Physical Sciences and Mathematics Commons^™

Chemical, Physical And Mineralogical Properties Of Mitchell And Tripp Soils In The Nebraska Panhandle, G. A. Uzochukwu, D. T. Lewis

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

Mitchell and Tripp soils are some of the most important agricultural soils in the Nebraska Panhandle. Yet, they have received little attention in terms of their basic chemical, physical, and mineral properties. Management decisions can be made on a more informed basis if this kind of information is available. This study was to acquire the information, with special emphasis on mineralogical properties of the soils and their parent materials. This emphasis was given because it is known that other soils in the region contain volcanic ash in measurable amounts. The presence of volcanic ash in soils has been associated with …

Cliff-Height And Slope-Angle Relationships In A Chronosequence Of Quaternary Marine Terraces, San Clemente Island, California, Russell Crittenden, Daniel R. Muhs

United States Geological Survey: Staff Publications

Zusammenfassung. Eine Abfolge quartarer Strandterrassen auf ~an Clemente Island, Kalifornien, liefert einen Rahmen fur die quantitative Analyse der Anderungen an vom Meer verlassenen Kustenkliffen als Funktion der Zeit. Es wurde eine Abschatzung der Anwendbarkeit von BUCKNAM & ANDERSON (1979) log-lin~arer Beziehung zwischen Wandhohe und Hangwinkel durchgefuhrt, indem Brandungskliffhohe und maximale Hangwinkel verwendet wurden. Die Ergebnisse zeigen eine regelhafte Zunahme des Hangwinkels mit dem Logarithmus der Kliffhohe, und Kliffe einer bestimmten Hohe zeigen m,it der Zeit eine Abnahmedes maximalen Hangwinkels. 1m ganzen waren die Relationen schwacher als fur FluBterrassen und Bruchstufen in unverfestigten Materialen, aber die Methode kann wahrscheinlich verwendet werden, …

Effect Of Pre-Burn Artificial Litter And Prescribed Burning On Smooth Brome (Bromus Inermis Leyss), Patricia R. Boehner

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

No abstract provided.

Late Pleistocene And Holocene Paleolimnology Of Two Mountain Lakes In Western Tasmania, J. Platt Bradbury

United States Geological Survey: Staff Publications

The analysis of diatoms from two lake-sediment cores from southwestern Tasmania that span the Pleistocene-Holocene boundary provides insight about paleolimnological and paleoclimatic change in this region. Both Lake Vera (550 m elevation), in west-central Tasmania, and Eagle Tarn (1,033 m elevation), in south-central Tasmania, have lacustrine records that begin about 12,000 years ago. Despite significant differences in location, elevation, and geologic terrane, both lakes have, had similar, as well as synchronous, limnological histories. Each appears to have been larger and more alkaline 12,000 years ago than at present, and both became shallower through time. Fossil diatom assemblages about 11,500 years …

Paleoclimates In Southwestern Tasmania During The Last 13,000 Years, Vera Markgraf, J. Platt Bradbury, J.R. Busby

United States Geological Survey: Staff Publications

Plant-sociological and climatic classification of the Australian Nothofagus cunninghamii rain forest provides the basis for a new, semiquantitative approach to interpretations of late-Quaternary paleoclimates from four pollen sequences in southwestern Tasmania. Varying proportions of rain-forest pollen types in the records were related to different modern rain-forest alliances and their specifc climatic regimes, such as Eastern Rain Forest, Leatherwood Rain Forest, and sclerophyllous, Subalpine Rain Forest. According to this interpretation, early Holocene climates were characterized by 1,600 mm annual precipitation and 10°C annual temperature, conditions substantially warmer and drier than previously thought. Maximum precipitation levels of 2,500 mm annually were not …

Moving Under, Around, And Through The Miocene Reconstruction Of Southern California, John Barron

United States Geological Survey: Staff Publications

Modern southern California is fragmented by faults that juxtapose blocks with contrasting topographies and differing geologic histories. Many of the tectonic events that have shaped southern California were initiated during the Miocene, as subduction along the ancient trench margin off southern California was replaced by transform (strikeslip) faulting, such as that along the San Andreas fault.

Improving Nebraska's Near-Real Time Weather-Based Products Through User Interaction, Steven J. Meyer

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

No abstract provided.

Groundwater Levels In Nebraska, 1985, Michael J. Ellis, Darryll T. Pederson

Conservation and Survey Division

No abstract provided.

The Population Biology Of Oak Middle Creek Structure 58-B After An Experimental Stocking With Adult Fish: A Three Year Evaluation, Donn A. Rodekohr

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

No abstract provided.

Hydrogeology Of Water-Quality Monitoring Transects In An Irrigated Area Of The Eastern Sand Hills, Nebraska, Dennis R. Lawton

Conservation and Survey Division

No abstract provided.

Environmental And Physiological Effects On Water Use Of Cereal Crops, Joon Kim

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

No abstract provided.

Interspecific Interactions Of Green Sunfish (Lepomis Cyanellus) And (Creek Chub (Semotilus Atromaculatus) In Small Streams In Southeast Nebraska, Steve L. Schleiger

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

No abstract provided.

Environmental And Physiological Effects On Water Use Of Cereal Crops, Joon Kim

Conservation and Survey Division

No abstract provided.

Policy Issue Study On Integrated Management Of Surface Water And Groundwater Report, Dayle E. Williamson, Bob Kuzelka

Conservation and Survey Division

No abstract provided.

Identification And Analysis Of Climatic Fields Through Dot-Density Shading, Stephen J. Lavin, Randall S. Cerveny

Department of Earth and Atmospheric Sciences: Faculty Publications

Gridded matrices of climatic data can be mapped by computer with a variety of symbolization methods, all of which have some shortcomings. A new mapping procedure, dot-density shading, is herein proposed as an alternative mapping form. Dot-density shading produces continuous-appearing dot patterns whose density is proportional to the data. Significant algorithms are those for computing dot numerosity and quasi-random dot placement. A number of application including data error detection and anomaly recognition are discussed.

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.

Resource Notes-Summer 1986

Conservation and Survey Division

No abstract provided.

Resource Notes-Spring 1986

Conservation and Survey Division

No abstract provided.

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

Conservation and Survey Division

No abstract provided.

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

Conservation and Survey Division

No abstract provided.

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 . …

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.

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. …

Diatom Stratigraphy Of The Lower Pliocene Part Of The Sisquoc Formation, Harris Grade Section, California, John A. Barron, Jack G. Baldau

United States Geological Survey: Staff Publications

Lower Pliocene diatoms were studied from the Sisquoc Formation and lowermost Foxen Mudstone, exposed along Hams Grade north of Lompoc, California, to refine the diatom biostratigraphy of post-Monterey Formation sediments in California. Sixty-seven diatom taxa were identified in the 25 samples examined from the 790-m thick (2950-ft) section. The diatoms are assignable to the uppermost Nitzschia reinholdii Zone and Thalassiosira oestrupii Zone of Damn (1981), and five tentative subzones for local correlation are proposed. Regional correlations and taxon occurrence are discussed, and the base of the Nitzschia reinholdii Zone is redefined as at the last occurrence of Thalassionema schraderi.

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

No abstract provided.