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Sedimentology

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Articles 1111 - 1140 of 1935

Full-Text Articles in Earth Sciences

Flat Water: A History Of Nebraska And Its Water, Robert D. Kuzelka, Charles A. Flowerday, Robert N. Manley, Bradley C. Rundquist, Sally J. Herrin Mar 1993

Flat Water: A History Of Nebraska And Its Water, Robert D. Kuzelka, Charles A. Flowerday, Robert N. Manley, Bradley C. Rundquist, Sally J. Herrin

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Calculation Of Acoustic Parameters By A Filter-Correlation Method, Robert C. Courtney, Larry A. Mayer Feb 1993

Calculation Of Acoustic Parameters By A Filter-Correlation Method, Robert C. Courtney, Larry A. Mayer

Affiliate Scholarship

This paper presents the filter correlation method, a technique for extracting consistent and accurate estimates of attenuation parameters from acoustic waveform data. The method minimizes problems associated with short time windows and multipath secondary arrivals. The method comprises two stages: a causal passband filter stage followed by a cross-correlation step. The results of the filter-correlation estimator are compared to those of the spectral difference approach for short time series with and without a secondary multipath arrival. Preliminary analyses of acoustic data collected on cored marine silts and clays show the attenuation properties of these materials cannot be described by a …


The Origin And Evolution Of The Southern Snake Range Decollement, East Central Nevada, Allen J. Mcgrew Feb 1993

The Origin And Evolution Of The Southern Snake Range Decollement, East Central Nevada, Allen J. Mcgrew

Department of Earth, Environment and Sustainability Faculty Publications

Regional and local stratigraphic, metamorphic, and structural constraints permit reconstruction of the southern Snake Range extensional deformational system in east central Nevada. The dominant structure of the range, the southern Snake Range décollement (SSRD), operated during Oligocene and Miocene extensional deformation to exhume a footwall of multiply deformed metasedimentary and plutonic rocks. Intrusion of three plutons (∼160 Ma, 79.1 ± 0.5 Ma, and 36 ± 1 Ma, respectively) and development of two cleavages preceded the onset of extensional deformation. Plastic deformation of lower plate metasedimentary rocks accompanied the early phases of regional extension and produced bedding-parallel grain shape foliations and …


Variations Of Porosity In Calcareous Sediments From The Ontong Java Plateau, Frank Bassinot, Janice C. Marsters, Larry A. Mayer, Roy H. Wilkens Jan 1993

Variations Of Porosity In Calcareous Sediments From The Ontong Java Plateau, Frank Bassinot, Janice C. Marsters, Larry A. Mayer, Roy H. Wilkens

Affiliate Scholarship

Based on index properties measurements made on board the JOIDES Resolution, we studied porosity changes with depth in the fairly homogeneous deep-sea calcareous sediments cored during Ocean Drilling Program Leg 130 on the Ontong Java Plateau. Using Leg 130 data, we present evidence that the rate of porosity decrease with burial in calcareous oozes and chalks is related to the depth of deposition and thus probably depends on the "conditioning" of calcareous sediments by winnowing or dissolution processes during the time of deposition. The ooze-to-chalk transition is not clearly reflected in porosity profiles. In the ooze-chalk sections studied (the upper …


Uranium Deposits In Nebraska, R. R. Burchett Jan 1993

Uranium Deposits In Nebraska, R. R. Burchett

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Geology Of Arbor Day Farm Nebraska City, Nebraska, R. R. Burchett Jan 1993

Geology Of Arbor Day Farm Nebraska City, Nebraska, R. R. Burchett

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Correlation Of The Tioga Bentonites Using Rhyolitic Melt Inclusions Found In Quartz Phenocrysts As Geochemical Fingerprints, John W. Waechter Jan 1993

Correlation Of The Tioga Bentonites Using Rhyolitic Melt Inclusions Found In Quartz Phenocrysts As Geochemical Fingerprints, John W. Waechter

Geology Theses and Dissertations

The Tioga bentonites were first noted by Fettke in 1931 from well cuttings in the Tioga gas fields of Tioga County, Pennsylvania. They have been used by many investigators (Oliver, 1954, 1956; Dennison, 1963; Dennison and Textoris, 1967, 1978; Epstein, 1986; Smith and Way, 1983; Way et al., 1986) as a time-plane to correlate stratigraphic units from eastern Pennsylvania to Illinois and from southern Ontario to Virginia. The Tioga bentonites are recognized as seven major volcanic ash layers labeled Tioga-A - Tioga-G as well as several minor layers labeled Tioga-A1 - Tioga-A3 (Way et al., 1986). They occur within the …


Resource News-March/April 1993 Jan 1993

Resource News-March/April 1993

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Cedar County Test Hole Logs, Raymond R. Burchett Jan 1993

Cedar County Test Hole Logs, Raymond R. Burchett

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Nebraska Mineral Operations Review, 1992, R. R. Burchett, Duane A. Eversoll Jan 1993

Nebraska Mineral Operations Review, 1992, R. R. Burchett, Duane A. Eversoll

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Geology And Mineral Resources Of Boone, Greeley, Nance, And Wheeler Counties, Nebraska, Raymond R. Burchett Jan 1993

Geology And Mineral Resources Of Boone, Greeley, Nance, And Wheeler Counties, Nebraska, Raymond R. Burchett

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Resource Notes-Academic Year 1992-93 Jan 1993

Resource Notes-Academic Year 1992-93

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Resource News-July/August 1993 Jan 1993

Resource News-July/August 1993

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Niobrara River Basin Geological References, Including Parts Of South Dakota Both In And Outside Of The Basin, Robert F. Diffendal Jr. Jan 1993

Niobrara River Basin Geological References, Including Parts Of South Dakota Both In And Outside Of The Basin, Robert F. Diffendal Jr.

Conservation and Survey Division: Faculty and Staff Publications

Includes Niobrara River Basin geological references, including parts of South Dakota both in and outside of the basin.


Cuming County Test Hole Logs, Raymond R. Burchett, Frank A. Smith Jan 1993

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

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Groundwater-Level Changes In Nebraska, 1991, Gregory V. Steele, Perry B. Wigley Oct 1992

Groundwater-Level Changes In Nebraska, 1991, Gregory V. Steele, Perry B. Wigley

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Depositional Environments And Paleoecology Of The Lower Ordovician Pogonip Group, Opd Unit, Arrow Canyon Range, Clark County, Nevada, Jeffrey K. Donovan Aug 1992

Depositional Environments And Paleoecology Of The Lower Ordovician Pogonip Group, Opd Unit, Arrow Canyon Range, Clark County, Nevada, Jeffrey K. Donovan

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Opd Unit of the Pogonip Group is a slope-forming carbonate sequence that crops out in the Arrow Canyon Range 75 miles north of Las Vegas, Nevada. It is composed mainly of grainstones, packstones, and intraformational conglomerates and also contains Calathium-bearing bioherms composed dominantly of wackestones. These rocks were deposited in a shallow-water, high-energy, subtidal, tropical marine environment. Nuia and Nuia-crinoid shoals developed on this shallow ramp and the area was frequently disturbed by storms.

Calathium-dominated carbonate mudmounds emerged on the Nuia and Nuia-crinoid shoals. Although Calathium dominated the mounds on a macroscopic scale, the mounds …


Relation Of Groundwater Fluoride Concentrations To Sediment Mineralogy, Potomac Formation (Cretaceous), Southeastern Virginia, Paul Anthony Maciuika Apr 1992

Relation Of Groundwater Fluoride Concentrations To Sediment Mineralogy, Potomac Formation (Cretaceous), Southeastern Virginia, Paul Anthony Maciuika

OES Theses and Dissertations

Thirty-seven Early cretaceous sediment samples of the Potomac Formation were obtained from four cores to determine if fluoride bearing minerals are responsible for elevated fluoride concentrations in Potomac Formation groundwaters of southeastern Virginia. Investigative methods included total sediment fluoride and particle size analysis, semiquantitative mineralogical analysis (achieved by X-Ray Diffraction) and statistical methods (cluster, canonical and regression analysis). The sediments showed wide variation in textures, ranging from clean sands and gravels to silty clays. Sediment mineralogies were dependent on the prevailing size fraction, with quartz and feldspar dominating the sand and silt fractions, muscovite primarily being found in the silt …


Hydrogeology Of Parts Of The Twin Platte And Middle Republican Natural Resources Districts, Southwestern Nebraska, J. W. Goeke, J. M. Peckenpaugh, R. E. Cady, J. T. Dugan, R. A. Engberg Apr 1992

Hydrogeology Of Parts Of The Twin Platte And Middle Republican Natural Resources Districts, Southwestern Nebraska, J. W. Goeke, J. M. Peckenpaugh, R. E. Cady, J. T. Dugan, R. A. Engberg

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Marine Sediment Classification Using The Chirp Sonar, Lester R. Leblanc, Larry A. Mayer, Manuel Rufino, Steven G. Schock, John King Jan 1992

Marine Sediment Classification Using The Chirp Sonar, Lester R. Leblanc, Larry A. Mayer, Manuel Rufino, Steven G. Schock, John King

Affiliate Scholarship

The chirpsonar is a calibrated wideband digital FMsonar that provides quantitative, high‐resolution, low‐noise subbottom data. In addition, it generates an acoustic pulse with special frequency domain weighting that provides nearly constant resolution with depth. The chirpsonar was developed with the objective of remote acoustic classification of seafloor sediments. In addition to producing high‐resolution images, the calibrated digitally recorded data are processed to estimate surficial reflection coefficients as well as a complete sediment acoustic impulse profile. In this paper, surficial sediments in Narragansett Bay, RI are used to provide ground truth for an acoustic model. Quantitative acoustic returns from the chirpsonar …


Resource News-May/June 1992 Jan 1992

Resource News-May/June 1992

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Solid Waste Management In Seismic Impact Zones, Raymond R. Burchett Jan 1992

Solid Waste Management In Seismic Impact Zones, Raymond R. Burchett

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Nebraska Mineral Operations Review, 1991, R. R. Burchett, Duane A. Eversoll Jan 1992

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

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


The Origin Of Metalliferous Argillites In The Shoal Arm Formation Of North-Central Newfoundland, Volker Brüchert Jan 1992

The Origin Of Metalliferous Argillites In The Shoal Arm Formation Of North-Central Newfoundland, Volker Brüchert

Geology Theses and Dissertations

The Middle Ordovician Shoal Arm Formation, which is located in the central volcanic belt of north-central Newfoundland, is a tripartite assemblage of hematitic argillites, grey cherts, and black shales directly underlying a flysch sequence. The hematitic argillites are enriched in Fe, Mn, Ni, Pb, and Co. Factor analysis and principal component analysis indicate the presence of a hydrothermal component, presumably derived from hydrothermal activity in the coeval Lawrence Head volcanics. Unusual, (?) calcareous Mn-Fe-oxide nodules are present in the top parts of turbidites in the hematitic argillites. Electron microprobe analysis of a color transition from a red to a green …


Groundwater Levels In Nebraska, 1991, Gregory V. Steele, Perry B. Wigley Jan 1992

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

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Greeley County Test Hole Logs, Raymond R. Burchett, Frank A. Smith Jan 1992

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

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Nance County Test Hole Logs, Raymond R. Burchett, Frank A. Smith Jan 1992

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

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Resource Notes-Academic Year 1991-92 Jan 1992

Resource Notes-Academic Year 1991-92

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Resource News-January/February 1992 Jan 1992

Resource News-January/February 1992

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Resource News-March/April 1992 Jan 1992

Resource News-March/April 1992

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.