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Articles 27031 - 27060 of 29958

Full-Text Articles in Geology

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 …


Climatic Cyclicity At Site 806; The Grape Record, Larry A. Mayer, Eystein Jansen, Jan Backman, Toshiaki Takayama Jan 1993

Climatic Cyclicity At Site 806; The Grape Record, Larry A. Mayer, Eystein Jansen, Jan Backman, Toshiaki Takayama

Affiliate Scholarship

We used the continuous saturated bulk density records collected by the gamma-ray attenuation porosity evaluator (GRAPE) at Ocean Drilling Program Site 806 on the top of the Ontong Java Plateau to evaluate the continuity of the recovered cores and to splice together a complete section from the multiple holes drilled at the site (for the upper 165 m, this is equivalent to approximately 0-5 Ma). The lack of offset in core breaks (between the 9.5-m-long, successive cores) from hole to hole made splicing difficult, and the results are not unambiguous. The composite section was converted to a time series by …


Bowling Green Lady Left Her Mark On Kentucky’S Oil Industry, Jonathan Jeffrey Jan 1993

Bowling Green Lady Left Her Mark On Kentucky’S Oil Industry, Jonathan Jeffrey

SCL Faculty and Staff Publications

Margaret Morehead Hobson (1890-1987), a native of Bowling Green, Kentucky, worked for over fifty years in the oil and gas industry in western Kentucky. This biographical article examines her life and contributions to the predominantly male field of geological exploration.


Evolution Of Pliocene Climate Cyclicity At Hole 806b (5-2 Ma); Oxygen Isotope Record, Eystein Jansen, Larry A. Mayer, Jan Backman, R. Mark Leckie, Toshiaki Takayama Jan 1993

Evolution Of Pliocene Climate Cyclicity At Hole 806b (5-2 Ma); Oxygen Isotope Record, Eystein Jansen, Larry A. Mayer, Jan Backman, R. Mark Leckie, Toshiaki Takayama

Affiliate Scholarship

A detailed Pliocene oxygen isotope record from the Ontong Java Plateau, based on measurements of the surface-dwelling planktonic foraminifer Globigerinoides sacculifer, was produced for the period from 5 to 2 Ma. The record documents major long and short-term climate changes. The results show periods of enhanced ice volume at 4.6 to 4.3 Ma and after 2.85 Ma, a long-term warming trend from 4.1 to 3.7 Ma, and a distinct cooling trend that was initiated at 3.5 Ma and progressed through the initiation of large-scale Northern Hemisphere glaciation after 2.85 Ma (according to the time scale of Shackleton and others proposed …


Detailed Stratigraphic Correlation Of The Neogene Sedimentary Sequences On The Ontong Java Plateau By Well Logging; Odp Sites 803, 805, 806, 807, And Dsdp Site 586, Mitchell Lyle, Roy H. Wilkens, Larry A. Mayer Jan 1993

Detailed Stratigraphic Correlation Of The Neogene Sedimentary Sequences On The Ontong Java Plateau By Well Logging; Odp Sites 803, 805, 806, 807, And Dsdp Site 586, Mitchell Lyle, Roy H. Wilkens, Larry A. Mayer

Affiliate Scholarship

We used well logs, in some cases combined with shipboard physical properties measurements to make more complete profiles and to correlate between sites on the Ontong Java Plateau. By comparing sediment bulk density, velocity, and resistivity logs from adjacent holes at the same site, we showed that even subtle features of the well logs are reproducible and are caused by variations in sedimentation. With only minor amounts of biostratigraphic information, we could readily correlate these sedimentary features across the entire top of the Ontong Java Plateau, demonstrating that for most of the Neogene the top of the plateau is a …


Velocity Anisotropy In Calcareous Sediments From Leg 130, Ontong Java Plateau, Frank Bassinot, Janice C. Marsters, Larry A. Mayer, Roy H. Wilkens Jan 1993

Velocity Anisotropy In Calcareous Sediments From Leg 130, Ontong Java Plateau, Frank Bassinot, Janice C. Marsters, Larry A. Mayer, Roy H. Wilkens

Affiliate Scholarship

During Leg 130, an intensive program of P-wave velocity measurements was conducted on calcareous sediments of varying induration (ranging from ooze to limestone) that cover the Ontong Java Plateau (west equatorial Pacific). The high quantity and quality of shipboard acoustical property measurements seemed to be particularly appropriate for gaining a better understanding of acoustic anisotropy in calcareous sediments. Major results can be summarized as follows: 1. In calcareous oozes, acoustic anisotropy exists even at shallow depths of burial. Values are low, ranging from -0.5% to 3.5% and averaging 1.2%. Anisotropy profiles are affected by coring disturbances, but they still roughly …


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.


Water-Quality Assessment Of The Central Nebraska Basins: Summary Of Data For Recent Conditions Through 1990, Ronald B. Zelt, P. R. Jordan Jan 1993

Water-Quality Assessment Of The Central Nebraska Basins: Summary Of Data For Recent Conditions Through 1990, Ronald B. Zelt, P. R. Jordan

United States Geological Survey: Publications

Among the first activities undertaken in each National Water-Quality Assessment (NAWQA) investigation are the compilation, screening, and statistical summary of available data concerning recent water-quality conditions in the study unit. The water-quality conditions of interest in addressing the objectives of the NAWQA program are those that are representative of the general water quality of a given stream reach or area of an aquifer. This report (1) identifies which existing water-quality data are suitable for characterizing general conditions in a nationally consistent manner and (2) describes, to the extent possible, recent, general water-quality conditions in the Central Nebraska Basins. The study …


Organic Geochemistry Of Permian Organic-Rich Sediments From The Sudetes Area, Sw Poland, Shareen R. Yawanarajah, Michael A. Kruge, Maria Mastalerz, Wojciech Sliwinski Jan 1993

Organic Geochemistry Of Permian Organic-Rich Sediments From The Sudetes Area, Sw Poland, Shareen R. Yawanarajah, Michael A. Kruge, Maria Mastalerz, Wojciech Sliwinski

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Lacustrine and marine sediments from the Permian rift-basins of southwestern Poland were analysed using GC-MS and petrographic techniques. High Pr/Ph ratios, gamma- and beta-carotanes and gammacerane in the lacustrine sediments indicate deposition under elevated water salinities. The primary organic matter is represented by bacterial and algal lipids with variable terrestrial input. Marine algal lipids with minor bacterial and cyanobacterial lipids are the primary source of organic matter in the marine sediments. Extended hopanes, n-alkanes with even-odd predominance and low Ts/Tm ratios are consistent with deposition in a closed, evaporitic basin with substantial carbonate sedimentation.


Gas Exploration In The Devonian Shales Of Kentucky, Terence Hamilton-Smith Jan 1993

Gas Exploration In The Devonian Shales Of Kentucky, Terence Hamilton-Smith

Bulletin--KGS

Devonian black shales constitute a major economic resource in Kentucky. These shales, known variously as the Ohio, Chattanooga, and New Albany Shales, are between 50 and 1, 700 feet thick and occur both in outcrop and in the subsurface, buried as deep as 4,200 feet below sea level.

Total gas in place for the Devonian shales in Kentucky is estimated to be between 63 and 112 trillion cubic feet; between 2 and 28 percent is recoverable. Known shale gas accumulations include the giant Big Sandy Field of eastern Kentucky and adjacent \/Vest Virginia, as well as a number of smaller …


Seasonal Sediment Migration And Sediment Dynamics On Sandy Point Beach, San Salvador Island, Bahamas, Nicholas T. Loizeaux, H. Allen Curran, William T. Fox Jan 1993

Seasonal Sediment Migration And Sediment Dynamics On Sandy Point Beach, San Salvador Island, Bahamas, Nicholas T. Loizeaux, H. Allen Curran, William T. Fox

Geosciences: Faculty Publications

A study of the dynamics of Sandy Point Beach along the southwestern corner of San Salvador Island over an eighteen-month period, beginning in June, 1990, has revealed that two seasonal phases of sediment transport are operative. Based primarily on analyses of the grain-size parameters of sand samples collected from the beach in June, 1990, a northerly direction of sediment transport was detected. This is herein termed the Spring/Summer phase of transport, and it results from the energy of waves generated by the prevailing easterly trade winds. Continued profiling of the beach in December, 1990, and January, 1992, revealed that a …


Long-Term, Seasonal, And Event-Driven Sediment Movement On East Beach, San Salvador Island, Bahamas, Andrew L. Brill, H. Allen Curran, William T. Fox Jan 1993

Long-Term, Seasonal, And Event-Driven Sediment Movement On East Beach, San Salvador Island, Bahamas, Andrew L. Brill, H. Allen Curran, William T. Fox

Geosciences: Faculty Publications

East Beach is a modern, medium-energy shoreline located on the northeast coast of San Salvador Island, Bahamas. Stake and horizon profiles were made at 9 sites along a 1-km section of the beach in June, 1990, and every six months thereafter through January,1992. These observations appear to confirm that East Beach is a prograding shoreline, building onto the eastern shelf of the island. Seasonally corrected volume calculations indicate that between June, 1990 and January, 1992 approximately 14,000 m3 of new sand per kilometer were added to the East Beach system, with most of the sand likely derived from the …


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.


Available Coal Resoures Of The Handshoe 7.5–Minute Quadrangle, Knott County, Kentucky, Gerald A. Weisenfluh, Robert E. Andrews, John K. Hiett, Richard E. Sergeant Jan 1993

Available Coal Resoures Of The Handshoe 7.5–Minute Quadrangle, Knott County, Kentucky, Gerald A. Weisenfluh, Robert E. Andrews, John K. Hiett, Richard E. Sergeant

Information Circular--KGS

Coal resources available for mining have been estimated for the Handshoe Quadrangle within the Hazard Coal Reserve District of the Eastern Kentucky Coal Field. Twelve coal beds within the quadrangle are potentially mineable and comprise the basis of these resource estimates. Seven of these beds have been commercially developed, but only four have produced more than 1 million tons: the Tiptop, Hazard No. 8, Hazard No. 4, and Upper Elkhorn No. 3. A computerized Geographic Information System was used to calculate estimates of original, mined-out, and remaining resources, restrictions to mining, and available resources.


Quality Of Private Ground-Water Supplies In Kentucky, Daniel I. Carey, James S. Dinger, O. Barton Davidson, Richard E. Sergeant, Joseph L. Taraba, Thomas W. Ilvento, Steve Coleman, Rayetta Boone, Laura M. Knoth Jan 1993

Quality Of Private Ground-Water Supplies In Kentucky, Daniel I. Carey, James S. Dinger, O. Barton Davidson, Richard E. Sergeant, Joseph L. Taraba, Thomas W. Ilvento, Steve Coleman, Rayetta Boone, Laura M. Knoth

Information Circular--KGS

About 3.7 million people live in Kentucky, of which 1.9 million (52 percent) live in urban areas (roughly defined as any community with 2,500 or more people) and 1.8 million (48 percent) live in rural areas (University of Kentucky, 1993). Figure 1 summarizes sources of drinking water for Kentucky residents. About 70 percent of Kentuckians get their daily supply of water from surface-water sources - lakes and streams; about 25 percent get their water from ground-water wells; and about 5 percent get their water from other sources - springs, cisterns, ponds, or hauled water.


Estimation Of A Water Budget For Agnes Marsh, Grand Forks County, North Dakota, Allen E. Comeskey Jan 1993

Estimation Of A Water Budget For Agnes Marsh, Grand Forks County, North Dakota, Allen E. Comeskey

Theses and Dissertations

Agnes Marsh is a semipermanent wetland in the Red River Valley of northeastern North Dakota. The marsh overlies and is in direct hydraulic connection with the unconfined Elk Valley aquifer. Recent irrigation development nearby raised concerns about the hydrological impact to the marsh by a declining water table in the aquifer. The purpose of this study was to determine how Agnes Marsh interacts with the underlying Elk Valley aquifer and how sensitive the marsh is to declining water levels in the aquifer.

Three methods were used to assess how the marsh interacts with the aquifer. First, stratigraphic analysis revealed the …


Petrography And Inorganic Geochemistry Of The Rosebud Coal Seam At The Absaloka, Big Sky And Rosebud Mines, Powder River Basin, Montana, Lingbu Kong Jan 1993

Petrography And Inorganic Geochemistry Of The Rosebud Coal Seam At The Absaloka, Big Sky And Rosebud Mines, Powder River Basin, Montana, Lingbu Kong

Theses and Dissertations

Quantitative maceral and microlithotype analyses, huminite reflectance measurements and inorganic constituent analyses of the samples of the Rosebud subbituminous coal seam from the Absaloka, Big Sky and Rosebud Mines were used in the interpretation of the depositional environment of the seam and for prediction of ash formation during combustion. The mean huminite reflectance varies from 0.31% at the Rosebud Mine to 0.34% at the Absaloka Mine and 0.39% at the Big Sky Mine, indicating that the coal rank is transitional from lignite to subbituminous C. Despite the variation in huminite reflectance, samples from the three mines are similar in mean …


Identifying Key Variables Associated With The Temporal And Spatial Distribution Of Prolific Marine Petroleum Source Rock (Mpsr) Units And Its Application To The Taconic Foreland Basin, Eastern New York, C. Mark Achong Jan 1993

Identifying Key Variables Associated With The Temporal And Spatial Distribution Of Prolific Marine Petroleum Source Rock (Mpsr) Units And Its Application To The Taconic Foreland Basin, Eastern New York, C. Mark Achong

Geology Theses and Dissertations

Correctly identifying key variables associated with the temporal and spatial distribution of prolific marine petroleum source rock (MPSR) units is of critical importance towards the future development of models accurately predicting their existence and effective exploitation. The geographic positioning and prevailing paleoclimatic conditions on paleocontinental reconstructions, in combination with the processes controlling the drowning of continental margins and parameters associated with the establishment of high biologic productivity and long term anoxic conditions within the water column, have been pursued as first-order constraints controlling the development of some prolific marine petroleum source rock (MPSR) deposits. From this, a model has been …


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 …


A Paleoseismic Investigation Of The Mcgregor Fault, East-Central New York, Steven J. Tice Jan 1993

A Paleoseismic Investigation Of The Mcgregor Fault, East-Central New York, Steven J. Tice

Geology Theses and Dissertations

The structural disposition and movement potential of the McGregor Fault System in Eastern New York State are reviewed from the perspective of a paleoseismic investigation. The McGregor Fault zone has been located beneath deltaic sediments west of West Glens Falls using commercial and residential bore hole data and microgravity surveys. A 34 m long trench was excavated in overburden near the western margin of the McGregor Fault zone to a depth of 3.2 m. Stratified fluvially deposited sediments were exposed which showed no evidence of earthquake induced deformation or offset. However, the overburden present here does not possess optimal qualities …


Trace-Element Modelling Of Melting In Spinel Peridotites, Susanne Petra Vogel Jan 1993

Trace-Element Modelling Of Melting In Spinel Peridotites, Susanne Petra Vogel

Geology Theses and Dissertations

This study addresses three independent topics related to trace element modeling of spinel peridotites that are suggested by the pioneering work of Johnson et al. (1990) on abyssal harzburgites.
First, the fractional non-modal melting equation derived by Johnson and coworkers (1990) is algebraically modified to present a "one-element/two-phase" model. This model suggests a simple test for estimating mantle heterogeneity in the source rock of spinel lherzolites. This model is applied to data from the literature for samples from Dreiser Weiher, Germany; San Luis Potosi, Mexico; and Western Victoria, Australia.
Second, trace elements in clinopyroxenes of abyssal peridotites and continental spinel …


Reconnaissance Data For Selected Herbicides, Two Atrazine Metabolites, And Nitrate In Surface Water Of The Midwestern United States, 1989-90, Elisabeth A. Scribner, E. Michael Thurman, Donald A. Goolsby, Michael T. Meyer, Margaret S. Mills, Michael L. Pomes Jan 1993

Reconnaissance Data For Selected Herbicides, Two Atrazine Metabolites, And Nitrate In Surface Water Of The Midwestern United States, 1989-90, Elisabeth A. Scribner, E. Michael Thurman, Donald A. Goolsby, Michael T. Meyer, Margaret S. Mills, Michael L. Pomes

United States Geological Survey: Publications

Water-quality data were collected from 147 rivers and streams during 1989-90 to determine the temporal and geographic distribution of selected preemergent herbicides, two atrazine metabolites, and nitrate in 10 Midwestern States. This report includes a description of the sampling design, data-collection techniques, laboratory and analytical methods, and a compilation of constituent concentrations and quality-assurance data. All water samples were collected by depth-integrating techniques at three to five locations across the wetted perimeter of each stream. Sites were sampled three times in 1989~before application of herbicides, during the first major runoff after application of herbicides, and in the fall during a …


Oil And Gas Maps Of The Pikeville 30 X 60 Minute Quadrangle, Kentucky, Dan Walker, Joseph F. Meglen, Brandon C. Nuttall, X. Mara Chen, Anna E. Watson Jan 1993

Oil And Gas Maps Of The Pikeville 30 X 60 Minute Quadrangle, Kentucky, Dan Walker, Joseph F. Meglen, Brandon C. Nuttall, X. Mara Chen, Anna E. Watson

Map and Chart--KGS

The purpose of these oil and gas maps is to portray the distribution of types of wells in a manner useful to the oil and gas industry and geologists interested in subsurface research. The maps are designed to help geologists better evaluate acreage holdings and exploratory/development potential.


Resource News-March/April 1993 Jan 1993

Resource News-March/April 1993

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.


Glacial Deposits, Vol. 21, 1992-1993, Department Of Geography-Geology Jan 1993

Glacial Deposits, Vol. 21, 1992-1993, Department Of Geography-Geology

Glacial Deposits

Newsletter of the Department of Geography-Geology


Sedimentology And Ichnology Of Holocene Dune And Backshore Deposits, Lee Stocking Island, Bahamas, Brian White, H. Allen Curran Jan 1993

Sedimentology And Ichnology Of Holocene Dune And Backshore Deposits, Lee Stocking Island, Bahamas, Brian White, H. Allen Curran

Geosciences: Faculty Publications

No abstract provided.


Using Fourier Transform Analysis To Extract Information From The Shapes Of Folded Layers, Thomas Billiard Jan 1993

Using Fourier Transform Analysis To Extract Information From The Shapes Of Folded Layers, Thomas Billiard

Honors Papers

Objective methods of fold shape analysis are nessesary to better understand the behavior of folds and the folding process. I examined two methods of analysis, and used a method based on the Fourier Transform to show that the method based on the Fourier Series was insufficient for identifying shape characteristics of aperiodic natural fold trains. I also showed that the Fourier Transform method accessed information that was inaccessable using the Fourier Series method.


Sinkhole Excavations In Peccary Cave, Newton County, Arkansas, Kenneth M. Ball, Leo Carson Davis Jan 1993

Sinkhole Excavations In Peccary Cave, Newton County, Arkansas, Kenneth M. Ball, Leo Carson Davis

Journal of the Arkansas Academy of Science

No abstract provided.


Aspects Of Gold Recovery From An Indigenous Ore, Cormac Patrick Mcnamee Jan 1993

Aspects Of Gold Recovery From An Indigenous Ore, Cormac Patrick Mcnamee

Masters

This project involved the investigation into the basic electrochemistry of the thiourea-formamidine disulphide redox couple and an estimation of the formal potential, Eo1 for the couple. By carrying out optimisation experiments on the leaching of gold from an ore sample from the Avoca mine in Co. Wicklow, the optimum leaching conditions were determined for maximum gold extraction. The effects of various organic and inorganic species on the adsorption of gold onto activated carbon and modified peat were investigated with the use of factorial designed experiments. The Langmuir Isotherm model was applied to estimate the capacity of the carbon for these …