Geochemistry Commons^™

Secondary Minerals From Salt Caves In The Atacama Desert (Chile): A Hyperarid And Hypersaline Environment With Potential Analogies To The Martian Subsurface, Jo De Waele, Cristina Carbone, Laura Sanna, Marco Vattano, Ermanno Galli, Francesco Sauro, Paolo Forti

International Journal of Speleology

Over the past 15 years several expeditions by French, American and especially Italian cavers have unveiled over 50 caves in the Cordillera de la Sal (Atacama Desert, Northern Chile). Many of these caves contain a variety of speleothems and minerals, some of which have rarely been observed within karst systems. Most of the secondary deposits in these caves are composed of halite, but also other halide, carbonate, sulphate, nitrate, phosphate, and silicate minerals have been found. Among the sixteen cave mineral species recognized, atacamite, darapskite, blödite, leonite, anhydrite, and especially antarcticite are worth mentioning. In one of the samples an …

Petrographical And Geochemical Changes In Bosnian Stalagmites And Their Palaeo-Environmental Significance, Veronica Chiarini, Isabelle Couchoud, Russell Drysdale, Petra Bajo, Simone Milanolo, Silvia Frisia, Alan Greig, John Hellstrom, Jo De Waele

International Journal of Speleology

Detailed petrographic observations have been coupled with trace element and δ¹³C - δ¹⁸O analyses in order to investigate their dynamics in two Holocene Bosnian speleothems. The potential of this multiproxy approach in providing a means to extract palaeo-environmental information from stalagmites whose stable isotope signals are noisy and without obvious trends has been tested. The studied stalagmites are mostly characterized by columnar microcrystalline fabric. At the sub-millimetre scale of lamination, different microcrystalline columnar sub-types (open and closed) have been detected and classified on the basis of the observed porosity and the crystallite size. The presence of …

Inventory And Analysis Of Some Obsidian Artifacts In The James M. Collins Collection, Matthew Boulanger, Alexis Graves

Anthropology Research

An inventory and analysis of four lots of Native American artifacts within the James M. Collins Collection curated at Southern Methodist University reveals the research value of archaeological materials with less than perfect provenience information. All that is known about the origins of these artifacts is that they appear to have come from Oregon. Elemental analysis by energy dispersive X-ray fluorescence identifies the most likely geochemical source for all of the obsidian artifacts in these lots. Source profiles identified from the 75 artifacts represent major sources located in southwestern Idaho. Similarly, the morphology of the artifacts is consistent with material …

Mono Lake Data, Larry V. Benson

United States Geological Survey: Datasets

Mono Lake Basin Data\ Depth CalAge TIC TOTC TOC 13C 18O

Mono Lake short cores.xlsx 03.03.2014 19:59:44 0.06 xlsx

Depth PSV age 18O 13C

TIC for Wilson Crk Fm.xlsx 02.03.2014 16:07:10 0.03 xlsx

Ostracode 18O and TE data Wilson Crk Fm.xlsx 10.11.2017 17:43:18 0.12 xlsx

Depth, calendar age, TIC, TOTC, TOC, ¹³C, and ¹⁸O of Mono Lake short cores were reported in:

Benson, L., Linsley, B., Smoot, J., Mensing, S., Lund, S., Stine, S., and Sarna-Wojcicki, A., 2003, Influence of the Pacific Decadal Oscillation on the climate of the Sierra Nevada, California and Nevada: Quaternary Research. Quaternary Research …

Summer Lake Basin Data, Larry V. Benson

United States Geological Survey: Datasets

Summer Lake Basin

Name Date modified Time modified Size MB Extension

Summer Lake Basin\

Depth PSV Age 13C 18O Summer Lake B&B core.xlsx 03.03.2014 16:51:12 0.03 xlsx

In the Summer Lake Basin folder:

Depth, PSV age, ¹⁸O, ¹³C data for Summer Lake core B&B are reported in:

Benson, L., Lund, S., Negrini, R., Linsley, B., and Zic, M. 2003. Response of North American Great Basin lakes to Dansgaard-Oeschger oscillations. Quaternary Science Reviews 22: 2,239-2,251.

General Comment: In most cases an age model based on ¹⁴C analyses is not included with the datasets although ones were created for …

Stable Isotope Investigation Of The Migratory Behavior Of Silverhaired Bats (Lasionycteris Noctivagans) In Eastern North America, Erin E. Fraser, Darin Brooks, Fred J. Longstaffe

Earth Sciences Publications

We investigated the migratory movements of silver-haired bats (Lasionycteris noctivagans) across the eastern extent of the species’ range. We conducted stable hydrogen isotope analysis of fur samples (δ²H_fur) from museum specimens collected across latitudes and at all times of the year. We first used these data to estimate the timing of fur replacement and to develop a model associating δ²H_fur with that of local precipitation (δ²H_precip) at the location where fur replacement occurred. We then used this model to 1) identify individuals that had migrated …

Origin Of Graphite In The Southwestern Grenville Province, Mehmet F. Taner, Cameron Drever, Chris Yakymhuk, Fred Longstaffe

Earth Sciences Publications

Two graphite deposits in the southwestern Grenville Province are investigated to evaluate the origin of graphitic carbon and to test if the graphite mineralization is syngenetic or epigenetic. Graphite mineralization in the Bissett Creek deposit is characterized by homogeneously distributed and disseminated graphite flakes (approximately 1 to 5 mm in size and 2 to 10 vol.%) within graphitic gneisses. The graphite flakes are intergrown with metamorphic minerals, most notably biotite. The Montpellier graphite showing in Qu´ebec contains graphite concentrations of up to 20 vol.%. In contrast to the disseminated and homogenously distributed graphite in the Bissett Creek deposit, graphite mineralization …

Great Basin Surface Water And Precipitation Isotope Data, Larry V. Benson

United States Geological Survey: Datasets

In the Great Basin Surface Water and Precipitation Isotope Data folder:

Farad, Nixon, and Pyramid Lake 18O data were reported in:

Benson, L.V., 1994, Stable isotopes of oxygen and hydrogen in the Truckee River-Pyramid Lake surface-water system. 1. Data analysis and extraction of paleoclimatic information: Limnology and Oceanography, vol. 39, p. 344-355. https://digitalcommons.unl.edu/usgsstaffpub/1015

Spring chemistry around Pyramid Lake data were reported in:

Benson, L.V., 1994, Carbonate deposition, Pyramid Lake subbasin, Nevada: 1. Sequence of formation and elevational distribution of carbonate deposits (tufas): Palaeogeography, Palaeoclimatology, Palaeoecology, vol. 109, p. 55-87.

Benson, L.V., Kashgarian M., and Rubin, M., 1995, Carbonate deposition, …

Zircon As A Proxy For "Taking The Temperature" Of Granites: An Example Using Zircon Thermometry Applied To Grenvillian Mid-Crustal Magmas In The Blue Ridge Province, Virginia, Samantha Rae Burk

Theses and Dissertations--Earth and Environmental Sciences

The Grenville orogeny was a protracted (~200 m.y.) series of “hot” magmatic- metamorphic events that contributed to the growth of the Laurentian margin in the late Mesoproterozoic. The granites contain remarkably high Zr content, lack xenocrysts, and become zircon saturated at high temperatures, which are all unusual for felsic magmas. The “hot Grenville granite” hypothesis is tested and use of high-Zr granitoids as potential zones of crustal magma generation through: U-Pb geochronology and cathodoluminescence imaging to assess inherited zircon components; quantitative modeling of zircon crystallization history using rhyolite-MELTS; and Ti-in-zircon thermometry. U-Pb zircon ages for two samples from the Virginia …

Spatial Patterns Of Sea Level Variability Associated With Natural Internal Climate Modes, Weiqing Han, Gerald A. Meehl, Detlef Stammer, Aixue Hu, Benjamin Hamlington, Jessica Kenigson, Hindumathi Palanisamy, Philip Thompson

OES Faculty Publications

Sea level rise (SLR) can exert significant stress on highly populated coastal societies and low-lying island countries around the world. Because of this, there is huge societal demand for improved decadal predictions and future projections of SLR, particularly on a local scale along coastlines. Regionally, sea level variations can deviate considerably from the global mean due to various geophysical processes. These include changes of ocean circulations, which partially can be attributed to natural, internal modes of variability in the complex Earth's climate system. Anthropogenic influence may also contribute to regional sea level variations. Separating the effects of natural climate modes …

Community Production Modulates Coral Reef Ph And The Sensitivity Of Ecosystem Calcification To Ocean Acidification, Thomas M. Decarlo, Anne L. Cohen, George T. F. Wong, Fuh-Kwo Shiah, Steven J. Lentz, Kristen A. Davis, Kathryn E. F. Shamberger, Pat Lohmann

OES Faculty Publications

Coral reefs are built of calcium carbonate (CaCO₃) produced biogenically by a diversity of calcifying plants, animals, and microbes. As the ocean warms and acidifies, there is mounting concern that declining calcification rates could shift coral reef CaCO3 budgets from net accretion to net dissolution. We quantified net ecosystem calcification (NEC) and production (NEP) on Dongsha Atoll, northern South China Sea, over a 2 week period that included a transient bleaching event. Peak daytime pH on the wide, shallow reef flat during the nonbleaching period was ~8.5, significantly elevated above that of the surrounding open ocean (~8.0-8.1) as …

A Zooarchaeological And Geochemical Analysis Of The Faunal Remains From The Tripolye Site Verteba Cave, Ukraine, Sarah Heins Ledogar

Legacy Theses & Dissertations (2009 - 2024)

This study combines zooarchaeological and geochemical analyses to examine the use of animals excavated from Verteba Cave (Ukraine), a unique archaeological site associated with the Eneolithic Tripolye culture (4900 – 2900 BC). Verteba Cave is atypical among Tripolye sites because it is located within a cave, and contains a large amount of human skeletal remains. Although research has been focused on understanding Tripolye subsistence economy, the strategies engaged for procuring domestic animals and the role of animal products in Tripolye life has been underexplored. The role of animals in social behaviors (i.e., mortuary practices, feasting) has not yet been thoroughly …

Owens Lake Core Data, Larry V. Benson

United States Geological Survey: Datasets

In the Owens Lake core data folder:

¹⁴C ages for cores OL84 and OL90 were reported in:

Benson, L.V., Burdett, J.W., Kashgarian, M., Lund, S.P., Phillips, F.M., and Rye, R.O., 1996, Climatic and hydrologic Oscillations in the Owens Lake basin and adjacent Sierra Nevada, California: Science, vol. 274, p. 746-749.

Benson, L.V., 1999, Records of millennial-scale climate change from the Great Basin of the Western United States: In Clark, P., Webb, R., Keigwin, L., eds., Mechanisms of Global Climate Change at Millennial Time Scales, American Geophysical Union Monograph 112, p. 203-225.

Benson, L., 2003, Western Lakes: Chapter 9 in …

Paleomagnetic Secular Variation (Psv) Ages Of Wilson Crk, Plc08-1, Bl04-4, Ol90-1 And 2, Larry V. Benson

United States Geological Survey: Datasets

In the paleomagnetic secular variation (PSV) ages folder:

The data for OL90-1 and 2 have not been published

The data for PLC08-1 are reported in:

Benson, L.V., Smoot, J.P., Lund, S.P., Mensing, S.A., Rye, R.O., 2013. Insights from a synthesis of old and new climate-proxy data from the western Lahontan Basin for the period 48 to 11.5 ka. Quaternary International310, 62-82.

Lund, S., Benson, L., Negrini, R., Liddicoat, J., Mensing, S., 2016. A full-vector paleomagnetic secular variation record (PSV) from Pyramid Lake (Nevada) from 47-17 ka: Evidence for the successive Mono Lake and Laschamp Excursions. Earth and Planetary Sciences …

Pyramid And Winnemucca Lake Basin Carbonate Data, Larry V. Benson

United States Geological Survey: Datasets

In the Pyramid and Winnemucca lake basin carbonate data folder:

New unpublished and previously published ¹⁴C and calibrated ages for materials in the Winnemucca Caves are reported in the table and in the references listed below the table

¹⁴C and calibrated ages for Winnemucca Lake Basin carbonates are reported in:

Benson, L.V., Hattori, E.M., Southon, J., Aleck, B., 2013. Dating North America’s oldest petroglyphs, Winnemucca Lake subbasin, Nevada. Journal of Archaeological Science 40, 4466-4476.

Tufa ⁸⁷Sr, ¹⁸O, and ¹³C data are reported in:

Benson, L.V., Smoot, J.P., Lund, S.P., Mensing, S.A., Rye, R.O., 2013. Insights …

Reconstructed Discharge For Truckee River, Larry V. Benson

United States Geological Survey: Datasets

Reconstructed Discharge for Truckee River

Name Date modified Time modified Size MB Extension

Reconstructed Discharge Truckee R\ Reconstructed Discharge for Truckee River.xlsx 11.11.2017 22:40:52 0.02 xlsx

Reconstructed discharge of the Truckee River was made considering losses to evaporation in all upstream reservoirs and corrected for diversion from the Derby Dam to the Newlands area. These data were never previously published.

General Comment: In most cases an age model based on ¹⁴C analyses is not included with the datasets although ones were created for the original publications. Given the general problems with ¹⁴C ages in the lakes of the …

Walker Lake Basin Data, Larry V. Benson, Steve P. Lund

United States Geological Survey: Datasets

Walker Lake Basin Data

Name Date modified Time modified Size MB Extension

Walker Lake Core 84-8 isotope and age data.xls 27.01.2018 15:25:52 0.03 xls

Walker Lake core WL002 PSV age and chemical data.xlsx 09.02.2018 20:04:50 0.03 xlsx

In the Walker Lake Basin folder:

Depth, ¹⁴C age (not corrected for reservoir effect), ¹⁸O, ¹³C data for core 84-8 are reported in:

Benson, L. V., 1988, Preliminary paleolimnologic data for the Walker Lake subbasin, California and Nevada: United States Geological Survey Water-Resources Investigations Report 87-4258, 50 p. Palaeogeography, Palaeoclimatology, Palaeoecology 240: 497-507.

Depth, PSV age, TIC , ¹⁸O, …

Pyramid Lake Core Data, Larry V. Benson

United States Geological Survey: Datasets

Pyramid Lake Core Data

14C and calibrated ages for core PLC08-1.xlsx 01.03.2014 19:45:30 0.01 xlsx

14C and calibrated ages for core PLC92B.xlsx 04.03.2014 16:41:30 0.01 xlsx

14C and calibrated ages for core PLC97-3.xlsx 01.03.2014 19:50:48 0.01 xlsx

CalKa Depth TOC TIC 18O 13C for PLC97-1.xlsx 09.11.2017 20:51:22 0.04 xlsx

Depth 14CAge Corrected 14C AGE CAL Age PLC98-4.xlsx 15.11.2017 18:26:12 0.01 xlsx

Depth 180 13C TOTC TOC TIC porosity CYBP Box Core PLB98-2.xlsx 01.03.2014 20:00:46 0.01 xlsx

Depth CalAge TIC TOTC TOC 13C 18O PLC98-4.xlsx 02.03.2014 00:32:20 0.05 xlsx

Depth Equivalent Depth in PLC08-1 PSV age 180 13C TIC TOC for …

Comparison Of The Scavenging Intensity, Remineralization And Residence Time Of 210po And 210pb At Key Interfaces (Biotic, Sediment-Water And Hydrothermal) Along The Geotraces East Pacific Zonal Transect, John Niedermiller

Wayne State University Theses

The contrasting geochemical behavior of two long-lived progeny of 222Rn, namely 210Po and 210Pb, provide valuable insights on the extent of recycling of biogenic particulate matter and their preferential removal from the water column. A total of 135 water samples were collected and analyzed from six vertical profiles for 210Po and 210Pb along the US GEOTRACES East Pacific Zonal Transect. This study shows decreasing atmospheric 210Pb flux from the measured 210Pb activity in aerosols indicating an overall decrease from east to west along the cruise transect. Differences in scavenging intensities, inventories, and residence times of 210Po and 210Pb at key …

Using 210po/210pb Disequilibria To Characterize The Biogeochemistry And Quantify The Dynamics Of Sea Ice In The Arctic, Katherine Denise Krupp

Wayne State University Theses

Understanding the biogeochemical cycles of the Arctic Ocean is highly significant due to its many unique characteristics which impact the cycling of important trace elements, isotopes, and nutrients. Furthermore, with its seasonally-changing sea ice extent and substantial role in the global radiation balance, the Arctic is considered a sensitive indicator of global change. The study of 210Po and 210Pb disequilibria is used to determine 1) the residence time of ice-rafted sediments in sea ice, 2) ice floe dynamics such as ice accumulation rates, and 3) biogeochemical characterization of the Arctic due to the natural occurrence and particle reactivity of 210Po …

Principles Of Stable Isotope Geochemistry, 2nd Edition, Zachary Sharp

Open Textbooks

Principles of Stable Isotope Geochemistry is written as a textbook to accompany a one semester course in Stable Isotope Geochemistry. There are 13 chapters, each dealing with a specific subtopic of the field. Other than Chapters 1 and 2 – introduction and definitions – most of the remaining chapters can be read without reliance on the preceding ones. It is also hoped that the book will serve as a general reference volume for researchers in the field.

Principles of Stable Isotope Geochemistry has been organized in such a way that major concepts are explained and accompanied by numerous examples. In …

Gypsum, Calcite, And Dolomite Caprock Fabrics And Geochemistry From The Gypsum Valley Salt Diapir, Paradox Basin, Southwestern Colorado, Kevin Lerer

Open Access Theses & Dissertations

Caprocks are found on top of or in a lateral position relative to salt diapirs. The caprocks predominantly comprise sulfate minerals such as anhydrite or gypsum, which presumably accreted during the dissolution of salt from evaporite sediments. In some cases, the sulfate minerals are replaced by carbonate minerals, referred to as "carbonate caprock". Carbonate caprocks associated with salt diapirs are important because they can act as reservoirs or conduits for hydrocarbons, and because they can be easily misidentified as carbonate lithologies belonging to the stratigraphy of the sedimentary sequences adjacent to the diapir, which can jeopardize the accurate interpretation of …

Genesis Of Unique Carbonate Fans In A Pre-Salt Reservoir Analogue, Indio Mountains, West Texas, Andre Llanos

Open Access Theses & Dissertations

Hydrocarbon exploration in pre-salt sediments of rift basins on the South Atlantic Margin have proven to be successful major oil plays. Located on the western margin of the rift, the Brazilian pre-salt reservoirs of the Santos, Campos, and Espirito Santo Basins are hosted by lacustrine/marine-influenced carbonates that comprise laterally extensive, laminated microbialite facies. The Indio Mountains, located in West Texas, provide well-exposed outcrops of Lower Cretaceous marine and non-marine rift basin strata that can be considered a reservoir-analog to the South Atlantic Margin pre-salt facies. Of particular interest for hydrocarbon exploration are unique carbonate features that have been discovered in …

Stratigraphic, Geochemical, And Geochronological Analysis Of The Wolfcamp-D Interval, Midland Basin, Texas, Zachary S. Perlman

Theses and Dissertations--Earth and Environmental Sciences

Subsurface data derived from ~388 ft of drill core from Martin County (TX) were used to understand the depositional setting of the Wolfcamp-D, a petroleum producing interval in the Midland Basin. Elemental geochemistry collected via x-ray fluorescence revealed a highly variable depositional history marked by the deposition of diverse siliciclastic and carbonate lithofacies. Integration of multiple datasets resulted in the interpretation of nine lithofacies, whose deposition appears cyclical. Correlations between molybdenum and total organic carbon indicate slow recharge of bottom waters and anoxic/euxinicconditions within the basin. The presence of phosphatic nodules coinciding with siliceous black mudrocks suggested high levels of …

Dam Removal In The Usa: Effects On River Water Quality, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Dam removal decisions should ideally be made after a thorough cost-benefit analysis. If dam obsolescence, structural safety, harm to fisheries, maintenance costs, and reservoir eutrophication are among the primary concerns, decommissioning would likely be favored. On the other hand, dams provide considerable benefits including water storage for agricultural and urban consumption, renewable electricity generation, support of navigational canal systems, flood control, and lakes for recreation. Because of these competing factors and interests, dam removal decision-making in the United States is often a slow process fraught with controversy, as in the case of the Klamath River.

Dams provided mechanical water power …

New And Improved Infra-Red Absorption Cross Sections And Ace-Fts Retrievals Of Carbon Tetrachloride (Ccl4), Jeremy J. Harrison, Christopher D. Boone, Peter F. Bernath

Chemistry & Biochemistry Faculty Publications

Carbon tetrachloride (CCl₄) is one of the species regulated by the Montreal Protocol on account of its ability to deplete stratospheric ozone. As such, the inconsistency between observations of its abundance and estimated sources and sinks is an important problem requiring urgent attention (Carpenter et al., 2014) [5]. Satellite remote-sensing has a role to play, particularly limb sounders which can provide vertical profiles into the stratosphere and therefore validate stratospheric loss rates in atmospheric models. This work is in two parts. The first describes new and improved high-resolution infra-red absorption cross sections of carbon tetrachloride/dry synthetic air over …

A Miniaturized Spectrophotometric In Situ Ph Sensor For Seawater, Reuben C. Darlington

Graduate Student Theses, Dissertations, & Professional Papers

Since the Industrial Revolution, the world's oceans have absorbed increasing amounts of CO2 and the resultant changes to the marine carbonate chemical system have reduced the pH by > 0.1 units (~ 30%) in surface waters. This acidification of the oceans has many far reaching impacts on marine life and there is great need of quality instrumentation to assess and follow the changing carbonate system. This MIS project aims to develop a low cost pH sensor with high precision and accuracy for open sea measurements with special emphasis on reduced size and cost. Design effort is based on the commercially available …

Tracing Anthropogenic Salinity Inputs To The Semi-Arid Rio Grande River: A Multi-Isotope Tracer Approach, Sandra Garcia

Open Access Theses & Dissertations

Water is an important component for life and as such water quality and availability are major concerns in the world today. In arid to semi-arid regions, freshwater quality is especially important due to its scarcity. Elevated salinity of rivers in arid regions poses potentially devastating consequences for the communities that depend on these rivers as a source of freshwater. In the Rio Grande region, high salinity has led to severe reductions in crop productivity and accumulation of salts in soils. Salinity inputs into the river may come from both anthropogenic and natural sources. Thus, identifying and quantifying salinity inputs to …

Evaluation Of Cryptic Sulfur Cycling In Marine Sediments, Michael Ngari Mathuri

Open Access Theses & Dissertations

Despite the importance of marine sediments as a carbon sink and many efforts to integrate microbiological with geochemical and geological data, the understanding of microbial organic carbon mineralization processes in marine sediments remains incomplete. There is growing evidence for the existence of an unrecognized oxidative sulfur cycling (cryptic sulfur cycling) above, within and below of the main sulfate reduction zone. For example, sulfate exists in supposedly sulfate-free methanogenic marine sediments from the Aarhus Bay and Black Sea. This implies that sulfur cycling is an ongoing process in the deep biosphere. Quantification of cryptic sulfur cycling is a major challenge because …

A New Method For Ultra-Low Sulfate Extraction And A Pilot Study In Arid Soils, Marisela Montelongo

Open Access Theses & Dissertations

Sulfur in soils is a crucial nutrient for all organisms including plants. Sulfate (SO42-), a water soluable anion, is a good source of this important element. Because of the importance of sulfur for agriculture, the use of sulfate has been well studied in temperate climate zones, and it is generally accepted that microbes play a critical role in controlling the availability of sulfate. Organically bound sulfur, such as sulfate esters and carbon-bonded sulfur, compounds that are generated and decomposed by microbes, are essential sulfur sources for plants under these conditions. For arid environments, knowledge of sulfate turnover in soils by …