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Full-Text Articles in Geology

A Geologic Record Of Competing Sulfate-Depletion Processes Within Continental-Rise Sediments Overlying Methane Gas Hydrates Of The Blake Ridge Region (Continental Rise, Offshore Southeastern United States), Walter S. Borowski, Kathryn G. Takacs, Matthew K. Thompson Mar 2006

A Geologic Record Of Competing Sulfate-Depletion Processes Within Continental-Rise Sediments Overlying Methane Gas Hydrates Of The Blake Ridge Region (Continental Rise, Offshore Southeastern United States), Walter S. Borowski, Kathryn G. Takacs, Matthew K. Thompson

EKU Faculty and Staff Scholarship

Geochemical signals locked within sediments and sedimentary rocks record geochemical processes through geologic time. Sulfide minerals (elemental sulfur, iron monosulfides, and pyrite) are formed within marine sediments as dissolved sulfide is produced by various geochemical processes, which include sulfate reduction and anaerobic methane oxidation (AMO). The concentration and sulfur isotopic composition (d34S) of sulfide minerals gives clues about the relative importance of these competing geochemical processes, and consequently about sedimentation rates and upward methane transport.

Marine sediments of the Blake Ridge(offshore South Carolina and Georgia) contain sulfide minerals that point to AMO as an important diagenetic process both …


Mapping Of A Detachment Fault In Kythera Island And Study Of The Related Structural Shear Sense Indicators, Antonios Marsellos Jan 2006

Mapping Of A Detachment Fault In Kythera Island And Study Of The Related Structural Shear Sense Indicators, Antonios Marsellos

Geology Theses and Dissertations

Kythera Island is located on the prominent submarine horst between Crete and the Peloponnese in the southwestern part of the Aegean. The structure of Kythera is characterized by a pile of tectonic slices derived from different paleogeographic zones. The upper unmetamorphosed units comprise pelagic limestones and cherts of Pindos zone emplaced by thrusting in the Eocene on top of Tripolis zone neritic limestones. These units are separated from the lower metamorphosed unit of Phyllite-Quartzite (PQU) exposed in the northern part of Kythera by an extensional detachment fault of Late Miocene age. The lower tectonic unit of PQU was affected by …


Thermochronology And Provenance Of The Yakutat Terrane, Southern Alaska Based On Fission-Track And U/Pb Analysis Of Detrital Zircon, Stephanie Ellen Perry Jan 2006

Thermochronology And Provenance Of The Yakutat Terrane, Southern Alaska Based On Fission-Track And U/Pb Analysis Of Detrital Zircon, Stephanie Ellen Perry

Geology Theses and Dissertations

Northward transport of the Yakutat terrane along the Transition and Queen Charlotte-Fairweather transform faults led to Neogene collision of the Yakutat terrane with the southern continental Alaska margin. Northward translation resulted in a stratigraphy that records the erosion of thermotectonic terranes along its path. The strata of the Yakutat terrane includes the Lower Oligocene to Lower Eocene Kulthieth Formation, the Upper Eocene to Lower Miocene Poul Creek Formation and the Miocene-Pleistocene Yakataga Formation. Detrital zircon fission-track (DZFT) ages from stratigraphically coordinated samples collected in the Northern Robinson Mountains yield provenance information of the units that can shed light on their …


Groundwater-Level Changes In Nebraska, Spring 2000 To Spring 2006/ Density Of Registered Irrigation Wells In Nebraska August 2005, Conservation Survey Division Jan 2006

Groundwater-Level Changes In Nebraska, Spring 2000 To Spring 2006/ Density Of Registered Irrigation Wells In Nebraska August 2005, Conservation Survey Division

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Spatial Distributions Of Perchloroethylene Reactive Transport Parameters In The Borden Aquifer, Richelle M. Allen-King, Dana Divine, Michel J. L. Robin, J. Richard Alldredge, David R. Gaylord Jan 2006

Spatial Distributions Of Perchloroethylene Reactive Transport Parameters In The Borden Aquifer, Richelle M. Allen-King, Dana Divine, Michel J. L. Robin, J. Richard Alldredge, David R. Gaylord

Conservation and Survey Division: Faculty and Staff Publications

We determined the descriptive statistical and spatial geostatistical properties of the perchloroethene ln Kd and the ln k of a 1.5 m thick by 10 m horizontal transect of the Borden aquifer near the location of the Stanford-Waterloo (SW) tracer experiment. The ln Kd distribution is not normal and is right skewed because of a few high values that occur localized in two regions of the transect. In contrast, the ln k data can be characterized by a normal distribution. A linear regression of ln Kd on ln k yields a statistically significant positive correlation, also shown …


Foraminiferal Faunas Of The Southern California Bight: A Temporal And Spatial Comparison Of Assemblages In The >150, 63-150, And >63 Μm Fractions, Amanda S. Shepard Dec 2005

Foraminiferal Faunas Of The Southern California Bight: A Temporal And Spatial Comparison Of Assemblages In The >150, 63-150, And >63 Μm Fractions, Amanda S. Shepard

All-Inclusive List of Electronic Theses and Dissertations

Analyses ofliving (Rose Bengal stained) deep-sea benthic foraminifera collected on the Southern California margin reveal temporal and spatial changes in foraminiferal assemblages related to changes in sea-surface productivity. Samples were collected from two sites in May, August, and October 1996. Results show that foraminiferal microhabitats are not static at these sites, and some species ( e.g., Bolivina spissa and Uvigerina peregrina) responded to the change in seasons with a change in their vertical distribution profiles, which is indicative of microhabitat preferences. Species such as Buliminella tenuata changed sediment depth in different stages of their life cycles, which has implications for …


Results Of Vadose Zone Sampling Within The Tri-Basin Natural Resources District, Mark E. Burbach Nov 2005

Results Of Vadose Zone Sampling Within The Tri-Basin Natural Resources District, Mark E. Burbach

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


A Geologic Record Of Methane Consumption Associated With Methane Gas Hydrates At Blake Ridge Region (Continental Rise, Offshore Southeastern United States), Walter S. Borowski, Kathryn G. Takacs, Matthew K. Thompson Nov 2005

A Geologic Record Of Methane Consumption Associated With Methane Gas Hydrates At Blake Ridge Region (Continental Rise, Offshore Southeastern United States), Walter S. Borowski, Kathryn G. Takacs, Matthew K. Thompson

EKU Faculty and Staff Scholarship

Geochemical signals locked within sedimentary rocks are a record of earth processes. Sulfide minerals (elemental sulfur, iron monosulfides, and pyrite) are formed within marine sediments by several different geochemical processes mediated by microbes. Investigating the concentration and sulfur isotopic composition (d34S) of sulfide minerals gives clues about the relative importance of these competing geochemical processes.

Marine sediments of the Blake Ridge(offshore South Carolina and Georgia) contain sulfide minerals that point to anaerobic methane oxidation (AMO) as an important diagenetic process both today and in the recent geological past (Miocene). At the present-day methane-sulfate interface, upward-diffusing methane is consumed …


Sulfide Mineralization In Deep-Water Marine Sediments Related To Methane Transport, Methane Consumption, And Methane Gas Hydrates, Matthew K. Thompson, Walter S. Borowski, Charles K. Paull, William Ussler Iii Apr 2005

Sulfide Mineralization In Deep-Water Marine Sediments Related To Methane Transport, Methane Consumption, And Methane Gas Hydrates, Matthew K. Thompson, Walter S. Borowski, Charles K. Paull, William Ussler Iii

EKU Faculty and Staff Scholarship

Patterns of sulfide sulfur concentration and sulfur isotopic composition (d34 S) are perhaps related to upward methane transport, especially in sediments underlain by methane gas hydrate deposits. Increased methane delivery augments the effect of anaerobic methane oxidation (AMO) occurring at the sulfate-methane interface (SMI). Sulfate and methane co-consumption results in production of dissolved sulfide at the interface that is eventually sequestered within sulfide minerals (elemental sulfur, iron monosulfide, pyrite).

We examine the sediments of two piston cores collected over the Blake Ridge gas hydrate deposits (offshore southeastern United States) by extracting total sedimentary sulfide using chromium reduction. We use …


Prevailing Weather Conditions During Summer Seasons Around Gangotri Glacier, Pratap Singh, Umesh K. Haritashya, K. S. Ramasastri, Naresh Kumar Mar 2005

Prevailing Weather Conditions During Summer Seasons Around Gangotri Glacier, Pratap Singh, Umesh K. Haritashya, K. S. Ramasastri, Naresh Kumar

Department of Earth, Environment and Sustainability Faculty Publications

Meteorological data collected near the snout of the Gangotri Glacier suggest that the study area receives less rainfall. The average seasonal rainfall is observed to be about 260 mm. The rainfall distribution does not show any monsoon impact. Amount of seasonal rainfall is highly variable (131.4-368.8 mm) from year to year, but, in general, August had the maximum rainfall. A verage daily maximum and minimum temperatures were 14.7 and 4.1°C respectively, whereas average mean temperature was 9.4°C. July was recorded as the warmest month. During daytime, wind speed was four times higher than that at night-time. The average daytime and …


Relative Concentration Of Solid-Phase Sulfide Species In Marine Sediments Overlying Gas Hydrate Deposits: Recognition Of The Role Of Anaerobic Methane Oxidation In Authigenic Sulfide Formation, Matthew K. Thompson, Walter S. Borowski, Charles K. Paull, William Ussler Iii Mar 2005

Relative Concentration Of Solid-Phase Sulfide Species In Marine Sediments Overlying Gas Hydrate Deposits: Recognition Of The Role Of Anaerobic Methane Oxidation In Authigenic Sulfide Formation, Matthew K. Thompson, Walter S. Borowski, Charles K. Paull, William Ussler Iii

EKU Faculty and Staff Scholarship

Sulfide mineralization in marine sediments occurs when dissolved sulfide, produced by sulfate reduction processes, combines with dissolved iron to form iron sulfide minerals. Sulfide can be produced by oxidation of organic matter or by anaerobic methane oxidation (AMO), which involves the co-consumption of sulfate and methane. The latter process seems especially important within gas hydrate terrains like that of theBlakeRidge(offshore southeasternUnited States), where appreciable amounts of methane diffuse upward to the base of the sulfate reduction zone, or sulfate-methane interface (SMI).

We examine the sediments of two piston cores collected over the Blake Ridge gas hydrate deposits by sequentially extracting …


Geologic Framework And Groundwater Occurrence (Kimball County, Nebraska), Robert F. Diffendal Jr. Jan 2005

Geologic Framework And Groundwater Occurrence (Kimball County, Nebraska), Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Geologic Framework

All of Kimball County is part of the Cheyenne Tablelands, a largely constructional part of the High Plains underlain primarily by sediments transported from the Rocky Mountains and deposited on the developing tablelands. Quaternary fluvial erosion cut away parts of the tablelands producing the valleys of Lodgepole Creek and its tributaries. The oldest rocks exposed in Kimball County belong to the upper part of the Brule Formation, youngest formation of the White River Group of rocks. The Brule Formation is Oligocene in age and was deposited from about 35 to 29 million years ago. The Brule Formation underlies …


Palaeogeography And Fluvial To Estuarine Architecture Of The Dakota Formation (Cretaceous, Alvian), Eastern Nebraska, Usa, Robert Matthew Joeckel, G. A. Ludvigson, B. J. Witzke, E. P. Kvale, P. L. Phillips, R. L. Brenner, S. G. Thomas, L. M. Howard Jan 2005

Palaeogeography And Fluvial To Estuarine Architecture Of The Dakota Formation (Cretaceous, Alvian), Eastern Nebraska, Usa, Robert Matthew Joeckel, G. A. Ludvigson, B. J. Witzke, E. P. Kvale, P. L. Phillips, R. L. Brenner, S. G. Thomas, L. M. Howard

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Source Of Meta-Igneous Blocks And Structure Of The Colebrooke Schist In The Snowcamp Peak Area, Pickett Peak Terrane, Southwestern Oregon, Jennifer Katrib Jan 2005

Source Of Meta-Igneous Blocks And Structure Of The Colebrooke Schist In The Snowcamp Peak Area, Pickett Peak Terrane, Southwestern Oregon, Jennifer Katrib

Geology Theses and Dissertations

The Colebrooke Schist of the Pickett Peak terrane, southwestern Oregon, is the easternmost, structurally highest unit of the Late Mesozoic-Cenozoic Franciscan Accretionary Complex. The Colebrooke Schist consists of mostly transitional greenschist-blueschist-facies meta-sedimentary rocks with common blocks of meta-volcanics and serpentinites, rare talc-schists and meta-plutonic rocks. The Colebrooke Schist meta-volcanic blocks are greenstones, in many cases with visible relict pillow structures and relict igneous textures.
Fifteen meta-volcanic samples and one meta-plutonic sample were analyzed by XRF and ICP-MS and were plotted with analyses from Plake (1989) and Coleman (1972). The Colebrooke Schist meta-volcanic rocks plot in mid-ocean ridge basalt (MORB), island …


Registered Irrigation Wells In Nebraska August 2005, Conservation And Survey Division Jan 2005

Registered Irrigation Wells In Nebraska August 2005, Conservation And Survey Division

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Keith County Test-Hole Logs: Nebraska Water Survey Test-Hole Report No. 51, Robert F. Diffendal Jr., James W. Goeke Apr 2004

Keith County Test-Hole Logs: Nebraska Water Survey Test-Hole Report No. 51, Robert F. Diffendal Jr., James W. Goeke

Robert F. Diffendal, Jr., Publications

In 1930, the Conservation and Survey Division (CSD) of the University of Nebraska and the U.S. Geological Survey began a program of cooperative groundwater studies in Nebraska. Since then test drilling by use of rotary drilling equipment has been an integral part of that program. This report contains logs of all the test holes drilled in the county under the program as well as those drilled by the Conservation and Survey Division with financial assistance from other government agencies.

The maps in this report show the locations of all test holes drilled in the county since 1934.

Present techniques of …


Sulfide Mineralization In Deep-Water Marine Sediments Related To Methane Transport, Methane Consumption, And Methane Gas Hydrates, Matthew K. Thompson, Walter S. Borowski, Charles K. Paull, William Ussler Iii Mar 2004

Sulfide Mineralization In Deep-Water Marine Sediments Related To Methane Transport, Methane Consumption, And Methane Gas Hydrates, Matthew K. Thompson, Walter S. Borowski, Charles K. Paull, William Ussler Iii

EKU Faculty and Staff Scholarship

Patterns of sulfide sulfur concentration and sulfur isotopic composition (d34 S) are perhaps related to upward methane transport, especially in sediments underlain by methane gas hydrate deposits. Increased methane delivery augments the effect of anaerobic methane oxidation (AMO) occurring at the sulfate-methane interface (SMI). Sulfate and methane co-consumption results in production of dissolved sulfide at the interface that is eventually sequestered within sulfide minerals (elemental sulfur, iron monosulfide, pyrite).

We examine the sediments of two piston cores collected over the Blake Ridge gas hydrate deposits (offshore southeastern United States) by extracting total sedimentary sulfide using chromium reduction. We use …


Geomorphic And Environmental Change Around A Large, Aging Reservoir: Lake C. W. Mcconaughy, Western Nebraska, Usa, R. Matthew Joeckel, Robert F. Diffendal Jr. Feb 2004

Geomorphic And Environmental Change Around A Large, Aging Reservoir: Lake C. W. Mcconaughy, Western Nebraska, Usa, R. Matthew Joeckel, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Lake C. W. McConaughy, a 63-year-old manmade reservoir in the North Platte Valley of western Nebraska, is the largest standing body of water in the state. From the time that Kingsley Dam was completed in 1941 until the present day (2004), many geomorphic and environmental changes have occurred along the shores and within the North Platte Valley. Erosion on the southeastern shoreline of the lake had been perceived as a problem for landowners and managers for at least three decades, but the full scale of erosion was revealed only after a cumulative 18-m drawdown in lake level: bedrock platforms, extending …


Groundwater-Level Changes In Nebraska - Spring 2002 To Spring 2003/Groundwater-Level Changes In Nebraska - Predevelopment To Spring 2003, Conservation Survey Division Jan 2004

Groundwater-Level Changes In Nebraska - Spring 2002 To Spring 2003/Groundwater-Level Changes In Nebraska - Predevelopment To Spring 2003, Conservation Survey Division

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Late-Holocene Dune Activity Linked To Hydrological Drought, Nebraska Sand Hills, Usa, Joseph A. Mason, James B. Swinehart, Ronald J. Goble, David B. Loope Jan 2004

Late-Holocene Dune Activity Linked To Hydrological Drought, Nebraska Sand Hills, Usa, Joseph A. Mason, James B. Swinehart, Ronald J. Goble, David B. Loope

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Lincoln County Test Hole Logs, James W. Goeke Jan 2004

Lincoln County Test Hole Logs, James W. Goeke

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Semianalytical Solutions For Stream Depletion In Partially Penetrating Streams, Xunhong Chen, Yanfeng Yin Jan 2004

Semianalytical Solutions For Stream Depletion In Partially Penetrating Streams, Xunhong Chen, Yanfeng Yin

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Hitchcock County Test Hole Logs, Duane A. Eversoll Jan 2004

Hitchcock County Test Hole Logs, Duane A. Eversoll

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Mcpherson County Test Hole Logs, James W. Goeke Jan 2004

Mcpherson County Test Hole Logs, James W. Goeke

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Webster County Test Hole Logs, Scott E. Summerside Jan 2004

Webster County Test Hole Logs, Scott E. Summerside

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Review Of Geologic Factors Affecting Underground Limestone Mining In The U.S. And An Overview Of Underground Limestone Mining In Nebraska, R. M. Joeckel Jan 2004

Review Of Geologic Factors Affecting Underground Limestone Mining In The U.S. And An Overview Of Underground Limestone Mining In Nebraska, R. M. Joeckel

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Sulfide Mineralization In Deep-Water Marine Sediments Related To Methane Transport, Methane Consumption, And Methane Gas Hydrates, Matthew K. Thompson, Walter S. Borowski, Charles K. Paull, William Ussler Iii Nov 2003

Sulfide Mineralization In Deep-Water Marine Sediments Related To Methane Transport, Methane Consumption, And Methane Gas Hydrates, Matthew K. Thompson, Walter S. Borowski, Charles K. Paull, William Ussler Iii

EKU Faculty and Staff Scholarship

Patterns of sulfide sulfur concentration and sulfur isotopic composition (d34S) are perhaps related to upward methane transport, especially in sediments underlain by methane gas hydrate deposits. Increased methane delivery augments the affect of anaerobic methane oxidation (AMO) occurring at the sulfate-methane interface (SMI). Sulfate and methane co-consumption results in production of dissolved sulfide at the interface that is eventually sequestered within sulfide minerals (elemental sulfur, iron monosulfide, pyrite).

We examine the sediments of two piston cores collected over the Blake Ridge gas hydrate deposits (offshore southeastern North America) by extracting total sedimentary sulfide using chromium reduction. We use …


History, Geology And Water In The Lower Platte River Valley In Eastern Nebraska, Dave Gosselin, Marv Carlson, Matt Joeckel Jun 2003

History, Geology And Water In The Lower Platte River Valley In Eastern Nebraska, Dave Gosselin, Marv Carlson, Matt Joeckel

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Southeast Nebraska Geology: Field Trip 3, Roger K. Pabian, Robert F. Diffendal, Jr. Jr., Darwin R. Boardman Ii Jun 2003

Southeast Nebraska Geology: Field Trip 3, Roger K. Pabian, Robert F. Diffendal, Jr. Jr., Darwin R. Boardman Ii

Robert F. Diffendal, Jr., Publications

The purpose of this trip is to familiarize you with the latest Pennsylvanian and earliest Permian rocks that are exposed in extreme southeastern Nebraska. You will see eight exposures of these rocks and will have ample opportunity to collect lithologic samples, as well as samples for both macro- and micro-fossils. The stops have been selected to show you examples of several different environments that existed in southeastern Nebraska in the late Paleozoic. These include subaerial deposits with paleosols, nearshore and offshore marine clastic and carbonate sequences. Each stop is covered in detail in the handouts that have been furnished to …


Ashfall Historic Park: Field Trip 5, Robert F. Diffendal Jr. Jun 2003

Ashfall Historic Park: Field Trip 5, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Ashfall Fossill Beds: A State Historical Park. Brochure. Nebraska Game and Parks Commission and University of Nebraska State Museum

Research Reports, 1978. Projects: A Miocene Rhinoceros Herd Buried in Volcanic Ash. Grant Recipient: Michael R. Voorhies, Division of Vertebrate Paleontology, University of Nebraska State Museum, Lincoln, Nebraska.

Geologic Framework of the Niobrara River Drainage Basin and Adjacent Areas in South Dakota Generally East of the 100th Meridian West Longitude and West of the Missouri River Robert F. Diffendal, Jr. and Michael R. Voorhies. Nebraska Geological Survey Report of Investigations, number 9.