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Articles 751 - 780 of 1754

Full-Text Articles in Geology

Banner County Test Hole Logs, Frank A. Smith Jan 2002

Banner County Test Hole Logs, Frank A. Smith

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Creep Critters From Nebraska's Past, Roger K. Pabian Jan 2002

Creep Critters From Nebraska's Past, Roger K. Pabian

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Field Trip Guide (For The Nebraska Well Drillers Association) Southwestern Nebraska Geology, D. Eversoll Jan 2002

Field Trip Guide (For The Nebraska Well Drillers Association) Southwestern Nebraska Geology, D. Eversoll

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Scotts Bluff County Test Hole Logs, Vincent H. Dreeszen, Steven S. Sibray, Frank A. Smith Jan 2002

Scotts Bluff County Test Hole Logs, Vincent H. Dreeszen, Steven S. Sibray, Frank A. Smith

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


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 …


Island Arcs, Accretionary Terranes And Midcontinent Structure New Understandings Of The Geologic Architecture Of The U.S. Midcontinent, Marvin P. Carlson Oct 2001

Island Arcs, Accretionary Terranes And Midcontinent Structure New Understandings Of The Geologic Architecture Of The U.S. Midcontinent, Marvin P. Carlson

Conservation and Survey Division: Faculty and Staff Publications

A data base collected over the last 100 years, containing both surface and subsurface information, has allowed us to begin to understand the physical framework of Nebraska. We have learned that even in the stable Midcontinent region of North America, there has been an active geologic history. This framework has been deciphered by our programs of surface geologic mapping and by the study of rock samples from both water wells and those deeper test wells for oil and gas. Determining the major structural features across the state (figure 1) has allowed us to better understand both the occurrences of its …


Environmental Change And The Central Great Plains, Carbon Sequestration, Mark A. Mesarch Aug 2001

Environmental Change And The Central Great Plains, Carbon Sequestration, Mark A. Mesarch

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Environmental Change And The Central Great Plains, David Gosselin Apr 2001

Environmental Change And The Central Great Plains, David Gosselin

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Environmental Change And The Central Great Plain, Water Resources, David Gosselin Apr 2001

Environmental Change And The Central Great Plain, Water Resources, David Gosselin

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Agricultural Management Practices And The Groundwater System Of Northern Holt County, Nebraska, With A Focus On The Holt County Groundwater Education Project, Susan Olafsen Lackey, Charles Shapiro, William Kranz Apr 2001

Agricultural Management Practices And The Groundwater System Of Northern Holt County, Nebraska, With A Focus On The Holt County Groundwater Education Project, Susan Olafsen Lackey, Charles Shapiro, William Kranz

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Nebraska's Test-Hole Drilling Program And Records, Duane R. Mohlman, Charles A. Flowerday Mar 2001

Nebraska's Test-Hole Drilling Program And Records, Duane R. Mohlman, Charles A. Flowerday

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Geology Of Pioneers Park, Lancaster County, Nebraska, Roger K. Pabian Mar 2001

Geology Of Pioneers Park, Lancaster County, Nebraska, Roger K. Pabian

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


In-Cave Dye Tracing And Drainage Basin Divides In The Mammoth Cave Karst Aquifer, Kentucky, Chris Groves, Joe Meiman, Shannon Herstein Feb 2001

In-Cave Dye Tracing And Drainage Basin Divides In The Mammoth Cave Karst Aquifer, Kentucky, Chris Groves, Joe Meiman, Shannon Herstein

Earth, Environmental, and Atmospheric Sciences Faculty Publications

Karst ground-water basin divides are generally depicted as two-dimensional lines on maps, but they are better considered as three-dimensional surfaces within the subsurface. Dye traces are necessary to map out these surfaces and to locate conduits inaccessible to cave surveyors, and are indispensable for understanding the geometry of the complex networks of flow paths through the aquifer. A key reason why the Mammoth Cave System is the world's longest known cave is that its passages extend over several major ground-water basins. The divides between these basins define the drainage system geometry and precise location of them is critical for understanding …


Refined Kinematics Of The Eastern California Shear Zone From Gps Observations, 1993-1998, M. Meghan Miller, Timothy H. Dixon, Roy K. Dokka Feb 2001

Refined Kinematics Of The Eastern California Shear Zone From Gps Observations, 1993-1998, M. Meghan Miller, Timothy H. Dixon, Roy K. Dokka

All Faculty Scholarship for the College of the Sciences

Global Positioning System (GPS) results from networks spanning the Eastern California shear zone and adjacent Sierra Nevada block, occupied annually between 1993 and 1998, constrain plate margin kinematics. We use an elastic block model to relate GPS station velocities to long‐term fault slip rate estimates. The model accounts for elastic strain accumulation on the San Andreas fault, as well as faults of the Eastern California shear zone. South of the Garlock fault, 14 mm/yr of dextral shear is distributed across the Eastern California shear zone. Some of this slip penetrates eastward into the Basin and Range, and a collective budget …


Ecoregions Of Nebraska And Kansas, Robert F. Diffendal Jr. Jan 2001

Ecoregions Of Nebraska And Kansas, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Ecoregions denote areas of general similarity in ecosystems and in the type, quality, and quantity of environmental resources; they are designed to serve as a spatial framework for the research, assessment, management, and monitoring of ecosystems and ecosystem components. Ecoregions are directly applicable to the immediate needs of state agencies, including the development of biological criteria and water quality standards, and the establishment of management goals for nonpoint-source pollution. They are also relevant to integrated ecosystem management, an ultimate goal of most federal and state resource management agencies. The approach used to compile this map is based on the premise …


Hydrogeology And Hydrochemistry Of The Jumbo And Pullman Valley Fens, Cherry County, Nebraska, F. E. Harvey, J. B. Swinehart, T. M. Kurtz Jan 2001

Hydrogeology And Hydrochemistry Of The Jumbo And Pullman Valley Fens, Cherry County, Nebraska, F. E. Harvey, J. B. Swinehart, T. M. Kurtz

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Adams County Test Hole Logs, Perry B. Wigley Jan 2001

Adams County Test Hole Logs, Perry B. Wigley

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


At-Satellite Reflectance: A First Order Normalization Of Landsat 7 Etm+ Images, Chengquan Huang, Limin Yang, Collin Homer, Bruce K. Wylie, James E. Vogelmann, Thomas Defelice Jan 2001

At-Satellite Reflectance: A First Order Normalization Of Landsat 7 Etm+ Images, Chengquan Huang, Limin Yang, Collin Homer, Bruce K. Wylie, James E. Vogelmann, Thomas Defelice

United States Geological Survey: Publications

Regional Landsat applications often rely on clear and near cloud-free images. With the spectral value being represented by digital number (DN), however, such images contain substantial noises. A significant proportion of such noises can be normalized by converting the DN to at-satellite reflectance value. Being physically based and ready to automate, the conversion method can serve as a first order normalization of Landsat 7 images, making it possible to derive land surface information from such images more consistently.


A Strategy For Estimating Tree Canopy Density Using Landsat 7 Etm+ And High Resolution Images Over Large Areas, C. Huang, Limin Yang, Bruce K. Wylie, Collin Homer Jan 2001

A Strategy For Estimating Tree Canopy Density Using Landsat 7 Etm+ And High Resolution Images Over Large Areas, C. Huang, Limin Yang, Bruce K. Wylie, Collin Homer

United States Geological Survey: Publications

INTRODUCTION

The Multi-Resolution Land Characteristics (MRLC) consortium was initiated in early 1990s to address the need for consistently developed national and regional land cover data (Loveland and Shaw, 1996). Through this consortium, a 1992-vintage National Land Cover Dataset (NLCD) was developed for the conterminous United States (Vogelmann et al., 2001), and a second generation National Land Cover Dataset (NLCD 2000) will be developed using 2000-vintage Landsat 7 Enhanced Thematic Mapper Plus (ETM+) images and ancillary data. The 2000 NLCD will consist of a suite of data layers relevant to many applications, including a tree canopy density layer describing percentage of …


Field Trip Guide (For The Nebraska Well Drillers Association) Western Nebraska Geology, J. Cannia, D. Weinert, D. Brost, C. Miller, D. Carlson Jan 2001

Field Trip Guide (For The Nebraska Well Drillers Association) Western Nebraska Geology, J. Cannia, D. Weinert, D. Brost, C. Miller, D. Carlson

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Logan County Test Hole Logs, Perry B. Wigley Jan 2001

Logan County Test Hole Logs, Perry B. Wigley

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


The Great Plains Natural Resources And Environmental Change Survey Report, D. C. Gosselin, R. Levy, D. Geise Jan 2001

The Great Plains Natural Resources And Environmental Change Survey Report, D. C. Gosselin, R. Levy, D. Geise

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Population Characteristics And Food Habitats Of White Perch (Morone Americana) In Branched Oak, Nebraska, Cara Hodking Jan 2001

Population Characteristics And Food Habitats Of White Perch (Morone Americana) In Branched Oak, Nebraska, Cara Hodking

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Saunders County Test Hole Logs, Raymond R. Burchett, Scott E. Summerside Jan 2001

Saunders County Test Hole Logs, Raymond R. Burchett, Scott E. Summerside

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Resource Notes-Academic Year 2000-01 Jan 2001

Resource Notes-Academic Year 2000-01

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


New Kinematic Models For Pacific‐North America Motion From 3 Ma To Present, Ii: Evidence For A “Baja California Shear Zone”, Timothy Dixon, Fred Farina, Charles Demets, Francisco Suarez-Vidal, John Fletcher, Bertha Marquez-Azua, M. Meghan Miller, Osvaldo Sanchez, Paul Umhoefer Dec 2000

New Kinematic Models For Pacific‐North America Motion From 3 Ma To Present, Ii: Evidence For A “Baja California Shear Zone”, Timothy Dixon, Fred Farina, Charles Demets, Francisco Suarez-Vidal, John Fletcher, Bertha Marquez-Azua, M. Meghan Miller, Osvaldo Sanchez, Paul Umhoefer

All Faculty Scholarship for the College of the Sciences

We use new models for present‐day Pacific‐North America motion to evaluate the tectonics of offshore regions west of the Californias. Vandenburg in coastal Alta California moves at the Pacific plate velocity within uncertainties (∼1 mm/yr) after correcting for strain accumulation on the San Andreas and San Gregorio‐Hosgri faults with a model that includes a viscoelastic lower crust. Modeled and measured velocities at coastal sites in Baja California south of the Agua Blanca fault, a region that most previous models consider Pacific plate, differ by 3–8 mm/yr, with coastal sites moving slower that the Pacific plate. We interpret these discrepancies in …


Field Trip Guide (For The Nebraska Well Drillers Association) Eastern Nebraska Geology, Scott Summerside, Duane Eversoll, Mark Kuzila, Matt Joeckel Sep 2000

Field Trip Guide (For The Nebraska Well Drillers Association) Eastern Nebraska Geology, Scott Summerside, Duane Eversoll, Mark Kuzila, Matt Joeckel

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Arthur County Test-Hole Logs: Nebraska Water Survey Test-Hole Report No. 3, Robert F. Diffendal Jr., James W. Goeke Sep 2000

Arthur County Test-Hole Logs: Nebraska Water Survey Test-Hole Report No. 3, 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 United States 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 Arthur 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 …


Keith County Test-Hole Logs: Nebraska Water Survey Test-Hole Report No. 51, Robert F. Diffendal Jr., James W. Goeke Jul 2000

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 (Figure la–d).

Present …


Field Trip Guide For The Upper Republican And Middle Republican Nrd's Southwestern Nebraska Geology And Soils, Duane Eversoll, Jim Goeke, Mark Kuzila Mar 2000

Field Trip Guide For The Upper Republican And Middle Republican Nrd's Southwestern Nebraska Geology And Soils, Duane Eversoll, Jim Goeke, Mark Kuzila

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.