and laboratory analyses were performed. Lithological varieties were documented. Major identified lithotypes are porous oolitic limestone, less porous bioclastic limestone and fine grained highly porous limestone. To identify wet zones portable moisture meter was applied. Surface strength and weathering grade were also assessed using Schmidt hammer and Duroscop. Decay features were diagnosed and mapped. The most common forms are white weathering crusts, scaling and blistering of crusts as well as granular disintegration. Black weathering crusts were also recognized. Laboratory tests were focused on mechanical properties of stones and on mineralogical and chemical compositional analyses. Small samples of stone were collected and tested by optical microscopy, SEM-EDX, XRD and Thermogravimetric analyses. Laboratory analyses proved that the major salt responsible for the damage of external walls is gypsum, although significant amount of halite and hygroscopic salts were found both on the external walls and in the interior parts of the fortress. During structural analyses displacement of walls, tilting and major amount of cracks were recognized. Loss of material and subsidence also caused problems and at some places unstable wall sections were recognized.

  15. Uranium-Series Dating of Corals and Oolites from Bahaman and Florida Key Limestones.

    PubMed

    Broecker, W S; Thurber, D L

    1965-07-01

    Samples of fossil coral and oolite from marine formations of the Bahamas and the Florida Keys have been analyzed for their concentrations of uranium and thorium isotopes. Ages calculated from the ratio Th(230): U(234) clearly indicate periods of marine limestone formation at about 85,000, 130,000, and 190,000 years ago, implying that the surface of the ocean was then close to its present level. PMID:17737788

  16. Feldspar concentrations in lower Cambrian limestones of the Moroccan Atlas: Pyroclastic vs authigenic processes

    NASA Astrophysics Data System (ADS)

    Álvaro, J. Javier; Bauluz, Blanca

    2008-02-01

    Carbonate strata containing abundant euhedral feldspar, usually considered as authigenic, are characteristic of some lower Cambrian exposures in the Atlas Mountains, Morocco. Impure limestones are abundant in the Issendalenian Amouslek Formation of the western Anti-Atlas, and in the Banian Lemdad Formation of the southern High Atlas. Some of their limestone beds contain up to 40% acid insoluble residue, of which feldspar comprises as much as 65% in some samples, the remainder consisting of detrital and authigenic quartz, apatite, pyrite, and clay minerals. The host limestones are bioclastic tempestites, ooidal-oncoidal-bioclastic shoal complexes, archaeocyathan-microbial peri-reef settings (mainly flanks but not reef cores), and microbial reefs. A volcanic origin is adopted for the feldspars based on: (i) fluctuations in feldspar concentration paralleling bedding, but unrelated to host-facies (except for the aforementioned archaeocyathan-microbial reef cores that were controlled by turbidity); (ii) the local association with glassy fragments (with feldspars embedded in glass shards); and (iii) the scattered occurrence of gradational lithofacies from silty tuff to tuffitic limestone. The mineral and chemical composition of the host-rock and diagenetic fluids was the determining factor for the kind of feldspar preservation. Although the primary type of K-feldspar replacement is albitization, secondary albite subsequently suffered from illitization, chloritization, and/or replacement by calcite. A direct implication of this work is the possible geochronological dating of both volcanic eruptions and archaeocyath- and trilobite-bearing host-rocks based on radiometric analyses within unaltered K-feldspar pyroclasts extracted after etching.

  17. Experimentally generated normal faults in single-layer and multilayer limestone specimens at confining pressure

    NASA Astrophysics Data System (ADS)

    Patton, Thomas L.; Logan, John M.; Friedman, Melvin

    1998-09-01

    We examined the deformation of single-layer and multilayer rock veneers at confining pressure due to slip on an underlying, pre-existing, 70°-dipping normal fault. Single-layer specimens consisted of centimeter-thick Indiana Limestone veneers; centimeter-thick multilayer specimens consisted of three layers of Indiana Limestone or two layers of Indiana Limestone separated by a middle layer of weaker, Austin Chalk. The experiments investigated the evolution of induced deformation features — fractures, faults and folds — as functions of; (1) offset on the pre-existing normal fault, (2) confining pressure (100 MPa and 200 MPa), (3) `bedding' (three-layer specimens), and (4) compositional layering (three-layer specimens with a weak middle layer). Single-layer limestone specimens deformed at 200-MPa confining pressure provided the most reproducible results, forming arrays of nested arcuate normal faults; the concave sides of the faults faced in the hanging wall direction. Older faults of the array, propagating from the tip of the pre-existing fault, died out upward into the hanging wall. Younger faults formed towards the footwall side of the array and propagated to the upper surface of the specimen. These latter faults accommodated subsequent slip on the pre-existent fault, and in doing so, fragmented and offset the monoclinally folded upper surface of the specimen. Reducing the confining pressure to 100 MPa produced a more brittle behavior in the specimen, manifested as fewer faults with more irregular profiles and less monoclinal folding at the upper surface of the specimen. Introducing bedding and weak layering in the specimens at 100-MPa confining pressure increased the bulk ductile response of the specimen. Our model-generated deformation features share strong similarities with those documented in other laboratory normal-fault experiments in sand and clay, and with normal-fault features found in outcrop.

  18. Selected data for wells and test holes used in structure-contour maps of the Inyan Kara Group, Minnekahta Limestone, Minnelusa Formation, Madison Limestone, and Deadwood Formation in the Black Hills area, South Dakota

    USGS Publications Warehouse

    Carter, J.M.

    1999-01-01

    This report presents selected data on wells and test holes that were used in the construction of structure-contour maps of selected formations that contain major aquifers in the Black Hills area of western South Dakota. Altitudes of the top of the Inyan Kara Group, Minnekahta Limestone, Minnelusa Formation, Madison Limestone, and Deadwood Formation are presented for the wells and test holes presented in this report.

  19. The sedimentological and diagenetic evolution of the Ratburi Limestone, Peninsular Thailand

    NASA Astrophysics Data System (ADS)

    Baird, Angus; Bosence, Dan

    The late Middle to early Late Permian Ratburi Limestone in Peninsular Thailand is a warm-water carbonate deposit formed in an extensive platform setting, suggesting that the Shan Thai craton occupied a subtropical-tropical position at this time. The distribution of facies, from peritidal, fenestral and algal laminated muds, to subtidal skeletal and ooid grainstones, bryozoa boundstones and carbonate slope deposits, is controlled by the platform topography, which is thought to have been controlled by extensional tectonics. Early diagenesis of the platform began with seawater-influenced dolomitisation, followed by uplift, producing karstification, in response to the Late Permian Indosinian orogeny. East dipping subduction of the Indian Ocean Plate resulted in granite magmatism in the peninsula during the Cretaceous. The effect on the Ratburi Limestone included neomorphism, dissolution, calcite cementation and dolomitisation. The petroleum potential of Ratburi Limestone comes from the extensive and long karstic history (Late Permian and Tertiary-present day) and the source potential of the widespread platform carbonate mudstone ( TOC <4.5%) .

  20. The influence of temperature on limestone sulfation and attrition under fluidized bed combustion conditions

    SciTech Connect

    Montagnaro, Fabio; Salatino, Piero; Scala, Fabrizio

    2010-04-15

    The influence of temperature on attrition of two limestones during desulfurization in a fluidized bed reactor was investigated. Differences in the microstructure of the two limestones were reflected by a different thickness of the sulfate shell formed upon sulfation and by a different value of the ultimate calcium conversion degree. Particle attrition and fragmentation were fairly small under moderately bubbling fluidization conditions for both limestones. An increase of temperature from 850 C to 900 C led to an increase of the attrition rate, most likely because of a particle weakening effect caused by a faster CO{sub 2} evolution during calcination. This weakening effect, however, was not sufficiently strong to enhance particle fragmentation in the bed. The progress of sulfation, associated to the build-up of a hard sulfate shell around the particles, led in any case to a decrease of the extent of attrition. Sulfation at 900 C was less effective than at 850 C, and this was shown to be related to the porosimetric features of the different samples. (author)

  1. Laboratory measurements of a complete set of poroelastic moduli for Berea sandstone and Indiana limestone

    NASA Astrophysics Data System (ADS)

    Hart, David J.; Wang, Herbert F.

    1995-09-01

    Measurements have been completed for eight different poroelastic moduli of water-saturated Berea sandstone and Indiana limestone as a function of confining pressure and pore pressure. The poroelastic moduli for Indiana limestone are generally consistent to ±10%, which was verified by a formal inversion procedure for independent moduli from the eight measurements. For Indiana limestone, best fit values were drained bulk modulus, 21.2 GPa; the undrained bulk modulus, 31.7 GPa; drained Poisson's ratio, 0.26; undrained Poisson's ratio, 0.33; and pore pressure buildup coefficient, 0.47 at 20-35 MPa effective stress. The poroelastic moduli for Berea sandstone are generally consistent to ±20%. The greater inconsistency is most likely caused by the nonlinear variation of the moduli at different strains. For Berea sandstone, best fit values were drained bulk modulus, 6.6 GPa; undrained bulk modulus, 15.8 GPa; drained Poisson's ratio, 0.17; undrained Poisson's ratio, 0.34; and pore pressure buildup coefficient, 0.75 at 10 MPa effective stress.

  2. Measurement of quartz in limestone reagent used in gypsum producing FGD systems

    SciTech Connect

    Luckevich, L.M.; Duffy, K.; Roth, T.

    1995-06-01

    The quartz concentration in limestone used as the reagent in gypsum producing FGD systems contributes to the amount of quartz in the gypsum product. Gypsum from FGD is being used to manufacture gypsum board or plasters and these gypsum based products must comply with legislated limits for respirable quartz. Gypsum from FGD may contain both crystalline silica (usually as quartz) and amorphous silica from coal ash. In addition SiO{sub 2} may be present in other crystalline materials such as clay minerals. The measurement of total SiO{sub 2} in FGD reagent limestone and FGD gypsum will measure SiO{sub 2} from all sources. A preliminary method has been developed to measure the quartz concentration in limestone or gypsum. The method comprises isolation of the acid insoluble residue followed by analysis of the residue by Differential Scanning Calorimetry (DSC). The energy of the {alpha} to {beta} quartz inversion is measured and used to calculate the quartz content of the sample.

  3. Sampling and analysis method for measuring airborne coal dust mass in mixtures with limestone (rock) dust.

    PubMed

    Barone, T L; Patts, J R; Janisko, S J; Colinet, J F; Patts, L D; Beck, T W; Mischler, S E

    2016-01-01

    Airborne coal dust mass measurements in underground bituminous coal mines can be challenged by the presence of airborne limestone dust, which is an incombustible dust applied to prevent the propagation of dust explosions. To accurately measure the coal portion of this mixed airborne dust, the National Institute for Occupational Safety and Health (NIOSH) developed a sampling and analysis protocol that used a stainless steel cassette adapted with an isokinetic inlet and the low temperature ashing (LTA) analytical method. The Mine Safety and Health Administration (MSHA) routinely utilizes this LTA method to quantify the incombustible content of bulk dust samples collected from the roof, floor, and ribs of mining entries. The use of the stainless steel cassette with isokinetic inlet allowed NIOSH to adopt the LTA method for the analysis of airborne dust samples. Mixtures of known coal and limestone dust masses were prepared in the laboratory, loaded into the stainless steel cassettes, and analyzed to assess the accuracy of this method. Coal dust mass measurements differed from predicted values by an average of 0.5%, 0.2%, and 0.1% for samples containing 20%, 91%, and 95% limestone dust, respectively. The ability of this method to accurately quantify the laboratory samples confirmed the validity of this method and allowed NIOSH to successfully measure the coal fraction of airborne dust samples collected in an underground coal mine. PMID:26618374

  4. Limestone surfaces in built-up environment as indicators of atmospheric pollution.

    PubMed

    Vella, A J; Camilleri, A; Tabone Adami, J P

    1996-12-01

    The concentration of sulphate on limestone surfaces of the external walls of churches in Malta is shown to be related to their position and distance from a power station, the main local point source of sulphur dioxide pollution. Limestone powder collected from these surfaces was examined for the presence of particles which, under low-power optical microscopy, appear as shiny black amorphous bodies which were interpreted as soot particles; the abundance of these bodies was expressed as a 'black particle count' (BPC). The degree of sulphation and BPC were shown to be correlated with each other and both appeared to be strongly dependent on the prevailing wind. The BPC contour map indicated an important contribution to the parameter from vehicular traffic. It is suggested that the degree of sulphation and BPC of limestone surfaces from the built environment should function as environmental indicators of the relative air quality with respect to SO2 and soot pollution. This data is possibly more accurately representative of the relative long-term air-quality status of different areas of habitation than that deduced from single or episodic measurements of atmospheric pollutant levels. PMID:24194411

  5. Stable isotope stratigraphy and larger benthic foraminiferal extinctions in the Melinau Limestone, Sarawak

    NASA Astrophysics Data System (ADS)

    Cotton, Laura J.; Pearson, Paul N.; Renema, Willem

    2014-01-01

    Important long-ranging groups of larger benthic foraminifera (LBF) are known to have become extinct during a period of global cooling and climate disruption at the Eocene-Oligocene transition (EOT) but the precise timing and mechanisms are uncertain. Recent study showed unexpectedly that the LBF extinction in Tanzania occurs very close to the Eocene/Oligocene boundary, as recognised by the extinction of the planktonic foraminiferal Family Hantkeninidae, rather than at the later period of maximum global ice growth and sea-level fall, as previously thought. Here we investigate the same phase of extinction in the Melinau Limestone of Sarawak, on the island of Borneo, Malaysia one of the most complete carbonate successions spanning the Eocene to Lower Miocene. Assemblages of LBF from the Melinau Limestone were studied extensively by Geoffrey Adams during the 1960s-80s, confirming a major extinction during the EOT, but the section lacked independent means of correlation. By analysing rock samples originally studied by Adams and now in the Natural History Museum, London, we provide new bulk stable isotope (δ13C and δ18O) records. This enables us to identify, albeit tentatively, the level of maximum stable isotope excursion and show that the LBF extinction event in the Melinau Limestone occurs below this isotope excursion, supporting the results from Tanzania and indicating that the extinction of LBF close to the Eocene/Oligocene boundary may be a global phenomenon.

  6. Use Of limestone resources in flue-gas desulfurization power plants in the Ohio River Valley

    USGS Publications Warehouse

    Foose, M.P.; Barsotti, A.F.

    1999-01-01

    In 1994, more than 41 of the approximately 160 coal-fired, electrical- power plants within the six-state Ohio River Valley region used flue-gas desulfurization (FGD) units to desulfurize their emissions, an approximately 100% increase over the number of plants using FGD units in 1989. This increase represents a trend that may continue with greater efforts to meet Federal Clean Air Act standards. Abundant limestone resources exist in the Ohio River Valley and are accessed by approximately 975 quarries. However, only 35 of these are believed to have supplied limestone for FGD electrical generating facilities. The locations of these limestone suppliers do not show a simple spatial correlation with FGD facilities, and the closest quarries are not being used in most cases. Thus, reduction in transportation costs may be possible in some cases. Most waste generated by FGD electrical-generating plants is not recycled. However, many FGD sites are relatively close to gypsum wallboard producers that may be able to process some of their waste.

  7. [Sodium-enhanced limestone wet FGD in rotating-stream tray scrubber].

    PubMed

    Sun, Wenshou; Wu, Zhongbiao; Li, Yue; Tan, Tianen

    2002-09-01

    Adding sodium sulfate to limestone slurry can increase SO2 removal efficiency. In this paper, sodium-enhanced limestone flue gas desulfurization(FGD) tests were conducted in rotating-stream tray scrubber. Changes of SO2 removal efficiency and pH value with time were experimentally studied and, at different pH range, the dissolution rates of limestone etc. were analyzed. The effects of plate number on SO2 removal efficiency and pressure drop were investigated at temperature approximated to industrial operating value. The average plate efficiencies were calculated. According to the experimental results, increasing plate number could increase SO2 removal efficiency, but the average plate efficiency decreased. Under the experimental conditions, when the plate number was increased from 1 to 4, the removal efficiency was increased from 25.5% to 48.6% at the liquid-to-gas ratio of 4 L/m3, but the average plate efficiency was decreased from 25.5% to 15.3%. The equation of the relation between the average plate efficiency and plate number was obtained. PMID:12533938

  8. Lacustrine and paludine facies: Cretaceous Baum Limestone, south-central Oklahoma

    SciTech Connect

    Balkan, E.D.; Elmore, R.D.

    1983-03-01

    The Lower Cretaceous Baum Limestone in the Arbuckle Mountains of south-central Oklahoma was deposited in lacustrine and paludine settings near the Cretaceous shoreline. The unit rests unconformably on folded Pennsylvanian rocks and is overlain by and grades into the Paluxy Formation, a sandstone deposit with numerous Ophiomorpha burrows. The lacustrine lithofacies include the following: (1) massive micrite containing charophyte fragments and ostracodes; (2) intraformational conglomerate composed of rounded micrite clasts in a micritic matrix; (3) rounded peloids and coated peloids; (4) laminated micrite; and (5) conglomerate composed of clasts derived from Paleozoic rocks within a micritic matrix. Disintegration of charophytes that grew in the littoral zone of the lake produced the massive micrite. Intraformational conglomerates and peloids represent reworking of massive micrite whereas the other conglomerates represent fluvial influx. Features found within the paludine facies include: (1) brecciated micritic limestone that probably formed as a result of shrinking and swelling due to an oscillating phreatic water table; (2) subspherical nodules of micrite (peds) separated by red shale (plasma) that represent pedogenic alteration of exposed lacustrine mud; and (3) subcylindrial columns composed of micritic limestone representing root-casts. These paludine features formed as a result of pedogenic processes in a marsh that rimmed the shallow lake where the lacustrine facies accumulated.

  9. XPS characterization of (copper-based) coloured stains formed on limestone surfaces of outdoor Roman monuments

    PubMed Central

    2012-01-01

    Limestone basements holding bronzes or other copper alloys artefacts such as sculptures, decorations and dedicatory inscriptions are frequently met both in modern and ancient monuments. In outdoor conditions, such a combination implies the corrosion products of the copper based alloy, directly exposed to rainwater, will be drained off and migrate through the porous surfaces, forming stains of different colours and intensities, finally causing the limestone structures to deteriorate. In this work we have analysed samples from two modern limestone monuments in Rome, the Botticino surfaces of the ‘Vittoriano’ (by G.Sacconi, 1885-1911- Piazza Venezia) and the travertine basement of the ‘Statua dello Studente’ (by A.Cataldi, 1920- University city, La Sapienza), and focussed our investigation on the chemical composition of the copper-stained zones using XPS (X-ray Photoelectron Spectroscopy) as a surface-specific technique. Based on observations reporting on the structure and bonding at the calcite surfaces we have identified copper complexes and mixed calcium/copper carbonates associated with the stains, as well as the chemical state of other elements therein included, and related the compositional changes with differences in chromatic characteristics and sampling locations. PMID:22594435

  10. PROCEEDINGS: INDUSTRY BRIEFING ON IERL-RTP LIME/LIMESTONE WET SCRUBBING TEST PROGRAMS (5TH) (DECEMBER 1979)

    EPA Science Inventory

    The proceedings document presentations made during the December 5, 1979, industry briefing conference which dealt with the status of EPA/IERL-RTP's flue gas desulfurization (FGD) research, development, and application programs. Subjects considered included: lime/limestone scrubbi...

  11. The microbial nature of laminated limestones: Lessons from the Upper Aptian, Araripe Basin, Brazil

    NASA Astrophysics Data System (ADS)

    Catto, Bruno; Jahnert, Ricardo Jorge; Warren, Lucas Verissimo; Varejao, Filipe Giovanini; Assine, Mario Luis

    2016-07-01

    The Araripe Basin, located in northeastern Brazil, originated during the Gondwana continental break-up responsible for the opening of the South Atlantic during the Early Cretaceous. In the Araripe Basin, the post-rift Aptian sequence corresponds to the Santana Group, which is composed, in upward succession, of mostly clastic continental and rare carbonate layers of the Barbalha, Crato, Ipubi and Romualdo Formations. The laminated limestones of the Crato Formation were deposited in a lacustrine environment preceding the deposition of the Ipubi Formation evaporites. They are age-equivalent to the limestones of the pre-salt interval of the east coast of Brazil, which contains large petroleum reserves. The excellent preservation of its macrofossils has made the Crato Formation known worldwide as a Fossil Lagerstätte. The limestones are macroscopically homogeneous, and their deposition has been previously attributed to chemical precipitation. Although the carbonate laminites are macroscopically undifferentiated, mineralogical variations, microscopic texture and distinctive biotic aspects supported the characterization of four microfacies: planar laminated, crustiform, nodular and rhythmic. The microfacies analysis indicated a strong and pervasive biological activity in the Crato limestone morphogenesis. Organominerals precipitated by the metabolic action of cyanobacteria and/or sulfate-reducing bacteria and methanogenic-oxidizing archea are represented by calcite and pyrite. Calcified coccoid and filaments are common, furthermore, the presence of calcified biofilms composed of exopolymeric substances (EPS) is ubiquitous. The presence of amorphous organic matter (AOM) and gypsum, particularly in the rhythmic microfacies, indicates anoxic/dysoxic conditions and stressful environments during periods of drought and low lake levels which favored the development and preservation of microbial biofilms. Phytoclasts and miospores when present in the succession indicate an

  12. Method for interpreting well log records to yield indications of gas/oil in an earth formation such as a sandstone, limestone, or dolostone

    SciTech Connect

    Thompson, D.D.; Brown, R.J.S.; Runge, R.J.

    1983-07-12

    The present invention indicates that acoustic characteristics associated with a first well penetrating a gas/oilcontaining strata such as a sandstone, limestone or dolostone, can be normalized (and favorably compared) with similar characteristics of a second, contiguous well of known hydrocarbon potential, such characteristics being calculated and displayed by means of a machineimplemented data processing method in which well logging and geologic data are fed thereto to calculate such characteristics without the need for shear-wave velocities. In more detail, in accordance with the invention brinesaturated bulk and shear moduli, (i.e., Kw and Gw) of a sandstone, limestone or dolostone penetrated by the second well can be predicted as a function of, say, brinesaturated P-wave modulus (Pw) alone (independent of shear-wave velocity). In that way, resulting acoustic values including distinct velocity and amplitude values as a function of a saturation operator can ultimately be provided. Such values, when compared to actual, inwell, field-generated characteristics of the first well, are surprisingly accurate predictors of the amount of gas/oil saturation in and around the first well. The method has particular accuracy in designating gas zones within formations of interest due to use of the complete Benedict-Webb-Rubin non-ideal gas law in psuedo-reduced form.

  13. Method for interpreting seismic records to yield indications of gas/oil in an earth formation such as a sandstone, limestone, or dolostone

    SciTech Connect

    Brown, R.J.; Runge, R.J.; Thompson, D.D.

    1983-02-22

    The present invention indicates that acoustic characteristics associated with gas/oil-containing strata such as a sandstone, limestone or dolostone, including reflectivity coefficients can be normalized (and favorably compared) with similar characteristics calculated and displayed by means of a machineimplemented data processing method in which well logging and geologic data are fed thereto to calculate such characteristics without the need for shear-wave velocities. In more detail, in accordance with the invention brine-saturated bulk and shear moduli, (i.e., kw* and gw*) of a sandstone, limestone or dolostone can be predicted as a function of, say, brine-saturated p-wave modulus (pw*) alone (Independent of shearwave velocity). In that way, resulting acoustic values including seismic velocities and amplitudes (also, reflectivities) as a function of a saturation operator can ultimately be provided. Such values, when compared to actual field-generated characteristics, are surprisingly accurate predictors of the amount of gas/oil saturation in the zone of interest. The method has particular accuracy in designating gas zones within formations of interest due to use of the complete Benedict-Webb-Rubin non-ideal gas law in pseudo-reduced form, as cited in Journal of Current Petroleum Technology, Vol. 22, pp. 889-895.

  14. Method for interpreting well log records to yield indications of gas/oil in an earth formation such as a sandstone, limestone, or dolostone

    SciTech Connect

    Thompson, D.D.; Brown, R.J.S.; Runge, R.J.

    1983-08-16

    The present invention indicates that acoustic characteristics associated with a first well penetration a gas/oil-containing strata such as a sandstone, limestone or dolostone, can be normalized (and favorably compared) with similar characteristics of a second, contiguous well of known hydrocarbon potential, such characteristics being calculated and displayed by means of a machine-implemented data processing method in which well logging and geologic data are fed thereto to calculate such characteristics without the need for shear-wave velocities. In more detail, in accordance with the invention brine-saturated bulk and shear moduli, (i.e., Kw and Gw) of a sandstone, limestone or dolostone penetrated by the second well can be predicted as a funtions of, say, brine-saturated P-wave modulus (PW *) alone (independent of shear-wave velocity). In that way, resulting acoustic values including distinct velocity and amplitude values as a function of a saturation operator can ultimately be provided. Such values, when compared to actual, in-well, field-generated characteristics of the first well, are surprisingly accurate predictors of the amount of gas/oil maturation in and around the first well. The method has particular accuracy in designating gas zones within formations of interest due to use of the complete Benedict-Webb-Rubin non-ideal gas law in pseudo-reduced form.

  15. Characterization of pore structure and strain localization in Majella limestone by X-ray computed tomography and digital image correlation

    NASA Astrophysics Data System (ADS)

    Ji, Yuntao; Hall, Stephen A.; Baud, Patrick; Wong, Teng-fong

    2015-02-01

    Standard techniques for computed tomography imaging are not directly applicable to a carbonate rock because of the geometric complexity of its pore space. In this study, we first characterized the pore structure in Majella limestone with 30 per cent porosity. Microtomography data acquired on this rock was partitioned into three distinct domains: macropores, solid grains, and an intermediate domain made up of voxels of solid embedded with micropores below the resolution. A morphological analysis of the microtomography images shows that in Majella limestone both the solid and intermediate domains are interconnected in a manner similar to that reported previously in a less porous limestone. We however show that the macroporosity in Majella limestone is fundamentally different, in that it has a percolative backbone which may contribute significantly to its permeability. We then applied for the first time 3-D-volumetric digital image correlation (DIC) to characterize the mode of mechanical failure in this limestone. Samples were triaxially deformed over a wide range of confining pressures. Tomography imaging was performed on these samples before and after deformation. Inelastic compaction was observed at all tested pressures associated with both brittle and ductile behaviors. Our DIC analysis reveals the structure of compacting shear bands in Majella limestone deformed in the transitional regime. It also indicates an increase of geometric complexity with increasing confinement-from a planar shear band, to a curvilinear band, and ultimately to a diffuse multiplicity of bands, before shear localization is inhibited as the failure mode completes the transition to delocalized cataclastic flow.

  16. Fault zones in Triassic Muschelkalk limestones of the Upper Rhine Graben: Infrastructure characterization and permeability structure analyses

    NASA Astrophysics Data System (ADS)

    Meier, Silke; Bauer, Johanna F.; Philipp, Sonja L.

    2014-05-01

    The characterization of fault zones is of particular importance in geothermal reservoirs since there may be great effects on fluid flow. Fault zones generally consist of two major hydromechanical units: the fault core and the damage zone, surrounded by the unaffected host rock. To improve predictions of fracture system parameters for each unit and resulting estimations of reservoir permeabilities at depths, we perform outcrop analogue studies. We analyze Middle Triassic Muschelkalk limestones that form one potential geothermal reservoir formation in the Upper Rhine Graben (URG), in quarries on its eastern graben shoulder. We measure the orientations and displacements of various fault zones and characterize the fracture systems within the fault zone units and the host rock. Important features in terms of reservoir permeability are the fracture aperture, the fracture connectivity and the fracture vertical extension. Fractures have to be connected to create a hydraulically relevant flow path and non-stratabound fractures could create a hydraulic connectivity between multiple layers. We observed a decreasing fracture length with increasing distance to the fault core but a better connectivity between shorter fractures in the well-developed damage zones. Our studies show, however, that the differing mechanical properties in the analyzed limestone-marl alternations are significant for the fracture propagation, even in the fault zones. Based on the field data we use analytical models to estimate the permeabilities of the analyzed fracture systems. Results show increased fracture frequencies in the fault zone damage zones and larger fracture apertures parallel or subparallel to fault zone strike and to the URG that lead to enhanced permeabilities compared with other fracture orientations. Mineralized fractures accumulated in directions parallel or subparallel to fault zone strike as well as observed mineralizations in some fault cores indicate a fluid flow along the fault

  17. Trepostome and cystoporate bryozoans from the Lexington Limestone and the Clays Ferry Formation (Middle and Upper Ordovician) of Kentucky

    USGS Publications Warehouse

    Karklins, O.L.

    1984-01-01

    The Lexington Limestone and the Clays Ferry Formation of Kentucky contain an abundant and diversified fossil invertebrate fauna. This report is concerned with the trepostome and cystoporate bryozoans that constitute a major part of that fauna. The Lexington Limestone, largely a biofragmental fossiliferous limestone, rests disconformably on the Tyrone Limestone (Middle Ordovician). The Clays Ferry Formation consists of approximately equal amounts of biofragmentallimestone and shale, and it overlies conformably, or intertongues with, the upper part of the Lexington Limestone. The Clays Ferry Formation is overlain by the Garrard Siltstone (Upper Ordovician) in central Kentucky and intertongues with the Kope Formation (Upper Ordovician) in northern Kentucky. The MiddleUpper Ordovician boundary falls within the upper part of the Lexington Limestone and laterally equivalent strata of the Clays Ferry Formation. The Lexington Limestone has been divided into 12 members, consisting of calcarenites, calcisiltites, calcilutites, nodular limestones, and shales in various amounts, that intertongue complexly. Because of the great abundance of bryozoans this study is generally limited to bryozoans recovered from, in ascending order, the Grier Limestone Member, the Perryville Limestone Member, the Brannon Member, the Tanglewood Limestone Member, and the Millersburg Member of the Lexington Limestone and from the Clays Ferry Formation and its Point Pleasant Tongue. The trepostome and cystoporate bryozoans discussed are referred to 36 species belonging to 22 genera. The trepostome component includes 29 species belonging to 16 genera: Amplexopora, Atactoporella, Balticopora, Batostoma, Cyphotrypa, Dekayia, Eridotrypa, Hetero-_ trypa, Homotrypa, Homotrypella, Mesotrypa, Parvohallopora, Peronopora, Prasopora, Stigmatella, and Tarphophragma, a new genus. Five of the trepostome species are new: Balticopora arcuatilis, Cyphotrypa switzeriensis, Dekayia epetrima, Eridotrypa sadievillensis

  18. Ixeridium calcicola (Compositae), a New Limestone Endemic from Taiwan, with Notes on Its Atypical Basic Chromosome Number, Phylogenetic Affinities, and a Limestone Refugium Hypothesis

    PubMed Central

    Kono, Yoshiko; Ho, Meng-Jung; Hsu, Tian-Chuan; Peng, Ching-I

    2014-01-01

    A new species Ixeridium calcicola (Compositae) endemic to middle altitude (ca 1,000–2,000 m asl) limestone mountains of eastcentral Taiwan is described based on morphological and chromosome cytological observations and molecular phylogenetic analyses. Ixeridium calcicola resembles Ixeridium transnokoense, endemic to upper montane and alpine ranges (2,600–3,500 m asl) of Taiwan, in the dwarf habit, but differs in the oblong to lanceolate leaf blades (vs. linear to linear-lanceolate), the presence of mucronulate teeth on the leaf margin and petiole (vs. smooth to very sparse), the dark purple lower leaf surface (vs. greenish), the capitulum with 10 to 12 florets (vs. 5 to 7) and 8 to 10 inner phyllaries (vs. 5, rarely to 7). The basic chromosome number in Ixeridium was known as X = 7. However, the new species has a basic chromosome number of X = 8, as recorded also in the closely related Ixeris. Molecular phylogenetic analyses with the expanded sampling of Ixeridium and Ixeris including both type species supported the monophyly of each of the genera and the placement of the new species in Ixeridium. The result of the phylogenetic analyses and detailed observation of the chromosome morphology revealed that X = 8 in Ixeridium calcicola is derived from centric fission in an ancestral karyomorphotype with X = 7 in Ixeridium. Ixeridium calcicola and Ixeridium transnokoense formed a Taiwan endemic lineage and their estimated divergence time was in the middle Pleistocene. Their common ancestral lineage may have experienced altitudinal distribution shifts in response to glacial-interglacial temperature fluctuation, and a lineage which had not retreated to alpine ranges in an interglacial period likely survived in a limestone refugium, where ordinary plant species did not grow, leading to allopatric speciation. PMID:25295587

  19. Short, Sharp, Tropical Magnetic Inclination Excursions: Comparison Between Pleistocene Lavas from Hawaii and Late Campanian (~C33R/33N) Scaglia Rossa Limestone of Italy

    NASA Astrophysics Data System (ADS)

    Penserini, B. D.; Kirschvink, J. L.; Slotznick, S. P.; Mitchell, R. N.; Thissen, C.; Montanari, A.; Holt, J. W.

    2013-12-01

    Hawaiian basalts and the Scaglia Rossa pelagic limestone of Central Italy are two of the most stably magnetized rock types ever encountered in the history of Paleomagnetism, both playing large roles in the development and calibration of the geomagnetic polarity time scale. During the course of high- resolution paleomagnetic studies of Hawaiian basalts from the NSF-DOSECC Hawaii Scientific Drilling Project (HSDP, e.g., Holt et al, JGR v 101, p. 11655, 1996), several sharp excursions were encountered that had the appearance of a sudden deviation (inversion) of inclination, without interrupting longer-term trends either in inclination or declination. These excursions were suspected to be the result of intense, short-lived reversed-polarity magnetohydrodynamic events (';cyclones') at the core/mantle boundary (CMB), directly underneath the low-latitude sampling localities. In the course of more recent, high-resolution (cm to dm scale) sampling of the classic Scaglia Rossa limestone of Central Italy to look for the possible presence of True Polar Wander (TPW), we were surprised to see several similar events, represented by single-sample excursions in which the inclination of the remanence vector inverted sign with no apparent effect on the declination. High-resolution digital images of the cores in the field accompanied by distinguishing marks on the core surface, recognizable in the field images, preclude laboratory orientation errors. Additionally, multiple specimens from the same core (drilled into the bedding plane) yield similar deviant results. We suspect that these somewhat rare events might be the result of small tangent cylinders on the core-mantle boundary (CMB) near the Equator, aligned antiparallel to the main dipole. Due to the inverse cube law, and the closer proximity to the surface, the total field direction geographically above this might show a directional excursion in inclination without a corresponding shift in declination. It might be worthwhile for

  20. Correlation of Twin Creek limestone with Arapien shale in Arapien embayment, Utah - preliminary appraisal

    SciTech Connect

    Sprinkel, D.A.; Waanders, G.L.

    1984-07-01

    Striking and important stratigraphic patterns have emerged as a result of recent work during which members of the Twin Creek Limestone were correlated with the Arapien Shale, all of Middle Jurassic age. These correlations, determined first on the basis of electric and lithologic logs, are supported by recent palynologic work. Three distinct dinoflagellate assemblages, assigned to the Bajocian(.), Bathonian, and Callovian stages, form the paleontologic basis for these correlations. The Bajocian(.) assemblage is found in rocks of the Sliderock and Rich Members of the Twin Creek Limestone. The Bathonian assemblage is found in units of the Boundary Ridge and Watton Canyon Members of the Twin Creek, and also in units of the lower Arapien Shale (lower Leeds Creek Member of the Twin Creek of Wyoming). The Callovian assemblage is found in rocks of the upper Arapien (upper Leeds Creek and Giraffe Creek Members of the Twin Creek of Wyoming). Isopach maps, based on these correlations, indicate that most of central Utah was the site of a large marine embayment - the Arapien embayment -that was flanked on the west, south, and east by highlands. The maps also suggest that the ancestral Uinta Mountains, a submerged feature, affected sedimentation as early as Bajocian time, and became a significant barrier from the late Bathonian through Callovian. In central Utah, marine carbonates were deposited in the Arapien embayment during deposition of the Gypsum Spring through Watton Canyon Members of the Twin Creek Limestone. During deposition of the Arapien Shale, a major northward regression occurred; the embayment shrank to form a smaller basin - the Arapien basin - that lay directly south of the ancestral Uinta Mountains. Most of the Arapien Shale is shallow-water deposits that formed in the basin under hypersaline conditions.

  1. Evaluation of Transport Through Sandstone and Limestone Cores of PAHs Dissolved Groundwater

    NASA Astrophysics Data System (ADS)

    Lasseigne, A. E.; Blanford, W. J.

    2006-12-01

    In this study, data on the transport characteristics within the rock matrix of limestone and sandstone of naphthalene dissolved in groundwater has been gathered. This information has been collected from miscible displacement studies executed with cores of Berea Sandstone and Edwards Aquifer Limestone. This entailed placing 2 inch diameter by 1 and 3 inch long cores in a Hassler type 2 core holder and flooding with aqueous solutions of naphthalene and for comparison bromide and penta-fluorinated benzoic acid. The results of these tracer studies were compared to 1D and 3D numerical simulations based on characteristics of the tracers and analysis of the compositional and hydraulic properties of the cores. Bulk mineral composition was determine with X-ray diffraction and organic matter content with a total organic carbon analyzer. Mean porosity was determined through comparison of precise dry and wet masses, and variability in porosity of the rock samples was determined by impregnation with epoxy and analysis of backscatter images from scanning electron microscope (SEM). Saturated hydraulic conductivity was determined by measuring differential pressures across rock columns under a range of flow rates from 0.49 to 0.87 ml/min. Using 1D numerical program STANMOD, dispersivity coefficients for the sandstone cores were determined through inverse models of the bromide and PFBA data. With this value, the naphthalene tracer results were found to be most closely simulated with a model with mixture of 10% equilibrium mass transfer and 90% rate- limited sorption sites. This analysis also yielded an R = 1.6 for naphthalene. Multi-dimensional modeling of sandstone using MODFLOW and MT3DMS and modeling of the limestone tracer studies is currently underway and will be presented.

  2. Attrition-enhanced sulfur capture by limestone particles in fluidized beds

    SciTech Connect

    Saastamoinen, J.J.; Shimizu, T.

    2007-02-14

    Sulfur capture by limestone particles in fluidized beds is a well-established technology. The underlying chemical and physical phenomena of the process have been extensively studied and modeled. However, most of the studies have been focused on the relatively brief initial stage of the process, which extends from a few minutes to hours, yet the residence time of the particles in the boiler is much longer. Following the initial stage, a dense product layer will be formed on the particle surface, which decreases the rate of sulfur capture and the degree of utilization of the sorbent. Attrition can enhance sulfur capture by removing this layer. A particle model for sulfur capture has been incorporated with an attrition model. After the initial stage, the rate of sulfur capture stabilizes, so that attrition removes the surface at the same rate as diffusion and chemical reaction produces new product in a thin surface layer of a particle. An analytical solution for the conversion of particles for this regime is presented. The solution includes the effects of the attrition rate, diffusion, chemical kinetics, pressure, and SO{sub 2} concentration, relative to conversion-dependent diffusivity and the rate of chemical reaction. The particle model results in models that describe the conversion of limestone in both fly ash and bottom ash. These are incorporated with the residence time (or reactor) models to calculate the average conversion of the limestone in fly ash and bottom ash, as well as the efficiency of sulfur capture. Data from a large-scale pressurized fluidized bed are compared with the model results.

  3. Estimation of deep infiltration in unsaturated limestone environments using cave lidar and drip count data

    NASA Astrophysics Data System (ADS)

    Mahmud, K.; Mariethoz, G.; Baker, A.; Treble, P. C.; Markowska, M.; McGuire, E.

    2016-01-01

    Limestone aeolianites constitute karstic aquifers covering much of the western and southern Australian coastal fringe. They are a key groundwater resource for a range of industries such as winery and tourism, and provide important ecosystem services such as habitat for stygofauna. Moreover, recharge estimation is important for understanding the water cycle, for contaminant transport, for water management, and for stalagmite-based paleoclimate reconstructions. Caves offer a natural inception point to observe both the long-term groundwater recharge and the preferential movement of water through the unsaturated zone of such limestone. With the availability of automated drip rate logging systems and remote sensing techniques, it is now possible to deploy the combination of these methods for larger-scale studies of infiltration processes within a cave. In this study, we utilize a spatial survey of automated cave drip monitoring in two large chambers of Golgotha Cave, south-western Western Australia (SWWA), with the aim of better understanding infiltration water movement and the relationship between infiltration, stalactite morphology, and unsaturated zone recharge. By applying morphological analysis of ceiling features from Terrestrial LiDAR (T-LiDAR) data, coupled with drip time series and climate data from 2012 to 2014, we demonstrate the nature of the relationships between infiltration through fractures in the limestone and unsaturated zone recharge. Similarities between drip rate time series are interpreted in terms of flow patterns, cave chamber morphology, and lithology. Moreover, we develop a new technique to estimate recharge in large-scale caves, engaging flow classification to determine the cave ceiling area covered by each flow category and drip data for the entire observation period, to calculate the total volume of cave discharge. This new technique can be applied to other cave sites to identify highly focussed areas of recharge and can help to better

  4. Analysis of limestones and dolomites by x-ray fluorescence spectroscopy

    SciTech Connect

    Wheeler, B.D.

    1999-07-01

    Sources of calcium are generally widespread and quite extensive. These sources are limestone, dolomite, marl, chalk, and oyster shell. Cement plants account for nearly half of the demand, while two hundred lime plants in the US and Puerto Rico consume about twenty five percent. Since the chemical composition of the limestone and other sources of calcium is critical in the cement and lime industry, particularly for the deleterious compounds such as sodium oxide, Na{sub 2}O, magnesium oxide, MgO, phosphorus pentoxide, P{sub 2}O{sub 5}, and potassium oxide, K{sub 2}O, accurate determinations are critical. Due to the tonnage per hour, these determinations must be made rapidly and accurately. X-ray fluorescence can thereby satisfy this need for accuracy and also precision. Production of lime is performed by calcining limestone or dolomite in which the industry is generally located and concentrated in the States of Michigan and Pennsylvania. The resulting product is quicklime, CaO, and hydrated lime, Ca(OH){sub 2}. Substantial amounts of quicklime is further processed into calcium carbide in order to produce acetylene gas. In this case, the determination of P{sub 2}O{sub 5} is critical since minor quantities of phosphorus in acetylene gas can cause premature explosions. Other uses for lime are well known in the treatment of water, the paper and pulp industry, and in the steel industry for the production of slag to remove impurities. Dolomitic lime is heavily utilized in the manufacture of magnesite refractories by reacting dolomitic lime with brines from the Michigan Basin to produce magnesium oxide, MgO, and calcium chloride, CaCl{sub 2}. Sample preparation for these materials usually is performed by grinding and pelletizing or fusion with lithium-tetra-borate, Li{sub 2}B{sub 4}O{sub 7}.

  5. Laboratory investigations in support of carbon dioxide-limestone sequestration in the ocean

    SciTech Connect

    Golomb, Dan; Barry, Eugene; Ryan, David; Lawton, Carl; Swett, Peter; Hannon, John

    2004-03-01

    In the first half of the second contractual year the High Pressure Flow Reactor (HPFR) was fully designed. Most components have been ordered, and assembly of the flow reactor has been started. Also, the High Pressure Batch Reactor (HPBR) was redesigned for more efficient operation and observation of the emulsion of liquid or supercritical CO{sub 2} dispersed in water stabilized by pulverized limestone and other particles. In this period we firmly established that when about equal volumes of liquid CO{sub 2} and a slurry of pulverized limestone (CaCO{sub 3}) in de-ionized or artificial seawater (3.5% NaCl solution in de-ionized water) are thoroughly mixed, a macro-emulsion ensues consisting of liquid CO{sub 2} droplets coated with a sheath of CaCO{sub 3} particles dispersed in water. We call the coated CO{sub 2} droplets globules, and the macro-emulsion a globulsion. Depending on the degree of mixing (rotational speed of the magnetic stir bar) and the size of the CaCO{sub 3} particles, the globules float on top of the water column, are suspended in it, or sink to the bottom of the water column. With CO{sub 2} droplet diameter in the 100-200 {micro}m range, and CaCO{sub 3} particles in the 6-20 {micro}m range, most of the globules sink to the bottom. The formation of sinking globules is desirable for ocean sequestration of CO{sub 2}. The properties and stability of the globules will be further investigated in the HPFR in the second contractual year. It has also been demonstrated that flyash can be substituted for pulverized limestone to obtain a stable globulsion of CO{sub 2}-in-water.

  6. Discovery of a new polyhydroxyalkanoate synthase from limestone soil through metagenomic approach.

    PubMed

    Tai, Yen Teng; Foong, Choon Pin; Najimudin, Nazalan; Sudesh, Kumar

    2016-04-01

    PHA synthase (PhaC) is the key enzyme in the production of biodegradable plastics known as polyhydroxyalkanoate (PHA). Nevertheless, most of these enzymes are isolated from cultivable bacteria using traditional isolation method. Most of the microorganisms found in nature could not be successfully cultivated due to the lack of knowledge on their growth conditions. In this study, a culture-independent approach was applied. The presence of phaC genes in limestone soil was screened using primers targeting the class I and II PHA synthases. Based on the partial gene sequences, a total of 19 gene clusters have been identified and 7 clones were selected for full length amplification through genome walking. The complete phaC gene sequence of one of the clones (SC8) was obtained and it revealed 81% nucleotide identity to the PHA synthase gene of Chromobacterium violaceum ATCC 12472. This gene obtained from uncultured bacterium was successfully cloned and expressed in a Cupriavidus necator PHB(-)4 PHA-negative mutant resulting in the accumulation of significant amount of PHA. The PHA synthase activity of this transformant was 64 ± 12 U/g proteins. This paper presents a pioneering study on the discovery of phaC in a limestone area using metagenomic approach. Through this study, a new functional phaC was discovered from uncultured bacterium. Phylogenetic classification for all the phaCs isolated from this study has revealed that limestone hill harbors a great diversity of PhaCs with activities that have not yet been investigated. PMID:26467694

  7. Wet separation processes as method to separate limestone and oil shale

    NASA Astrophysics Data System (ADS)

    Nurme, Martin; Karu, Veiko

    2015-04-01

    Biggest oil shale industry is located in Estonia. Oil shale usage is mainly for electricity generation, shale oil generation and cement production. All these processes need certain quality oil shale. Oil shale seam have interlayer limestone layers. To use oil shale in production, it is needed to separate oil shale and limestone. A key challenge is find separation process when we can get the best quality for all product types. In oil shale separation typically has been used heavy media separation process. There are tested also different types of separation processes before: wet separation, pneumatic separation. Now oil shale industry moves more to oil production and this needs innovation methods for separation to ensure fuel quality and the changes in quality. The pilot unit test with Allmineral ALLJIG have pointed out that the suitable new innovation way for oil shale separation can be wet separation with gravity, where material by pulsating water forming layers of grains according to their density and subsequently separates the heavy material (limestone) from the stratified material (oil shale)bed. Main aim of this research is to find the suitable separation process for oil shale, that the products have highest quality. The expected results can be used also for developing separation processes for phosphorite rock or all others, where traditional separation processes doesn't work property. This research is part of the study Sustainable and environmentally acceptable Oil shale mining No. 3.2.0501.11-0025 http://mi.ttu.ee/etp and the project B36 Extraction and processing of rock with selective methods - http://mi.ttu.ee/separation; http://mi.ttu.ee/miningwaste/

  8. Key Largo Limestone revisited: Pleistocene shelf-edge facies, Florida Keys, USA

    USGS Publications Warehouse

    Gray, Multer H.; Gischler, E.; Lundberg, J.; Simmons, K.R.; Shinn, E.A.

    2002-01-01

    New dates and analysis of 12 deep and 57 shallow cores allow a more detailed interpretation of the Pleistocene shelf edge of the Florida Platform as found in various facies of the Key Largo Limestone beneath the Florida Keys. In this study a three-phase evolution of the Quaternary units (Q1-Q5) of the Key Largo is presented with new subdivision of the Q5. (1) In the first phase, the Q1 and Q2 (perhaps deposited during oxygen-isotope stage 11) deep-water quartz-rich environment evolved into a shallow carbonate phase. (2) Subsequently, a Q3 (presumably corresponding to oxygen-isotope stage 9) flourishing reef and productive high-platform sediment phase developed. (3) Finally, a Q4 and Q5 (corresponding to oxygen-isotope stages 7 and 5) stabilization phase occured with reefs and leeward productive lagoons, followed by lower sea levels presenting a sequence of younger (isotope substages 5c, 5a) shelf-margin wedges, sediment veneers and outlier reefs. The Key Largo Limestone provides an accessible model of a carbonate shelf edge with fluctuating water depth, bordering a deep seaward basin for a period of at least 300 ka. During this time, at least four onlaps/offlaps, often separated by periods of karst development with associated diagenetic alterations, took place. The story presented by this limestone not only allows a better understanding of the history of south Florida but also aids in the interpretation of similar persistent shelf-edge sites bordering deep basins in other areas.

  9. Cross-bedded limestone facies on San Salvador Island, Bahamas: New perspective on eolian calcarenites

    SciTech Connect

    Caputo, M.V. )

    1989-08-01

    Limestones of eolian origin have been known from worldwide tropical regins since the early 1900s. On San Salvador Island, most of the exposed bed rock is Holocene and Pleistocene eolian calcarenite made of skeletal, peloidal, and oolitic fine to medium sand. The Pleistocene Grotto Beach Formation is composed of 50-90% ooids. An eolian interpretation for this interval is supported by paleosols, subaerial crusts, vadose cement, terrestrial fossils, karst features, associated reef and beach deposits, grainfall, sandflow, and climbing ripple strata, and shore-parallel sand bodies. Whole dune-forms are locally preserved; they were stabilized or frozen in place by early cementation and/or vegetation.

  10. Hydrogeology of the North Coast Limestone aquifer system of Puerto Rico

    USGS Publications Warehouse

    Rodríguez-Martínez, Jesús

    1995-01-01

    The North Coast Limestone aquifer system of Puerto Rico is composed of three regional hydrogeologic units: an upper aquifer that contains an underlying saltwater zone near the coast, a middle confining unit, and a lower aquifer. The upper aquifer is unconfined, except in coastal areas where it is locally confined by fine-grained surficial deposits. The upper aquifer is mostly absent in the Rio Piedras area of northeastern Puerto Rico. The confining unit is composed of calcareous claystone, marl, chalky and silicified limestone, and locally clayey fine-grained sandstone. Test hole data indicate that the confining unit is locally leaky in the San Juan metropolitan area. An artesian zone of limited areal extent exists within the middle confining unit, in the central part of the study area. The lower aquifer mostly contains ground water under confined conditions except in the outcrop areas, where it is unconfined. The lower aquifer is thickest and most transmissive in the north-central part of the study area. Water in the lower aquifer is fresh throughout much of the area, but is brackish in some areas near San Juan and Guaynabo. West of the Rio Grande de Arecibo, the extent of the lower aquifer is uncertain. Data are insufficient to determine whether or not the existing multiple water-bearing units in this area are an extension of the more productive lower aquifer in the Manati to Arecibo area. Zones of moderate permeability exist within small lenses of volcanic conglomerate and sandstone of the San Sebastian Formation, but in general this formation is not a productive aquifer. Transmissivity values for the upper aquifer range from 200 to more than 280,000 feet squared per day. The transmissivity values for the upper aquifer generally are highest in the area between the Rio de la Plata and Rio Grande de Arecibo, where transmissivity values have been reported to exceed 100,000 feet squared per day in six locations. Transmissivity estimates for the lower aquifer are

  11. Magnetic resonance sounding and radiomagnetotelluric measurements used to characterize a limestone aquifer in Gotland, Sweden

    NASA Astrophysics Data System (ADS)

    Perttu, Nils; Persson, Lena; Erlström, Mikael; Elming, Sten-Åke

    2012-03-01

    SummaryAlmost all drinking water in Gotland is groundwater and is mainly found in karst limestone. However, the unpredictable location and geometry of the karst cracks and caverns makes it very difficult to estimate groundwater storage and movement, as well as contaminant transport. The aim of this study was to test the performance of different geophysical techniques like Magnetic Resonance Sounding (MRS), Radiomagnetotelluric (RMT), Vertical Electrical Sounding (VES) and Ground Penetrating Radar (GPR) to characterize aquifers in Gotland, in respect to geometry and storage as well as connectivity over a wider area. The investigated area is located on the south-eastern part of Gotland. The geology here is dominated by 50-60 m thick successions of limestone that gradually turn into marlstone. The use of multiple techniques has shown to give a more coherent interpretation. However, the shallow penetration depth of GPR and the lack of soil cover in some places of the investigated area limit the use of geoelectrical methods and GPR. With MRS, water are found down to 60 m in depth, with a maximum water content at depths of 20-30 m. This coincides with the most resistive sections of the limestone. The water content varies between 0% and 3%, with a relaxation time (T1MRS) less than 400 ms suggesting that the aquifer is hosted in small fractures, molds and vugs rather than larger karst fractures and caverns. Two potential aquifers were identified with MRS, possibly separated by marlstone. From modeling it can be seen that such boundary separating two aquifer apart can be more easily discriminated in the N/S-, than in the E/W direction. In summary, MRS is therefore the only method in this survey that can detect and determine the vertical and lateral distribution of water within the aquifer together with the total volume of free water. The RMT method has shown to be effective in characterizing the limestone/marl interface, but also to locate anomalous low resistive zones

  12. Treatment of coal mine drainage with a compost-limestone reactor

    SciTech Connect

    Tarutis, W.J. Jr.; Walski, T.M.; Klemow, K.M.

    1995-11-01

    A bench-scale system containing spent mushroom compost (SMC) and limestone (in series) was used to evaluate reactor efficiency in treating synthetic coal mine drainages of varying quality over a 234-day period. Pore water samples taken along the direction of flow revealed an acidic oxidation front which progressively penetrated the SMC, resulting in reduced treatment performance, decreased iron and manganese retention, and a shortened reactor life expectancy. It is thought that acidification depressed pH and leached sufficient organic carbon to permanently inhibit bacterial sulfate reduction and the consequent formation of iron sulfides.

  13. Biostratigraphy and paleoenvironment of Miocene- Pliocene hemipelagic limestone: Kingshill Seaway, St. Croix, US Virgin Islands.

    USGS Publications Warehouse

    Lidz, B.H.

    1982-01-01

    The Kingshill Limestone and younger carbonate rocks constitute the central portion of St. Croix, forming the remains of an ancient seaway that was flanked by emergent highlands. The seaway has been filled with thick epipelagic sediments alternating with carbonate turbidites and ash falls and capped with shallow-water reefal and terrigenous debris. Planktonic foraminifera indicate that ages of these rocks range sequentially in a SW direction from the middle Miocene to lower Pliocene. Scanning electron micrographs illustrate 42 species and subspecies of pelagic foraminifera and 13 selected paleoenvironmentally significant aberrant forms.-from Author

  14. Geology and configuration of the top of the Tertiary limestone aquifer system, southeastern United States

    USGS Publications Warehouse

    Miller, James A.

    1982-01-01

    The Tertiary limestone aquifer system of the southeastern United States is a thick sequence of carbonate rocks that vary in age and that are hydraulically connected in varying degrees. A map is presented that shows the altitude and configuration of the top of the aquifer system, as well as the extent of the youngest rock that is judged to be part of the system. Several types of geologic structures that affect the configuration of the top of the system may be readily recognized. (USGS)

  15. Geology and configuration of the base of the Tertiary limestone aquifer system, southeastern United States

    USGS Publications Warehouse

    Miller, James A.

    1982-01-01

    The Tertiary limestone aquifer system of the southeastern United States is a thick sequence of carbonate rocks that vary in age land that are hydraulically connected in varying degrees. A map is presented that shows at the altitude and configuration of base of the aquifer system. The age and lithology of the different low-permeability materials that mark the base of the system are delineated and briefly described. Several types of geologic structures that affect the configuration of the base of the system may be readily recognized. (USGS)

  16. Investigating the Variable Durability of Malta's Lower Globigerina Limestone to Soluble-Salt Damage.

    NASA Astrophysics Data System (ADS)

    Zammit, Tano; Cassar, JoAnn

    2014-05-01

    Investigating the Variable Durability of Malta's Lower Globigerina Limestone to Soluble-Salt Damage. Tano Zammit, JoAnn Cassar Department of the Built Heritage, Faculty for the Built Environment. University of Malta. The millenary use of Lower Globigerina Limestone (LGL) as a building stone in the Maltese Islands, and its export to other Mediterranean countries in the past, is confirmation of its validity. Notwithstanding the diminishing economic importance of this once principal resource of the local building industry, the ever growing need for conservation of Malta's rich patrimony of archaeological/historical buildings and structures built of this stone, emphasise the need for on-going research particularly that investigating its variable durability. The research under discussion here forms part of a wider research programme on the characterisation of this locally very important resource. In this investigation the durability of the LGL is considered in terms of two main climatic features, namely a temperate Mediterranean climate involving i) a salt-laden marine environment together with ii) relatively short spans of heavy precipitations alternating with longer periods of virtual drought. It is virtually impossible to all but the quarry owners to identify 'good' from 'bad' quality stone simply through the visual observation, as LGL is a fine-grained, white to yellow, homogenous limestone. On the other hand, it is empirically known that LGL is a moderately weak limestone, characterized by the predominance of the mineral calcite (86 - 99%) and by a high total porosity (up to 40%) of which, over 85%, is microporosity below 5µm. In theory, these physical properties should render such stone-type particularly susceptible to deterioration involving a) mechanisms of capillary salt-laden moisture accumulation and movement together with, b) thermodynamic changes of soluble-salts during dissolution and crystallization cycles. The adopted research methodology investigating

  17. Superfund Record of Decision: (EPA Region 3): Limestone Road Site, Cumberland, Maryland, September 1986. Final report

    SciTech Connect

    Not Available

    1986-09-30

    The Limestone Road site is located 2.5 miles east southeast of Cumberland, Allegheny County, Maryland, on the western flank of Irons Mountain and includes large areas of landfilled and dumped commercial, residential, and demolition refuse. A variety of waste has reportedly been dumped into a ravine on the property such as chromium, lead, and cadmium. In addition, an alleged 11 tons of hazardous waste have been reportedly disposed of as an extension of filling and grading operations. The primary contaminants of concern include: VOCs, base-neutral compounds, TCE, PCE, and heavy metals. Remedial action is proposed and included in the report.

  18. Solute changes during aquifer storage recovery testing in a limestone/clastic aquifer

    USGS Publications Warehouse

    Mirecki, J.E.; Campbell, B.G.; Conlon, K.J.; Petkewich, M.D.

    1998-01-01

    Aquifer storage recovery (ASR) was tested in the Santee Limestone/Black Mingo Aquifer near Charleston, South Carolina, to assess the feasibility for subsurface storage of treated drinking water. Water quality data obtained during two representative ASR tests were interpreted to show three things: (1) recovery efficiency of ASR in this geological setting; (2) possible changes in physical characteristics of the aquifer during ASR testing; and (3) water quality changes and potability of recovered water during short (one- and six-day) storage durations in the predominantly carbonate aquifer. Recovery efficiency for both ASR tests reported here was 54%. Successive ASR tests increased aquifer permeability of the Santee Limestone/Black Mingo Aquifer. It is likely that aquifer permeability increased during short storage periods due to dissolution of carbonate minerals and amorphous silica in aquifer material by treated drinking water. Dissolution resulted in an estimated 0.3% increase in pore volume of the permeable zones. Ground water composition generally evolved from a sodium-calcium bicarbonate water to a sodium chloride water during storage and recovery. After short duration, stored water can exceed the U.S. Environmental Protection Agency maximum contaminant level (MCL) for chloride (250 mg/L). However, sulfate, fluoride, and trihalomethane concentrations remained below MCLs during storage and recovery.Aquifer storage recovery (ASR) was tested in the Santee Limestone/Black Mingo Aquifer near Charleston, South Carolina, to assess the feasibility for subsurface storage of treated drinking water. Water quality data obtained during two representative ASR tests were interpreted to show three things: (1) recovery efficiency of ASR in this geological setting; (2) possible changes in physical characteristics of the aquifer during ASR testing; and (3) water quality changes and potability of recovered water during short (one- and six-day) storage durations in the predominantly

  19. Summary and interpretive synthesis

    SciTech Connect

    1995-05-01

    This chapter summarizes the major advances made through our integrated geological studies of the Lisburne Group in northern Alaska. The depositional history of the Lisburne Group is discussed in a framework of depositional sequence stratigraphy. Although individual parasequences (small-scale carbonate cycles) of the Wahoo Limestone cannot be correlated with certainty, parasequence sets can be interpreted as different systems tracts within the large-scale depositional sequences, providing insights on the paleoenvironments, paleogeography and platform geometry. Conodont biostratigraphy precisely established the position of the Mississippian-Pennsylvanian boundary within an important reference section, where established foraminiferal biostratigraphy is inconsistent with respect to conodont-based time-rock boundaries. However, existing Carboniferous conodont zonations are not readily applicable because most zonal indicators are absent, so a local zonation scheme was developed. Diagenetic studies of the Lisburne Group recognized nineteen subaerial exposure surfaces and developed a cement stratigraphy that includes: early cements associated with subaerial exposure surfaces in the Lisburne Group; cements associated with the sub-Permian unconformity; and later burial cements. Subaerial exposure surfaces in the Alapah Limestone are easily explained, being associated with peritidal environments at the boundaries of Sequence A. The Lisburne exposed in ANWR is generally tightly cemented and supermature, but could still be a good reservoir target in the adjacent subsurface of ANWR given the appropriate diagenetic, deformational and thermal history. Our ongoing research on the Lisburne Group will hopefully provide additional insights in future publications.

  20. Water quality changes in acid mine drainage streams in Gangneung, Korea, 10 years after treatment with limestone

    SciTech Connect

    Shim, Moo Joon; Choi, Byoung Young; Lee, Giehyeon; Hwang, Yun Ho; Yang, Jung-Seok; O'Loughlin, Edward J.; Kwon, Man Jae

    2015-12-01

    To determine the long-term effectiveness of the limestone treatment for acid mine drainage (AMD) in Gangneung, Korea, we investigated the elemental distribution in streams impacted by AMD and compared the results of previous studies before and approximately 10 years after the addition of limestone. Addition of limestone in 1999 leads to a pH increase in 2008, and with the exception of Ca, the elemental concentrations (e.g., Fe, Mn, Mg, Sr, Ni, Zn, S) in the streams decreased. The pH was 2.5–3 before the addition of limestone and remained stable at around 4.5–5 from 2008 to 2011, suggesting the reactivity of the added limestone was diminished and that an alternative approach is needed to increase the pH up to circumneutral range and maintain effective long-term treatment. To identify the processes causing the decrease in the elemental concentrations, we also examined the spatial (approximately 7 km) distribution over three different types of streams affected by the AMD. The elemental distribution was mainly controlled by physicochemical processes including redox reactions, dilution on mixing, and co-precipitation/adsorption with Fe (hydr)oxides.

  1. Relevant influence of limestone crystallinity on CO₂ capture in the Ca-looping technology at realistic calcination conditions.

    PubMed

    Valverde, J M; Sanchez-Jimenez, P E; Perez-Maqueda, L A

    2014-08-19

    We analyze the role of limestone crystallinity on its CO2 capture performance when subjected to carbonation/calcination cycles at conditions mimicking the Ca-looping (CaL) technology for postcombustion CO2 capture. The behavior of raw and pretreated limestones (milled and thermally annealed) is investigated by means of thermogravimetric analysis (TGA) tests under realistic sorbent regeneration conditions, which necessarily involve high CO2 partial pressure in the calciner and quick heating rates. The pretreatments applied lead to contrasting effects on the solid crystal structure and, therefore, on its resistance to solid-state diffusion. Our results show that decarbonation at high CO2 partial pressure is notably promoted by decreasing solid crystallinity. CaO regeneration is fully achieved under high CO2 partial pressure at 900 °C in short residence times for the milled limestone whereas complete regeneration for raw limestone requires a minimum calcination temperature of about 950 °C. Such a reduction of the calcination temperature and the consequent mitigation of multicyclic capture capacity decay would serve to enhance the efficiency of the CaL technology. On the other hand, the results of our study suggest that the use of highly crystalline limestones would be detrimental since excessively high calcination temperatures should be required to attain full decarbonation at realistic conditions. PMID:25029532

  2. The role of petrography on the thermal decomposition and burnability of limestones used in industrial cement clinker

    NASA Astrophysics Data System (ADS)

    Marinoni, Nicoletta; Bernasconi, Andrea; Della Porta, Giovanna; Marchi, Maurizio; Pavese, Alessandro

    2015-12-01

    The present research examines the influence of the petrographic features on the thermal decomposition and burnability of three limestones, the main raw materials for Portland cement-making. A detailed characterisation of the limestones has been performed by means of optical microscopy and X-Ray Powder Diffraction. The carbonate thermal decomposition was conducted under isothermal conditions by means of in situ High Temperature X-Ray Powder Diffraction and the heated samples were further investigated by Scanning Electron Microscopy. Three kiln feeds were then prepared and submitted to burning trials and the temperature of occurrence of the main clinker phases was investigated as well as the content of the uncombined CaO in the heated samples was determined by using the Franke method. The results attest that the microfabric, a combination of depositional and diagenetic features, drives the kinetics of the thermal decomposition of the selected limestones as well as it appears to influence the temperature of crystallisation of the main clinker phases and the uncombined CaO content in the final clinker. In particular, the limestone with the lowest micrite to sparite ratio (1) exhibits the lowest Apparent Activation Energy ( E a ) value and the highest rate of calcination and (2) requires a lower temperature for observing the clinker phases crystallisation and has the lowest content of uncombined CaO in the final clinker, thus reflecting a high burnability of the limestone.

  3. Drilling of Arun gas field

    SciTech Connect

    Bolt, L.H.; Soepardi, M.; Suherman, D.

    1984-05-01

    The Arun gas field was discovered in late 1971 when the discovery Well Arun A-1 penetrated the thick Arun limestone reef. During the following 3 years, 12 delineation wells were drilled. Three of these delineation wells are used for observation wells, five for dry gas injection, one for condensate water disposal, and three are abandoned. Clustered development well drilling started in Sept. 1976. At this writing 40 wells have been drilled to delineate and develop the field. Drilling continues so that the growing demand from the expanding liquefied natural gas (LNG) plant is met. The problems of high temperatures, abnormally highpressured shales, and saltwater sands overlying the lower-pressured Arun limestone have been conquered by numerous technique changes. The current techniques include the use of inverted oil emulsion muds, cements containing 35% silica flour, high-strength heavyweight tubulars, and clear packer fluids. The evolution of drilling and completion practices are discussed in the paper.

  4. Limestone Corrosion and Sulfur Cycling by Biofilms in the Frasassi Caves, Italy

    NASA Astrophysics Data System (ADS)

    Jones, D. S.; Macalady, J. L.; Druschel, G. K.; Eastman, D. D.; Albertson, L. K.

    2006-12-01

    In the Frasassi cave system, central Italy, a microbial-based ecosystem thrives on chemolithoautotrophic energy derived from hydrogen sulfide oxidation. Microbial life is prolific near the watertable, and biofilms cover nearly all subaerial and subaqueous surfaces. Subaerial biofilms are dominated by acidophilic members of the archaeal lineage Thermoplasmales and bacterial genus Acidithiobacillus. Subaqueous biofilms are diverse and are dominated by sulfide oxidizing, sulfate reducing, and sulfur disproportionating Proteobacteria. The morphology, abundance, and distribution of biofilms is controlled by physical and chemical factors such as seasonal changes in the cave hydrologic regime. In situ microelectrode voltammetry has revealed that stream biofilms speciate sulfur in diverse ways, with implications for acid production and limestone dissolution rates. Hydrogen sulfide loss from the streams cannot be accounted for solely by volatilization. Based on degassing measurements and abiotic sulfide oxidation rate calculations, stream biofilms are responsible for the majority of sulfide disappearance in streams. Rates of limestone corrosion are comparable in subaerial and subaqueous cave regions, indicating that subaerial microbial communities also have an important role in speleogenesis. Metagenomic studies targeting subaerial biofilms have confirmed that they have extremely low diversity, and offer glimpses into the physiology and biogeochemistry of extreme acidophiles in sulfidic cave communities.

  5. Influence of Water Content on the Mechanical Behaviour of Limestone: Role of the Clay Minerals Content

    NASA Astrophysics Data System (ADS)

    Cherblanc, F.; Berthonneau, J.; Bromblet, P.; Huon, V.

    2016-06-01

    The mechanical characteristics of various sedimentary stones significantly depend on the water content, where 70 % loss of their mechanical strengths can be observed when saturated by water. Furthermore, the clay fraction has been shown to be a key factor of their hydro-mechanical behaviour since it governs for instance the hydric dilation. This work aims at investigating the correlations between the clay mineral content and the mechanical weakening experienced by limestones when interacting with water. The experimental characterization focuses on five different limestones that exhibit very different micro-structures. For each of them, we present the determination of clay mineral composition, the sorption isotherm curve and the dependences of tensile and compressive strengths on the water content. It emerges from these results that, first, the sorption behaviour is mainly governed by the amount of smectite layers which exhibit the larger specific area and, second, the rate of mechanical strength loss depends linearly on the sorption capacity. Indeed, the clay fraction plays the role of a retardation factor that delays the appearance of capillary bridges as well as the mechanical weakening of stones. However, no correlation was evidenced between the clay content and the amplitude of weakening. Since the mechanisms whereby the strength decreases with water content are not clearly established, these results would help to discriminate between various hypothesis proposed in the literature.

  6. An Upper Ordovician sponge-bearing micritic limestone and implication for early Palaeozoic carbonate successions

    NASA Astrophysics Data System (ADS)

    Park, Jino; Lee, Jeong-Hyun; Hong, Jongsun; Choh, Suk-Joo; Lee, Dong-Chan; Lee, Dong-Jin

    2015-04-01

    A potentially new type of non-reef sponge-bearing micritic limestone is reported from the Upper Ordovician Xiazhen Formation of south-eastern China. The sponges are preserved as incomplete skeletons that consist of curved bifurcated and trifurcated spicules embedded in dark micrite, and can only be recognized under a petrographic microscope. The characteristics of the spicule networks suggest that the sponges are probably belonging to demosponges. However, based on the absence of features such as desma, zygome, a distinct dermal layer, and a canal system, they are not considered to be lithistids. The majority of the sponges are found in a lime mudstone facies, together with some micritic portions of wackestone to grainstone facies, comprising approximately 13% of the 50-m thick micritic limestone successions. It is interpreted that the non-lithistid demosponges flourished on soft substrates over shallow marine carbonate platform. Such sponge-bearing carbonates are similar to spiculites and spongolites in terms of being a major constituent of the sedimentary rocks and their potential contribution as sediment producers, but affinity and modes of preservation of the Xiazhen sponges are significantly different to those of the spiculites and spongolites. In light of the present finding, it is suggested that non-lithistid demosponges may have been more widespread in early Palaeozoic non-reef carbonates than has previously been recognized, thus indicating the critical need for further detailed studies if we are to understand their distributions and sedimentological contributions.

  7. Carbonate Crystals Precipitated by Freshwater Bacteria and Their Use as a Limestone Consolidant▿

    PubMed Central

    Zamarreño, Dania V.; Inkpen, Robert; May, Eric

    2009-01-01

    Bacterial carbonate precipitation is known to be a natural phenomenon associated with a wide range of bacterial species. Recently, the ability of bacteria to produce carbonates has been studied for its value in the conservation of limestone monuments and concrete. This paper describes investigations of carbonate crystals precipitated by freshwater bacteria by means of histological (Loeffler's methylene blue and alcian blue-periodic acid-Schiff stain) and fluorescence (CTC [5-cyano-2,3-ditolyl tetrazolium chloride]) stains, determination of cell viability inside carbonate crystals, and pore size reduction in limestone by image analysis. Carbonate crystals were found to be composed of bacteria embedded in a matrix of neutral and acid polysaccharides. Cell viability inside the carbonate crystals decreased with time. On stone, bacteria were found to form carbonate crystals, with only a few bacteria remaining as isolated cells or as cell aggregates. Pore size was reduced by about 50%, but no blockage was detected. Taken together, the results of this research provide some reassurance to conservators that biocalcification by bacteria could be a safe consolidation tool in a restoration strategy for building stone conservation. PMID:19617383

  8. Rift tectonics and limestone sedimentation: Jurassic of the central and eastern High Atlas, Morocco

    SciTech Connect

    Warme, J.E.; Hazlett, B.H.; Crevello, P.D.; Letsch, D.K.; Burke, R.B. )

    1988-08-01

    The central and eastern High Atlas ranges of southern Morocco represent deposition in an Early to Middle Jurassic rift which first collected continental basalts, red beds, and evaporites. Carbonate deposition was initiated by a euxinic phase, followed by a mosaic of normal marine limestones and marls controlled by regional subsidence and local differential fault-block movements and overprinted by global sea level changes. The High Atlas is now an en echelon series of high-angle reverse faults, creating abrupt and discontinuous fault-bounded ridges separated by broad synclines. Facies relationships of the Jurassic carbonates show that the faults were originally synrift normal faults, probably transtensional, now structurally reversed. Overlying Aalenian to Bajocian shelf limestones prograded into an axial seaway filled with thick marls, punctuated in the Bajocian by horizons of spectacularly exposed coralgal reefs which appear structurally isolated on separate fault blocks. Sedimentation eventually outpaced subsidence, culminating in continental deposits as the sea finally retreated in the mid-Dogger. Although abundant potential source rocks of this rift are thermally overmature, the basin serves as a well-exposed model for comparison with carbonate-filled rifts elsewhere.

  9. Laboratory velocities and attenuation of p-waves in limestones during freeze-thaw cycles

    SciTech Connect

    Remy, J.M.; Bellanger, M.; Homand-Etienne, F. )

    1994-02-01

    The velocity and the attenuation of compressional P-waves, measured in the laboratory at ultrasonic frequencies during a series of freezing and thawing cycles, are used as a method for predicting frost damage in a bedded limestone. Pulse transmission and spectral ratio techniques are used to determine the P-wave velocities and the attenuation values relative to an aluminum reference samples with very low attenuation. Limestone samples were water saturated under vacuum conditions, jacketed with rubber sleeves, and immersed in an antifreeze bath (50 percent methanol solution). They were submitted to repeated 24-hour freezing and thawing cycles simulating natural environment conditions. During the freeze/thaw cycles, P-wave velocities and quality factor Q diminished rapidly in thawed rock samples, indicating modification of the pore space. Measurements of crack porosity were conducted by hydrostatic compression tests on cubic rock samples that had been submitted to these freeze/thaw cycles. These measurements are used as an index of crack formation. The hydrostatic compression tests confirmed the phases of rock damage that were shown by changes in the value of Q. Furthermore, comparison between Q values and crack porosity demonstrate that the variations of P-wave attenuation are caused by the creation of new cracks and not by the enlargement of pre-existing cracks.

  10. Use of borehole radar tomography to monitor steam injection in fractured limestone

    USGS Publications Warehouse

    Gregoire, C.; Joesten, P.K.

    2006-01-01

    Borehole radar tomography was used as part of a pilot study to monitor steam-enhanced remediation of a fractured limestone contaminated with volatile organic compounds at the former Loring Air Force Base, Maine, USA. Radar tomography data were collected using 100-MHz electric-dipole antennae before and during steam injection to evaluate whether cross-hole radar methods could detect changes in medium properties resulting from the steam injection. Cross-hole levelrun profiles, in which transmitting and receiving antennae are positioned at a common depth, were made before and after the collection of each full tomography data set to check the stability of the radar instruments. Before tomographic inversion, the levelrun profiles were used to calibrate the radar tomography data to compensate for changes in traveltime and antenna power caused by instrument drift. Observed changes in cross-hole radar traveltime and attenuation before and during steam injection were small. Slowness- and attenuation-difference tomograms indicate small increases in radar slowness and attenuation at depths greater than about 22 m below the surface, consistent with increases in water temperature observed in the boreholes used for the tomography. Based on theoretical modelling results, increases in slowness and attenuation are interpreted as delineating zones where steam injection heating increased the electrical conductivity of the limestone matrix and fluid. The results of this study show the potential of cross-hole radar tomography methods to monitor the effects of steam-induced heating in fractured rock environments. ?? 2006 European Association of Geoscientists & Engineers.

  11. Noise suppression using preconditioned least-squares prestack time migration: application to the Mississippian limestone

    NASA Astrophysics Data System (ADS)

    Guo, Shiguang; Zhang, Bo; Wang, Qing; Cabrales-Vargas, Alejandro; Marfurt, Kurt J.

    2016-08-01

    Conventional Kirchhoff migration often suffers from artifacts such as aliasing and acquisition footprint, which come from sub-optimal seismic acquisition. The footprint can mask faults and fractures, while aliased noise can focus into false coherent events which affect interpretation and contaminate amplitude variation with offset, amplitude variation with azimuth and elastic inversion. Preconditioned least-squares migration minimizes these artifacts. We implement least-squares migration by minimizing the difference between the original data and the modeled demigrated data using an iterative conjugate gradient scheme. Unpreconditioned least-squares migration better estimates the subsurface amplitude, but does not suppress aliasing. In this work, we precondition the results by applying a 3D prestack structure-oriented LUM (lower–upper–middle) filter to each common offset and common azimuth gather at each iteration. The preconditioning algorithm not only suppresses aliasing of both signal and noise, but also improves the convergence rate. We apply the new preconditioned least-squares migration to the Marmousi model and demonstrate how it can improve the seismic image compared with conventional migration, and then apply it to one survey acquired over a new resource play in the Mid-Continent, USA. The acquisition footprint from the targets is attenuated and the signal to noise ratio is enhanced. To demonstrate the impact on interpretation, we generate a suite of seismic attributes to image the Mississippian limestone, and show that the karst-enhanced fractures in the Mississippian limestone can be better illuminated.

  12. Pore space evolution and elastic properties of platform carbonates (Urgonian limestone, Barremian-Aptian, SE France)

    NASA Astrophysics Data System (ADS)

    Fournier, François; Léonide, Philippe; Kleipool, Luuk; Toullec, Renault; Reijmer, John J. G.; Borgomano, Jean; Klootwijk, Thomas; Van Der Molen, Jeroen

    2014-07-01

    A dataset of 214 ultrasonic velocity and porosity measurements on Barremian-Aptian carbonates from Provence (SE France) provides well-constrained velocity-porosity transforms and allows the quantification of the impact of pore type and diagenetic history on these velocities. A numerical approach (EPAR: equivalent pore aspect ratio) was used to link diagenetic transformations, pore network evolution and elastic properties. Three categories of samples characterized by their dominant pore type were discriminated from the velocity and porosity database by means of the EPAR values derived from bulk (K-EPAR) and shear (μ-EPAR) moduli: 1) purely microporous limestones (low K- and μ-EPAR < 0.22), 2) samples with preserved intergranular and moldic pores (intermediate K- and μ-EPAR), and 3) vuggy limestones (K- and μ-EPAR > 0.3). Three velocity-porosity trajectories related to three diagenetic paths were defined and quantified from the Urgonian database: 1) EPAR-preserving micro-scale cementation of micrite, 2) non-EPAR-preserving dissolution with moldic pore development and 3) EPAR-preserving sparry calcite cementation of molds. Equivalent Pore Aspect Ratio can therefore be regarded as a robust tool to decipher diagenetic trends in velocity-porosity transforms and may help predicting pore architecture from subsurface data.

  13. Thermo-Hydro-Mechanical-Chemical Coupled Modeling of Geothermal Doublet Systems in Limestones -revised

    NASA Astrophysics Data System (ADS)

    Rühaak, Wolfram; Heldmann, Claus-Dieter; Pei, Liang; Bartels, Jörn; Weinert, Sebastian; Sass, Ingo

    2016-04-01

    Limestone aquifers in Southern Germany have been used within the last decade very successfully for geothermal heating and - to a lesser extent - for power generation. As an example the region around Munich has been extensively explored. While the extent of usage of this reservoir is increasing there is also an increased interest in better understanding of the reservoir properties and its change in the course of operation. For instance, the observed production and injection pressures are partly hard to explain. They may be related to mechanical or chemical processes, or both. Based on extensive data of outcrop studies and drillings, a data-base for the relevant physical properties of the respective limestones has been complied. The data include thermal conductivity, density, specific heat capacity, permeability, as well as mechanical properties like thermal expansion coefficient and elasticity modules. By using the hydro-thermo-chemical simulator FEFLOW together with an extension for thermo- and hydro-mechanical coupling the relevant processes are studied and compared with observed data. At the EGU Meeting in 2015 results of an initial study have been presented. This time results based on a completely new model setup and also using newly developed code will be presented. As a conclusion main challenges while modeling THMC fracture flow by using a multi-continua approach will be discussed.

  14. Hydrobiogeochemical interactions in 'anoxic' limestone drains for neutralization of acidic mine drainage

    USGS Publications Warehouse

    Robbins, E.I.; Cravotta, C.A., III; Savela, C.E.; Nord, G.L., Jr.

    1999-01-01

    Processes affecting neutralization of acidic coal mine drainage were evaluated within 'anoxic' limestone drains (ALDs). Influents had pH???3.5 and dissolved oxygen <2 mg/l. Even though effluents were near neutral (pH 6 and alkalinity acidity), two of the four ALDs were failing due to clogging. Mineral-saturation indices indicated the potential for dissolution of calcite and gypsum, and precipitation of Al3+ and Fe3+ compounds. Cleavage mounts of calcite and gypsum that were suspended within the ALDs and later examined microscopically showed dissolution features despite coatings by numerous bacteria, biofilms, and Fe-Al-Si precipitates. In the drain exhibiting the greatest flow reduction, Al-hydroxysulfates had accumulated on limestone surfaces and calcite etch points, thus causing the decline in transmissivity and dissolution. Therefore, where Al loadings are high and flow rates are low, a pre-treatment step is indicated to promote Al removal before diverting acidic mine water into alkalinity-producing materials. ?? 1998 Elsevier Science Ltd.

  15. Increasing shallow groundwater CO2 and limestone weathering, Konza Prairie, USA

    USGS Publications Warehouse

    Macpherson, G.L.; Roberts, J.A.; Blair, J.M.; Townsend, M.A.; Fowle, D.A.; Beisner, K.R.

    2008-01-01

    In a mid-continental North American grassland, solute concentrations in shallow, limestone-hosted groundwater and adjacent surface water cycle annually and have increased steadily over the 15-year study period, 1991-2005, inclusive. Modeled groundwater CO2, verified by measurements of recent samples, increased from 10-2.05 atm to 10-1.94 atm, about a 20% increase, from 1991 to 2005. The measured groundwater alkalinity and alkaline-earth element concentrations also increased over that time period. We propose that carbonate minerals dissolve in response to lowered pH that occurs during an annual carbonate-mineral saturation cycle. The cycle starts with low saturation during late summer and autumn when dissolved CO2 is high. As dissolved CO2 decreases in the spring and early summer, carbonates become oversaturated, but oversaturation does not exceed the threshold for precipitation. We propose that groundwater is a CO2 sink through weathering of limestone: soil-generated CO2 is transformed to alkalinity through dissolution of calcite or dolomite. The annual cycle and long-term increase in shallow groundwater CO2 is similar to, but greater than, atmospheric CO2. ?? 2008 Elsevier Ltd. All rights reserved.

  16. Penetration Experiments with Limestone Targets and Ogive-Nose Steel Projectiles

    SciTech Connect

    Forrestal, M.J.; Frew, D.J.; Hanchak, S.J.

    1999-04-08

    We conducted three sets of depth-of-penetration experiments with limestone targets and 3.0 caliber-radius-head (CRH), ogive-nose steel rod projectiles. The limestone targets had a nominal unconfined compressive strength of 60 MPa, a density of 2.31 kg/m{sup 3}, a porosity of 15%, and a water content less than 0.4%. The ogive-nose rod projectiles with length-to-diameter ratios often were machined from 4340 R{sub c} 45 and Aer Met 100 R{sub c} 53 steel, round stock and had diameters and masses of 7.1 mm, 0.020 kg; 12.7 mm, 0.117 kg; and 25.4 mm, 0.931 kg. Powder guns or a two-stage, light-gas gun launched the projectiles at normal impacts to striking velocities between 0.4 and 1.9 km/s. For the 4340 R{sub c} 45 and Aer Met 100 R{sub c} 53 steel projectiles, penetration depth increased as striking velocity increased to a striking velocity of 1.5 and 1.7 km/s, respectively. For larger striking velocities, the projectiles deformed during penetration without nose erosion, deviated from the shot line, and exited the sides of the target. We also developed an analytical penetration equation that described the target resistance by its density and a strength parameter determined from depth of penetration versus striking velocity data.

  17. Paleobiology of distinctive benthic microfossils from the upper Proterozoic Limestone-Dolomite "Series," central East Greenland

    NASA Technical Reports Server (NTRS)

    Green, J. W.; Knoll, A. H.; Golubic, S.; Swett, K.

    1987-01-01

    Populations of Polybessurus bipartitus Fairchild ex Green et al., a large morphologically distinctive microfossil, occur in silicified carbonates of the Upper Proterozoic (700-800 Ma) Limestone-Dolomite "Series," central East Greenland. Large populations of well-preserved individuals permit reconstruction of P. bipartitus as a coccoidal unicell that "jetted" upward from the sediment by the highly unidirectional secretion of extracellular mucopolysaccharide envelopes. Reproduction by baeocyte formation is inferred on the basis of clustered envelope stalks produced by small cells. Sedimentological evidence indicates that P. bipartitus formed surficial crusts locally within a shallow peritidal carbonate platform. Among living microorganisms a close morphological, reproductive, and behavioral counterpart to Polybessurus is provided by populations of an as yet underscribed cyanobacterium found in coastal Bahamian environments similar to those in which the Proterozoic fossils occur. In general morphology and "jetting" behavior, this population resembles species of the genus Cyanostylon, Geitler (1925), but reproduces via baeocyte formation. Polybessurus is but one of the more than two dozen taxa in the richly fossiliferous biota of the Limestone-Dolomite "Series." This distinctive population, along with co-occurring filamentous cyanobacteria and other microfossils, contributes to an increasingly refined picture of ecological heterogeneity in late Proterozoic oceans.

  18. The paleomagnetism of clastic and precipitate deposits in limestone and dolomite caves

    SciTech Connect

    Latham, A.G. ); Ford, D.C. )

    1991-03-01

    Clastic sediments and calcite precipitates (stalagmites, flowstones, etc.) are abundant in modern limestone caves and normally are the dominant infillings in buried (paleokarst) caves. Clastic sediment fillings are chiefly of fluviatile or local breakdown origin, but lacustrine, colluvial, eolian, and glacial deposits are known. Paleomagnetism has been studied in the fluviatile and lacustrine types: (1) reversal stratigraphy aids dating of geomorphic and paleoclimatic events in the late Pliocene/Pleistocene; (2) fine magnetostratigraphy has yielded estimates of the westward drift. Calcite precipitates (speleothems) may display natural remanent magnetism of either depositional (DRM) or chemical (CRM) origin. NRMs of modern speleothems are primary, not diagenetic; CRMs are invariably associated with the degradation of surface organic matter. (1) Coarse reversal stratigraphy dates geomorphic, etc., events and erosion rates. (2) Fine stratigraphy combined with {sup 230}Th:{sup 234}U dating gives high precision estimates of secular variation, westward drift, and rate of change of geomagnetic anomalies in upper Pleistocene and Holocene deposits. Magnetostratigraphy of paleokarst speleothem fillings associated with hydrocarbons in Ordovician limestones suggest a Permian age for the karstification. Potential applications of magnetostratigraphy to paleokarst deposits of many different scales are considerable.

  19. Seismic characteristics of cavity decoupled explosions in limestone: An analysis of Soviet high explosive test data

    NASA Astrophysics Data System (ADS)

    Murphy, J. R.; Kitov, I. O.; Rimer, N.; Adushkin, V. V.; Barker, B. W.

    1997-12-01

    During the summer of 1960, Soviet scientists conducted a series of high-explosive, cavity decoupling tests in a mine in Kirghizia. These decoupled tests were carried out in a variety of mined cavities in limestone, including spherical cavities with diameters ranging from 3.5 to 10 m as well as nonspherical cavities with volumes of about 25 m3. The experiments of this test series consisted of 10 tamped and 12 decoupled explosions having yields of 0.1, 1.0, and 6.0 t, and seismic data were recorded at locations in the mine over a distance range extending from about 10 to 250 m from the sources. These data provide valuable new insight into the dependence of decoupling effectiveness on variables such as cavity volume, cavity shape, and charge emplacement geometry. In particular, analyses indicate that chemical explosions at a depth of 290 m in limestone are essentially fully decoupled in spherical cavities with scaled cavity radii larger than about 27 m/kt⅓ and that the low-frequency decoupling effectiveness under such conditions is approximately independent of cavity shape for roughly cylindrical cavities with length-to-width ratios of as much as 6-12. These results suggest that the possibility of cavity decoupling in nonspherical cavities in hard rock media will have to be carefully evaluated in establishing the seismic verification regime for the Comprehensive Test Ban Treaty.

  20. Hydration of spent limestone and dolomite to enhance sulfation in fluidized-bed combustion

    SciTech Connect

    Shearer, J.A.; Smith, G.W.; Moulton, D.S.; Turner, C.B.; Myles, K.M.; Johnson, I.

    1980-01-01

    The utilization of CaO in fluidized bed combustion can be markedly increased to reduce the cost and environmental impact of quarrying and disposing of large quantities of solid waste. A new method of treatment of spent bed material to reactivate its SO/sub 2/ capturing ability has been found. Partially sulfated spent overflow material from a fluidized-bed combustor is treated with water and then reintroduced to the combustor as renewed feed that further reacts with SO/sub 2/. This material has sufficient physical integrity, due to the outer layer of CaSO/sub 4/, and high reactivity to make it suitable as a sorbent feedstock. The work reported here details observations on a number of limestones and dolomites reacted in laboratory furnaces under simulated combustion conditions as well as verification of the effectiveness of the method in a 15-cm-ID process development unit scale atmospheric fluidized-bed coal combustor. Initial kinetic studies have also been made on the hydration reaction of partially sulfated limestone. A proposed mechanism of interaction is discussed to explain the enhanced reactivity. Changes in total porosity and pore size distribution in the partially sulfated material due to Ca(OH)/sub 2/ formation and its dehydration serve to open up the particle interior and its residual CaO to further reaction with SO/sub 2/. Almost complete utilization of the available CaO can be achieved by successive applications of this promising new technique.

  1. Damage characterization in dimension limestone cladding using noncollinear ultrasonic wave mixing

    NASA Astrophysics Data System (ADS)

    McGovern, Megan; Reis, Henrique

    2016-01-01

    A method capable of characterizing artificial weathering damage in dimension stone cladding using access to one side only is presented. Dolomitic limestone test samples with increasing levels of damage were created artificially by exposing undamaged samples to increasing temperature levels of 100°C, 200°C, 300°C, 400°C, 500°C, 600°C, and 700°C for a 90 min period of time. Using access to one side only, these test samples were nondestructively evaluated using a nonlinear approach based upon noncollinear wave mixing, which involves mixing two critically refracted dilatational ultrasonic waves. Criteria were used to assure that the detected scattered wave originated via wave interaction in the limestone and not from nonlinearities in the testing equipment. Bending tests were used to evaluate the flexure strength of beam samples extracted from the artificially weathered samples. It was observed that the percentage of strength reduction is linearly correlated (R2=98) with the temperature to which the specimens were exposed; it was noted that samples exposed to 400°C and 600°C had a strength reduction of 60% and 90%, respectively. It was also observed that results from the noncollinear wave mixing approach correlated well (R2=0.98) with the destructively obtained percentage of strength reduction.

  2. Porosity change after gypsum crust formation on macro-porous limestones

    NASA Astrophysics Data System (ADS)

    Dewanckele, Jan; Cnudde, Veerle; de Kock, Tim; Boone, Marijn; Boone, Matthieu; van Hoorebeke, Luc; Jacobs, Patric

    2010-05-01

    The deterioration of stone is a complex process in which physical, biological and chemical mechanisms are involved. In this research, pore structure changes inside two types of porous limestone were analyzed before, during and after strong acid tests with SO2. Sulphatation and crust formation phenomena on natural building stones exposed to a polluted environment, are largely described in literature. As far as rocks rich in calcium carbonate are concerned, the main processes involved are the dissolution of the calcium carbonate and the formation of gypsum (CaSO4.2H2O) in presence of an acid atmosphere. The low mobility of this newly formed salt favours its accumulation in porous materials and at the surface of less porous media. The main actor in the process of gypsum crystallization on limestone is the aggressive sulphur dioxide gas (SO2). In this study, the Savonnières and Euville limestone were subjected to tests with a strong acid. According to the standard EN 13919:2002E, samples were put in acid environment for 21 days. At the bottom of the container a mixture of 500 ± 10 ml H2SO3 and 150 ± 10 ml de-mineralized H2O was added. No airborne particles or oxides of nitrogen (NOx) were added. Before exposure, after 6 days in the polluted environment and at the end of the test, the two samples were scanned with X-ray computed tomography (X-ray CT) at the Centre for X-ray Tomography at Ghent University, Belgium (UGCT; www.ugct.ugent.be). This visualization technique allows 2D and 3D reconstructions on a micrometer scale of the internal structure of an object without damaging the material. It thus enables to scan the same sample in a sequential way. In order to obtain information about the sample's interior of which the characteristics can be compared before, during and after the test, the same scanning parameters (exposure time, amount of frames, energy, etc.) were used. In addition, the same adjustments like beam hardening correction, normalizing, ring and spot

  3. Laboratory Investigations in Support of Carbon Dioxide-Limestone Sequestration in the Ocean

    SciTech Connect

    Dan Golomb; Eugene Barry; David Ryan; Carl Lawton; Stephen Pennell; Peter Swett; Huishan Duan; Michael Woods

    2005-11-01

    This semi-annual progress reports includes further findings on CO{sub 2}-in-Water (C/W) emulsions stabilized by fine particles. In previous semi-annual reports we described the formation of stable C/W emulsions using pulverized limestone (CaCO{sub 3}), flyash, beach sand, shale and lizardite, a rock rich in magnesium silicate. For the creation of these emulsions we used a High-Pressure Batch Reactor (HPBR) equipped with view windows for illumination and video camera recording. For deep ocean sequestration, a C/W emulsion using pulverized limestone may be the most suitable. (a) Limestone (mainly CaCO{sub 3}) is cheap and plentiful; (b) limestone is innocuous for marine organisms (in fact, it is the natural ingredient of shells and corals); (c) it buffers the carbonic acid that forms when CO{sub 2} dissolves in water. For large-scale sequestration of a CO{sub 2}/H{sub 2}O/CaCO{sub 3} emulsion a device is needed that mixes the ingredients, liquid carbon dioxide, seawater, and a slurry of pulverized limestone in seawater continuously, rather than incrementally as in a batch reactor. A practical mixing device is a Kenics-type static mixer. The static mixer has no moving parts, and the shear force for mixing is provided by the hydrostatic pressure of liquid CO{sub 2} and CaCO{sub 3} slurry in the delivery pipes from the shore to the disposal depth. This semi-annual progress report is dedicated to the description of the static mixer and the results that have been obtained using a bench-scale static mixer for the continuous formation of a CO{sub 2}/H{sub 2}O/CaCO{sub 3} emulsion. The static mixer has an ID of 0.63 cm, length 23.5 cm, number of baffles 27. Under pressure, a slurry of CaCO{sub 3} in artificial seawater (3.5% by weight NaCl) and liquid CO{sub 2} are co-injected into the mixer. From the mixer, the resulting emulsion flows into a Jerguson cell with two oblong windows on opposite sides, then it is vented. A fully ported ball valve inserted after the Jerguson

  4. Influence of mineralogical, petrographical, and geochemical characteristics of impure limestones on the composition of fired hydraulic lime: a case study on Lower Palaeozoic limestones from the Prague Basin (Barrandian area, Czech Republic)

    NASA Astrophysics Data System (ADS)

    Kozlovcev, Petr; Přikryl, Richard

    2014-05-01

    Prague Basin, making part of the Barrandian area (Bohemian Massif, Czech Republic), is a rift-like depression filled with non-metamorphosed sedimentary series of Upper Proterozoic - Lower Palaeozoic age. Among other sedimentary rocks, different types of limestones are present. These limestone were historically exploited and used for various purposes including natural and decorative stone, common construction material, and also a raw material for firing of inorganic binders: aerial lime, hydraulic lime and/or, more recently, Ordinary Portland Cement (OPC). Lithotypes with higher amount of silica and/or clay component were of special interest due to the hydraulicity of fired product known as "pasta di Praga" in Baroque. However, our recent knowledge of these limestones is incomplete in terms of the contribution of mineralogical, geochemical, and petrographical characteristics on the properties of fired hydraulic lime. In the recent study, representative samples of 4 facies of the Lower Devonian limestone (Kosoř ls., Řeporyje ls., Dvorce-Prokop ls., and Zlíchov ls.) were subjected to a detailed mineralogical and petrographic study of raw material by means of polarizing microscopy, cathodoluminiscence of thin sections and scanning electron microscopy with an energy dispersive spectrometer (SEM-EDS). X-ray diffraction (XRD) of insoluble residues obtained by treatment with both the hydrochloric acid and the acetic acid solution was used. Wet silicate analysis provided data on the content of major elements from which standard cement and lime indexes and modules were calculated. Laboratory firing experiments of these limestone were performed by a calcination at temperature ranging from 850 to 1200°C (after 50°C). XRD of fired products shows that limestones with high content of silica (some of the Dvorce-Prokop ls.) produced binder with high amount of newly formed calcium silicates (larnite). Gehlenite and others calcium aluminates and aluminosilicates are typical for

  5. Photothermal Radiometry Characterization of Limestone Rocks from the Península of Yucatán

    NASA Astrophysics Data System (ADS)

    May-Crespo, J.; Martínez-Torres, P.; Alvarado-Gil, J. J.; Quintana, P.; Vilca-Quispe, L.

    2012-11-01

    Limestone is a sedimentary rock composed of calcium carbonate with minor amounts of silica, iron oxide, clay, dolomite, and organic material. These types of stones have been used extensively as building materials. Due to this, determination of their thermal properties is of the utmost importance. These properties depend on the microstructure and composition of each type of rock. In this study, the effect of the thermal treatment of three different limestone rocks from the Peninsula of Yucatán were studied, in the range from 100 °C up to 600 °C, using photothermal radiometry. These studies were complemented by the characterization of the crystalline phases using X-ray diffraction and effective porosity measurements performed by the saturation technique. It is shown that the thermal diffusivity, thermal conductivity, and specific heat of the limestone decrease as the temperature increases. This behavior can be related to increases in microcracks and effective porosity due to thermal treatments.

  6. Carbonate bank sedimentation in a volcaniclastic arc setting: Lower Carboniferous limestones of the eastern Klamath terrane, California

    SciTech Connect

    Watkins, R. . Dept. of Geology)

    1993-09-01

    Carboniferous volcaniclastic-arc deposits of the eastern Klamath terrane, California, include Late Visean/Namurian limestone lenses that formed as small carbonate banks. The limestone lenses, within the Bragdon and Baird formations, reach 17 m in thickness and 1.2 km in length. Slope deposits consist of argillaceous spiculitic wackestone, and bank-edge deposits include ooid grainstone, Striatifera packstone, argillaceous phylloid algal packstone, and argillaceous skeletal packstone, Bank-interior deposits include skeletal wackestone/packstone and argillaceous sandy mudstone. The limestone lenses overlie proximal deltaic deposits of thick-bedded volcaniclastic sandstone and conglomerate. Carbonate banks developed on delta lobes during intervals of minimal clastic sedimentation, possibly related to sea-level rise and volcanic quiescence. The carbonate banks were short-lived depositional systems, and they were covered by prograding deposits of younger volcaniclastic sands.

  7. Mobile laboratory “Explosive destruction of natural materials”: Investigation of the behavior of ice and limestone under explosive loading

    NASA Astrophysics Data System (ADS)

    Orlov, M. Yu; Orlova, Yu N.; Tolkachev, V. F.

    2015-11-01

    In the paper, the behavior of ice and natural limestone under explosion condition was investigated. The objects of study were the river ice and natural limestone quarry on Siberia. The practical significance of research due to the need to increase production of oil and gas in permafrost regions, the fight against ice jams, etc. We organized a mobile laboratory ’’Explosive destruction of the natural materials” at the National Research Tomsk State University. The main purpose of the laboratory is express analyzing of explosive destruction of natural materials. The diameters and depths of explosive craters in the limestone and explosive lane in the ice were obtained. The results can be used to test new models and numerical methods for calculating shock and explosive loading of different materials, including ice.

  8. Origin of intraformational folds in the Jurassic Todilto Limestone, Ambrosia Lake uranium mining district, McKinley and Valencia counties, New Mexico

    USGS Publications Warehouse

    Green, M.W.

    1982-01-01

    The Todilto Limestone of Middle Jurassic age in the Ambrosia Lake uranium mining district of McKinley and Valencia Counties, New Mexico, is the host formation for numerous small- to medium-sized uranium deposits in joints, shear zones, and fractures within small- to large-scale intraformational folds. The folds probably were formed as a result of differential sediment loading when eolian sand dunes of the overlying Summerville Formation of Middle Jurassic age migrated over soft, chemically precipitated, lime muds of the Todilto shortly after their deposition in a regressive, mixed fresh and saline lacustrine or marine environment of deposition. Encroachment of Summerville eolian dunes over soft Todilto lime muds was apparently a local phenomenon and was restricted to postulated beltlike zones which trended radially across the Todilto coastline toward the receding body of water. Intraformational folding is believed to be confined to the pathways of individual eolian dunes or clusters of dunes within the dune belts. During the process of sediment loading by migrating sand dunes, layers of Todilto lime mud were differentially compacted, contorted, and dewatered, producing both small- and large-scale plastic deformation structures, including convolute laminations, mounds, rolls, folds, and small anticlines and synclines. With continued compaction and dewatering, the mud, in localized areas, reached a point of desaturation at which sediment plasticity was lost. Prolonged loading by overlying dune sands thus caused faulting, shearing, fracturing, and jointing of contorted limestone beds. These areas or zones of deformation within the limestone became the preferred sites of epigenetic uranium mineralization because of the induced transmissivity created by sediment rupture. Along most of the prograding Todilto coastline, adjacent to the eolian dune belts, both interdune and coastal sabkha environments dominated during Todilto-Summerville time. Sediments in coastal areas

  9. Stratigraphic variations and secondary porosity within the Maynardville Limestone in Bear Creek Valley, Y-12 Plant, Oak Ridge, Tennessee

    SciTech Connect

    Goldstrand, P.M.

    1995-05-01

    To evaluate groundwater and surface water contamination and migration near the Oak Ridge Y-12 plant, a Comprehensive Groundwater Monitoring Plan was developed. As part of the Maynardville exit pathways monitoring program, monitoring well clusters were ii installed perpendicular to the strike of the Maynardville Limestone, that underlies the southern part of the Y-12 Plant and Bear Creek Valley (BCV). The Maynardville Project is designed to locate potential exit pathways of groundwater, study geochemical characteristics and factors affecting the occurrence and distribution of water-bearing intervals, and provide hydrogeologic information to be used to reduce the potential impacts of contaminants entering the Maynardville Limestone.

  10. Roughening, recession, and chemical alteration of marble and limestone sample surfaces during atmospheric exposure in the eastern United States

    SciTech Connect

    Youngdahl, C.A.; Doe, B.R.

    1986-02-01

    Marble and limestone surfaces were exposed to atmospheric conditions at four eastern US sites and were monitored for changes in surface chemistry, surface roughness/recession, and weight. The effect of acid deposition, to which calcareous materials are especially sensitive, was of particular interest. Results are described for the first year of testing, and aspects of a preliminary equation to relate damage to environmental factors are discussed. Thus far, findings support that acid deposition substantially damages marble and limestone surfaces. Improvements in methods to reduce uncertainties in the quantitative contributions of important chemical species are outlined for the ongoing effort.

  11. Assessment of postcrumble addition of limestone and calcium-specific appetite in broilers during the starter phase1

    PubMed Central

    Li, W.; Angel, R.; Kim, S.-W.; Jiménez-Moreno, E.; Proszkowiec-Weglarz, M.; Iglesias, B. F.; Wilkinson, S. J.; Cowieson, A. J.

    2014-01-01

    A study was done to determine whether broilers can regulate Ca intake when limestone is provided separately or mixed with a crumbled feed of variable Ca and P content, and the influence of this on performance and apparent ileal digestibility (AID) of Ca and P (AIDP). Twelve crumbled diets were fed from 10 to 20 d of age (8 replicates, 8 broilers/replicate). Diets A to D contained 0.28% nonphytate P (nPP) and 0.27, 0.51, 0.77, and 1.02% Ca, respectively. Diets E to H contained 0.48% nPP and 0.41, 0.51, 0.77, and 1.02% Ca, respectively. A large particle size limestone was mixed manually to the crumbled diet on a daily basis to achieve 1.02% total Ca in diets A to H. Diets I to L had the same Ca and nPP as diets A to D, but limestone was provided in a separate feeder to assess spatial importance of limestone supply. Limestone consumption, provided in a separate feeder, decreased as Ca concentration increased in the crumble diet (P < 0.05). Calcium intake increased as Ca concentration in crumbled diets increased (P < 0.05). Increased tibia ash and decreased AIDP were observed as Ca intake increased (P < 0.05). When limestone was added to diets containing 0.28% nPP postcrumble, Ca intake (6.38 g/bird), tibia ash (717 mg/bone), and AIDP (39.78%) were not affected by crumbled diet Ca concentration or consumed Ca. Broilers fed diets containing 0.48% nPP and limestone mixed with the crumble, Ca intake changed (5.96, 6.93, 6.59, and 6.04 g/bird for crumble diet with 0.41, 0.51, 0.77, and 1.02% Ca, respectively). Increasing Ca concentration in the crumble from 0.41 to 1.02% resulted in greater tibia ash (875 mg/bone) but lower AIDP (P < 0.05), although Ca intake was similar. In conclusion, when large particle size limestone was provided ad libitum, the ability of broilers to select for Ca was not sufficient to meet their requirement when crumble Ca was less than 0.77%. The AIDP was highest in birds fed the 0.27% Ca concentration diet. PMID:25085931

  12. Laboratory study of SO2 dry deposition on limestone and marble: Effects of humidity and surface variables

    USGS Publications Warehouse

    Spiker, E. C.; Hosker, R.P., Jr.; Weintraub, V.C.; Sherwood, S.I.

    1995-01-01

    The dry deposition of gaseous air pollutants on stone and other materials is influenced by atmospheric processes and the chemical characteristics of the deposited gas species and of the specific receptor material. Previous studies have shown that relative humidity, surface moisture, and acid buffering capability of the receptor surface are very important factors. To better quantify this behavior, a special recirculating wind tunnel/environmental chamber was constructed, in which wind speed, turbulence, air temperature, relative humidity, and concentrations of several pollutants (SO2, O3, nitrogen oxides) can be held constant. An airfoil sample holder holds up to eight stone samples (3.8 cm in diameter and 1 cm thick) in nearly identical exposure conditions. SO2 deposition on limestone was found to increase exponentially with increasing relative humidity (RH). Marble behaves similarly, but with a much lower deposition rate. Trends indicate there is little deposition below 20% RH on clean limestone and below 60% RH on clean marble. This large difference is due to the limestone's greater porosity, surface roughness, and effective surface area. These results indicate surface variables generally limit SO2 deposition below about 70% RH on limestone and below at least 95% RH on marble. Aerodynamic variables generally limit deposition at higher relative humidity or when the surface is wet.The dry deposition of gaseous air pollutants on stone and other materials is influenced by atmospheric processes and the chemical characteristics of the deposited gas species and of the specific receptor material. Previous studies have shown that relative humidity, surface moisture, and acid buffering capability of the receptor surface are very important factors. To better quantify this behavior, a special recirculating wind tunnel/environmental chamber was constructed, in which wind speed, turbulence, air temperature, relative humidity, and concentrations of several pollutants (SO2, O3

  13. Cementation in Oligo-Miocene non-tropical shelf limestones, Otway Basin, Australia

    NASA Astrophysics Data System (ADS)

    Nicolaides, Stelios

    1995-02-01

    The Oligocene to Miocene Heytesbury Group of the Otway Basin, southeastern Australia, is a non-tropical carbonate shelf succession. This subsurface stratigraphic succession consists of bioclastic grainstones to mudstones containing bryozoa, benthonic and planktonic foraminifera, echinoderms, brachiopods, and molluscs. The basal bryozoa-dominated Clifton Formation was deposited in relatively shallow waters. The overlying Gellibrand Marl, rich in planktonic foraminifera and bryozoa, formed under deep waters. The uppermost unit, benthonic foraminifera-dominated Port Campbell Limestone, was deposited in a moderately deep, middle shelf environment. Cementation is limited and includes: (1) scalenohedral calcite (non-luminescent to bright, Mn- and Fe-poor, in inter- and intraparticle porosity); (2) blocky equant calcite (dull, Mn- and Fe-rich, in interparticle porosity); (3) syntaxial calcite overgrowths on echinoderm particles (non/bright/dull-zoned); (4) euhedral dolomite (in the interparticle pore space of the Port Campbell Limestone); (5) bladed-prismatic calcite (ferroan, in planktonic foraminifera); (6) fibrous calcite (non-luminescent, in intraparticle porosity); and (7) glauconite and iron-oxides (only in intraparticle porosity). All CaCO 3 cements are low-Mg calcites (< 4 mol% MgCO 3). The cements observed in the Heytesbury Group appear to have formed in three successive diagenetic environments: (1) early shallow burial (early Fe- and Mn-poor, non-luminescent syntaxial overgrowths and non-luminescent scalenohedral calcite, under oxidising conditions); (2) late shallow burial (bright, more Mn-rich syntaxial overgrowth zone, i.e., more than the initial non-luminescent one, and bright scalenohedral calcite, under moderately reducing pore water conditions); and (3) moderate burial (ferroan, dull blocky calcite and dull syntaxial overgrowth zone, under reducing conditions). Pressure solution was the main cement-producing mechanism, although seawater and aragonite

  14. Isotopic labeling for the understanding of the alteration of limestone used in built cultural heritage

    NASA Astrophysics Data System (ADS)

    Saheb, Mandana; Chabas, Anne; Mertz, Jean-Didier; Rozenbaum, Olivier; Verney-Carron, Aurélie

    2015-04-01

    This project belongs to a specific work aiming at developing isotopic tools to better understand the alteration of materials used in the built cultural heritage. It is focused on the study of the alteration of limestone used in the facades of historic buildings subject to atmospheric polluted environment. Actually in the elevated parts of the buildings, water as rainfall (runoff or wet deposition) or in vapor form (condensation or dry deposition) is the main agent of alteration. Thus, the rock/water interactions need to be well understood to propose adapted solution to better preserve the buildings. To identify the water transfer within the porous limestone and locate the reaction preferential sites, two isotopic tracers (D and 18O) are used to monitor the alteration solution (D) and locate the zones containing the secondary phases (18O). The Saint-Maximin limestone used in many monuments in the suburbs of Paris (France) as a building and restoration stone has been specifically studied. Pristine materials, stones from monuments (monuments in the Paris area) and samples altered in laboratory constitute the analytical corpus to compare different stages of alteration. In a first step the stones are characterized at different scales to identify the alteration pattern (SEM-EDS, Raman microspectrometry, XRD, rugosimetry) and study the water transfers (X-ray tomography, mercury porosimetry, imbibition kinetics). The samples are then altered in the laboratory by realistic and controlled wet or dry deposition using isotopically labeled solutions to locate the reaction zones by SIMS. The multiscale characterization of the alteration pattern has allowed proposing alteration mechanisms linked to the properties of the stones and their location inside the building. Moreover, the location of the reactive zones inside the materials determined by the isotopic experiments helps examining the role of the evolution of porosity and formation of alteration products within the material

  15. Brittle-ductile shear zone formation in the McKim Limestone: eastern Monument Upwarp, Utah

    NASA Astrophysics Data System (ADS)

    Seyum, S.; Pollard, D. D.

    2011-12-01

    The McKim Limestone is part of a regressive, marine sedimentary sequence of strata that was deposited in the Pennsylvanian to Permian periods. It is well-exposed across large portions of Raplee anticline and Comb monocline; a pair of kilometer-scale folds that mark the Monument Upwarp of the Colorado Plateau in southeastern Utah. Two conjugate sets of echelon vein arrays, with complementary echelon pressure solution seam arrays, occur as bed-perpendicular, systematic deformation features in the 1-3 m thick McKim Limestone unit. Based on large vein to vein array angles, large vein aperture to length ratios, and the presence of vein-perpendicular pressure solution seams, these structures are interpreted to have developed within localized, brittle-ductile shear zones. Topics of debate among structural geologists regarding the formation mechanism of echelon veins include the initiation mode of vein segments (tensile or shear), the relative age between shear zone initiation and vein formation, the interpretation of strain within a shear zone, and the development of sigmoidal veins as being indicative of rotation. These concepts often are founded on geometric observations and kinematic models of deformation (e.g. simple shear) that are independent of the constitutive properties of the rock, are not constrained by the equations of motion, and do not honor the boundary conditions on the vein surfaces. Here we show a more realistic representation of brittle-ductile shear zone formation by introducing numerical models that consider the mechanical properties of limestone, are constrained by the equations of motion, and explicitly define the vein surfaces and their boundary conditions. The commercial finite element software, Abaqus FEA, is used to investigate the deformed geometry of model echelon vein arrays as a function of the remotely applied stress, the initial geometry of the vein arrays, and the constitutive properties of the solid. These geometric patterns are compared

  16. Altitude of the Top of the Minnekahta Limestone in the Black Hills area, South Dakota, 1999

    USGS Publications Warehouse

    Carter, Janet M.; Redden, Jack A.

    2000-01-01

    This map is a product of the Black Hills Hydrology Study, which was initiated in 1990 to assess the quantity, quality, and distribution of surface water and groundwater in the Black Hills area of South Dakota (Driscoli, 1992). This long-term study is a cooperative effort between the U.S. Geological Survey (USGS), the South Dakota Department of environment and Natural Resources, and the West Dakota Water development District, which represents various local and county cooperators. This map is part of a series of 1:100,000-scale maps for the study. The maps include a hydrogeologic map, structure-contour maps (altitudes of the tops of formations) for five formations that contain major aquifers in the study area, and potentiometric maps for these five major aquifers (the Inyan Kara. Minnekahta, Minnelusa, Madison, and Deadwood aquifers).The study area consists of the topographically defined Black Hills and adjacent areas located in western South Dakota. The Black Hills area is an elongated, dome-shaped feature, about 125 miles long and 60 miles wide, which was uplifted during the Laramide orogeny (Feldman and Heimlich, 1980). The oldest geologic units in the study area are Precambrian metamorphic and igneous rocks, which are exposed in the central core of the Black Hills. Surrounding the Precambrian core is a layered series of sedimentary rocks including limestones, sandstones, and shales that are exposed in roughly concentric rings around the uplifted flanks of the Black Hills. The bedrock sedimentary units typically dip away from the uplifted Black Hills at angles that approach or exceed 10 degrees near the outcrops, and decrease with distance from the uplift. Many of the sedimentary units contain aquifers, both within and beyond the study area. Recharge to these aquifers occurs from infiltration of precipitation upon the outcrops and, in some cases, from infiltration of streamflow (Hortness and Driscoll, 1998). Artesian conditions generally exist within these

  17. Altitude of the Top of the Madison Limestone in the Black Hills area, South Dakota, 1999

    USGS Publications Warehouse

    Carter, Janet M.; Redden, Jack A.

    2000-01-01

    This map is a product of the Black Hills Hydrology Study, which was initiated in 1990 to assess the quantity, quality, and distribution of surface water and groundwater in the Black Hills area of South Dakota (Driscoll, 1992). This long-term study is a cooperative effort between the U.S. Geological Survey (USGS), the South Dakota Department of Environment and Natural Resources, and the West Dakota Water Development District, which represents various local and county cooperators. This map is part of a series of 1:100,000-scale maps for the study. The maps include a hydrogeologic map, structure-contour maps (altitudes of the tops of formations) for five formations that contain major aquifers in the study area, and potentiometric maps for these five major aquifers (the Inyan Kara, Minnekahta, Minnelusa, Madison, and Deadwood aquifers).The study area consists of the topographically defined Black Hills and adjacent areas located in western South Dakota. The Black Hills area is an elongated, dome-shaped feature, about 125 miles long and 60 miles wide, which was uplifted during the Laramide orogeny (Feldman and Heimlich, 1980). The oldest geologic units in the study arca arc Precambrian metamorphic and igneous rocks, which are exposed in the central core of the Black Hills. Surrounding the Precambrian core is a layered series of sedimentary rocks including limestones, sandstones, and shales that are exposed in roughly concentric rings around the uplifted flanks of the Black Hills. The bedrock sedimentary units typically dip away from the uplifted Black Hills at angles that approach or exceed 10 degrees near the outcrops, and decrease with distance from the uplift. Many of the sedimentary units contain aquifers, both within and beyond the study area. Recharge to these aquifers occurs from infiltration of precipitation upon the outcrops and, in some cases, from infiltration of streamflow (Hortness and Driscoll, 1998). Artesian conditions generally exist within these

  18. Limestone-based technosols: a suitable way for the remediation of sediments contaminated by heavy metals.

    NASA Astrophysics Data System (ADS)

    Martínez-Sanchez, Maria Jose; Garcia-Lorenzo, Mari Luz; Martínez, Salvadora; Gonzalez, Eva; Molina, Jose; Hernández, Carmen; Pérez-Sirvent, Carmen

    2013-04-01

    The aim of this work was to assess the suitability of limestone-based technosols for decreasing the toxicity of the leachates caused by rain in sites contaminated by heavy metals. For such a purpose, 64 technosols were prepared in containers of 0.75m3, filled with 4 types of sediments collected from Portman Bay and subjected to different stabilizer proportions (limestone filler), different thickness of a drainage layer and presence/absence of a topsoil cover. The technosols were then submitted to different humidity/dryness cycles simulating the usual rain conditions in the zone. Portman bay is situated close to the mining region of La Unión. The entire area around the bay was subject to mining from the time of the Roman Empire to 1991. Since 1957, the wastes from mining operations were discharged directly into the sea in the inner part of the bay, while later on, they were also discharged to sea at a distance of the shore. These wastes mainly consisted in ore materials (galena, pyrite and sphalerite), phyllosilicates, in addition to siderite, iron oxides and sometimes alteration products such as jarosite, alunite, kaolinite and greenalite. These materials have suffered a concentration process by floatation with sea water and as a result of the discharge, the whole of the bay has filled up with wastes which also extend into the Mediterranean Sea. The pH and the electrical conductivity (EC) was determined in obtained percolates, together with major ion content, determined by ionic chromatography. The Zn, Pb, Cd and Cu content was determined by electrothermal atomization atomic absorption spectrometry (ETAAS). The As content was measured by atomic fluorescence spectrometry. In addition, the mineralogical composition was determined in the evaporated samples by X-Ray diffraction. A battery of bioassays was applied for the ecotoxicological screening of obtained percolates . Particularly, the toxicity was evaluated by using three assays: microtox bioassay (Vibrio

  19. An ichnofabric approach to the depositional interpretation of the intensely burrowed Bateig Limestone, Miocene, SE Spain

    NASA Astrophysics Data System (ADS)

    de Gibert, Jordi M.; Goldring, Roland

    2007-01-01

    The foraminiferal-rich pelagic Bateig Limestone forms several varieties of the important building stones quarried at Bateig Hill in southeastern Spain. Three principal ichnofabrics ( Bichordites, mottled- Palaeophycus and mottled- Ophiomorpha) are recognized, which are present in at least two (possibly up to four) repeated successions (cycles). Each succession begins with an erosional event. The Bichordites ichnofabric represents a new type of facies, formed as thin turbidity/grain flow, stratiform units derived from sediment slips off a fault into deep water. Each slipped unit became almost completely bioturbated by infaunal echinoids, colonizing by lateral migration. Because of the thinness of the units, successive colonizations tended to truncate the underlying burrows giving rise to a pseudo-stratification. As the Bichordites ichnofabric accumulated on the fault apron, thus reducing the effective height of the fault scarp, the substrate gradually came under the influence of currents traversing the shelf. This led to a change in hydraulic regime, and to the mottled- Palaeophycus and mottled- Ophiomorpha ichnofabrics in sediment deposited under bed load transport, and associated with laminar and cross-stratified beds and local muddy intervals. Reactivation of the fault triggered erosion and channeling and a return to grain flow sedimentation, and to the Bichordites ichnofabric of the succeeding cycle. The highest unit of the Bateig Limestone is formed entirely of cross-stratified calcarenites with occasional Ophiomorpha ( Ophiomorpha-primary lamination ichnofabric) and is similar to many shallow marine facies but they still bear a significant content of pelagic foraminifera. The sedimentary setting bears resemblance with that described for the Pleistocene Monte Torre Paleostrait and the modern Strait of Messina (Italy), where the narrow morphology of the depositional area enhanced tidal currents and allowed for high-energy sandy deposition in relatively deep

  20. Changes in the Style of Neritic Carbonate Production in the Tropics during the End-Ordovician Hirnantian Glaciation : atypical limestone facies from the Anticosti succession, eastern Canada

    NASA Astrophysics Data System (ADS)

    Desrochers, A.; Long, D. G. F.; Ghienne, J.-F.

    2012-04-01

    During the End-Ordovician (Hirnantian) glacial maxima, carbonate platforms in the tropics were exposed extensively and their own diverse endemic faunas, displaced to the continental margins, suffered massive extinction. One of the best exposed and most complete stratigraphic records from a paleotropical area spanning the Ordovician/Silurian (O/S) boundary is on Anticosti Island in eastern Canada. The Anticosti sequence developed within a far-field Taconic foreland basin along the eastern margin of Laurentia under the influence of high tectonic subsidence and sustained carbonate sediment supply. Our biostratigraphically well-controlled δ13C curves and depth sensitive facies analysis allow us to recognize a distinctive Hirnantian stratigraphic architecture and its related sea level curve at the Milankovitch-cyclicity scales. The sudden appearance of abundant oncolites and calcimicrobial-coral reefs marks the Anticosti succession near the O/S boundary at the same time of a major faunal turnover (conodont, chitinozoan, acritarch, shelly faunas). These microbial limestones, a prominent regional marker unit on Anticosti Island known as the Laframboise Member, formed mainly during the peak interval and falling limb of the main Hirnantian positive isotopic carbon excursion. A comparison with the sequence stratigraphy of Morocco suggests that the Laframboise limestones correspond to the Late Ordovician glacial climax (middle to upper Hirnantian in age), characterised by a continental-scale ice sheet. A comparison between the Laframboise succession and other coeval shallow-water tropical successions in Laurentia, Avalonia, Baltica, Siberia and South China shows that the style of carbonate production changed from one derived largely from various carbonate secreting organisms to one dominated by widespread microbial and/or oolitic production. In contrast to the normal marine shelly faunas of pre- and post- extinction Hirnantian strata, shallow water tropical carbonates appear

  1. Tectonic interpretation of the connectivity of a multiscale fracture system in limestone

    NASA Astrophysics Data System (ADS)

    Lei, Qinghua; Wang, Xiaoguang

    2016-02-01

    This paper studies the statistics and tectonism of a multiscale natural fracture system in limestone. The fracture network exhibits a self-similar characteristic with a correlation between its power law length exponent a and fractal dimension D, i.e., a ≈ D + 1. Contradicting the scale-invariant connectivity of idealized self-similar systems, the percolation state of trace patterns mapped at different scales and localities of the study area varies significantly, from well to poorly connected. A tectonic interpretation based on a polyphase fracture network evolution history is proposed to explain this discrepancy. We present data to suggest that the driving force for fracture formation may be dissipated at the end of a tectonic event when the system becomes connected. However, the "effective" connectivity can successively be reduced by cementation of early fractures and reestablished by subsequent cracking, rendering a variable "apparent" connectivity that can be significantly above the percolation threshold.

  2. New Ediacara fossils preserved in marine limestone and their ecological implications

    PubMed Central

    Chen, Zhe; Zhou, Chuanming; Xiao, Shuhai; Wang, Wei; Guan, Chengguo; Hua, Hong; Yuan, Xunlai

    2014-01-01

    Ediacara fossils are central to our understanding of animal evolution on the eve of the Cambrian explosion, because some of them likely represent stem-group marine animals. However, some of the iconic Ediacara fossils have also been interpreted as terrestrial lichens or microbial colonies. Our ability to test these hypotheses is limited by a taphonomic bias that most Ediacara fossils are preserved in sandstones and siltstones. Here we report several iconic Ediacara fossils and an annulated tubular fossil (reconstructed as an erect epibenthic organism with uniserial arranged modular units), from marine limestone of the 551–541 Ma Dengying Formation in South China. These fossils significantly expand the ecological ranges of several key Ediacara taxa and support that they are marine organisms rather than terrestrial lichens or microbial colonies. Their close association with abundant bilaterian burrows also indicates that they could tolerate and may have survived moderate levels of bioturbation. PMID:24566959

  3. Model predictive control of a wet limestone flue gas desulfurization pilot plant

    SciTech Connect

    Perales, A.L.V.; Ollero, P.; Ortiz, F.J.G.; Gomez-Barea, A.

    2009-06-15

    A model predictive control (MPC) strategy based on a dynamic matrix (DMC) is designed and applied to a wet limestone flue gas desulfurization (WLFGD) pilot plant to evaluate what enhancement in control performance can be achieved with respect to a conventional decentralized feedback control strategy. The results reveal that MPC can significantly improve both reference tracking and disturbance rejection. For disturbance rejection, the main control objective in WLFGD plants, selection of tuning parameters and sample time, is of paramount importance due to the fast effect of the main disturbance (inlet SO{sub 2} load to the absorber) on the most important controlled variable (outlet flue gas SO{sub 2} concentration). The proposed MPC strategy can be easily applied to full-scale WLFGD plants.

  4. Instantaneous stabilization of floating oils by surface application of natural granular materials (beach sand and limestone).

    PubMed

    Boglaienko, Daria; Tansel, Berrin

    2015-02-15

    When granular materials are applied to hydrophobic liquids floating over another liquid (i.e., water), particles form aggregates which can be separated from the floating phase. This concept can be used for controlling mobility of floating oils, especially after oil spills near coastal areas. The objectives of this research were to characterize oil capture efficiency and determine effectiveness of particles for converting the floating phase to a heavier phase for effective separation. Experiments were conducted with South Louisiana crude oil contaminated salt water, limestone and quartz sand. Although the oil removal efficiency increased with the increasing amount of granular material applied, it did not increase linearly. About 50% of the floating oil was removed by aggregates, regardless of the material used, when granular material to floating oil ratio was about 1 g/g. The aggregates separated had higher amounts of oil content when smaller amounts of granular materials were added. PMID:25555617

  5. New Ediacara fossils preserved in marine limestone and their ecological implications.

    PubMed

    Chen, Zhe; Zhou, Chuanming; Xiao, Shuhai; Wang, Wei; Guan, Chengguo; Hua, Hong; Yuan, Xunlai

    2014-01-01

    Ediacara fossils are central to our understanding of animal evolution on the eve of the Cambrian explosion, because some of them likely represent stem-group marine animals. However, some of the iconic Ediacara fossils have also been interpreted as terrestrial lichens or microbial colonies. Our ability to test these hypotheses is limited by a taphonomic bias that most Ediacara fossils are preserved in sandstones and siltstones. Here we report several iconic Ediacara fossils and an annulated tubular fossil (reconstructed as an erect epibenthic organism with uniserial arranged modular units), from marine limestone of the 551-541 Ma Dengying Formation in South China. These fossils significantly expand the ecological ranges of several key Ediacara taxa and support that they are marine organisms rather than terrestrial lichens or microbial colonies. Their close association with abundant bilaterian burrows also indicates that they could tolerate and may have survived moderate levels of bioturbation. PMID:24566959

  6. New Ediacara fossils preserved in marine limestone and their ecological implications

    NASA Astrophysics Data System (ADS)

    Chen, Zhe; Zhou, Chuanming; Xiao, Shuhai; Wang, Wei; Guan, Chengguo; Hua, Hong; Yuan, Xunlai

    2014-02-01

    Ediacara fossils are central to our understanding of animal evolution on the eve of the Cambrian explosion, because some of them likely represent stem-group marine animals. However, some of the iconic Ediacara fossils have also been interpreted as terrestrial lichens or microbial colonies. Our ability to test these hypotheses is limited by a taphonomic bias that most Ediacara fossils are preserved in sandstones and siltstones. Here we report several iconic Ediacara fossils and an annulated tubular fossil (reconstructed as an erect epibenthic organism with uniserial arranged modular units), from marine limestone of the 551-541 Ma Dengying Formation in South China. These fossils significantly expand the ecological ranges of several key Ediacara taxa and support that they are marine organisms rather than terrestrial lichens or microbial colonies. Their close association with abundant bilaterian burrows also indicates that they could tolerate and may have survived moderate levels of bioturbation.

  7. Study to define points of entry for potential contaminants in limestone aquifers. [in Alabama

    NASA Technical Reports Server (NTRS)

    Doyle, F. L.

    1973-01-01

    Visual examinations of both prints and transparencies from ERTS 1 and U-2 aircraft imagery provided a method for discovering possible points of entry of potential contaminants into the limestone aquifer in Madison County, Alabama. Knowledge of the locations at which contaminants could enter the aquifer is an important consideration in water quality management, particularly for regions that depend, at least partially, on ground water for their water supply. ERTS 1 imagery recorded on December 28, 1972 in the Multispectral Scanner-5 (MSS-5) and MSS-7 bands, and a false-color composite of the MSS-4 (green), MSS-5 (red), and MSS-7 (near infrared) bands were the principal materials used, along with thermography recorded by an RS-7 infrared scanner onboard a U-2 aircraft. The results of the study are discussed in detail, providing information on prominent lineations and major fracture trends which are related to aquifer contamination. Maps depicting the observations are also presented.

  8. Minimum Temperatures, Diurnal Temperature Ranges and Temperature Inversions in Limestone Sinkholes of Different Sizes and Shapes

    SciTech Connect

    Whiteman, Charles D.; Haiden, Thomas S.; Pospichal, Bernhard; Eisenbach, Stefan; Steinacker, Reinhold

    2004-08-01

    Air temperature data from five enclosed limestone sinkholes of various sizes and shapes on the 1300 m MSL Duerrenstein Plateau near Lunz, Austria have been analyzed to determine the effect of sinkhole geometry on temperature minima, diurnal temperature ranges, temperature inversion strengths and vertical temperature gradients. Data were analyzed for a non-snow-covered October night and for a snow-covered December night when the temperature fell as low as -28.5°C. Surprisingly, temperatures were similar in two sinkholes with very different drainage areas and depths. A three-layer model was used to show that the sky-view factor is the most important topographic parameter controlling cooling for basins in this size range and that the cooling slows when net longwave radiation at the floor of the sinkhole is nearly balanced by the ground heat flux.

  9. Laboratory Investigations in Support of Dioxide-Limestone Sequestration in the Ocean

    SciTech Connect

    Dan Golomb; Eugene Barry; David Ryan; Stephen Pennell; Carl Lawton; Peter Swett; Devinder Arora; John Hannon; Michael Woods; Huishan Duan; Tom Lawlor

    2008-09-30

    Research under this Project has proven that liquid carbon dioxide can be emulsified in water by using very fine particles as emulsion stabilizers. Hydrophilic particles stabilize a CO{sub 2}-in-H{sub 2}O (C/W) emulsion; hydrophobic particles stabilize a H{sub 2}O-in-CO{sub 2} (W/C) emulsion. The C/W emulsion consists of tiny CO{sub 2} droplets coated with hydrophilic particles dispersed in water. The W/C emulsion consists of tiny H{sub 2}O droplets coated with hydrophobic particles dispersed in liquid carbon dioxide. The coated droplets are called globules. The emulsions could be used for deep ocean sequestration of CO{sub 2}. Liquid CO{sub 2} is sparsely soluble in water, and is less dense than seawater. If neat, liquid CO{sub 2} were injected in the deep ocean, it is likely that the dispersed CO{sub 2} droplets would buoy upward and flash into vapor before the droplets dissolve in seawater. The resulting vapor bubbles would re-emerge into the atmosphere. On the other hand, the emulsion is denser than seawater, hence the emulsion plume would sink toward greater depth from the injection point. For ocean sequestration a C/W emulsion appears to be most practical using limestone (CaCO{sub 3}) particles of a few to ten ?m diameter as stabilizing agents. A mix of one volume of liquid CO{sub 2} with two volumes of H{sub 2}O, plus 0.5 weight of pulverized limestone per weight of liquid CO{sub 2} forms a stable emulsion with density 1087 kg m{sup -3}. Ambient seawater at 500 m depth has a density of approximately 1026 kg m{sup -3}, so the emulsion plume would sink by gravity while entraining ambient seawater till density equilibrium is reached. Limestone is abundant world-wide, and is relatively cheap. Furthermore, upon disintegration of the emulsion the CaCO{sub 3} particles would partially buffer the carbonic acid that forms when CO{sub 2} dissolves in seawater, alleviating some of the concerns of discharging CO{sub 2} in the deep ocean. Laboratory experiments showed

  10. Experimental Study on the Thermal Damage Characteristics of Limestone and Underlying Mechanism

    NASA Astrophysics Data System (ADS)

    Zhang, Weiqiang; Sun, Qiang; Hao, Shuqing; Wang, Bo

    2016-08-01

    This work discusses an experimental investigation on the thermal damage characteristics of limestone and underlying mechanism. Cylindrical rock samples were heated to a specific temperature level of 25, 100, 200, 300, 400, 500, 600, 700, 800, and 900 °C. Then the thermal damage evolution equation was established based on the experimental results and the characteristics of thermal damage were analyzed. Last, possible mechanisms for the observed thermo-physical and mechanical response are discussed. The results show that with the increase of temperature in the tested range of temperature, the P-wave velocity, peak compressive strength and elastic modulus decrease, but the peak strain increases; the damage factors increase faster in 200-600 °C; the development of high-temperature-induced cracks conforms to the dislocation theory; the decomposition of magnesium carbonate and dolomite is the main reaction in the tested temperature range.

  11. Limestone and chert in tectonic blocks from the Esk Head subterrane, South Island, New Zealand

    USGS Publications Warehouse

    Silberling, Norman J.; Nichols, K.M.; Bradshaw, J.D.; Blome, C.D.

    1988-01-01

    The Esk Head subterrane is a continuous belt, generally 10-20 km wide, of tectonic melange and broken formation on the South Island of New Zealand. This subterrane separates older and younger parts of the Torlesse terrane which is an extensive accretionary prism composed mostly of quartzo-feldspathic, submarine-fan deposits ranging from Permian to Early Cretaceous in age. The Esk Head subterrane of the Torlesse is especially informative because it includes within it conspicuous tectonic blocks of submarine basalt and a variety of basalt-associated seamount and sea-floor limestones and cherty rocks thought to be representative of the subducted plate. Paleogeographic inferences drawn from megafossils, bioclasts, and radiolarians, as well as from carbonate cements, indicate deposition of the oceanic sedimentary rocks at paleolatitudes somewhat lower than that of the New Zealand part of the Gondwana margin, but higher than paleoequatorial latitudes. -Authors

  12. Er:YAG Laser Applications on Marble and Limestone Sculptures with Polychrome and Patina Surfaces

    NASA Astrophysics Data System (ADS)

    deCruz, A.; Wolbarsht, M. L.; Palmer, R. A.; Pierce, S. E.; Adamkiewicz, E.

    The Er:YAG laser (2.94 µm) has been used safely and effectively to ablate contaminants from polychrome surfaces of marble and limestone sculptures. The pieces studied were 13th, 14th and 15th century polychromes and a patina surface of a Roman marble sculpture from the 2nd Century AD. The surface encrustations removed included calcite, gypsum, whewellite, soluble salts, atmospheric deposits, organic films, lichen and other fungal growths that cover the sculptures. The laser removal of organic deposits with the Er:YAG laser was especially effective. A microscopic study of the polychrome surfaces before and after removal of the encrustations showed preservation of the polychrome pigments. Infrared absorption and x-ray fluorescence spectral analyses of the ablated materials and of the surfaces before and after laser ablation were used for evaluation of the mechanism of the laser action and for comparison of the results of Er:YAG laser treatment with traditional conservation methods.

  13. SEISMIC-REFLECTION STUDIES OF SINKHOLES AND LIMESTONE DISSOLUTION FEATURES ON THE NORTHEASTERN FLORIDA SHELF.

    USGS Publications Warehouse

    Popenoe, Peter; Kohout, F.A.; Manheim, F. T.

    1984-01-01

    High-resolution seismic-reflection profiles show that the shelf off northern Florida is underlain by solution deformed limestone of Oligocene, Eocene, Paleocene and late Cretaceous age. Dissolution and collapse features are widely scattered. They are expressed in three general forms: as sinkholes that presently breach the sea floor, such as Red Snapper Sink and the Crescent Beach submarine spring; as sinkholes that have breached the seafloor in the past but are now filled with shelf sands; and as dissolution collapse structures that originate deep within the section and have caused buckling and folding of overlying Eocene, Oligocene, and to a lesser extent, Neogene strata. Although deformation caused by solution and collapse can be shown to be a continuous process, the major episode of karstification occurred in the late Oligocene and early Miocene when the shelf was exposed to subaerial conditions.

  14. A biodetrital coral mound complex: Key to early diagenetic processes in the mississippian bangor limestone

    USGS Publications Warehouse

    Haywick, D.W.; Kopaska-Merkel, D. C.; Bersch, M.G.

    2009-01-01

    The Bangor Limestone is a Mississippian (Chesterian) shallow marine carbonate formation exposed over a large portion of the Interior Low Plateaus province of northern Alabama. It is dominated by oolitic grainstone and skeletal wackestone and packstone, but in one outcrop near Moulton, Alabama, the Bangor contains a five m thick, 25 m wide, oolitebiodetrital moundtidal flat succession. This sequence is interpreted as a 4th order sea level cycle. Four petrofacies (oolite, mound, skeletal and mudstone/dolomicrite) and four diagenetic phases (iron oxide, fibrous calcite cement, calcite spar cement and dolomite) are distinguished at the study site. Iron oxide, a minor component, stained and/or coated some ooids, intraclasts and skeletal components in the oolite petrofacies. Many of the allochems were stained prior to secondary cortical growth suggesting a short period of subaerial exposure during oolite sedimentation. The oolite petrofacies also contains minor amounts of fibrous calcite cement, a first generation marine cement, and rare infiltrated micrite that might represent a second phase of marine cement, or a first phase of meteoric cement (i.e., "vadose silt") (Dunham 1969). Intergranular pore space in all four petrofacies is filled with up to three phases of meteoric calcite spar cement. The most complete record of meteoric cementation is preserved within coralline void spaces in the mound petrofacies and indicates precipitation in the following order: (1) non-ferroan scalenohedral spar, (2) ferroan drusy spar (0.1-0.4 wt% Fe2+) and (3) non-ferroan drusy spar. The first scalenohedral phase of meteoric cement is distributed throughout the oolite and mound petrofacies. The ferroan phase of meteoric calcite is a void-filling cement that is abundant in the mound petrofacies and less common in the skeletal and mudstone/dolomicrite petrofacies. Non-ferroan drusy calcite is pervasive throughout the Bangor Limestone at the Moulton study site. Growth of the fourth

  15. Principal Slip Zones in Limestone: Natural and Experimental Examples of `Clast-Cortex Grains' and Implications for the Seismic Cycle

    NASA Astrophysics Data System (ADS)

    Smith, S. A.; Billi, A.; di Toro, G.; Niemeijer, A. R.

    2010-12-01

    Many earthquakes in central Italy (e.g L’Aquila Mw 6.3, 6 April 2009), and in other areas worldwide, nucleate within and rupture through limestones. During individual earthquakes a majority of fault displacement is accommodated by thin principal slip zones (PSZs). At present, however, there are no reliable microstructural or geochemical indicators of seismic slip in carbonate rocks. We present detailed field and microstructural observations of the PSZs of seismically active normal faults that cut limestones in central Italy, and compare these PSZs to experiments on layers of simulated calcite gouge using a recently-installed high velocity rotary shear apparatus at INGV, Rome. Geological constraints indicate that the natural PSZs are exhumed from <3km depth, where ambient temperatures are <100°C. SEM and XRD observations suggest that the PSZs are composed of c. 100% calcite. The PSZs contain a 2-10mm thick, texturally-distinct ultracataclasite layer immediately adjacent to the slip surface. The ultracataclasite is itself internally zoned; 200-300μm thick ultracataclastic sub-layers record extreme localization of slip, and some of the sub-layers contain microstructural evidence for fluidization. 100-200μm thick, syn-tectonic calcite veins suggest fluid involvement in faulting. Peculiar rounded grains up to 3mm in diameter consisting of a central (often angular) clast wrapped by a laminated outer cortex of ultra-fine grained calcite are found in the ultracataclasite. The cortex can display concentric or lensoid internal laminations and appears to have developed by progressive accretion of matrix material. These ‘clast-cortex grains’ closely resemble: 1) accretionary lapilli in pyroclastic deposits; 2) ‘armoured’ grains found in the basal detachments of mega-landslides, and; 3) ‘clay-clast aggregates’ produced in saturated high-velocity friction experiments and found in some natural clay-bearing faults. We suggest that localized fluidization of

  16. Isotope tools to support conceptual model building of the Carboniferous limestone aquifer of Northern France and Belgium

    NASA Astrophysics Data System (ADS)

    Gourcy, L.; Castres de Paulet, F.; Rorive, A.; Bastien, J.

    2012-04-01

    Since the beginning of the 20th century, the Carboniferous aquifer was known as a high potential limestone aquifer. Groundwater has been exploited for decades to provide drinkable water and supply heavy factories in north of France and Belgium. Over-pumped during the last century, the Carboniferous aquifer has seen its water level dramatically decreased between Lille (Fr), Mouscron and Tournai (Be). Since the end of industrial period and some agreements to reduce pumpings, groundwater consumption has declined and water table is now stabilized and slowly coming back to a more "natural" level in some areas. In order to sustainably manage this aquifer, French and Belgian environmental agencies and local authorities underlined the need of a better hydrogeological knowledge. Within the framework of the "Scaldwin" project (launched in 2008), a hydrogeological model will be built. To reach these objectives, existing data were compiled, updated and treated. Moreover, new data were collected since 2009: 11 boreholes were drilled, 2 piezometrical maps were drawn and 2 field sampling campaigns were carried out in March and November 2011 to collect groundwater for further analyses. As a first step, the conceptual hydrogeological map was reviewed considering new knowledge of the geometry and water levels of this aquifer. Then, the hydrogeochemical study was undertaken in order to dispel doubts on some specific aspects such as: relationships between the deep (carbonated Carboniferous) and the surface (chalky Cretaceous) aquifers, delineation of the southern Carboniferous aquifer limit, mechanisms of sulphate enrichment… Major and trace elements, dissolved gases (CFC-11, CFC-12, CFC-113, SF6) and various isotopes (δ2H, δ18O, δ11B, δ34S, δ18O-SO4, δ13C, 14C) were analysed in water sampled from 36 wells exploiting the Carboniferous limestones (16 in the French part and 20 in Belgium) and 4 waters from the chalk aquifer. Cation exchange process is playing an important role

  17. Influence of superplasticizers on the rheology and stability of limestone and cement pastes

    SciTech Connect

    Mikanovic, Nikola Jolicoeur, Carmel

    2008-07-15

    The influence of superplasticizers on the rheological properties and dynamic stability of cement and reference limestone pastes were examined at room temperature. The pastes were initially formulated to exhibit nearly identical rheological parameters and bleeding-segregation characteristics, with w/c = 0.50 for the limestone and 0.55 for the cement. The former was examined at equilibrium pH {approx} 10 and at pH 12.5 following addition of Ca(OH){sub 2} to allow distinction of effects related to high pH and Ca{sup +2} from those related to cement hydration reactions. Both polynaphthalene- (PNS) and polyacrylate-type (PC) superplasticizers were investigated, adjusting the dosages to cover the same range of paste fluidity. Superplasticizer-particle interactions were monitored through binding isotherms and zeta potential measurements. The rheology of the pastes was evaluated through the mini-slump test and dynamic viscosity measurements which yielded key rheological parameters: yield stress, elastic and loss moduli (G' and G'') and zero-shear viscosity ({eta}{sub 0}). The paste stability was monitored as function of time, i.e. migration of solids and liquid phase measured in-situ and in 'real time', through surface bleeding measurements and from a multipoint conductivity method. The results provide new insight on the relative modes of action of PNS- and PC-type superplasticizers as dispersants. Also, the combined rheology and stability data allow an improved description of the processes responsible for bleeding and segregation in cementitious and reference systems.

  18. Mixed siliciclastic and carbonate sedimentation within Spar Mountain Member of Ste. Genevieve Limestone, Hamilton County, Illinois

    SciTech Connect

    Roberts, M.J.; Pryor, W.A.

    1985-02-01

    The Spar Mountain Member of the Ste. Genevieve Limestone (middle Mississippian) in Hamilton County, Illinois, consists of 40-60 ft (12-18 m) of interbedded limestones, shales, and sandstones. Five cores and 1400 electric logs were used to delineate two shallowing-upward carbonate cycles and 2 major clastic pulses within the Spar Mountain. Eight lithofacies representing 6 depositional environments were identified. They are: (A) echinoderm-brachiopod dolostone to packstone (outer ramp), (B) ooid-peloidal grainstone (intermediate ramp), (C) skeletal grainstone (intermediate ramp), (D) ooid-molluscan-intraclastic wackestone to grainstone (inner ramp), (E) pelletal-skeletal wackestone (inner ramp), (F) quartzarenite (channelized nearshore), (G) quartz-sublithic arenite to wacke (delta platform), and (H) quartz mudstone (prodelta, delta platform). Deposition occurred on a southwest-dipping carbonate ramp, with siliciclastic sediments originating from the northeast. The sequence of facies and their inferred depositional environments record 2 major progradational episodes. Oolitic facies are interpreted to be of tidal-bar belt origin and quartzarenite facies are interpreted to be of delta-distributary channel origin. Their distribution is partially controlled by antecedent and syndepositional topography. Many of these paleotopographic highes are positive features today and yield pinch-out stratigraphic relationships. Paleogeographic reconstructions demonstrate that the primary control on facies distribution was the position of the delta proper along strike. However, depositional topography also influenced sedimentation, particularly in the sand-sized fraction. Using this concept, better prediction of underlying porous buildups (ooid shoals) is possible if thickness of the overlying siliciclastic is known. Within buildups, a complex diagenetic history complicates the distribution of porosity.

  19. Biotic Composition In Transgressive Levels Of Pennsylvanian Cyclothems: Bachende Limestone, Cantabrian Zone, Spain

    NASA Astrophysics Data System (ADS)

    Corrochano, D.; Barba, P.

    2009-12-01

    Distribution of biotic communities in eustatic cyclothems can be used as an indicator of relative sea level changes. Photic zone and wave base are controlled by glacio-eustatic fluctuations and have direct implications in biota distribution. Our study consists of quantitative and qualitative analysis of skeletal and nonskeletal grains in cyclothems from Bachende Limestone (Middle Pennsylvanian). Bachende Limestone was deposited in a mixed siliciclastic-carbonate ramp located in the distal parts of a foreland basin, developed during Pennsylvanian times in the Cantabrian Zone, Spain. This stratigraphic unit includes several high frequency transgressive-regressive sequences (cyclothems). The lower part of the cycles is formed by carbonates corresponding to the transgressive system track, while the upper part includes siliciclastics that represents the progradation of deltaic bodies during regression. Microfacies analysis shows two different biotic communities related with changes of base level. Early transgressive system track, is dominated by ooids, quartz grains, fusulinids, calcisphers and photozoan organisms, like calcareous algae Anthracoporella, Beresella and Archaelythophyllum. The lack of siliciclastic input during transgressions favoured the photosynthetic activity. Late transgressive assemblage is characterized by heterozoan association (red algae, bryozoans, brachiopods, rugose solitary corals and crinoids), the abundance of the foraminifer Ozawainella and the presence of pyrite. These sediments are related to deep subtidal environments and they are followed by maximum flooding interval (drowning surface), formed by dark shales with crinoids and brachiopods. Changes in paleodepth and in paleoceanographic conditions, including sediment influx, nutrients and temperature, strongly influence the biotic distribution in the cyclothem. Waxing and waning of Gondwana continental ice-sheets seems to be the most important factor controlling these changes.

  20. Physical and microstructural aspects of sulfate attack on ordinary and limestone blended Portland cements

    SciTech Connect

    Schmidt, Thomas; Lothenbach, Barbara; Romer, Michael; Neuenschwander, Juerg; Scrivener, Karen

    2009-12-15

    The consequences of external sulfate attack were investigated by traditional test methods, i.e. length and mass change, as well as by a newly developed, surface sensitive ultrasonic method, using Leaky Rayleigh waves (1 MHz). The macroscopic changes are discussed and compared with thermodynamic calculations and microstructural findings (SEM/EDS). The results show that the main impact of limestone additions on resistance to sulfate degradation are physical - i.e. addition of a few percent in Portland cement reduces the porosity and increases the resistance of Portland cement systems to sulfate; but higher addition of 25% increase porosity and lower resistance to sulfate. The kinetics of degradation were dramatically affected by the solution concentration (4 or 44 g Na{sub 2}SO{sub 4}/l) and the higher concentration also resulted in the formation of gypsum, which did not occur at the low concentration. However the pattern of cracking was similar in both cases and it appears that gypsum precipitates opportunistically in pre-formed cracks so it is not considered as making a significant contribution to the degradation. At 8 deg. C limited formation of thaumasite occurred in the surface region of the samples made from cement with limestone additions. This thaumasite formation led to loss of cohesion of the paste and loss of material from the surface of the samples. However thaumasite formation was always preceded by expansion and cracking of the samples due to ettringite formation and given the very slow kinetics of thaumasite formation it was probably facilitated by the opening up of the structure due to ettringite induced cracking. The expansion of the samples showed a steady stage, followed by a rapidly accelerating stage, with destruction of the samples. The onset of the rapidly accelerating stage occurred when the thickness of the cracked surface layer reached about 1-1.5 mm-10-15% of the total specimen thickness (10 mm).

  1. Stratigraphic and facies analysis of Ste. Genevieve Limestone, Putnam County, Indiana

    SciTech Connect

    Stevenson, G.M.

    1987-05-01

    The Ste. Genevieve Limestone (Mississippian) in Putnam County, Indiana, was deposited on a southwestward-sloping ramp in the northeastern portion of the Illinois basin. This portion of the Ste. Genevieve Limestone is divided into three members which, in ascending order, are the Fredonia, the Spar Mountain, and the Levias. The Fredonia Member appears to be homogeneous biomicrite on out-crop, but petrographic analysis reveals mottling and distinguishable pellets and is classified as pelbiosparite. Storm deposits are observed and typically are composed of fossil hash zones (biopelsparite) overlain by calcitic shale layers. Bioclasts consist of stenohaline forms with foraminifera, echinoderms, and bryozoans predominant. The gray-green shale layers represent punctuated terrigenous influx in this shallow restricted shelf. The Spar Mountain Member is commonly cross-bedded calcarenite but commonly lacks the quartz and is oolitic-pelbiosparite. The dominant particle types are quartz-centered ooids, peloids, and echinoderm fragments. Relatively high energy conditions and herringbone-cross-beds suggest deposition of a shoal with tidal current influence. The Levias Member is thin-bedded biopelsparite which represents shallow shelf deposition. The Bryantsville Breccia Bed varies in thickness across the study area and marks the top of the Levias Member. Oolitic-biopelsparite centimeter-sized clasts are contained in a matrix of similar material, suggesting an intraformational mode of origin, possibly a collapse breccia. Two incomplete shoaling-upward cycles are present in this Ste. Genevieve sequence. The lower portion of each cycle is pelbiosparite/biopelsparite overlain by oolitic-pelbiosparite and/or calcarenite.

  2. Bivalves and gastropods from the middle Campanian Anacacho limestone, South Central Texas

    USGS Publications Warehouse

    Elder, W.P.

    1996-01-01

    The Anacacho Limestone was deposited during the Campanian and represents two depositional intervals, one of early Campanian and one of middle Campanian age. These two intervals correspond to periods of major eustatic sea level rise. This study focuses on the molluscan paleontology of the middle Campanian interval in the eastern part of the Anacacho exposure belt in Medina County, Texas. Molluscan assemblages in this area are indicative of inner to mid-shelf environments. No significant reef components are present. These eastern Anacacho deposits are interpreted to represent more offshore, deeper water environments than those to the southwest, where reef and lagoonal deposits have been reported. Analysis of the macrofossil components from these eastern localities has expanded the number of invertebrate species known from the Anacacho Limestone by nearly three-fold. This increase in diversity, based on a small amount of new work, suggests that many more taxa are yet to be identified, particularly in the western part of the exposure belt in Uvalde and Kinney Counties. This paper documents the bivalve and gastropod fauna, discussing and illustrating 24 bivalve taxa and 11 gastropod species. Two new bivalve species are named, Panopea anacachoensis new species and Spondylus siccus new species, and two potentially new gastropod species are identified but not named herein due to inadequate material. This paper expands the distribution of many eastern Gulf Coast and Atlantic Coast taxa westward into Texas and shows strong ties between the Anacacho fauna and that of the Campanian Tar Heel and Bladen Formations of the Black Creek Group in North Carolina. The taxonomic ties between these two areas probably reflect the thorough documentation of the North Carolina fauna, which is the best documented Campanian bivalve fauna in the Gulf or Atlantic Coast regions.

  3. Vertical distribution of soil organic carbon in limestone Mediterranean mountains areas, southern Spain

    NASA Astrophysics Data System (ADS)

    Gil, Juan; Jordan, Antonio; Martínez-Zavala, Lorena; Parras-Alcántara, Luis; Lozano-García, Beatriz

    2015-04-01

    Normally, soil organic carbon (SOC) investigations are related to fertility and/or soil quality so refer to surface horizon. In other cases, soil control sections or soil horizons are used to study soil carbon pool, especially in forest areas. In this line, in order to provide quantitative data of organic carbon in soils and sediments in relation to depth, the organic carbon vertical distribution was studied in selected areas of southern Spain. Significant variations in depth of organic carbon may be related with different vegetation and/or land use changes, so it can be used to select sampling points for studying these changes through pollen analysis. For this study, ten sinkholes in hard limestone Mediterranean mountains areas of southern Spain have been selected following scientific interest criteria and/or minimal human influence. Soil and sediment samples extraction was carried out using tensile steel drills up to four meters in deep driven by an electric striking hammer. Once extracted the soil columns, soil control sections are taken every 5 cm, obtaining 470 samples in the ten sinkholes selected and making four replications for each soil control section. The soil and sediments exploration in different sinkholes highlights the karst heterogeneity formations, especially in terms of its depth. Thus, it was possible to take samples of varying depth, ranging between 1 and 5 m, being the limiting factor the hard pan forming which can be soil nature (petrocalcic horizon) or lithological nature (hard limestone). SOC in every sampling point varied between 2.5 and 16.7 g kg-1. In general, SOC concentrations decreases progressively in depth, although in some sampling point 10 g kg-1 were obtained at 200 cm in depths. On the other hand, it had been observed significant increases at 100 cm in deep, sometimes repeating at high deep, which could be related to ancient sedimentary past or with edaphogenic processes past. Definitely more comprehensive studies could shed new

  4. Deep-to-shallow carbonate ramp transition in Viola Limestone (Ordovician), southwest Arbuckle Mountains, Oklahoma

    SciTech Connect

    Glavin, P.K.

    1983-03-01

    The Viola Limestone (Middle and Upper Ordovician) of the southwest Arbuckle Mountains was deposited on a carbonate ramp within the southern Oklahoma Aulacogen. Depositional environments include (1) anaerobic, deep-ramp setting represented by microfacies RL, CH, CGL, and A, (2) dysaerobic, mid-ramp setting represented by microfacies B, and (3) aerobic, shallow-ramp setting represented by microfacies C and D. Deposition in the deep- and mid-ramp environments was dominated by bottom-hugging currents produced by off-platform flow of denser waters. Primary sedimentary structures include millimeter-size laminations, starved ripples, and concave-up and inclined erosional surfaces. Shelly benthic fauna are rare in A and B; trace fossils are common only in B. Deposits associated with the line-source gully, microfacies RL, CH, and CGL, are laterally confined; they have been observed only in the southwest Arbuckle Mountains. Primary sedimentary structures present in RL include wavy and ripple-cross laminae. Microfacies CH, contained within RL and interpreted as a submarine channel deposit, is present only at one locality. Primary sedimentary structures present in CH include an erosional base and several internal erosional surfaces, lateral accretionary sets, and imbricated, locally derived intraclasts. High total organic carbon (TOC) values have been reported for the lower Viola. TOC values of 1% have been reported from microfacies A, and TOC values of 5% have been reported from microfacies RL. These high values suggest that A and RL may act as hydrocarbon source rocks. Recognition of these microfacies in the subsurface will contribute to our knowledge of the Viola Limestone as an exploration target.

  5. Introducing dolomite seams: hybrid compaction-dissolution bands in dolomitic limestones

    NASA Astrophysics Data System (ADS)

    Tavani, Stefano; Vitale, Stefano; Grifa, Celestino; Iannace, Alessandro; Parente, Mariano; Mazzoli, Stefano

    2016-04-01

    Anastomosing dolomite seams occur at different stratigraphic levels of a clay-poor Mesozoic carbonate platform succession of the Apennines. Millimeter-thick seams, roughly parallel to bedding, are composed of a high concentration of dolomite crystals compared to the hosting dolomitic limestone micrite. Rare calcite veins emanating from the seams are observed in thin-section, while m-thick micro-stylolites frequently occur within the seams. Veins and micro-stylolites are perpendicular and parallel to the dolomite seams, respectively. Scanning electron microscope images and energy dispersive x-ray spectroscopy analysis document crushing and fragmentation of dolomite crystals, and accumulation of non-carbonate insoluble material along stylolites and around dolomite crystals of the seams. All these features suggest that the described seams are hybrid structures between pressure dissolution seams and compaction bands, and formed parallel to bedding during sedimentary burial. The dolomite crystals scattered in the micritic matrix represent the main body of the insoluble residue produced by the progressive dissolution of calcite. As calcite dissolution proceeds, the concentration of dolomite crystals increases, eventually resulting in a dolomite seam in which locally a dolomite crystal-supported texture is attained. At this stage, the dolomite crystals within the seam start to collide, crush and fragment, so that the dolomite seam behaves like a compaction band for high dolomite crystals concentrations. This new type of compaction structure is likely to be widespread in clay-poor dolomitic limestones, where it may have a significant role in controlling syn-burial porosity evolution and post-dolomitization calcite to dolomite ratio decrease.

  6. Local facies variability in the Mission Canyon Limestone, west flank, Bighorn Mountains, Wyoming

    SciTech Connect

    Vice, M.A.; Utgaard, J.E. )

    1991-06-01

    Comparison of two sections of the Mission Canyon Limestone (Madison Group, Mississippian) located approximately one-half mile (850-900 m) apart and at opposite ends of a single flatiron reveals significant lateral facies variations. The southern section, Dry Fork of Horse Creek, is 83 ft (25 m) thicker than the northern Horse Creek section. This substantial difference in thickness cannot be attributed solely to pre-Amsden erosion and solution collapse: all three members are thicker and more variable lithologically at Dry Fork. The lower (Big Goose) member is composed mostly of cherty, dolomitized lime mudstones at both locations. At Dry Fork, it contains numerous skeletal facies, particularly in the upper part. Skeletal facies are insignificant at Horse Creek. The two upper members are composed mainly of skeletal limestones; however, grain-supported facies are much more abundant at Dry Fork. Dolomitized mudstones predominate in the major breccia at the base of the middle (Little Tongue) member at Horse Creek, and lime mudstones predominate at Dry Fork. Additional breccias occur at other horizons: five at Dry Fork, four at Horse Creek. Conclusions drawn from the initial study of these two outcrops follow: (1) the local extent of grainstones and packstones suggests that the shoals were geographically less extensive than the subtidal muddy bottoms and intertidal-supratidal mud flats. (2) The limited geographic and vertical extent of some breccias suggests evaporiate deposition in localized muddy facies. (3) Conditions favoring dolomitization were limited mainly to the mudstones and occurred during and shortly after deposition of the Big Goose Member.

  7. Experimental characterization of porosity structure and transport properties changes in limestone undergoing different dissolution regimes

    NASA Astrophysics Data System (ADS)

    Gouze, P.; Luquot, L.; Rodriguez, O.; Mangane, P. O.

    2013-12-01

    Limestone rock dissolution induces geometrical parameters changes such as porosity, pore size distribution (connectivity), or tortuosity which may consequently modify transport properties (permeability, diffusion coefficient). Characterizing these changes is essential for modeling flow and CO2 transport during and after the CO2 injection. Indeed, these changes can affect the storage capacity and the injectivity of the formation. We report experimental results from CO2 rich-brine injection into limestone core samples of 9 mm diameter, 18 mm length. Experiments were performed at in situ conditions (T = 100°C and P = 12 MPa) and with four different CO2 partial pressures (PCO2) varying from 0.034 to 3.4 MPa. X-ray microtomography (XMT) images are used to characterize, from pore scale to Darcy scale, the changes in the structural properties induced by the percolation of the CO2-rich brine. Coupling imaging techniques with sample scale measurements of the time-resolved permeability and chemical fluxes, allows determining the change in the chemical and physical parameters of the sample induced by the dissolution processes. The experiment results show localized dissolution features (wormhole formation) for the highest PCO2, whereas homogeneous dissolution is observed for the lower. The higher the CO2 concentration is the more ramifications at macro scale have growth into the sample and consequently the higher the permeability has increased. During low CO2 concentration injections, the dissolution processes may include transport of fine particles, which locally clog the porous space. This process is controlled by the differential dissolution rate of the calcite cement and calcite grains. This mechanism induces a decrease of permeability (while porosity increases) that may alter the CO2 injectivity.

  8. Laboratory evaluation of limestone and lime neutralization of acidic uranium mill tailings solution. Progress report

    SciTech Connect

    Opitz, B.E.; Dodson, M.E.; Serne, R.J.

    1984-02-01

    Experiments were conducted to evaluate a two-step neutralization scheme for treatment of acidic uranium mill tailings solutions. Tailings solutions from the Lucky Mc Mill and Exxon Highland Mill, both in Wyoming, were neutralized with limestone, CaCO/sub 3/, to an intermediate pH of 4.0 or 5.0, followed by lime, Ca(OH)/sub 2/, neutralization to pH 7.3. The combination limestone/lime treatment methods, CaCO/sub 3/ neutralization to pH 4 followed by neutralization with Ca(OH)/sub 2/ to pH 7.3 resulted in the highest quality effluent solution with respect to EPA's water quality guidelines. The combination method is the most cost-effective treatment procedure tested in our studies. Neutralization experiments to evaluate the optimum solution pH for contaminant removal were performed on the same two tailings solutions using only lime Ca(OH)/sub 2/ as the neutralizing agent. The data indicate solution neutralization above pH 7.3 does not significantly increase removal of pH dependent contaminants from solution. Column leaching experiments were performed on the neutralized sludge material (the precipitated solid material which forms as the acidic tailings solutions are neutralized to pH 4 or above). The sludges were contacted with laboratory prepared synthetic ground water until several effluent pore volumes were collected. Effluent solutions were analyzed for macro ions, trace metals and radionuclides in an effort to evaluate the long term effectiveness of attenuating contaminants in sludges formed during solution neutralization. Neutralized sludge leaching experiments indicate that Ca, Na, Mg, Se, Cl, and SO/sub 4/ are the only constituents which show solution concentrations significantly higher than the synthetic ground water in the early pore volumes of long-term leaching studies.

  9. Stable isotope tracing of trout hatchery carbon to sediments and foodwebs of limestone spring creeks.

    PubMed

    Hurd, Todd M; Jesic, Slaven; Jerin, Jessica L; Fuller, Nathan W; Miller, David

    2008-11-01

    Limestone springs support productive ecosystems and fisheries, yet aquaculture may modify or impair these ecosystems. We determined trout hatchery organic contribution to spring creek sediments and foodwebs with natural abundance stable isotope methods. Hatchery feed, waste, and trout were significantly enriched in delta(13)C relative to autotrophs and wild fish. Spring creek sediments were enriched in delta(13)C toward the hatchery endmember relative to reference streams without hatcheries and relative to a larger larger-order, spring-influenced stream. Contribution of hatchery C to spring creek sediments was greatest during March and associated with greatest sediment %C. Contribution of hatchery C to pollution-tolerant isopod diet was 39-51% in a stream receiving limestone spring water via hatchery effluent. Isopods of one spring creek also relied on hatchery-derived C within one month of hatchery closure. Four years later, less pollution pollution-tolerant amphipods dominated and consumed non-vascular over vascular autotrophs (86%). Isopods of a second spring creek with an active hatchery did not appear to be using hatchery matter directly, but were enriched in delta(34)S relative to a spring creek tributary with no hatchery influence. Isopods in both of these streams were relatively enriched in delta(15)N, indicating general nutrient enrichment from surrounding agricultural land use. The contribution of hatchery vs. wild fish in diet of herons and egrets was traced with delta(13)C of guano. These birds were strongly dependent on stocked trout in a spring creek with a recently closed state trout hatchery, and also near another large, state-run hatchery. Heron dependence on hatchery fish in the spring creek decreased with time since hatchery closure. Use of stable isotope natural abundance techniques in karst spring creeks can reveal stream impairment due to aquaculture, specific C sources to bio-indicating consumers, losses of farmed fish to predation, and

  10. A global review on ambient Limestone-Precipitating Springs (LPS): Hydrogeological setting, ecology, and conservation.

    PubMed

    Cantonati, Marco; Segadelli, Stefano; Ogata, Kei; Tran, Ha; Sanders, Diethard; Gerecke, Reinhard; Rott, Eugen; Filippini, Maria; Gargini, Alessandro; Celico, Fulvio

    2016-10-15

    Springs are biodiversity hotspots and unique habitats that are threatened, especially by water overdraft. Here we review knowledge on ambient-temperature (non-geothermal) freshwater springs that achieve sufficient oversaturation for CaCO3 -by physical CO2 degassing and activity of photoautotrophs- to deposit limestone, locally resulting in scenic carbonate structures: Limestone-Precipitating Springs (LPS). The most characteristic organisms in these springs are those that contribute to carbonate precipitation, e.g.: the mosses Palustriella and Eucladium, the crenophilous desmid Oocardium stratum, and cyanobacteria (e.g., Rivularia). These organisms appear to be sensitive to phosphorus pollution. Invertebrate diversity is modest, and highest in pools with an aquatic-terrestrial interface. Internationally, comprehensive legislation for spring protection is still relatively scarce. Where available, it covers all spring types. The situation in Europe is peculiar: the only widespread spring type included in the EU Habitat Directive is LPS, mainly because of landscape aesthetics. To support LPS inventorying and management to meet conservation-legislation requirements we developed a general conceptual model to predict where LPS are more likely to occur. The model is based on the pre-requisites for LPS: an aquifer lithology that enables build-up of high bicarbonate and Ca(2+) to sustain CaCO3 oversaturation after spring emergence, combined with intense groundwater percolation especially along structural discontinuities (e.g., fault zones, joints, schistosity), and a proper hydrogeological structure of the discharging area. We validated this model by means of the LPS information system for the Emilia-Romagna Region (northern Italy). The main threats to LPS are water diversion, nutrient enrichment, and lack of awareness by non-specialized persons and administrators. We discuss an emblematic case study to provide management suggestions. The present review is devoted to LPS but

  11. Diagenesis of silica-rich mound-bedded chalk, the Coniacian Arnager Limestone, Denmark

    NASA Astrophysics Data System (ADS)

    Madsen, H. B.; Stemmerik, L.; Surlyk, F.

    2010-01-01

    The Coniacian Arnager Limestone Formation is exposed on the Danish island of Bornholm in the Baltic Sea. It is composed of mound-bedded siliceous chalk, and X-ray diffraction and scanning electron microscopy indicate a content of 30-70% insoluble minerals, including authigenic opal-CT, quartz, clinoptilolite, feldspars, calcite, dolomite, and barite. Opal-CT and clinoptilolite are the most common and constitute 16-53% and 2-9%, respectively. The content of insoluble minerals varies laterally both within the mounds and in planar beds, and the opal-CT content varies by up to 10% vertically. The mounds consist of two microfacies, spiculitic wackestone and bioturbated spiculitic wackestone, containing 10-22% and 7-12% moulds after spicules, respectively. Subsequent to deposition and shallow burial, dissolution of siliceous sponge spicules increased the silica activity of the pore water and initiated precipitation of opal-CT. The opal-CT formed at temperatures around 17 °C, the precipitation lowered the silica activity and the Si/Al ratio of the pore water, resulting in precipitation of clinoptilolite, feldspar and smectite. Calcite formed synchronously with the latest clinoptilolite. Minor amounts of quartz precipitated in pore water with low silica activity during maximum burial, probably to depths of 200-250 m. The dissolution of sponge spicules and decomposition of the sponge tissue also resulted in the release of Ba 2+, Sr 2+, Mg 2+, Ca 2+ and CO 32-, facilitating precipitation of barite and dolomite. Precipitation of especially opal-CT reduced the porosity to an average of 40% and cemented the limestone. The study highlights the diagenetic pathways of bio-siliceous chalk and the effects on preservation of porosity and permeability.

  12. Assessment of Alaska's North Slope Oil Field Capacity to Sequester CO{sub 2}

    SciTech Connect

    Umekwe, Pascal; Mongrain, Joanna; Ahmadi, Mohabbat; Hanks, Catherine

    2013-03-15

    The capacity of 21 major fields containing more than 95% of the North Slope of Alaska's oil were investigated for CO{sub 2} storage by injecting CO{sub 2} as an enhanced oil recovery (EOR) agent. These fields meet the criteria for the application of miscible and immiscible CO{sub 2}-EOR methods and contain about 40 billion barrels of oil after primary and secondary recovery. Volumetric calculations from this study indicate that these fields have a static storage capacity of 3 billion metric tons of CO{sub 2}, assuming 100% oil recovery, re-pressurizing the fields to pre-fracturing pressure and applying a 50% capacity reduction to compensate for heterogeneity and for water invasion from the underlying aquifer. A ranking produced from this study, mainly controlled by field size and fracture gradient, identifies Prudhoe, Kuparuk, and West Sak as possessing the largest storage capacities under a 20% safety factor on pressures applied during storage to avoid over-pressurization, fracturing, and gas leakage. Simulation studies were conducted using CO{sub 2} Prophet to determine the amount of oil technically recoverable and CO{sub 2} gas storage possible during this process. Fields were categorized as miscible, partially miscible, and immiscible based on the miscibility of CO{sub 2} with their oil. Seven sample fields were selected across these categories for simulation studies comparing pure CO{sub 2} and water-alternating-gas injection. Results showed that the top two fields in each category for recovery and CO{sub 2} storage were Alpine and Point McIntyre (miscible), Prudhoe and Kuparuk (partially miscible), and West Sak and Lisburne (immiscible). The study concludes that 5 billion metric tons of CO{sub 2} can be stored while recovering 14.2 billion barrels of the remaining oil.

  13. The Influence of Sorbent Properties and Reaction Conditions on Attrition of Limestone by Impact Loading in Fluidized Beds

    NASA Astrophysics Data System (ADS)

    Scala, Fabrizio; Salatino, Piero

    The extent of attrition associated with impact loading was studied for five different limestones pre-processed in fluidized bed under different reaction conditions. The experimental procedure was based on the measurement of the amount and the particle size distribution of the debris generated upon impact of sorbent samples against a target at velocities between 10 and 45 m/s. The effect of calcination, sulfation and calcination/re-carbonation on impact damage was assessed. Fragmentation by impact loading of the limestones was significant and increased with the impact velocity. Lime samples displayed the largest propensity to undergo impact damage, followed by sulfated, re-carbonated and raw limestones. Fragmentation of the sulfated samples followed a partem typical of the failure of brittle materials. On the other hand, the behavior of lime samples better conformed to a disintegration failure mode, with extensive generation of very fine fragments. Raw limestone and re-carbonated lime samples followed either of the two patterns depending on the sorbent nature. The extent of particle fragmentation increased after multiple impacts, but the incremental amount of fragments generated upon one impact decreased with the number of successive impacts.

  14. ACID DEPOSITION STRATEGIES, THE LIMB (LIMESTONE INJECTION/MULTISTAGE BURNERS) PROGRAM AND IMPLICATIONS FOR CONTROL TECHNOLOGY REQUIREMENTS

    EPA Science Inventory

    The paper summarizes the various acid deposition bills introduced in the U.S. Congress during the past 2 years and discusses emission sources. A rapidly emerging technology called Limestone Injection/Multistage Burners (LIMB), which has the potential for simultaneous SO2 and NOx ...

  15. Limestone treatment for sulfur dioxide removal. (Latest citations from the EI compendex*plus database). Published Search

    SciTech Connect

    1998-02-01

    The bibliography contains citations concerning the use of limestone for the control of sulfur dioxide emmisions in flue gases. The various designs for flue gas desulfurization are discussed, including dry fluidized beds and wet scrubbers. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  16. Stone-boiling maize with limestone: experimental results and implications for nutrition among SE Utah preceramic groups

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The presence of limestone among midden scatters associated with Grand Gulch phase (A.D. 200 to 400) Basketmaker II period habitation sites (Matson et al. 1988) on Cedar Mesa, southeastern Utah has suggested that these fragments are remnants of stone boiling activities that may have altered nutrition...

  17. LIME/LIMESTONE WET-SCRUBBING TEST RESULTS AT THE EPA ALKALI SCRUBBING TEST FACILITY. CAPSULE REPORT

    EPA Science Inventory

    This Capsule Report describes a program conducted by EPA to test prototype lime and limestone wet-scrubbing systems for removing sulfur dioxide and particulate matter from coal-fired boiler flue gases. The program is being carried out in a test facility which is integrated into t...

  18. Alteration in the Madera Limestone and Sandia Formation from core hole VC-1, Valles caldera, New Mexico

    USGS Publications Warehouse

    Keith, T.E.C.

    1988-01-01

    Core hole VC-1 penetrated the southwestern ring fracture zone of the 1.1 Ma Valles caldera and at a depth of 333 m intersected the top of the Paleozoic section including the Abo Formation, Madera Limestone, and Sandia Formation, reaching a total depth of 856 m. The Paleozoic rocks, which consist of thin-bedded limestone, siltstone, mudstone, sandstone, and local conglomerate, are overlain by volcanic rocks of the caldera moat that are less than 0.6 Ma. Diagenetic and at least three hydrothermal alteration stages were identified in the Madera Limestone and Sandia Formation. Diagenetic clay alteration was pervasive throughout the sedimentary rocks. Volcanic activity at 16.5 Ma and continuing through the formation of the Valles caldera resulted in high thermal gradients, which caused recrystallization of diagenetic clay minerals. Interstratified smectite-illite is the most diagnostic clay mineral throughout the section; structurally, the illite component in the ordered interstratified illite-smectite changes gradationally from 70% at the top of the Madera Limestone to 95% at the base of the section in the Sandia Formation. Pyrite that occurs as small clots and lenses as well as finely disseminated is interpreted as being of diagenetic origin, especially in organic-rich beds. Low permeability of much of the paleozoic section precluded the deposition of hydrothermal minerals except in fractures and intergranular space in some of the more permeable sandstone and brecciated horizons. Three stages of hydrothermal mineral deposition are defined. -from Author

  19. ADIPIC ACID-ENHANCED LIME AND LIMESTONE TESTING AT THE EPA ALKALI SCRUBBING TEST FACILITY. VOLUME 1

    EPA Science Inventory

    The report gives results of an advanced test program on a prototype lime/limestone wet-scrubbing test facility for removing SO2 and particulates from coal-fired boiler flue gases. Major effort during the tests was concentrated on evaluating adipic acid as an additive for enhancin...

  20. ADIPIC ACID-ENHANCED LIME AND LIMESTONE TESTING AT THE EPA ALKALI SCRUBBING TEST FACILITY. VOLUME 2: APPENDICES

    EPA Science Inventory

    The report gives results of an advanced test program on a prototype lime/limestone wet-scrubbing test facility for removing SO2 and particulates from coal-fired boiler flue gases. Major effort during the tests was concentrated on evaluating adipic acid as an additive for enhancin...

  1. Uranium-series dating of lacustrine limestones from pan deposits with final Acheulian assemblage at Rooidam, Kimberley district, South Africa

    USGS Publications Warehouse

    Szabo, B. J.; Butzer, K.W.

    1979-01-01

    Lacustrine limestone samples from sedimentary pan deposits at Rooidam, near Kimberley, South Africa, that contain late Acheulian (Fauresmith) artifacts have been dated by 230Th 234U and 231Pa 235U methods. Results indicate a minimum age of about 200,000 yr B.P. for the terminal Acheulian in the interior of South Africa. ?? 1979.

  2. TiO₂ nanoparticle transport and retention through saturated limestone porous media under various ionic strength conditions.

    PubMed

    Esfandyari Bayat, Ali; Junin, Radzuan; Derahman, Mohd Nawi; Samad, Adlina Abdul

    2015-09-01

    The impact of ionic strength (from 0.003 to 500mM) and salt type (NaCl vs MgCl2) on transport and retention of titanium dioxide (TiO2) nanoparticles (NPs) in saturated limestone porous media was systematically studied. Vertical columns were packed with limestone grains. The NPs were introduced as a pulse suspended in aqueous solutions and breakthrough curves in the column outlet were generated using an ultraviolent-visible spectrometry. Presence of NaCl and MgCl2 in the suspensions were found to have a significant influence on the electrokinetic properties of the NP aggregates and limestone grains. In NaCl and MgCl2 solutions, the deposition rates of the TiO2-NP aggregates were enhanced with the increase in ionic strength, a trend consistent with traditional Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. Furthermore, the NP aggregates retention increased in the porous media with ionic strength. The presence of salts also caused a considerable delay in the NPs breakthrough time. MgCl2 as compared to NaCl was found to be more effective agent for the deposition and retention of TiO2-NPs. The experimental results followed closely the general trends predicted by the filtration and DLVO calculations. Overall, it was found that TiO2-NP mobility in the limestone porous media depends on ionic strength and salt type. PMID:25889359

  3. An investigation into the correlation between different surface area determination techniques applied to various limestone-related compounds

    SciTech Connect

    Potgieter, J.H.; Strydom, C.A.

    1996-11-01

    This communication reports an investigation between various methods used to measure the surface area of ground materials used in the cement industry. From the results it seems possible to make a reasonable estimate of the limestone, lime and gypsum BET surface areas from a Blaine surface area determination.

  4. Viscosity, electrical conductivity, and cesium volatility of ORNL (Oak Ridge National Laboratory) vitrified soils with limestone and sodium additives

    SciTech Connect

    Shade, J.W.; Piepel, G.F.

    1990-05-01

    Engineering- and pilot-scale tests of the in situ vitrification (ISV) process have been conducted for Oak Ridge National Laboratory (ORNL) to successfully demonstrate the feasibility of applying ISV to seepage trenches and pits at ORNL. These sites contain soil that overlies crushed limestone fill; therefore, the ISV process is applied to a soil-limestone mixture. Previous testing indicated that while a good retention level of {sup 137}Cs and {sup 90}Sr was achieved in the melt, it would be desirable to improve {sup 137}Cs retention to 99.99% if possible to minimize activity in the off-gas system. Previous testing was limited to one soil-limestone composition. Both Cs volatility and ISV power requirements are in part dependent on melt temperature and viscosity, which depend on melt composition. The study described in this report determined the effect of varying soil and limestone compositions, as well as the addition of a sodium flux, on melt viscosity, electrical conductivity, and Cs volatility. 10 refs., 15 figs., 9 tabs.

  5. STATUS OF EPA'S (ENVIRONMENTAL PROTECTION AGENCY'S) LIMB (LIMESTONE INJECTION MULTISTAGE BURNER) DEMONSTRATION PROGRAM AT OHIO EDISON'S EDGEWATER UNIT 4

    EPA Science Inventory

    The paper describes and discusses the key design features of the retrofit of EPA's Limestone Injection Multistage Burner (LIMB) system to an operating, wall-fired utility boiler at Ohio Edison's Edgewater Station. It further describes results of the pertinent projects in EPA's LI...

  6. Provenance of Modern Soils and Limestone and Chert Bedrock of Middle Tennessee Assessed Using Detrital Zircon U-Pb Geochronology

    NASA Astrophysics Data System (ADS)

    Ayers, J. C.; Katsiaficas, N. J.; Wang, X.

    2014-12-01

    Relatively thick soils mantle limestone bedrock throughout much of middle TN. Detrital zircon U-Pb geochronology was used to test two hypotheses: 1) That soil formed by accumulation of insoluble residue during chemical weathering of "dirty" limestone bedrock. 2) That an exotic component, perhaps wind-blown loess, was deposited and weathered to form soil. Samples of soil and underlying bedrock were collected from flat surfaces at the tops of cliffs. At Site 1 the Mississippian cherty limestone of the Fort Payne Formation was collected along with the B1 and B2 horizons of the overlying ultisol. At Site 2 a composite sample of A and B horizons of an alfisol and a sample of the underlying Ordovician limestone of the Hermitage Formation were collected. Zircon was recovered from soil and limestone samples, imaged using cathodoluminescence, and analyzed for trace elements and U-Pb isotopes using a 193 nm laser and quadrupole ICP-MS. Discordant analyses were discarded and 206Pb/238U ages are reported. Trace element concentrations and ratios in zircon seem to not be useful as provenance indicators. However, comparison of U-Pb age spectra showed that soils at both sites predominantly formed by weathering of limestone, with a small exotic component. The Hermitage has significant age peaks at ~1330, 1043, 955 and 439 Ma, and its overlying soil has age peaks at 1410, 1235, 1036 and 442 Ma. The age spectra are significantly different (Kolmogorov-Smirnov probability P = 0.01 < 0.05 significance). The Fort Payne has age peaks at ~1253, 967 and 417 Ma, while the B1 has age peaks at 1440, 1182, 1012 and 450 Ma (K-S P = 0.051) and the B2 at 1240, 941, 362, 81 and 33 Ma (K-S P = 0.073). The young ages in B2 require an exotic component that may account for ~25% of the measured ages. The source of the exotic material has not yet been identified, but its zircon age spectrum does not match previously published age spectra for the regional Pleistocene Peoria loess. Bedrock age peaks

  7. Plan of study to define hydrogeologic characteristics of the Madera Limestone in the east mountain area of central New Mexico

    USGS Publications Warehouse

    Rankin, D.R.

    1999-01-01

    The east mountain area of central New Mexico includes the eastern one-third of Bernalillo County and portions of Sandoval, Santa Fe, and Torrance Counties. The area covers about 320 square miles. The Madera Limestone, the principal aquifer in the east mountain area, is the sole source of water for domestic, municipal, industrial, and agricultural uses for many residents. Some water is imported from wells near Edgewood by the Entranosa Water Cooperative, which serves a population of approximately 3,300. The remaining population is served by small water systems that derive supplies locally or by individually owned domestic wells. The population of the east mountain area has increased dramatically over the past 20 years. In 1970, the population of the east mountain area was about 4,000. Demographic projections suggest that approximately 1,000 people per year are moving into the area, and with a growth rate of 3.0 percent the population will be 16,700 in 2000. Consequently, ground-water withdrawals have increased substantially over the past 20 years, and will continue to increase. Little is known about the flow characteristics and hydrogeologic properties of the Madera Limestone. This report describes existing information about the geologic and hydrologic framework and flow characteristics of the Madera Limestone, and presents a plan of study for data-collection activities and interpretive studies that could be conducted to better define the hydrogeologic characteristics of the Madera Limestone. Data-collection activities and interpretive studies related to the hydrogeologic components of the Madera Limestone are prioritized. Activities that are necessary to improve the quantification of a component are prioritized as essential. Activities that could add additional understanding of a component, but would not be necessary to improve the quantification of a component, are prioritized as useful.

  8. Shallow-water marl-limestone alternations in the Late Jurassic of western France: Cycles, storm event deposits or both?

    NASA Astrophysics Data System (ADS)

    Colombié, Claude; Schnyder, Johann; Carcel, Damien

    2012-10-01

    The contribution of event deposits to various basin fills can be very significant, higher than 90% in some cases. Events may lead to the formation of marl-limestone alternations, which can also result from cyclic changes in sea level or climate, for example. The marl-limestone alternations of the Late Jurassic of western France contain abundant coarse-grained accumulations that resemble storm deposits described in other western European successions. The detailed analysis of facies evolution and hierarchical, high-frequency stacking pattern of depositional sequences of the Phare de Chassiron section (Ile d'Oléron, western France) allows the controls on marl-limestone formation to be defined. This section contains nearshore and shallow-marine mud deposits that were exposed to high-energy events. Elementary, small-, and medium-scale depositional sequences are defined. The stacking-pattern and the duration of these sequences suggest an orbital control on sedimentation. Precession (20 ka) cycles notably controlled the formation of elementary sequences that correspond to marl-limestone alternations. The deposition of marly or carbonate mud occurred in this storm-dominated system because of muddy sea beds, the gentle slope of the shelf, and the great amount of particles in suspension, which reduced water energy resulting from storms. Sediment supply was also sufficient to limit bioturbation and favour the preservation of numerous storm deposits. The production of carbonate mud was localised on positive structures and partly controlled by Milankovitch-scale sea-level cycles. Transport by storms of carbonate mud to the adjacent marly depressions during high carbonate production periods led to the formation of calcareous beds. Marl-limestone alternations in the Late Jurassic of western France therefore result from the combined effects of cyclic changes in carbonate production and high-energy, episodic events.

  9. Geologic framework and hydrogeologic features of the Glen Rose Limestone, Camp Bullis Training Site, Bexar County, Texas

    USGS Publications Warehouse

    Clark, Allan K.

    2003-01-01

    The Glen Rose Limestone crops out over most of the Camp Bullis Training Site in northern Bexar County, Texas, where it consists of upper and lower members and composes the upper zone and the upper part of the middle zone of the Trinity aquifer. Uncharacteristically permeable in northern Bexar County, the Glen Rose Limestone can provide avenues for recharge to and potential contamination of the downgradient Edwards aquifer, which occupies the southeastern corner of Camp Bullis. The upper member of the Glen Rose Limestone characteristically is thin-bedded and composed mostly of soft limestone and marl, and the lower Glen Rose typically is composed mostly of relatively massive, fossiliferous limestone. The upper member, about 410 to 450 feet thick at Camp Bullis, was divided in this study into five hydrogeologic subdivisions, A through E (youngest to oldest). The approximately 120-foot-thick Interval A has an abundance of caves, which is indicative of its generally well developed fracture, channel, and cavern porosity that in places provides appreciable permeability. The 120- to 150-foot-thick Interval B is similar to Interval A but with less cave development and considerably less permeability. The 10- to 20-foot-thick Interval C, a layer of partly to mostly dissolved soluble carbonate minerals, is characterized by breccia porosity, boxwork permeability, and collapse structures that typically divert ground water laterally to discharge at land surface. The 135- to 180-foot-thick Interval D generally has low porosity and little permeability with some local exceptions, most notably the caprinid biostrome just below the top of the interval, which appears to be permeable by virtue of excellent moldic, vug, fracture, and cavern porosity. The 10- to 20-foot-thick Interval E, a layer of partly to mostly dissolved evaporites similar to Interval C, has similar hydrogeologic properties and a tendency to divert ground water laterally.

  10. The stratification and cyclicity of the Dachstein Limestone in Lofer, Leogang and Steinernes Meer (Northern Calcareous Alps, Austria)

    NASA Astrophysics Data System (ADS)

    Schwarzacher, W.

    2005-11-01

    The Dachstein Limestone of the Northern Calcareous Alps contains massive limestone beds, capped by dolomitic horizons. Groups of beds form bundles or stratification cycles and spectral analysis gives evidence of at least 3 orders of cycle frequencies. The regularity in the repetition of the limestones and dolomites was first pointed out by Sander (1936) [Sander, B., 1936. Beitrage zur Kenntniss der Anlagerungsgefuege. Mineral. Petrogr. Mitt. 48, 27-139] and the repetition of definite groups by Schwarzacher (1948, 1954) [Schwarzacher, W., 1948. Ueber die sedimentaere Rhytmik des Dachstein Kalkes von Lofer. Verh. Geol. Bundesanst. 1947 (Heft 10-12), 176-188; Schwarzacher, W., 1954. Ueber die Grossrhytmik des Dachstein Kalkes von Lofer. Tschermaks Mineral. Petrogr. Mitt. 4, 44-54]. The facies associated with the change from limestone to dolomite was interpreted by Fischer (1964) [Fischer, A.G., 1964. The Lofer cyclothems of the alpine Triassic. In: Merriam, D.F. (Ed), Symposium on Cyclic Sedimentation. Kansas Geological Survey Bull. 169, 107-146] as an environmental change from lagoonal to peritidal and consequently as evidence of rising and falling sea level. The present paper is based on the study of over 500 aerial photographs from the Loferer and Leoganger Steinberge and also on a detailed section, measured by Paul Enos and E. Samankassou in the Steinernes Meer. It was found that the Dachstein Limestone from Lofer and Leogang comprised about 35 stratification cycles of approximately 20 m thickness. This may correspond to a similar number of cycles in the Steinernes Meer where the spectral analysis gave a cycle thickness of 27 m and 13.6 m. The interpretation of the bundle as being caused by the 100 ka eccentricity cycle is considered tenable.

  11. Depositional and tectonic interpretation of limestone insoluble residues from modern and ancient carbonate rocks, Caribbean and southeastern United States

    SciTech Connect

    Isphording, W.C.; Bundy, M.E.; George, S.M.

    1995-10-01

    Mineral compositions have long been used as indicators of the provenance and tectonic setting of source rocks for sandstones and shales. Extraction of the same information from limestones is less common because of the general paucity of the non-carbonate phase and the greater processing time that is required to concentrate the frequently encountered small quantities of detrital (and authigenic) minerals. The insoluble component, however, contains a great deal of valuable information and should not be ignored. The clays and other insoluble minerals in limestones from southeastern United States and the Caribbean region, for example, clearly reflect the volcanic activity that was associated with formation of the Mid-Atlantic Ridge rift system and the opening of the Atlantic Ocean and Gulf of Mexico. Similarly, major periods of orogeny during the Paleozoic and Mesozoic have left their signature, even in carbonate rocks that originated far from the sites where uplift was taking place. In other cases, the insoluble residue component clearly manifests periods of quiescence in adjacent land areas or testifies to the airborne transport of insoluble components from sources as far distant as the Saharan Desert of Africa. Similarly, insoluble components have convincingly shown that the origin of the extensive bauxite deposits found in Jamaican limestones are the result of alteration of interbedded volcanic ash units and have not resulted from accumulation of the detritus in the limestones. Residue analysis in Gulf Coast limestones can be successfully used for subsurface identification and correlation of carbonate units in the exploration for hydrocarbons, to reconstruct sedimentary environments, to identify missing sections, and to identify paraconformable realtionships between adjacent carbonate units that are otherwise similar in appearance. The latter is especially useful where extensive recrystallization has taken place and fossils have been destroyed.

  12. Dynamic properties of Indiana, Fort Knox and Utah test range limestones and Danby Marble over the stress range 1 to 20 GPa

    SciTech Connect

    Furnish, M.D.

    1994-12-01

    The responses of the following carbonate materials to shock loading and release have been measured: Indiana limestone (18% porosity; saturated and dry), Jeffersonville/Louisville Limestones (Fort Knox limestone) (variable dolomitization, low porosity), Danby Marble (essentially pure calcite; low porosity), and a limestone from the Utah Test and Training Range (low porosity, with 22% silica). Various experimental configurations were used, some optimized to yield detailed waveform information, others to yield a clean combination of Hugoniot states and release paths. All made use of velocity interferometry as a primary diagnostic. The stress range of 0 - 20 GPa was probed (in most cases, emphasizing the stress range 0 -10 GPa). The primary physical processes observed in this stress regime were material strength, porosity, and polymorphic phase transitions between the CaCO{sub 3} phases I, II, III and VI. Hydration was also a significant reaction under certain conditions. The Indiana Limestone studies in particular represent a significant addition to the low-pressure database for porous limestone. Temperature dependence and the effect of freezing were assessed for the Fort Knox limestone. Experimental parameters and detailed results are provided for the 42 impact tests in this series.

  13. The relative merits of dolomitic and calcitic limestone in detoxifying and revegetating acidic, nickel- and copper-contaminated soils in the Sudbury mining and smelting region of Canada

    SciTech Connect

    McHale, D.; Winterhalder, K.

    1996-12-31

    Soils in the Sudbury mining and smelting region have been rendered phytotoxic and barren by acidification and Particulate metal contamination, but can be detoxified revegetated by the surface application of an growth is better on soil treated ground limestone. On certain barren sites, plant growth is better on soil treated with dolomitic limestone than with calcitic limestone and greenhouse experiments using mung beans (Vigna radiata) have shown superior root and shoot growth on certain contaminated soils when the limestone is dolomitic rather than calcitic. Results of experiments with species used in revegetation (Agrostis gigantea and Lotus corniculatus) suggest that leguminous species are more sensitive to Ca:Mg ratio than grasses, that the plant response to this ratio is greater at lowering liming levels, and that the response is more marked on more toxic soils. The effects of calcium:magnesium ratio of the limestone used in revegetating acidic, metal-contaminated soils are clearly complex, interactive and difficult to interpret. Further studies are needed, but meanwhile it is recommended that the practice of using dolomitic limestone to detoxify barren Sudbury soils