Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Earth Sciences

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 17401 - 17430 of 17781

Full-Text Articles in Entire DC Network

A New Species Of Menoceras From The Marsland Formation Of Nebraska, Lloyd G. Tanner Jul 1972

A New Species Of Menoceras From The Marsland Formation Of Nebraska, Lloyd G. Tanner

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

Further study indicates that the Menoceras remains collected from the "Bridgeport Quarries" (lower port:on or the Marsland Formation, Middle Miocene, of the Hemingford Group) are of a new species.

In 1962, these dicerathere remains were considered to be a geologic variety of Diceratherium niobrarensis (Stecher, Schultz, and Tanner). However, later (Tanner, 1969) a generic distinction was revived, separating the Menoceras Troxell from Diceratherium Marsh. Diceretherium niobrarensis was then placed in synonymy with Menoceras arikarense (Barbour).

The new species is an intermediate between Menoceras arikarense (Barbour) from the Harrison Formation and Menoceras marslandensis Tanner, from the upper portion of the Marsland …


Two Lynx-Like Cats From The Pliocene And Pleistocene, C. Bertrand Schultz, Larry D. Martin Jul 1972

Two Lynx-Like Cats From The Pliocene And Pleistocene, C. Bertrand Schultz, Larry D. Martin

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

A new species (Lynx stouti) of small felid is described from the lower Pliocene of Colorado. This form has several characters in common with the modern Lynx and may be ancestral to that genus. A new subspecies of Lynx issiodorensis Croizet and Jobert is described as L. i. kurteni from the Mullen Assemblage, Cherry County, Nebraska. The relationships of this form to other lynxes are discussed along with the paleo-distribution of the genus.

The classification of the felinae has always been somewhat controversial, especially at the generic level. One fairly homogenous group of cats which has been separated …


Determination Of Nutrient Levels And Proposed Predictive Models For Phosphate In The Lafayette River, Norfolk, Virginia, John R. Montgomery Jul 1972

Determination Of Nutrient Levels And Proposed Predictive Models For Phosphate In The Lafayette River, Norfolk, Virginia, John R. Montgomery

OES Theses and Dissertations

The Lafayette River, an Urban, well-mixed estuarine embayment, was sampled from October, 1970 to January, 1972 for phosphate, nitrate, nitrite, oxygen, water temperature and salinity. The mean values found for these samples were: oxygen saturation from 69% to 106% nitrate from 0 to 4 microgram-atoms per liter, and salinity from 13 ‰ to 24 ‰. The mouth of the Elizabeth River to Hampton Roads as also sampled from May, 1971 to August, 1971. The Lafayette and Elizabeth Rivers were also sampled over a 24 hour period in the summer of 1971 and the Lafayette River again in the winter of …


Phyletic Trends In Certain Lineages Of Quaternary Mammals, C. Bertrand Schultz, Lloyd G. Tanner, Lary D. Martin Jun 1972

Phyletic Trends In Certain Lineages Of Quaternary Mammals, C. Bertrand Schultz, Lloyd G. Tanner, Lary D. Martin

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

Evolutionary trends in certain carnivores, rodents, bovids, and proboscideans are examined. Chronoclines are demonstrated for muskrats, beavers, mammoths, and bison. The Pliocene-Pleistocene boundary and Quaternary climatic fluctuations are also discussed.

The University of Nebraska State Museum contains a large stratigraphically controlled collection of Pleistocene animals. This collection provides a unique opportunity for the study of phyletic trends in certain lineages of mammals. Although a few phylogenetic lineages have been proposed (Schultz and Frankforter, 1946; Hibbard, et al., 1965), this has not been done for the vast majority of Pleistocene mammals. However, there is much more data available than this would …


Saltmarsh Ecology And Resource Protection, Gerard Desire Blais Jr. May 1972

Saltmarsh Ecology And Resource Protection, Gerard Desire Blais Jr.

Marine Affairs Theses and Major Papers

A panoramic lack of conservation education has produced a populace largely unaware of the value of marshland resources or measures for their protection. In a relentless era of ecological abuse, wetlands and salt marshes rank with endangered animal species in the quantitative loss culminating in extinction. Challenged continually by the relentless sea and exploited by unsound attempts at development, management, or even conservation, the efficiency of the marshlands is decreasing with each successive invasion. There is a demonstrated reduction in biological productivity, flood control, and water quality in areas where dredging, draining, and filling of marshes has taken place.


The Microtine Rodents Of The Mullen Assemblage From The Pleistocene Of North Central Nebraska, Larry D. Martin May 1972

The Microtine Rodents Of The Mullen Assemblage From The Pleistocene Of North Central Nebraska, Larry D. Martin

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

The University of Nebraska State Museum has had an active collecting program in Hooker and Cherry counties, Nebraska, since the 1930's. The following University of Nebraska State Museum collecting localities have been extensively excavated: Cr-10, Cr-102, Cr-11, Ho-101, Ho-102, and Ho-103. These localities have produced a large vertebrate fauna described by Jakway as the Mullen Local Fauna which he considered for the most part to be Early lllinoian. Further study of this local fauna now demonstrates that assemblage does include Early as well as Middle Pleistocene animals. The purpose of this paper is to report on the evidence regarding the …


Model For Estimating Soil Water Flow, Water Content, Evapotranspiration And Root Extraction, Musa N. Nimah May 1972

Model For Estimating Soil Water Flow, Water Content, Evapotranspiration And Root Extraction, Musa N. Nimah

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A mathematical model was developed to predict water content profiles, evapotranspiration, water flow from or to the water table, root extraction and root water potential at the surface as functions of time under unsteady state conditions.

The model was tested in the field at The Hullinger Farm near Vernal, Utah, in 1970 and 1971. Comparison of water content-depth profiles show excellent agreement at the end of a 9- day run in 1970 on oats seeded to alfalfa. In 1971 with alfalfa as the crop, the data show best agreement, between predicted and computed water content-depth profiles, 48 hours after any …


An Examination Of The Inorganic Nitrogen Status Of A Soil Of The Alaskan Coastal Tundra Plain, Norton R. Munn May 1972

An Examination Of The Inorganic Nitrogen Status Of A Soil Of The Alaskan Coastal Tundra Plain, Norton R. Munn

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This experiment was designed to measure in situ concentrations of NH4+ and NO3--N in a soil of the arctic coastal tundra plain, to determine if nitrification was taking place in this soil and to determine if the vascular plants growing in this soil could assimilate NH4+-N.

The extractable NH4+-N concentration was approximately 40 μg/g in the 01 horizon and 10 μg/g in the 02 horizon. The NO3--N concentration was approximately 5 μg/g in the 01 horizon and 4 μg/g in the 02 …


Stratigraphy And Environmental Analysis Of The Swan Peak Formation And Eureka Quartzite, Northern Utah, George Gregory Francis May 1972

Stratigraphy And Environmental Analysis Of The Swan Peak Formation And Eureka Quartzite, Northern Utah, George Gregory Francis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Swan Peak Formation in north-central Utah thickens westward, from zero feet near Logan to 687 feet in the Promontory Range. The unit is subdivided into three distinct members: 1) A lower member of interbedded shales, limestones, and quartzites; 2) A middle member of interbedded shales and brown quartzites; and 3) An upper member of white quartzites. The Swan Peak thins southward toward the east-west-trending Tooele Arch in the area of study; this thinning probably reflects both lesser deposition and greater subsequent erosion there than elsewhere. The lower member in northern Utah probably was deposited in shallow-shelf and/or traditional shoreface-shelf …


Some Physical Characteristics Of A Small Agricultural Watershed In East-Central Illinois, Ruth Laurence Davis May 1972

Some Physical Characteristics Of A Small Agricultural Watershed In East-Central Illinois, Ruth Laurence Davis

Senior Honors Papers / Undergraduate Theses

No abstract provided.


Petrology Of The Ordovician Swan Peak Formation, Southeastern Idaho And North-Central Utah, Warren J. Schulingkamp Ii May 1972

Petrology Of The Ordovician Swan Peak Formation, Southeastern Idaho And North-Central Utah, Warren J. Schulingkamp Ii

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Swan Peak Formation in southeastern Idaho and north-central Utah is a sedimentary unit consisting of orthoquartzite, sandstone, siltite, shale, and limestone. The formation is divisible into three members, and the lower two members each are divisible into two informal lithologic subunits.

The lower member consists of a lower subunit of gray, calcareous sandy siltite composed of subangular to subrounded quartz grains cemented by quartz overgrowths, calcite, or iron oxide, and an upper subunit of black shale with minor interbedded silty quartzose sandstone and biomicrite (limestone).

The middle member consists of a lower subunit of interbedded pale green shale and …


Evaluation Of The Filter Paper Method For Estimating Soil Water Potential, Samir Al-Khafaf May 1972

Evaluation Of The Filter Paper Method For Estimating Soil Water Potential, Samir Al-Khafaf

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The filter paper method for measuring soil water potential was evaluated. The method was calibrated using salt solutions (-1.4 bars to -22.4 bars), sample chamber psychrometer (-1 to -50 bars), pressure plate (-0.1 to -15 bars) and soil column at equilibrium (0 to -0.2 bars). It was found that the absolute temperature had little effect on the predicted soil water potential, but a temperature variation had a large effect. It was found that the temperature fluctuation must be small. The predicted water potential was influenced by the type of contact of the soil with the filter paper. It is suggested …


Methodological And Validation Study Of Seed Reserves In Desert Soils, David W. Goodall, Stuart Childs, Herman Wiebe Apr 1972

Methodological And Validation Study Of Seed Reserves In Desert Soils, David W. Goodall, Stuart Childs, Herman Wiebe

Memorandum

The development of a method for separating seeds from desert soils, and enumerating them, is described.

In the Great Basin desert, species differed greatly in their depth distribution, some having a peak at or just below the surface, while others were still abundant below 5 cm. Much higher seed densities were found beneath the canopies of shrubs and of tussock grasses than in the inter-spaces; no consistent differences were found, however, associated with the species of the canopy plant, or with distance from its center.

Tentative estimates are given of the seed population in the four validation sites in Curlew …


Eutrophication Factors In North Central Florida Lakes, H. D. Putnam, Patrick L. Brezonik, Earl E. Shannon Feb 1972

Eutrophication Factors In North Central Florida Lakes, H. D. Putnam, Patrick L. Brezonik, Earl E. Shannon

United States Environmental Protection Agency: Publications

A small Florida lake has been receiving a regimen of nutrient addition equivalent to 500 mg/m3-yr N and 43 mg/m3-yr P since 1967. Data has been accumulated through 1969. The effect on the lacustrine ecosystem of various biogenes includes production by primary producers, species diversity of plankton and certain production estimates at the secondary trophic level using natural populations of planktivorous fish. Plankton production using isotopic carbon is ca. 58 grms/m2-yr; Species diversity is slowly changing to a mixed chlorophycean and yellow-green. Biomass of benthic green filamentous types has increased slightly. Nutrient addition has …


Standing Crop And Productivity Of Marsh Vegetation At Saratoga Springs, California, W. G. Bradley Jan 1972

Standing Crop And Productivity Of Marsh Vegetation At Saratoga Springs, California, W. G. Bradley

Memorandum

No abstract provided.


Application Of Remote Sensing Techniques For Analysis Of Desert Biome Validation Studies, Paul T. Tueller, Garwin Lorain Jan 1972

Application Of Remote Sensing Techniques For Analysis Of Desert Biome Validation Studies, Paul T. Tueller, Garwin Lorain

Memorandum

No abstract provided.


Seasonal Use Of Soil Moisture By Mature Velvet Mesquite, Dwight R. Cable Jan 1972

Seasonal Use Of Soil Moisture By Mature Velvet Mesquite, Dwight R. Cable

Memorandum

No abstract provided.


Ingestion Rates, Live Weight Caloric Densities And Standing Crop Estimates For Desert Biome Rodents, R. K. Schreiber, D. R. Johnson Jan 1972

Ingestion Rates, Live Weight Caloric Densities And Standing Crop Estimates For Desert Biome Rodents, R. K. Schreiber, D. R. Johnson

Memorandum

No abstract provided.


Life History And Life Process Studies Of The Water Scavenger Beetle, Hydrophilus Triangularie Say, M. D. Hallmark, C. R. Ward Jan 1972

Life History And Life Process Studies Of The Water Scavenger Beetle, Hydrophilus Triangularie Say, M. D. Hallmark, C. R. Ward

Memorandum

No abstract provided.


Demography And Role Of Herbivorous Ants In A Desert Ecosystem As Functions Of Vegetation, Soil And Climate Variables, W. G. Whiteford, G. Ettershank Jan 1972

Demography And Role Of Herbivorous Ants In A Desert Ecosystem As Functions Of Vegetation, Soil And Climate Variables, W. G. Whiteford, G. Ettershank

Memorandum

No abstract provided.


Radiative Environment And The Surface Temperature On A Microscale In A Sagebrush Biome, Inge Dirmhirn Jan 1972

Radiative Environment And The Surface Temperature On A Microscale In A Sagebrush Biome, Inge Dirmhirn

Memorandum

No abstract provided.


Gaseous Losses Of Nitrogen From The Soil Of Semi-Arid Regions, T. C. Tucker, R. L. Westerman Jan 1972

Gaseous Losses Of Nitrogen From The Soil Of Semi-Arid Regions, T. C. Tucker, R. L. Westerman

Memorandum

No abstract provided.


Role Of Algae In Crust Formation And Nitrogen Cycling In Desert Soils, Raymond I. Lynn, Roy E. Cameron Jan 1972

Role Of Algae In Crust Formation And Nitrogen Cycling In Desert Soils, Raymond I. Lynn, Roy E. Cameron

Memorandum

No abstract provided.


Assimilation, Metabolism And Growth Of Utah Chub, Gila Artaria, F. C. Cheng, R. L. Wallace, T. C. Bjornn, C. Macphee Jan 1972

Assimilation, Metabolism And Growth Of Utah Chub, Gila Artaria, F. C. Cheng, R. L. Wallace, T. C. Bjornn, C. Macphee

Memorandum

No abstract provided.


Validation Studies And Bacterial Mineralization Of Organic Carbon At Locomotive Springs, J. Anne Holman, F. W. Post, I. Walkiw Jan 1972

Validation Studies And Bacterial Mineralization Of Organic Carbon At Locomotive Springs, J. Anne Holman, F. W. Post, I. Walkiw

Memorandum

No abstract provided.


Curlew Valley Validation Site Report, David F. Balph Jan 1972

Curlew Valley Validation Site Report, David F. Balph

Memorandum

No abstract provided.


Tucson Validation Sites Report, John L. Thames Jan 1972

Tucson Validation Sites Report, John L. Thames

Memorandum

No abstract provided.


Rock Valley Validation Site Report, Frederick B. Turner Jan 1972

Rock Valley Validation Site Report, Frederick B. Turner

Memorandum

No abstract provided.


Gas Exchange And Productivity For Opuntia Spp., I. P. Ting, H. B. Johnson, S. R. Szarek, G. D. Brum Jan 1972

Gas Exchange And Productivity For Opuntia Spp., I. P. Ting, H. B. Johnson, S. R. Szarek, G. D. Brum

Memorandum

No abstract provided.


Productivity And Water Stress In Cacti, Duncan T. Patten Jan 1972

Productivity And Water Stress In Cacti, Duncan T. Patten

Memorandum

No abstract provided.