Environmental Changes Across The Early Mississippian Carbon Isotope Excursion,
2017
University of Nevada, Las Vegas
Environmental Changes Across The Early Mississippian Carbon Isotope Excursion, Dev Krishna Maharjan
UNLV Theses, Dissertations, Professional Papers, and Capstones
The Early Mississippian K–O (Kinderhookian-Osagean) δ13C excursion or TICE (mid-Tournaisian carbon isotope excursion) is characterized by an anomalous carbonate carbon isotope value of ≥5‰ that has been documented from numerous stratigraphic sections across the globe. This δ13C excursion coincides with global cooling and sea-level fall and predicts a significant change in seawater chemistry. However, sulfate sulfur isotope data across the K-O δ13C excursion reported in previous studies seem not to be responsive to the carbon cycle. Likewise, a recent study has documented a unidirectional increase in nitrogen isotopes across this excursion, which is not anticipated considering the amount of organic …
Mapping The Spatial-Temporal Variation In Ras Ghanada Seagrass Meadows And Sand Shoals Between 1996, 2006 & 2012,
2017
Nova Southeastern University
Mapping The Spatial-Temporal Variation In Ras Ghanada Seagrass Meadows And Sand Shoals Between 1996, 2006 & 2012, Ryan Brookbank
HCNSO Student Theses and Dissertations
Seagrass meadows offshore Ras Ghanada, as elsewhere, are an important component to the ecosystem providing numerous benefits to both aquatic and human life. This work focused on mapping the spatial and temporal distribution of seagrass meadows offshore Ras Ghanada using aerial photography acquired in 1996 and high-resolution satellite images captured in 2006 and 2012. The movements of sand shoals were also tracked, so as to further explain the dynamics of this ecosystem, as it is the area between the shoal crests that hosts the best developed seagrass meadows. The natural limiting factor for seagrass on the Ras Ghanada coastal shelf …
Slope, Grain Size, And Roughness Controls On Dry Sediment Transport And Storage On Steep Hillslopes,
2017
Pennsylvania State University
Slope, Grain Size, And Roughness Controls On Dry Sediment Transport And Storage On Steep Hillslopes, Roman A. Dibiase, Michael P. Lamb, Vamsi Ganti, Adam M. Booth
Geology Faculty Publications and Presentations
Existing hillslope sediment transport models developed for low-relief, soil-mantled landscapes are poorly suited to explain the coupling between steep rocky hillslopes and headwater channels. Here we address this knowledge gap using a series of field and numerical experiments to inform a particle-based model of sediment transport by dry ravel—a mechanism of granular transport characteristic of steep hillslopes. We find that particle travel distance increases as a function of the ratio of particle diameter to fine-scale (1m) topographic variability associated with rocky landscapes. Applying a 2-D dry-ravel-routing model to lidar-derived surface topography, we show how spatial patterns of local and nonlocal …
Mineralogical Analysis Of Aeolian Dune Deposits, White River Badlands, South Dakota,
2017
Nova Southeastern University
Mineralogical Analysis Of Aeolian Dune Deposits, White River Badlands, South Dakota, Megan O'Connor, Paul Baldauf
Biology Faculty Proceedings, Presentations, Speeches, Lectures
The goal of this study is to test our hypothesis that sand dunes in the White River Badlands (WRB), South Dakota, northern Great Plains, formed during one or more prolonged prehistoric droughts. WRB dune fields are located on tabletops north of the White River in southwestern South Dakota. These parabolic dunes have maximum relief of 30 m and open to the northwest, consistent with the dominant wind direction for the region. Currently, dunes are stabilized by a drought-adapted, mixed grass prairie community.
Sand dunes form when 1) prolonged drought kills prairie vegetation, allowing wind to erode and transport sediment, forming …
Results Of Test-Hole Drilling For Observation Well Planning In The Upper Loup Natural Resources District, Fall 2016,
2017
University of Nebraska-Lincoln
Results Of Test-Hole Drilling For Observation Well Planning In The Upper Loup Natural Resources District, Fall 2016, Douglas Hallum, Sue Olafsen Lackey
Conservation and Survey Division: Faculty and Staff Publications
The High Plains Aquifer underlies much of Nebraska (Figure 1). It is the primary source of groundwater within the Upper Loup Natural Resources District (ULNRD) of central Nebraska (Figure 2). Water derived from the aquifer is an important natural resource for the area and supplies water for recreation, wildlife and agriculture, as well as domestic, municipal, and industrial uses. A general lack of water level observations in the region (Figure 3), recently developed groundwater irrigated acres along the upper Calamus River (Figure 4), falling spring water levels measured in existing irrigation wells (Figure 5), and a stable to falling stream …
Lithology And Depositional Environments Of A Portion Of The Clays Ferry Formation (Middle And Upper Ordovician) Exposed At Silver Creek, Madison County, Kentucky,
2017
Eastern Kentucky University
Lithology And Depositional Environments Of A Portion Of The Clays Ferry Formation (Middle And Upper Ordovician) Exposed At Silver Creek, Madison County, Kentucky, Autumn Murray, Walter S. Borowski
EKU Faculty and Staff Scholarship
We measure, describe, and interpret a carbonate stratigraphic section within the Clays Ferry Formation (Middle and Upper Ordovician) cropping out in Madison County, Kentucky (USGS Kirksville 7.5” quadrangle). Outcrops are exposed within the bed of Silver Creek along Ky 876 (Barnes Mill Road) from ~100 m downstream of where a bridge crosses the stream, then upstream and upsection for a distance of ~300 m over several sets of falls until bedrock exposure becomes sporadic to absent. We sampled the stratigraphic section at approximately half-meter intervals, also taking samples at lithology changes. We collected a total 18 samples, all of which …
The Fate Of Carbon In Sediments Of The Xingu And Tapajós Clearwater Rivers, Eastern Amazon,
2017
University of São Paulo, Brazil
The Fate Of Carbon In Sediments Of The Xingu And Tapajós Clearwater Rivers, Eastern Amazon, Dailson J. Bertassoli Jr., André O. Sawakuchi, Henrique O. Sawakuchi, Fabiano N. Pupim, Gelvam A. Hartmann, Michael M. Mcglue, Cristiano M. Chiessi, Matthias Zabel, Enno Schefuß, Tatiana S. Pereira, Rudney A. Santos, Samantha B. Faustino, Paulo E. Oliveira, Denise C. Bicudo
Earth and Environmental Sciences Faculty Publications
The Xingu and Tapajós rivers in the eastern Amazon are the largest clearwater systems of the Amazon basin. Both rivers have “fluvial rias” (i.e., lake-like channels) in their downstream reaches as they are naturally impounded by the Amazon mainstem. Fluvial rias are widespread in the Amazon landscape and most of the sedimentary load from the major clearwater and blackwater rivers is deposited in these channels. So far, little is known about the role of Amazon rias as a trap and reactor for organic sediments. In this study, we used organic and inorganic geochemistry, magnetic susceptibility, diatom, and pollen analyses in …
The Tuscaloosa Marine Shale: Geologic History, Depositional Analysis, And Exploration Potential,
2017
Stephen F Austin State University
The Tuscaloosa Marine Shale: Geologic History, Depositional Analysis, And Exploration Potential, Jessica D. Pair
Electronic Theses and Dissertations
The Tuscaloosa Marine Shale (TMS) was deposited across southern Louisiana and Mississippi during the Upper Cretaceous. The study focuses on a core region containing vast deposits of Cretaceous-aged sediments that have economic importance for oil and gas exploration. This region has been conventionally drilled for decades, focusing on the recovery of the Cretaceous hydrocarbons. Explorers within this region had traditionally targeted the massive sand units of the Lower and Upper Tuscaloosa Group while neglecting the middle Tuscaloosa Marine Shale unit. With the onset of unconventional drilling technology, new explorers to the region have begun to delineate the Tuscaloosa Marine Shale’s …
Basic Meteorological Data Derived 30-Year Normas (1981-2010) Of Actual Evapotranspiration Rates In Nebraska, Usa,
2017
University of Nebraska-Lincoln
Basic Meteorological Data Derived 30-Year Normas (1981-2010) Of Actual Evapotranspiration Rates In Nebraska, Usa, Jozsef Szilagyi
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Petrographical And Geochemical Changes In Bosnian Stalagmites And Their Palaeo-Environmental Significance,
2017
University of Bologna
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 …
Mono Lake Data,
2017
United States Geological Survey
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,
2017
United States Geological Survey
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 …
Morpho-Sedimentary Characteristics Of Proximal Gravel Braided River Deposits In A Froude-Scaled Physical Model,
2017
Western University
Morpho-Sedimentary Characteristics Of Proximal Gravel Braided River Deposits In A Froude-Scaled Physical Model, Peter Ashmore, Tobias Gardner, Pauline Leduc
Geography & Environment Publications
A Froude‐scaled physical model of a proximal gravel‐bed braided river was used to connect the river morphological characteristics, and sedimentary processes and forms, to deposit geometry. High resolution continuous three‐dimensional topographic data were acquired from sequential photogrammetric digital elevation models paired with grain‐size surface maps derived from image analysis of textural properties of the surface. From these data, the full three‐dimensional development of the braided river deposit and grain‐size sorting patterns was compiled over an experimental time period of 41 h during which the model river reworked a large portion of the braided channel. The minimum surface of the deposit …
Great Basin Surface Water And Precipitation Isotope Data,
2017
United States Geological Survey
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, …
2016 Nebraska Water Leaders Academy - Final Report,
2017
University of Nebraska-Lincoln
2016 Nebraska Water Leaders Academy - Final Report, Mark E. Burbach, Connie Reimers-Hild
Conservation and Survey Division: Faculty and Staff Publications
The effective management of Nebraska’s water resources is evermore challenged by variations in weather, climate, technology, socioeconomic policies, and regulation. Anthropogenic climate change, declining water tables and stream flows, increasing demands on freshwater, aging water infrastructure, fiscal constraints, and impacts on aquatic organisms are particularly imminent challenges in Nebraska and around the world (Pahl-Wostl et al., 2013; Pittock et al., 2008; USACE, 2010). Sustaining freshwater ecosystem services in the face of emerging environmental threats presents an immense societal dilemma worldwide (Pittock et al., 2013; Rockström et al., 2009, Millenium Ecosystem Assessment, 2005). The rapidly changing conditions of water resources in …
Paleoecology Of Foraminifera From The Late Miocene - Early Pliocene Pullen And Saint George Formations, Northwestern California,
2017
Cal Poly Humboldt
Paleoecology Of Foraminifera From The Late Miocene - Early Pliocene Pullen And Saint George Formations, Northwestern California, Trenton J. Ryan
Cal Poly Humboldt theses and projects
The Pullen and Saint George formations are coeval late Miocene-early Pliocene sedimentary formations in northwestern California. The type localities of both formations were studied from a micropaleontologic perspective that focused primarily on Foraminifera, but with additional observations of other fossil groups to reconstruct their past depositional environments. The results obtained in this study provided a photomicrographic inventory of the microfossils from both formations, aided in investigating changes in paleobathymetry of the formations during the late Miocene and early Pliocene based on Foraminifera, and allowed for interpretation of paleoecological signals from the foraminiferan associations. Foraminifera have not been previously described in …
Lateral Heterogeneity And Architectural Analysis Of The Wall Creek Member Of The Upper Cretaceous (Turonian) Frontier Formation,
2017
University of Montana
Lateral Heterogeneity And Architectural Analysis Of The Wall Creek Member Of The Upper Cretaceous (Turonian) Frontier Formation, John Zupanic
Graduate Student Theses, Dissertations, & Professional Papers
The Upper Turonian Wall Creek Member (WCM) of the Frontier Formation is part of a series of marine sandstones that were deposited on the western flank of the Cretaceous Western Interior Seaway (KWIS). The KWIS was a low accommodation shallow-marine foreland basin system that included many large deltaic complexes on its western margin. Deposition of WCM deltaic deposits was strongly influenced by fourthorder glacioeustatic cycles, oceanographic circulation patterns, and tectonics related to the active Sevier fold and thrust belt to the west. An in-depth field study of the WCM was performed on the western flank of the Powder River Basin …
Owens Lake Core Data,
2017
United States Geological Survey
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,
2017
United States Geological Survey
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,
2017
United States Geological Survey
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 …
