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Geochemistry

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2002

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Articles 1 - 17 of 17

Full-Text Articles in Physical Sciences and Mathematics

Energy‐Constrained Open‐System Magmatic Processes 3. Energy‐Constrained Recharge, Assimilation, And Fractional Crystallization (Ec‐Rafc), Frank J. Spera, Wendy A. Bohrson Dec 2002

Energy‐Constrained Open‐System Magmatic Processes 3. Energy‐Constrained Recharge, Assimilation, And Fractional Crystallization (Ec‐Rafc), Frank J. Spera, Wendy A. Bohrson

All Faculty Scholarship for the College of the Sciences

Geochemical data for igneous rock suites provide conclusive evidence for the occurrence of open‐system processes within thermally and compositionally evolving magma bodies. The most significant processes include magma Recharge (with possible enclave formation and magma mixing), Assimilation of anatectic melt derived from wallrock partial melting and formation of cumulates by Fractional Crystallization (RAFC). In this study, we extend the Energetically Constrained Assimilation and Fractional Crystallization (EC‐AFC) model [Spera and Bohrson, 2001; Bohrson and Spera, 2001] to include the addition of compositionally and thermally distinct recharge melt during simultaneous assimilation and fractional crystallization. Energy‐Constrained Recharge, Assimilation, and Fractional …


Geoelectrical Response Of An Aged Lnapl Plume: Implications For Monitoring Natural Attenuation, Douglas D. Werkema Jr. Dec 2002

Geoelectrical Response Of An Aged Lnapl Plume: Implications For Monitoring Natural Attenuation, Douglas D. Werkema Jr.

Dissertations

The geoelectric stratigraphy at a site impacted with light non-aqueous phase liquids (LNAPLs) is investigated for its link to natural biodegradation, its contribution to the conductive model for aged (i.e. mature) LNAPL contaminated sites, and the relationship to the natural hydrologic regime. The highest conductivities (lowest resistivities) were observed in portions o f soils where LNAPL was in residual and free phase. Corroborating evidence from bacteria enumeration from soil close to the vertical resistivity probe (VRP) installations show orders-of-magnitude increase in both heterotrophic and oil degrading microbes at the depths where the conductivity was at a maximum. The coincidence o …


Preliminary Geochemical Evaluation Of Groundwaters From Wells Of The Nye County Early Warning Drilling Program, Irene Farnham, Klaus J. Stetzenbach, Amy J. Smiecinski Sep 2002

Preliminary Geochemical Evaluation Of Groundwaters From Wells Of The Nye County Early Warning Drilling Program, Irene Farnham, Klaus J. Stetzenbach, Amy J. Smiecinski

Publications (YM)

As part of the Yucca Mountain Oversight program, the Nye County Nuclear Waste Repository Project Office (NWRPO) has established a groundwater monitoring program to protect groundwater resources for the residents of Nye County in Amargosa and Pahrump Valleys. This groundwater monitoring program, referred to as the Nye County Early Warning Drilling Program (NCEWDP), involves drilling a series of wells down-gradient from Yucca Mountain for long term groundwater monitoring and also to provide much needed geologic and hydrologic information in this area. A comprehensive database of aquifer parameters in the alluvial, volcanic, and carbonate aquifers down-gradient hydrogeologically of Yucca Mountain is …


Support For Infiltration And Seepage Studies In Exploratory Studies Facility Niches And Alcoves, Irene Farnham, Klaus J. Stetzenbach, Amy J. Smiecinski Jul 2002

Support For Infiltration And Seepage Studies In Exploratory Studies Facility Niches And Alcoves, Irene Farnham, Klaus J. Stetzenbach, Amy J. Smiecinski

Publications (YM)

This report details the analyses performed under Task 9 of the University and Community College System of Nevada (UCCSN) Cooperative Agreement with the US Department of Energy (DOE). This task, titled "Analysis of Chemical Tracers in Conjunction with the Vadose Zone Infiltration and Seepage Studies", provided for the development of analytical procedures and the analysis of samples from a tracer test currently in progress at Alcove 8 /Niche 3 in the Exploratory Studies Facility (ESF). The concentration of two tracers (bromide andpentafluorobenzoic acid) were quantified in the initial injectate solution and also the seepage samples collected from Niche 3. Samples …


Organic Geochemical Analysis Of Late-Glacial And Early-Holocene Ecosystem Changes: A Case Study From Northern New England Lakes, Michael A. Kruge, Andrea Lini Jun 2002

Organic Geochemical Analysis Of Late-Glacial And Early-Holocene Ecosystem Changes: A Case Study From Northern New England Lakes, Michael A. Kruge, Andrea Lini

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The lacustrine sedimentary archive of organic remains provides important evidence for the reconstruction of the environmental histories of lakes and their watersheds, recording the response of the Earth's biota to changes on scales varying from the local to the global. The last Glacial-Interglacial transition presents an opportunity to investigate how, and at what rates, watershed and lake ecosystems were established on once glaciated, carbon and nutrient-poor landscapes. The small lakes of northern Vermont (USA) provide an appropriate setting in which to investigate such changes.

As part of a multidisciplinary study of three Vermont lake sediment cores, samples ranging in age …


Thermochronological Evolution Of Calcite Formation At The Proposed Yucca Mountain Repository Site, Nevada: Part 1, Secondary Mineral Paragenesis And Geochemistry, Jean S. Cline, Amy J. Smiecinski, Robert Bodnar May 2002

Thermochronological Evolution Of Calcite Formation At The Proposed Yucca Mountain Repository Site, Nevada: Part 1, Secondary Mineral Paragenesis And Geochemistry, Jean S. Cline, Amy J. Smiecinski, Robert Bodnar

Publications (YM)

In the near future a decision will be made as to whether or not Yucca Mountain, 90 miles northwest of Las Vegas, Nevada is a suitable site for a permanent, underground, high level nuclear waste repository. A major factor in determining the suitability of Yucca Mountain as a repository is the potential for the site to be flooded by water during the regulatory lifetime. The current study was undertaken to examine the past fluid history at the site, to gain a better understanding of the possibility of flooding in the near geologic future. To estimate the past fluid flux into …


Geochemical Characteristics And Origin Of Barite Deposits Between Şarki̇karaağaç (Isparta) And Hüyük (Konya), Oya Cengi̇z, Mustafa Kuşcu Apr 2002

Geochemical Characteristics And Origin Of Barite Deposits Between Şarki̇karaağaç (Isparta) And Hüyük (Konya), Oya Cengi̇z, Mustafa Kuşcu

Bulletin of the Mineral Research and Exploration

No abstract provided.


Chemical, Isotopic, And Hydrogeologic Investigations Of An Agriculturally Impacted Area, Nottawa Creek Watershed, Calhoun County, Michigan, Gerald A. Unterreiner Apr 2002

Chemical, Isotopic, And Hydrogeologic Investigations Of An Agriculturally Impacted Area, Nottawa Creek Watershed, Calhoun County, Michigan, Gerald A. Unterreiner

Dissertations

A 4 km2 agricultural area within the somewhat poorly drained Nottawa Creek Watershed, south central Michigan, was investigated to help understand transport and transformation processes of nutrients and herbicides to surface water. Geology o f the study area is comprised of a thin glacial drift cover overlying shale bedrock. A one layer, two-dimensional numerical triangular finite element groundwater flow model was developed to evaluate regional groundwater flow. Selected horizontal hydraulic conductivities ranged from 3 x 10‘3 m/day to 107 m/day. Field-scale infiltration modeling with the computer program GLEAMS, substantiated with water level measurements, suggest significant recharge events occur during summer, …


The Use Of A Synthetic Binary Solid Solution To Model Igneous Textural Evolution, Elizabeth Scott Jan 2002

The Use Of A Synthetic Binary Solid Solution To Model Igneous Textural Evolution, Elizabeth Scott

Geology Theses and Dissertations

Crystallization experiments using a synthetic igneous analog have shown that grain boundary migration can take place in melt-present environments (Means and Park, 1994). In order to evaluate the importance of metamorphic processes during the textural evolution of a crystal mush, microstructural evidence is needed to link them with final igneous textures. In natural magmatic systems, plagioclase may provide a microstructural link; plagioclase solid solution enables the process of chemical zoning and preserves a record of crystal morphology (and chemistry) during growth. If metamorphic processes are common, they should affect the zoning patterns of plagioclase crystals.
A petrographic stage heater apparatus …


Early Cretaceous Normal Faulting In Southern New England: Evidence From Apatite And Zircon Fission-Track Ages, Mary K. Roden-Tice, Robert P. Wintsch Jan 2002

Early Cretaceous Normal Faulting In Southern New England: Evidence From Apatite And Zircon Fission-Track Ages, Mary K. Roden-Tice, Robert P. Wintsch

Mary K. Roden-Tice

New apatite and zircon fission‐track (AFT, ZFT) ages from Mesozoic sediments and adjacent crystalline rocks from southern New England reveal age gradients from Middle Jurassic to Early Cretaceous. These gradients reflect the rotation of crustal blocks after the setting of the youngest AFT ages (∼140 Ma). The AFT ages of 168–98 Ma for 32 samples of Paleozoic metamorphic rocks east and west and within the Hartford Basin of Massachusetts and Connecticut indicate that unroofing in these regions occurred from Late Jurassic through Early Cretaceous. In both the Hartford Basin and rocks from crystalline terranes east of the basin, AFT ages …


The Meeting Of Two Microbial Worlds: Geochemistry Of The Sulfate-Methane Interface, Walter S. Borowski, Charles K. Paull, William Ussler Iii Jan 2002

The Meeting Of Two Microbial Worlds: Geochemistry Of The Sulfate-Methane Interface, Walter S. Borowski, Charles K. Paull, William Ussler Iii

EKU Faculty and Staff Scholarship

No abstract provided.


Development Of A Circa 2000 Landcover Database For The United States, Collin Homer, Chengquan Huang, Limin Yang, Bruce K. Wylie Jan 2002

Development Of A Circa 2000 Landcover Database For The United States, Collin Homer, Chengquan Huang, Limin Yang, Bruce K. Wylie

Publications of the US Geological Survey

Multi-Resolution Land Characterization 2000 (MRLC 2000) is a second-generation federal consortium to create an updated pool of nation-wide Landsat 7 imagery, and derive a second-generation National Land Cover Database (NLCD 2000). This multi-layer, multisource database will include a suite of 30-meter resolution data that will serve as standardized ingredients for the production of land cover – both nationally and locally. This database will also provide the framework to allow flexibility in developing and applying suites of independent data layers. These nationally standardized independent data layers or components, will be useful not only within the land-cover classification but as data themes …


Derivation Of A Tasseled Cap Transformation Based On Landsat 7 At-Satellite Reflectance, C. Huang, Bruce K. Wylie, Limin Yang, Collin Homer, Gregory Zylstra Jan 2002

Derivation Of A Tasseled Cap Transformation Based On Landsat 7 At-Satellite Reflectance, C. Huang, Bruce K. Wylie, Limin Yang, Collin Homer, Gregory Zylstra

Publications of the US Geological Survey

A new tasseled cap transformation based on Landsat 7 at-satellite reflectance was developed. This transformation is most appropriate for regional applications where atmospheric correction is not feasible. The brightness, greenness and wetness of the derived transformation collectively explained over 97% of the spectral variance of the individual scenes used in this study.


Assessment Of Elemental Concentrations In Streams Of The New Lead Belt In Southeastern Missouri, 2002–05, William G. Brumbaugh, Thomas W. May, John M. Besser, Ann L. Allert, Christopher J. Schmitt Jan 2002

Assessment Of Elemental Concentrations In Streams Of The New Lead Belt In Southeastern Missouri, 2002–05, William G. Brumbaugh, Thomas W. May, John M. Besser, Ann L. Allert, Christopher J. Schmitt

Publications of the US Geological Survey

Concerns about possible effects of lead-mining activities on the water quality of federally protected streams located in southeastern Missouri prompted a suite of multidisciplinary studies to be conducted by the U.S. Geological Survey. As part of this investigation, a series of biological studies were initiated in 2001 for streams in the current mining region and the prospecting area. In this report, results are examined for trace elements and other selected chemical measurements in sediment, surface water, and sediment interstitial (pore) water sampled between 2002 and 2005 in association with these biological studies. Compared to reference sites, fine sediments collected downstream …


Nitrate Anomaly In The Upper Nutricline In The Northern South China Sea - Evidence For Nitrogen Fixation, George T. F. Wong, Shi-Wei Chung, Fuh-Kwo Shiah, Chung-Chi Chen, Liang-Saw Wen, Kon-Kee Liu Jan 2002

Nitrate Anomaly In The Upper Nutricline In The Northern South China Sea - Evidence For Nitrogen Fixation, George T. F. Wong, Shi-Wei Chung, Fuh-Kwo Shiah, Chung-Chi Chen, Liang-Saw Wen, Kon-Kee Liu

OES Faculty Publications

[1] Up to 2 μM of nitrate anomaly, N*, were found in the upper nutricline at the South East Asia Time-series Study (SEATS) site in the northern South China Sea (SCS). These concentrations were among the higher values reported in the Pacific and indicate the significant contribution of the remineralization of nitrogen-rich organic matter formed by nitrogen fixation to the nutrient dynamics of the area. The concentrations were systematically higher, by up to 2.5 μM, in the Fall through the early Spring, during the northeast monsoon, than in the Summer, suggesting that the impact of nitrogen fixation was higher during …


Strontium Isotopic Signatures Of The Streams And Lakes Of Taylor Valley, Southern Victoria Land, Antarctica: Chemical Weathering In A Polar Climate, W. B. Lyons, Carmen A. Nezat, Larry V. Benson, Thomas D. Bullen, Elizabeth Y. Graham, Jesicca Kidd, Kathleen A. Welch, James M. Thomas Jan 2002

Strontium Isotopic Signatures Of The Streams And Lakes Of Taylor Valley, Southern Victoria Land, Antarctica: Chemical Weathering In A Polar Climate, W. B. Lyons, Carmen A. Nezat, Larry V. Benson, Thomas D. Bullen, Elizabeth Y. Graham, Jesicca Kidd, Kathleen A. Welch, James M. Thomas

United States Geological Survey: Staff Publications

We have collected and analyzed a series of water samples from three closed-basin lakes (Lakes Bonney, Fryxell, and Hoare) in Taylor Valley, Antarctica, and the streams that flow into them. In all three lakes, the hypolimnetic waters have different 87Sr/86Sr ratios than the surface waters, with the deep water of Lakes Fryxell and Hoare being less radiogenic than the surface waters. The opposite occurs in Lake Bonney. The Lake Fryxell isotopic ratios are lower than modern-day ocean water and most of the whole-rock ratios of the surrounding geologic materials. A conceivable source of Sr to the system …


Intra-Annual Variation In The Stable Oxygen And Carbon And Trace Element Composition Of Sclerosponges, P. K. Swart, S. Thorrold, B. Rosenheim, A. Eisenhauer, C. G. A. Harriason, M. Grammer, C. Latkoczy Jan 2002

Intra-Annual Variation In The Stable Oxygen And Carbon And Trace Element Composition Of Sclerosponges, P. K. Swart, S. Thorrold, B. Rosenheim, A. Eisenhauer, C. G. A. Harriason, M. Grammer, C. Latkoczy

Biological Sciences Faculty Publications

This paper presents data to support the presence of (1) intra-annual signals in the chemical composition (δ18O and Sr/Ca) of the skeletons ofsclerosponges from the Bahamas and (2) variable rates of skeletal accretion. These conclusions are based on data obtained by using a microsampling method for the stable oxygen and carbon isotopes in which material was extracted at a resolution of one sample every 34 μm and a laser microprobe which obtained trace element data every 20 μm (Sr, Mg, and Pb). An age model was established using a combination of changes in the concentration of Pb, the …