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Nutrients As A Link Between Ionic Concentration/Composition And Diatom Distributions In Saline Lakes, J. E. Saros, Sherilyn C. Fritz Jan 2000

Nutrients As A Link Between Ionic Concentration/Composition And Diatom Distributions In Saline Lakes, J. E. Saros, Sherilyn C. Fritz

Department of Earth and Atmospheric Sciences: Faculty Publications

Diatom profiles in closed-basin lake sediments are commonly used to reconstruct climate change based on the observed correlations between salinity (ionic concentration) and modern diatom assemblages. Diatom assemblages are strongly correlated not only with salinity but also anion composition, with certain taxa characteristic of carbonate systems and others sulfate-dominated waters. Although strong correlations exist, the actual mechanisms behind these correlations are unknown. Here we briefly review the influence of salinity and ionic composition on nutrient dynamics in saline lakes and suggest that these interactions may drive shifts in diatom species composition along gradients of ionic concentration/ composition. We discuss the …

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Isotopic Signature Of Burial Diagenesis And Primary Lithological Contrasts In Periplatform Carbonates (Miocene, Great Bahama Bank), Tracy D. Frank, Karin Bernet Jan 2000

Isotopic Signature Of Burial Diagenesis And Primary Lithological Contrasts In Periplatform Carbonates (Miocene, Great Bahama Bank), Tracy D. Frank, Karin Bernet

Department of Earth and Atmospheric Sciences: Faculty Publications

The stable isotope geochemistry of Miocene sediments from the leeward margin of the Great Bahama Bank was examined to investigate burial diagenetic processes in periplatform carbonates. Data indicate that, in addition to differences in bulk proportions of neritic and pelagic carbonate along the slope, rhythmic variation in primary carbonate content has controlled patterns of burial diagenesis and associated geochemical signatures throughout much of the succession examined. The present study focuses on Ocean Drilling Program Sites 1006 and 1007, the most distal of five sites drilled from marginal to deep basin environments during Leg 166. These Miocene sections are characterized by …

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Preliminary Results Of Bitumen And Whole-Rock Elemental Analyses Of Crp-2/2a, Victoria Land Basin, Antarctica, Richard Kettler, E. Papastavros Jan 2000

Preliminary Results Of Bitumen And Whole-Rock Elemental Analyses Of Crp-2/2a, Victoria Land Basin, Antarctica, Richard Kettler, E. Papastavros

Department of Earth and Atmospheric Sciences: Faculty Publications

Sediments and rocks recovered in CRP-2/2A coring operations contain relatively little organic matter (average TOC=0.28%) and very small amounts of solvent-soluble organic matter. Because Early Oligocene sediment included significant amounts of coal detritus, TOC values are higher in Early Oligocene rocks than in younger rocks. TOC values are highest in the fine-grained rocks deposited as part of the highstand systems tract (HST) and TOC values decrease from the bottom to the top of the HST. The TOC:TN ratios observed in the CRP-2/2A core typically exceed 10, and are strong evidence that the preserved organic matter comprises a mixture of detrital …

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Laser-Derived, Particle Size Data From Crp-2/2a: Implications For Sequence And Seismic Stratigraphy, K J. Woolfe, L K. Stewart, Christopher R. Fielding, M Lavelle Jan 2000

Laser-Derived, Particle Size Data From Crp-2/2a: Implications For Sequence And Seismic Stratigraphy, K J. Woolfe, L K. Stewart, Christopher R. Fielding, M Lavelle

Department of Earth and Atmospheric Sciences: Faculty Publications

Gravel-free, high-resolution (1-metre spacing, 32 channel) particle size data from the CRP-2/2A drill core indicate that many of the diamictites were likely deposited from floating ice. Textural dislocations occur at most sequence boundaries and provide independent corroboration of the sequence stratigraphic interpretation. Likewise the data largely support the correlation drawn (Fielding et al., this volume) between the sequence stratigraphic cycles and the regional seismic stratigraphy (an alternative correlation to Reflector ‘f’ is also suggested). The gravel-free data appear to be reflecting predominantly regional (global?) forcing with some possible local effects, and long-term trends persisting through gravelly textural dislocations.

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Palaeogene Calcareous Nannofossils From Crp-2/2a, Victoria Land Basin, Antarctica, David K. Watkins, G. Villa Jan 2000

Palaeogene Calcareous Nannofossils From Crp-2/2a, Victoria Land Basin, Antarctica, David K. Watkins, G. Villa

Department of Earth and Atmospheric Sciences: Faculty Publications

Rare calcareous nannofossils from the Cape Roberts Project drillhole CRP-2A indicate that this area was episodically invaded by marginal oceanic surface waters during the late and late early Oligocene. These depauperate assemblages lack most of the biostratigraphic index fossils for the Oligocene, but do provide two datums that aid in constraining the age of the section: the last appearance datum (LAD) of Dictyococcites bisectus (23.9 Ma) at 149.28 mbsf and the LAD of Chiasmolithus altus (26.1 Ma) at 412.25 mbsf. Calcareous nannofossil assemblages stratigraphically below c. 440 mbsf contain conspicuous evidence of reworking of older (late Eocene) specimens that renders …

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Morphology And Taxonomic Position Of The Late Cretaceous Diatom Genus Pomphodiscus Barker & Meakin, Vladimir A. Nikolaev, David M. Harwood Jan 2000

Morphology And Taxonomic Position Of The Late Cretaceous Diatom Genus Pomphodiscus Barker & Meakin, Vladimir A. Nikolaev, David M. Harwood

Department of Earth and Atmospheric Sciences: Faculty Publications

Results from our investigation of Upper Cretaceous diatoms from the Marca Shale Member of the Moreno Shale in California and from Ocean Drilling Program (ODP) Hole 748C on the Kerguelen Plateau ,Southern Indian Ocean enable a clarification of the taxonomic position of several diatoms. Differences in areola structure ,a primary and conservative character of the diatom valve, are used to separate diatoms recently included in the genus Benetorus. We resurrect he genus Pomphodiscusto include species with locular areolae, a central rimoportula ,and a central inflated chamber .We propose the new species Pomphodiscusk erguelensisn. sp. and new combination Pomphodiscusc …

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Kinematic Structure Of Minipermeameter Flow, Daniel M. Tartakovsky, J. David Moulton, Vitaly A. Zlotnik Jan 2000

Kinematic Structure Of Minipermeameter Flow, Daniel M. Tartakovsky, J. David Moulton, Vitaly A. Zlotnik

Department of Earth and Atmospheric Sciences: Faculty Publications

Minipermeameters are rapidly becoming a popular tool for collecting localized
measurements of permeability in both laboratory and field studies. While one of the main advantages of minipermeameters is their ability to collect data on various support volumes, there have been only limited attempts to analyze their size and geometry. We define the support volume of minipermeameter measurements as a region containing 90% of the total gas flow, i.e., a region bounded by the 10% streamline. Using our new semianalytical solutions for the Stokes' stream function, we demonstrate that the support volume has a shape of the semitoroid adjacent to the …

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Oligocene And Lower Miocene Siliceous Microfossil Biostratigraphy Of Cape Roberts Project Core Crp-2/2a, Victoria Land Basin, Antarctica, R. Scherer, S. M. Bohaty, David M. Harwood Jan 2000

Oligocene And Lower Miocene Siliceous Microfossil Biostratigraphy Of Cape Roberts Project Core Crp-2/2a, Victoria Land Basin, Antarctica, R. Scherer, S. M. Bohaty, David M. Harwood

Department of Earth and Atmospheric Sciences: Faculty Publications

Marine diatoms are the primary biostratigraphical and palaeoenvironmental tool for interpreting the upper Palaeogene and lower Neogene strata recovered during the second drilling season of the Cape Roberts Project at site CRP-2 in the western Ross Sea, Antarctica. Silicoflagellates, ebridians, and a chrysophyte cyst provide supporting biostratigraphical information. More than 100 dominantly planktic diatom taxa are recognised. Of these, more than 30 are treated informally, pending SEM examination and formal description. Many other taxa are noted only to generic level. Lower Oligocene (c. 31Ma) through lower Miocene (c. 18.5 Ma) diatoms occur from 28 mbsf down to 565 …

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Dissolved Solids Sampling Sites And Zones Of Concentration Jan 2000

Dissolved Solids Sampling Sites And Zones Of Concentration

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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Validation Of Algorithms For Remote Sensing Of Aerosols Over Land From The Eos Moderate Resolution Imaging Spectroradiometer (Modis), Anatoly Gitelson Jan 2000

Validation Of Algorithms For Remote Sensing Of Aerosols Over Land From The Eos Moderate Resolution Imaging Spectroradiometer (Modis), Anatoly Gitelson

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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Late Quaternary Landscape Evolution In The South Fork Of The Big Nemaha River Valley, Southeastern Nebraska And Northeastern Kansas, Rolfe D. Mandel, E. Arthur Bettis Iii, Richard G. Baker, Glen G. Fredlund, Jeremy S. Dillon Jan 2000

Late Quaternary Landscape Evolution In The South Fork Of The Big Nemaha River Valley, Southeastern Nebraska And Northeastern Kansas, Rolfe D. Mandel, E. Arthur Bettis Iii, Richard G. Baker, Glen G. Fredlund, Jeremy S. Dillon

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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Dakota County Test Hole Logs, Raymond R. Burchett, Frank A. Smith Jan 2000

Dakota County Test Hole Logs, Raymond R. Burchett, Frank A. Smith

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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Gosper County Test Hole Logs, Larry D. Cast Jan 2000

Gosper County Test Hole Logs, Larry D. Cast

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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Arthur County Test Hole Logs, Robert F. Diffendal Jr., James W. Goeke Jan 2000

Arthur County Test Hole Logs, Robert F. Diffendal Jr., James W. Goeke

Conservation and Survey Division: Faculty and Staff Publications

Arthur County, Nebraska test hole logs (2000).

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Kimball County Test Hole Logs, Frank A. Smith Jan 2000

Kimball County Test Hole Logs, Frank A. Smith

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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Perkins County Test Hole Logs, Vincent H. Dreeszen Jan 2000

Perkins County Test Hole Logs, Vincent H. Dreeszen

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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Rock County Test Hole Logs, Susan Olafsen Lackey, Frank A. Smith, Keonard R. Borcya Jan 2000

Rock County Test Hole Logs, Susan Olafsen Lackey, Frank A. Smith, Keonard R. Borcya

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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Pierce County Test Hole Logs, Susan Olafsen Lackey, Frank A. Smith, Raymond R. Burchett Jan 2000

Pierce County Test Hole Logs, Susan Olafsen Lackey, Frank A. Smith, Raymond R. Burchett

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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York County Test Hole Logs, Frank A. Smith Jan 2000

York County Test Hole Logs, Frank A. Smith

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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Resource Notes-Academic Year 1999-2000 Jan 2000

Resource Notes-Academic Year 1999-2000

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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Resource News-Summer 2000 Jan 2000

Resource News-Summer 2000

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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Principal Reservoirs In Nebraska, University Of Nebraska - Lincoln Jan 2000

Principal Reservoirs In Nebraska, University Of Nebraska - Lincoln

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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Natural Resource Districts In Nebraska, Nebraska Natural Resource Commission Jan 2000

Natural Resource Districts In Nebraska, Nebraska Natural Resource Commission

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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Nebraska Information, Number Of Topographical Maps Per County, University Of Nebraska - Lincoln Jan 2000

Nebraska Information, Number Of Topographical Maps Per County, University Of Nebraska - Lincoln

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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Oregon Trail/Other Points Of Interest In Nebraska, University Of Nebraska - Lincoln Jan 2000

Oregon Trail/Other Points Of Interest In Nebraska, University Of Nebraska - Lincoln

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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Aquatic Dissipation Of The Herbicide Triclopyr In Lake Minnetonka, Minnesota, Kurt D. Getsinger, David G. Petty, John D. Madsen, John G. Skogerboe, Bruce A. Houtman, William T. Haller, Alison M. Fox Jan 2000

Aquatic Dissipation Of The Herbicide Triclopyr In Lake Minnetonka, Minnesota, Kurt D. Getsinger, David G. Petty, John D. Madsen, John G. Skogerboe, Bruce A. Houtman, William T. Haller, Alison M. Fox

United States Army Corps of Engineers, Omaha District

A study of the aquatic fate of the triethylamine salt of triclopyr (3,5,6-trichloro-2- pyridinyloxyacetic acid) was conducted in three bays of Lake Minnetonka, Minnesota. Triclopyr is under review by the US Environmental Protection Agency as a selective aquatic herbicide. The primary purpose of this study was to determine dissipation rates of the parent active ingredient, triclopyr, and its major metabolites, 3,5,6-trichloropyridinol (TCP) and 3,5,6-trichloro-2-methoxypyridine (TMP) in selected matrices including water, sediment, plants, finfish and shellfish. Two 6.5- ha plots dominated by the weedy species Eurasian watermilfoil (Myriophyllum spicatum L) were treated with triclopyr-triethylammonum at a rate of 2.5mg AE liter …

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Nest Predation On Black-Tailed Prairie Dog Colonies, Bruce Baker, Thomas R. Stanley, Glenn Plumb Jan 2000

Nest Predation On Black-Tailed Prairie Dog Colonies, Bruce Baker, Thomas R. Stanley, Glenn Plumb

United States Geological Survey: Staff Publications

Nest predation is the principal cause of mortality for many grassland birds. Predation rates may be higher on prairie dog colonies because they may have less available nesting cover and may increase predator abundance. We compared 14-day nest predation rates for 1,764 artificial nests on 102 black-tailed prairie dog (Cynovnys ludovicianus) colonies and their paired off-colony sites (similar habitat lacking prairie dogs) from 14 May to 26 June 1998 in South Dakota and Wyoming. Predation rates on colonies (66.2 ± 2.2%; x ± SE) were 29.5% higher than at off-colony sites (51.1 ± 2.7%). Nesting cover on colonies …

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Multivariate Correlation Between Concentrations Of Selected Herbicides And Derivatives In Outflows From Selected U.S. Midwestern Reservoirs, R. Tauler, D. Barcelo, E. Michael Thurman Jan 2000

Multivariate Correlation Between Concentrations Of Selected Herbicides And Derivatives In Outflows From Selected U.S. Midwestern Reservoirs, R. Tauler, D. Barcelo, E. Michael Thurman

United States Geological Survey: Staff Publications

Multivariate correlations between the concentrations of selected herbicides and herbicide derivatives in outflows from selected reservoirs in the Midwestern United States for April 1992 through September 1993 were investigated using principal component analysis (PCA) and multivariate curve resolution (MCR). Two independent sources for alachlor ethanesulfonic acid, one major source related to spring flush and seasonal runoff and another minor source related to groundwater, were identified using PCA. Results of MCR provided a semiquantitative interpretation of the environmental sources of the observed herbicide concentrations in reservoir outflows and allowed the examination of their temporal and geographical distributions. Samples with higher herbicide …

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Geochemical And Mineralogical Evidence From Eolian Sediments For Northwesterly Mid-Holocene Paleowinds, Central Kansas, Usa, Alan F. Arbogast, Daniel R. Muhs Jan 2000

Geochemical And Mineralogical Evidence From Eolian Sediments For Northwesterly Mid-Holocene Paleowinds, Central Kansas, Usa, Alan F. Arbogast, Daniel R. Muhs

United States Geological Survey: Staff Publications

A prominent (4500 km2) dune field in the Great Plains is the Great Bend Sand Prairie of south-central Kansas. Dunes here overlie late Quaternary alluvium and were reactivated extensively in the late Holocene. Geomorphic and soil evidence suggests that the most likely eolian sand source is the Arkansas River valley to the northwest. Nevertheless, orientations of stabilized dunes indicate that the most recent dune-forming winds came from the south or southwest, in agreement with modern wind data.

Mineralogy and trace element concentrations in eolian sands of the Great Bend Sand Prairie are similar to those of the Arkansas …

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Clay Mineral Composition Of Glacial Erratics, Mcmurdo Sound, Mary Anne Holmes Jan 2000

Clay Mineral Composition Of Glacial Erratics, Mcmurdo Sound, Mary Anne Holmes

Department of Earth and Atmospheric Sciences: Faculty Publications

Twenty-two erratics collected from coastal moraines along the shores of Mount Discovery, Brown Peninsula, Minna Bluff, on Black Island, and from the Salmon and Miers valley floors in East Antarctica were examined for their mineral composition in the <2 m fraction by x-ray diffraction to determine their provenance and the climate under which the sediment in the erratics formed. Semi-quantitative results from peak areas were subjected to principal components analysis and indicate that there are two distinct mineral compositions in the erratics (C = 0.05): A) dominant smectite group minerals, minor illite and kaolinite, and no chlorite, and B) dominant illite, subordinate smectite group, and either chlorite and R=l US clay or R=3 US clay. Group A erratics include two types: 1) Eocene age siliciclastic sediment and 2) volcaniclastics of unknown age. Group B erratics comprise three types: 1) Eocene age siliciclastic sediment dominated by illite with subordinate smectite, no chlorite, and very low levels of kaolinite and mixed-layer clays; 2) post Eocene age erratics dominated by illite with a major component of chlorite and R=l US clay, minor or no smectite and kaolinite; and 3) post Eocene age erratics dominated by illite and containing R=3 US clay. Eocene age sediment occurs in either group and so had two distinct provenances for the clay fraction: a smectite-dominant area and an illite-rich, smectite-poor area. Post Eocene age sediment also had two distinct provenances for the clay fraction and are different from the Eocene sources: a metamorphic + ancient sedimentary terrain that supplied chlorite, illite, and R=l US clay to some of the erratics, and a sedimentary terrain that supplied illite and R=3 US clay. Kaolinite levels are low, indicating the absence of intense weathering and/or any significant contribution from the Beacon Supergroup.

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