Earth Sciences Commons^™

Estimate Of Livestock Water Use In Nebraska During 1980, Eugene K. Steele Jr.

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Age Of The Earliest African Anthropoids, John G. Fleagle, Thomas M. Bown, John D. Obradovich, Elwyn L. Simons

United States Geological Survey: Staff Publications

The earliest fossil record of African anthropoid prunates (monkeys and apes) comes from the Jebel Qatrani Formation in the Fayum depression of Egypt. Reevaluation of both geologic and faunal evidence indicates that this formation was deposited in the early part of the Oligocene Epoch, more than 31 million years ago, earlier than previous estimates. The great antiquity of the fossil higher prunates from Egypt accords well with their primitive morphology compared with later Old World higher prunates. Thus, the anthropoid primates and hystricomorph rodents from Fayum are also considerably older than the earliest higher primates and rodents from South America.

Thalassiosira Praeoestrupii- A New Diatom Species For Recognizing The Miocene/Pliocene Epoch Boundary In Coastal California, Michael P. Dumont, Jack G. Baldauf, John A. Barron

United States Geological Survey: Staff Publications

A new diatom species, Thalassiosira praeoestrupii Dumont, Baldauf and Barron, is described. The first occurrence of T. praeoestrupii in coastal California diatom-bearing outcrops occurs between the last occurrence of Rouxia californica at 6.0 Ma, and the first occurrence of Thalassiosira oestrupii at 5.1 Ma. The latter two species have customarily been used to identify the Miocene/Pliocene boundary. Paleomagnetic studies at Santa Cruz, California, demonstrate that the first occurrence of T. praeoestrupii coincides with the top of magnetic polarity Chron 5, which closely approximates the Miocene/Pliocene Epoch boundary.

Reconnaissance Bathymetry Of Basins Occupied By Pleistocene Lake Lahontan, Nevada And California, Larry Benson, M. D. Mifflin

United States Geological Survey: Staff Publications

Beginning about 12,500 years B.P., Lake Lahontan began to decline (fig. 1: Black Rock Desert data from Davis [1983]; Truckee River Delta data from Born [1972]; tufa data from Benson [1981]; packrat-midden data from Thompson and others [1985]) . As water levels declined, their altitudes fell below sill altitudes (table 1); locations of these sills are shown in figure 2. Today, five surface-water bodies (Black Rock Playa, Humboldt-Carson Sink, Walker Lake, Pyramid Lake, Honey Lake) exist in four of the seven subbasins (fig. 2).

The collective surface area of the modern lakes today (1985) totals less than 1,600 km2 . …

Discovery Of Two Additional Prosimian Primate Families (Omomyidae, Lorisidae) In The African Oligocene, Elwyn L. Simons, Thomas M. Bown, D. Tab Rasmussen

United States Geological Survey: Staff Publications

Three new specimens reported here are referable to the Omomyidae and Lorisidae, and represent only the second and third prosimian primates found in the Oligocene rocks of the Fayum, Egypt. The Fayum omomyid extends the range of the Omomyidae into Africa, while the Fayum lorisid is the oldest record of the Lorisidae world-wide. Afrotarsius established ?Tarsiidae as a third prosimian family present in Oligocene rocks of the Fayum region of Egypt (Simons & Bown, 1985). These new occurrences significantly reorient paleogeographic study of primate origins. In a fauna famed for the presence of about a thousand specimens of early Anthropoidea-viz. …

A Possible Mechanism For The Diurnal Oscillations Of Tropical Cyclones, Jay S. Hobgood

Department of Earth and Atmospheric Sciences: Faculty Publications

A possible mechanism for the diurnal oscillations of tropical cyclones is presented. In the conceptual model developed to explain these features, the diurnal cycle of net radiation at the cloud tops is identified as the primary cause of the oscillations. Radiative cooling of the cloud tops at night steepens the lapse rate and increases convection. This generates a slight intensification in the storm. The reverse occurs during the daytime as the cloud tops absorb solar radiation. This process may be augmented by differential cooling of cloudy and clear areas.

This conceptual model is tested through the use of a numerical …

Annual Outflow Of Water From Nebraska, 1950-1985, Conservation Survey Division

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Nebraska Mineral Operations Review, 1985, Ray R. Burchett, Duane A. Eversoll

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Annual Outflow/Inflow Of Water From Nebraska, 1950-1985, Conservation And Survey Division

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Thiram And Methiocarb As Deer Mouse Repellents And Agents For Conditioned Aversion, Bobbi A. Holm

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

The Amphibians And Reptiles Of Nebraska, George E. Hudson

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Overview Of Nebraska And The Regional Aquifer From Proceedings Of The 1985 Water Resources Seminar Series, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

During each spring semester, the Nebraska Water Resources Center sponsors a Water Resources Seminar Series at the University of Nebraska-Lincoln. The 1985 seminar series was entitled "Aspects of Groundwater Quality." This article appeared in the proceedings.

Aspects Of Groundwater Quality Proceedings 1985 Water Resources Seminar Series

Conservation and Survey Division: Faculty and Staff Publications

During each spring semester, the Nebraska Water Resources Center sponsors a Water Resources Seminar Series at the University of Nebraska - Lincoln. The 1985 seminar series was entitled "Aspects of Groundwater Quality".

Groundwater Levels In Nebraska 1984, Michael J. Ellis, Darryll T. Pederson

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Groundwater Levels In Nebraska, 1984, Michael J. Ellis, Darryll T. Pederson

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Changes In Photosynthesis Rate In Pinus Sylvestris L. And Pinus Banksiana Lamb Seedlings Subjected To Drought Stress, George A. Riggs Jr.

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

Sedimentation In A Blast-Zone Lake At Mount St. Helens, Washington-Implications For Varve Formation, Roger Y. Anderson, Edward Nuhfer, Walter E. Dean

United States Geological Survey: Staff Publications

Sediment collected in traps in a newly formed lake in the blast-impact area at Mount St. Helens recorded a sediment yield that is about two orders of magnitude greater than for comparable basins with vegetation and similar precipitation. Most sediment was mobilized by storms and run off at the onset of the wet season. The sedimentation response to strongly seasonal precipitation, in the absence of vegetation, produced turbidites and graded annual couplets. The style of sedimentation suggests an alternate mechanism for the formation of long sequences of graded clastic varves.

Magnetic Polarity Stratigraphy And Mammalian Fauna Of The Deseadan (Late Oligocene-Early Miocene) Salla Beds Of Northern Bolivia, Bruce J. Macfadden, Kenneth E. Campbell Jr., Richard L. Cifelli, Oscar Siles, Noye M. Johnson, Charles W. Naeser, Peter K. Zeitler

United States Geological Survey: Staff Publications

The Salla Beds contain a rich assemblage of Deseadan mammals that traditionally has been considered of early Oligocene age. These deposits, located 90-100 km SE of La Paz, Bolivia, consist of more than 540 m of principally fluviatile clays and silts with numerous interbedded tuffs. Paleomagnetic samples were collected from 104 sites spaced at stratigraphic intervals of about 6 m. As a result of thermal demagnetization (at 400°Co r greater), unambiguous polarities were determined for 76 of the 104 originally sampled ites. The pattern of reversals, stage of evolution of the fossils, and preliminary isotopic dates (including a K/Ar age …

Middle Miocene To Recent Stratigraphy And Paleogeography Of Western Nebraska, James B. Swinehart, Vernon L. Souders, H. M. Degraw, Robert F. Diffendal Jr.

School of Natural Resources: Faculty Publications

Two generally distinctive suites of sediments occur in western Nebraska, one dominantly volcaniclastic in origin deposited from the Oligocene through Early Miocene, and the other mainly epiclastic in origin deposited from the Middle Miocene through the Holocene. We have combined the epiclastic deposits usually placed in the Hemingford and Ogallala groups into an expanded Ogallala Group and have abandoned the member subdivisions of the Broadwater Formation.

New Evidence Supporting The Blancan Age Of The Sand And Gravel Sequence Capping The Ash Hollow Formation, Garden, Keith, And Lincoln Counties, Nebraska, Robert F. Diffendal Jr., James W. Goeke, Michael R. Voorhies

School of Natural Resources: Faculty Publications

Sandwiched between the overlying eolian Quaternary loesses and sands and the underlying beds of the Ash Hollow Formation, Ogallala Group, buried beneath the sliver of Cheyenne Tableland in Keith County and adjacent areas of western Nebraska, is a mass of fluvially deposited sand, gravelly sand, and sandy gravel of previously uncertain age. Some authors assigned these sediments to the Ogallala Group, while others have called them either the Broadwater Formation (Blancan), or a combination of the two rock units.

Seasonal Temperature Forecasts As Products Of Antecedent Linear And Spatial Temperature Arrays, Merlin Lawson, Randall S. Cerveny

Department of Earth and Atmospheric Sciences: Faculty Publications

Our objective is to evaluate the potential for extracting the maximum information contained in antecedent temperature patterns that operationally could be used in formulating winter seasonal forecasts in the United States. In particular, examination of the predictability of winter temperatures given autumn temperatures is made using derived contingency tables, discriminant equations of antecedent principal components, and canonical correlation analysis.

Contingency tables were constructed based on tercile classifications of a seventy-five-year dependent record (1895-1969). Testing of an independent data period (1970-78) using these tables produced winter forecasts with no appreciable skill in the aggregate (-0.04). Discriminant analysis derived linear combinations of …

Classification, Paleoecology, And Biostratigraphy Of Crinoids From The Stull Shale (Late Pennsylvanian) Of Nebraska, Kansas, And Iowa, Roger K. Pabian, Harrell L. Strimple

Bulletin of the University of Nebraska State Museum (1924–2023)

Thirteen species of crinoids representing the families Diphuicrinidae, catacrinidae, Pirasocrinidae, Erisocrinidae, Cromyocrinidae, Cymbiocrinidae, Scytalocrinidae, and Ampelocrinidae have been collected from the Stull Shale Member of the Kanwaka Formation in the Shawnee Group of the Virgil Series (Upper Pennsylvanian) from near Weeping Water and Plattsmouth, Nebraska, and near Pacific Junction, Iowa. Exposures of the Stull Shale near Melvern, Kansas, have yielded 14 species of crinoids representing the families Diphuicrinidae, Catacrinidae, Pirasocrinidae, Lophocrinidae Allagecrinidae, Cymbiocrinidae, Erisocrinidae, Apographiocrinidae, and Stellarocrinidae. All but two of the species present in the Stull Shale have been previously reported from other stratigraphic horizons, including the Vinland Shale …

Cenozoic Paleogeography Of Western Nebraska, James B. Swinehart, Vernon F. Souders, Harold M. Degraw, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

The Cenozoic strata of western Nebraska are an extensive sequence of continental deposits that extend eastward from the Hartville, Laramie, and Front Range uplifts and southeast from the Black Hills. The oldest Cenozoic sediments (Chadron Formation, White River Group) are Early Oligocene alluvial valley fills. Subsequent to filling of these drainages and continuing for about the next 7 million years, landscape development in western Nebraska was dominated by eolian deposition of tremendous volumes of rhyolitic volcanic ash derived from western eruptions. A plain of low relief, with only an occasional narrow drainage heading in the western highlands, was maintained during …

The Inapplicability Of The Concept Of The "Sidney Gravel" To The Ogallala Group (Late Tertiary) In Part Of Southern Banner County, Nebraska, Robert F. Diffendal Jr.

School of Natural Resources: Faculty Publications

A series of geologic maps of counties in western Nebraska was prepared for the Nebraska Geological Survey during the mid-1 930s. These maps showed the distribution of rock units of Tertiary age including a formation designated as the “Sidney.” The Sidney Gravel was described as a widespread sheetlike complex of channel deposits, but with small areas where it is not developed. In southern Banner County, Nebraska, there are several channels filled with sand and gravel that were mapped as Sidney in this series. Recently one of these channel fills has been observed to cut across the other. The fills are …

Hydraulic Fracturing Stress Measurements At Yucca Mountain, Nevada, And Relationship To The Regional Stress Field, J. M. Stock, J. H. Healy, S. H. Hickman, M. D. Zoback

United States Geological Survey: Staff Publications

Hydraulic fracturing stress measurements and acoustic borehole televiewer logs were run in holes USW G-1 and USW G-2 at Yucca Mountain as part of the Nevada Nuclear Waste Storage Investigations for the U.S. Department of Energy. Eight tests in the saturated zone, at depths from 646 to 1288 m, yielded values of the least horizontal stress S_h that are considerably lower than the vertical principal stress S_v. In tests for which the greatest horizontal principal stress S_H could be determined it, was found to be less than S _ν, indicating a normal faulting stress regime. …

Chemical Composition Of Ground Water In The Yucca Mountain Area, Nevada, 1971-84, Larry Benson, P. W. Mckinley

United States Geological Survey: Publications

Fifteen test wells in the Yucca Mountain area of southern Nevada have been sampled for chemical analysis at least once during 1971-84. Samples were obtained by pumping water from the entire well bore (composite sample), and, in three instances, by pumping from one or more isolated intervals within a well bore. Sodium was the most abundant cation, and bicarbonate was the most abundant anion in all water samples. Samples from the deep carbonate aquifer penetrated by well UE-25p#l contained higher relative concentrations of calcium and magnesium than did samples from overlying volcanic tuffs. Concentrations of the stable isotopes of oxygen …

On The Classification Of The Early Tertiary Erinaceomorpha (Insectivora, Mammalia), Michael J. Novacek, Thomas M. Bown, David Schankler

United States Geological Survey: Staff Publications

Definitions are provided for three Early Tertiary families of Erinaceomorpha. The family Dormaaliidae includes Dormaalius, Macrocranion, Scenopagus, Ankylodon, Crypholestes, Sespedectes, and Proterixoides.

Permeability Versus Depth In The Upper Oceanic Crust' In Situ Measurements In Dsdp Hole 504b, Eastern Equatorial Pacific, Roger N. Anderson, Mark D. Zoback, Stephen H. Hickman, Robin L. Newmark

United States Geological Survey: Staff Publications

In situ permeabilities measured within the upper kilometer of oceanic crust in hole 504B on the south flank of the Costa Rica Rift decrease exponentially from 10^-13 to 10^-14 m² in layer 2A (the upper 150m) to 10 ^-15 to 10^-17 m² in layer 2B (150-550 m into basement), and to 10^-17 m² and lower in layer 2C (deeper than 550 m). We estimate the permeability (k) versus depth (z) to vary as k(z)=0.11e^(-z/50)x 10^-12 m². If this permeability versus depth function is representative of …

Atlas Illustrating The Characteristics Of Groundwater In Nebraska, Vince Dreeszen

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Annual Outflow Of Water From Nebraska, 1950-1984, Conservation Survey Division

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.