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Geomorphology Commons

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1991

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Articles 1 - 29 of 29

Full-Text Articles in Geomorphology

Groundwater Levels In Nebraska, 1990, Gregory V. Steele, Perry B. Wigley Dec 1991

Groundwater Levels In Nebraska, 1990, Gregory V. Steele, Perry B. Wigley

Conservation and Survey Division

No abstract provided.


The Geomorphology Of Alluvial Fan Deposits On The West Flank Of The Blue Ridge, Augusta County, Virginia, Debra Lynn Duffy Oct 1991

The Geomorphology Of Alluvial Fan Deposits On The West Flank Of The Blue Ridge, Augusta County, Virginia, Debra Lynn Duffy

OES Theses and Dissertations

Large coalescing alluvial fans mantle the carbonate and shale formations west of the Blue Ridge mountains near Stuarts Draft, Virginia. Fan sediments are predominantly boulder and cobble gravels derived from the Antietam Quartzite, The fan complex consists of three alluvial units of significantly different ages. The surface of each fan unit was mapped using relative geomorphic position, soil color, clay content and thickness of Bt horizons, clast weathering, and degree of removal of depositional surfaces by stream incision. A five-category quartzite clast weathering scale developed for this study was very effective as a measure to distinguish map units. Stratigraphic data …


Scanning Electron Microscopic Study Of Quartz Sand Surface Features, Ash Hollow Formation, Ogallala Group, Western Nebraska, Patricia E. Helland, Robert F. Diffendal Jr. Apr 1991

Scanning Electron Microscopic Study Of Quartz Sand Surface Features, Ash Hollow Formation, Ogallala Group, Western Nebraska, Patricia E. Helland, Robert F. Diffendal Jr.

School of Natural Resources: Faculty Publications

In field studies of the late Tertiary Ash Hollow Formation of the Ogallala Group in western Nebraska the alluvial deposits are composed of large volumes of sand and gravel up to large cobbles. Because the current understanding of the climate of the region at the time of deposition does not provide for a source for deposits of this character, a scanning electron microscopic study of the surface features on the quartz sand grains from these sediments was undertaken. Nine samples, collected from locations in Banner, Morrill and Keith Counties, were examined to see if they had one or more of …


Plate Tectonics, Space, Geologic Time, And The Great Plains: A Primer For Non-Geologists, Robert F. Diffendal Jr. Apr 1991

Plate Tectonics, Space, Geologic Time, And The Great Plains: A Primer For Non-Geologists, Robert F. Diffendal Jr.

School of Natural Resources: Faculty Publications

For most Americans, "The Great Plains" evokes images of grasslands, dust storms, prairie fires, Native Americans on horseback, cowboys and wheat lands, and perhaps flat valleys crossed by braided rivers carrying a heavy load of sand and gravel, extremes of weather, and a climate typified by an alternation of droughts and wetter periods. Geologists picture such general images, too, but they also see radical changes in the landscape over periods expressed in millions rather than hundreds of years. Geologically speaking, human activities on the Great Plains are too recent to have much of a place in the broad geologic history …


Late Paleozoic Cyclic Sedimentation In Southeastern Nebraska: A Field Guide, Roger K. Pabian, Robert F. Diffendal Jr. Apr 1991

Late Paleozoic Cyclic Sedimentation In Southeastern Nebraska: A Field Guide, Roger K. Pabian, Robert F. Diffendal Jr.

School of Natural Resources: Faculty Publications

People studying and collecting sedimentary rocks, minerals, and fossils in eastern Nebraska often find that locating rock exposures can be difficult. Most of the rolling hills in the eastern sixth of the state are underlain by thick, interlayered, glacial deposits, loess (windblown silt), and alluvium (stream-deposited sediments) of very young geologic age. These sediments cover the bedrock in most of that area. Natural exposures and human excavations of bedrock are mostly confined to the sides and floors of stream valleys. However, in the southeasternmost counties of the state, the younger sediment cover is commonly thin or absent. Pawnee and Richardson …


Late Paleozoic Cyclic Sedimentation In Southeastern Nebraska: A Field Guide, Roger K. Pabian, Robert F. Diffendal Jr. Apr 1991

Late Paleozoic Cyclic Sedimentation In Southeastern Nebraska: A Field Guide, Roger K. Pabian, Robert F. Diffendal Jr.

Conservation and Survey Division

A field guide to Late Paleozoic cyclic sedimentation in southeastern Nebraska.


Bazile Triangle Groundwater Quality Study, David C. Gosselin Mar 1991

Bazile Triangle Groundwater Quality Study, David C. Gosselin

Conservation and Survey Division

No abstract provided.


Facts And Figures About Nebraska Rivers, Ray Bentall Feb 1991

Facts And Figures About Nebraska Rivers, Ray Bentall

Conservation and Survey Division

No abstract provided.


Ice-Wedge Casts Of Wisconsinan Age In Eastern Nebraska, William J. Wayne Jan 1991

Ice-Wedge Casts Of Wisconsinan Age In Eastern Nebraska, William J. Wayne

Department of Earth and Atmospheric Sciences: Faculty Publications

Sand-filled, wedge-shaped structures beneath a thin layer of aeolian sand penetrate a preIllinoian till and gravel in northeastern Nebraska. Interpreted to be relic thermal contraction crack wedges, they provide the first definite evidence in this State of the former presence of permafrost. The wedges are 5- 7 m apart, 1.8-2.8 m deep and 0.6-0.9 m across at the top, taper downward to a crack and intersect to form polygons. They are filled with medium sand that contains mostly rounded and frosted grains. Vertical fabric is present in each wedge. Ventifacts lie along the top of the till, which is covered …


Slickenside Petrography: Slip-Sense Indicators And Classification, Young-Joon Lee Jan 1991

Slickenside Petrography: Slip-Sense Indicators And Classification, Young-Joon Lee

Geology Theses and Dissertations

Petrographic study has been carried out on slickenside thin sections, to find out reliable microstructures for determining the slip-sense of faults, and to classify slickensides morphologically. Thin sections are made cut parallel to the striation and perpendicular to the slip plane. Many useful slip-sense indicators are found in thin section even though such indicators may be absent in hand specimens. They are (1) off-set or bending of once-continuous bodies such as veins, layers, grains or twin lamellae, (2) crystal fibers growing nearly parallel to the slip direction, (3) extensional fractures aligned oblique to the slip plane, (4) S-C geometries in …


Annual Report Of Nebraska-1991, Eileen K. Peterson, Raymond R. Burchett Jan 1991

Annual Report Of Nebraska-1991, Eileen K. Peterson, Raymond R. Burchett

Conservation and Survey Division

No abstract provided.


Groundwater Levels In Nebraska, 1990, Gregory V. Steele, Perry B. Wigley Jan 1991

Groundwater Levels In Nebraska, 1990, Gregory V. Steele, Perry B. Wigley

Conservation and Survey Division

No abstract provided.


Explanation Of Water-Level Hydrographs, P. B. Wigley, M. J. Ellis, G. V. Steele Jan 1991

Explanation Of Water-Level Hydrographs, P. B. Wigley, M. J. Ellis, G. V. Steele

Conservation and Survey Division

No abstract provided.


Nebraska Mineral Operations Review, 1990, Raymond R. Burchett, Duane A. Eversoll Jan 1991

Nebraska Mineral Operations Review, 1990, Raymond R. Burchett, Duane A. Eversoll

Conservation and Survey Division

No abstract provided.


Annual Installation Of Irrigation Wells In Nebraska Through 1990, Conservation Survey Division Jan 1991

Annual Installation Of Irrigation Wells In Nebraska Through 1990, Conservation Survey Division

Conservation and Survey Division

No abstract provided.


Conservation And Survey Division, 1991. Annual Outflow/Inflow Of Water From Nebraska, 1950-1990, Conservation Survey Divis Jan 1991

Conservation And Survey Division, 1991. Annual Outflow/Inflow Of Water From Nebraska, 1950-1990, Conservation Survey Divis

Conservation and Survey Division

No abstract provided.


Development Of A Land Cover Characteristics Data Base For The Conterminous U.S., Thomas R. Loveland, James W. Merchant, Donald O. Ohlen, Jesslyn F. Brown Jan 1991

Development Of A Land Cover Characteristics Data Base For The Conterminous U.S., Thomas R. Loveland, James W. Merchant, Donald O. Ohlen, Jesslyn F. Brown

Conservation and Survey Division

No abstract provided.


Chemical Analyses Of Water From Selected Wells And Springs In The Yucca Mountain Area, Nevada And Southeastern California, P. W. Mckinley, M. P. Long, Larry Benson Jan 1991

Chemical Analyses Of Water From Selected Wells And Springs In The Yucca Mountain Area, Nevada And Southeastern California, P. W. Mckinley, M. P. Long, Larry Benson

Publications of the US Geological Survey

Chemical analysis of water samples from 279 wells and springs in the Yucca Mountain area are presented. Where data are available, this report includes: site location expressed as Nevada Central Coordinates and latitude and longitude; source of data; name of analyzing laboratory; geologic unit from which water was obtained; lithology; water use; elevation of well or spring; well depth; depth to water; time pumped before taking the sample; yield; type of filtration; sampling method; date the sample was collected; and anion-cation balance.

Yucca Mountain, Nevada (fig. 1), is being investigated by the U.S. Geological Survey, in cooperation with the U.S. …


Geologic Map Showing Configuration Of The Bedrock Surface, North Platte, 1 ° X 2 ° Quadrangle, Nebraska, Robert F. Diffendal Jr. Jan 1991

Geologic Map Showing Configuration Of The Bedrock Surface, North Platte, 1 ° X 2 ° Quadrangle, Nebraska, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

The map area, in west-central Nebraska, is largely covered by surficial deposits of eolian sand, loess, and alluvium ranging in age from Holocene to Pliocene. Holocene and late Pleistocene(?) eolian sand, as much as 300 ft (91 m) thick, covers most of the area north of the North Platte and Platte Rivers, and also covers a small area south of those rivers. The Peoria Loess of Quaternary age overlies most of the remaining upland north of the Platte River in southwestern Logan, northeastern Lincoln, and much of western Custer and extreme northwestern Dawson Counties. Loess also mantles the divide between …


Investigation Of Isolated Sand Shoals On The Inner Shelf Of Southern Virginia : Final Report, Suzette M. Kimball, James K. Dame, Carl H. Hobbs Iii Jan 1991

Investigation Of Isolated Sand Shoals On The Inner Shelf Of Southern Virginia : Final Report, Suzette M. Kimball, James K. Dame, Carl H. Hobbs Iii

Reports

Offshore of Sandbridge Beach, Virginia, the surface of the inner continental shelf is a generally featureless, gently sloping plain, broken by several isolated sand shoals. The westernmost shoal, commonly called the Sandbridge Shoal, is located approximately 5.5 km from the shoreline in 1 O - 12 m of water. An analogous feature is located approximately 15 km northeast of the Sandbridge Shoal at depths greater than 15 m. During a pretiminary study conducted in 1987, 534 km of trackline were surveyed with acoustic subbottom and side-scan sonar systems. Geophysical data were recorded for an additional 318 km of trackline between …


Master Of Science Theses And Doctor Of Philosophy Dissertations, Dept. Of Geology, University Of Nebraska-Lincoln, R. R. Burchett Jan 1991

Master Of Science Theses And Doctor Of Philosophy Dissertations, Dept. Of Geology, University Of Nebraska-Lincoln, R. R. Burchett

Conservation and Survey Division

No abstract provided.


Groundwater-Level Changes In Nebraska, Predevelopment To Fall 1991, Conservation Survey Division Jan 1991

Groundwater-Level Changes In Nebraska, Predevelopment To Fall 1991, Conservation Survey Division

Conservation and Survey Division

No abstract provided.


Thurston County Test Hole Logs, Raymond R. Burchett, Frank A. Smith Jan 1991

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

Conservation and Survey Division

No abstract provided.


Resource News-November/December 1991 Jan 1991

Resource News-November/December 1991

Conservation and Survey Division

No abstract provided.


Ocher Deposits In Nebraska, R. R. Burchett Jan 1991

Ocher Deposits In Nebraska, R. R. Burchett

Conservation and Survey Division

No abstract provided.


Cement Operations In Nebraska, R. R. Burchett Jan 1991

Cement Operations In Nebraska, R. R. Burchett

Conservation and Survey Division

No abstract provided.


Radon Deposits In Nebraska, R. R. Burchett Jan 1991

Radon Deposits In Nebraska, R. R. Burchett

Conservation and Survey Division

No abstract provided.


Composite Section Of Outcropping Rocks Along The Missouri River, R. R. Burchett Jan 1991

Composite Section Of Outcropping Rocks Along The Missouri River, R. R. Burchett

Conservation and Survey Division

No abstract provided.


Peat Deposits In Nebraska, R. R. Burchett Jan 1991

Peat Deposits In Nebraska, R. R. Burchett

Conservation and Survey Division

No abstract provided.