Earth Sciences Commons^™

Cyclostephanos Lacrimis N. Sp. And Cyclostephanos Guatemalae N. Sp.: Two New Centric Diatoms From The Fossil Record Of Guatemala, Edward Theriot, J. Platt Bradbury

United States Geological Survey: Staff Publications

Two new species of Cyclostephanos are described from Pleistocene diatomites near Lago de Atitlan, Guatemala. In both species, radiating costae continue un- branched to the valve margin and the external expression of the single labiate process is an elongate pore on the mantle beneath a spine. Cyclostephanos lacrimis n. sp. is 7-75 jum in diameter and has no central area strutted processes. Each mantle strutted process is located within a marginal alveolus directly adjacent to a costa; this unique location is usually visible with light microscopy. C. guatemalae n. sp. is smaller (5-23 μm), with a single eccentrically-located strutted process …

Geochemical Evidence For Suppression Of Pelagic Marine Productivity At The Cretaceous/Tertiary Boundary, James C. Zachos, Michael A. Arthur, Walter E. Dean

United States Geological Survey: Staff Publications

The normal, biologically productive ocean is characterized by a gradient of the ¹³C /¹²C ratio from surface to deep waters. Here we present stable isotope data from planktonic and benthic microfossils across the Cretaceous/Tertiary boundary in the North pacific, which reveal a rapid and complete breakdown in this biologically mediated gradient. The fluxes of barium (a proxy for organic carbon) and CaCO, also decrease significantly at the time of the major marine plankton extinctions. The implied substantial reduction in oceanic primary productivity persisted for ~0.5 Myr before the carbon isotope gradient was gradually re-established. In addition, the …

State Of Stress And Modern Deformation Of The Northern Basin And Range Province, Mary Lou Zoback

United States Geological Survey: Staff Publications

Constraints on the current stress regime of the actively extending northern Basin and Range province are provided by deformation data (focal mechanisms and fault slip studies), hydraulic fracturing in situ stress measurements, borehole elongation ("breakouts") analyses, and alignment of young volcanic vents. The integrated data indicate significant variations both in principal stress orientations and magnitudes. An approximately E-W least principal stress direction appears to characterize both the eastern and western margins of the Basin and Range province, whereas in the active interior parts of the province extension occurs in response to a least principal stress oriented NW to N60 °W. …

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

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Oil In Nebraska, M. P. Carlson

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Nebraska Mineral Operations Review, 1988, Raymond R. Burchett, Duane A. Eversoll

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Mineral Yearbook Of Nebraska-1989, Karl Starch, Raymond R. Burchett

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Resultats Preliminaires De La Campagne De Forages Du Joides Resolution Sur Le Plateau De Kerguelen (Odp Leg 120)/ Preliminary Results Of Odp Leg 120 In The Central And Southern Kerguelen Plateau, Roland Schlich, Marc Munschy, Hubert Whitechurch, Marie-Pierre Aubry, Sherwood Wise Jr., Amanda Palmer, William Berggren, Peter Bitschene, Neal Blackburn, James Breza, Millard Coffin, David M. Harwood, Franz Heider, Mary Anne Holmes, William Howard, Hiroo Inokuchi, Kerry Kelts, David Lazarus, Andreas Mackenzen, Toshiaka Maruyama, Elizabeth Pratson, Patrick Quilty, Frank Rack, Vincent Salters, James Sevigny, Michael Storey, Atsushi Takemura, David Watkins, James Zachos

Department of Earth and Atmospheric Sciences: Faculty Publications

Resume - Le Leg 120 du programme international de forages oceaniques (Ocean Drilling Project) a permis de determiner la nature et l'age du plateau de Kerguelen et de decrire son evolution depuis Ie Cretace. Le socle, fore aux sites 747, 749 ct 750, est compose de coulees basaltiqucs qui correspondent a des tholeiites transitionnelles saturees en silice. Ces basaltes se sont mis en place dans des conditions aeriennes ou sub-aeriennes avant Ie Cenomanien sur une surface quasiment horizontalc. Les premiers sediments, d'age Cenomanien, se sont deposes en milieu fluviatile. Au Campanien et a la fin du Maestrichtien Ie plateau a …

The Uranium-Trend Dating Method: Principles And Application For Southern California Marine Terrace Deposits, Daniel R. Muhs, John N. Rosholt, Charles L. Bush

United States Geological Survey: Staff Publications

Uranium-trend dating is an open-system method for age estimation of Quaternary sediments, using disequilibrium in the ²³⁸U–²³⁴U–²³⁰Th decay series. The technique has been applied to alluvium, colluvium, loess, till, and marine sediments, in this study we tested the U-trend dating method on calcareous marine terrace deposits from the Palos Verdes Hills and San Nicolas Island, California. Independent age estimates indicate that terraces in these areas range from –80 ka to greater than 1.0 Ma. Two low terraces on San Nicolas Island yielded U-trend plots that have a clustered array of points and the ages of …

Evolution Of The Aeluroid Carnivora: Significance Of The Ventral Promontorial Process Of The Petrosal, And The Origin Of Basicranial Patterns In The Living Families, Robert M. Hunt Jr.

Department of Earth and Atmospheric Sciences: Faculty Publications

In studies of carnivoran phylogeny, the configuration and ontogenetic development of the auditory bulla enclosing the middle ear have been useful in tracing modern lineages to their first appearances in the mid-Cenozoic. Pre-Oligocene carnivorans, however, lack preserved bullae and have been difficult to relate to later Cenozoic groups. The carnivoran petrosal bone, because of its durability both in intact skulls and as an isolated element, can be tracked through Cenozoic time, and can supply new information on lineage continuity through its geometry and spatial relationships. Aeluroid carnivorans are united by a petrosal of characteristic shape, distinguished by a ventral promontorial …

Significant Rises And Declines In Nebraska Groundwater Levels (From Pre-Development As Of Fall 1987)/Registered Irrigation Wells In Nebraska (As Of January 1, 1988), Conservation Survey Division

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Resource Notes-Academic Year 1988-89

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Nebraska Natural Resources District Boundaries, Nebraska Natural Resources Commission

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Nebraska Natural Resources District Boundaries, Nebraska Department Of Natural Resources

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

River Potholes: Modern And Ancient, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

A river pothole is a cylindrical, bowl-shaped, or irregular hollow that is usually deeper than wide. It is formed in the rocky bed of a stream by either the grinding action of sediment whirled around by stream eddies or the force of fast flowing water. Potholes usually have spirally grooved surfaces. Their widths and depths range from a few inches to many feet. Potholes on the floor of the Susquehanna River near Columbia, Pennsylvania, for example, are large enough to hold objects the size of a small car.

Potholes generally are formed in fairly homogeneous rock by streams that at …

Early Lake Ontogeny Following Neoglacial Ice Recession At Glacier Bay, Alaska, Daniel R. Engstrom, Sherilyn C. Fritz

Department of Earth and Atmospheric Sciences: Faculty Publications

This study explores the environmental forces controlling lake ontogeny at Glacier Bay as a model for early Holocene lake evolution in north temperate lakes worldwide. Long-term chemical and biological changes in lakes are investigated with two complementary research strategies: (1) limnological conditions are compared among 32 lakes of known age and in different stages of primary catchment succession and (2) sediment cores from these same lakes are analyzed stratigraphically for fossil diatoms to ascertain developmental trends in pH, alkalinity, algal composition, and trophic status at individual sites.

Trends in water chemistry inferred from the chronosequence approach include a progressive loss …

State Water Quality Standards Summary: Nebraska, U.S. Environmental Protection Agency

United States Environmental Protection Agency: Publications

This publication was prepared by Battelle under contract to the U,S. Environmental Protection Agency (Contract 68-03-3534). Secondary information sources were used to compile data presented in this document. Each State was given an opportunity to review and provide comments on a draft of this information document. In no event shall either the United States or Battelle have any responsibility or liability for any use, misuse, or reliance upon the information contained herein, nor does either warrant or otherwise represent in any way .the accuracy, adequacy, efficacy, or applicability of the contents hereof.

The reader should consult the water quality standards …

Groundwater Levels In Nebraska, 1987, Michael J. Ellis, Perry B. Wigley

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Singleton Ranch Quadrangle, Nebraska—Banner, Kimball, And Cheyenne Counties, 7.5 Minute Series (Topographic), Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Singleton Ranch Quadrangle, Nebraska—Banner, Kimball, and Cheyenne Counties

7.5 minute series (topographic), scale 1:24000

103°22'30" to 103°30'

41°22'30" to 41°30'

Toa, Ql, Qalc

June 13, 1988

Courthouse Rock Quadrangle, Morrill County, Nebraska, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

7.5' topgraphic quadrangle showing exposures of bedrock formations and other geologic information.

41° 30' — 41° 37'30"

103° 00' — 103° 07'30"

Scale 1:24,000

Completed June 6, 1988

High resolution .tif file attached below as supplemental file

Estimated Use Of Water In Nebraska, 1985, Eugene K. Steele Jr.

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

A Guide To The Practical Use Of Aerial Color-Infrared Photography In Agriculture, Donald C. Rundquist, Scott A. Samson

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Redington Quadrangle, Nebraska—Banner And Morrill Counties, 7.5 Minute Series (Topographic), Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Redington Quadrangle, Nebraska—Banner and Morrill Counties

7.5 minute series (topographic), scale 1:24000

103°15' to 103°22'30"

41°30' to 41°37'30"

Twb, Qalc, Toa, IW, Tamch, Lower Whitney, Upper Whitney

April 5, 1988

Lisco Nw Quadrangle, Nebraska—Garden, Morrill, And Cheyenne Counties, 7.5 Minute Series (Topographic), Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Lisco NW Quadrangle, Nebraska—Garden, Morrill, and Cheyenne Counties

7.5 minute series (topographic), scale 1:24,000

102°37'30" to 102°45'

41°22'30" to 41°30'

March 31, 1988

Fairchild Ranch Quadrangle, Morrill And Cheyenne Counties, Nebraska, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

7.5' topgraphic quadrangle showing exposures of bedrock formations and other geologic information.

41° 22'30" — 41° 30'

102° 45' — 102° 52'30"

Scale 1:24,000

Completed March 29, 1988

High resolution .tif file attached below as supplemental file

Dalton Quadrangle, Morrill And Cheyenne Counties, Nebraska, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

7.5' topgraphic quadrangle showing exposures of bedrock formations and other geologic information.

41° 22'30" — 41° 30'

102° 52'30" — 103° 00'

Scale 1:24,000

Completed March 28, 1988

High resolution .tif file attached below as supplemental file