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Articles 27931 - 27960 of 29955

Full-Text Articles in Geology

Depositional Environments And Sandstone Diagenesis In The Tyler Formation (Pennsylvanian), Southwestern North Dakota, Stephen D. Sturm Jan 1982

Depositional Environments And Sandstone Diagenesis In The Tyler Formation (Pennsylvanian), Southwestern North Dakota, Stephen D. Sturm

Theses and Dissertations

The Tyler Formation, of Early Pennsylvanian age, in southwestern North Dakota may be divided into upper and lower units, reflecting both a change in lithology and depositional environments. The lower unit is dominated by varicolored, noncalcareous shales and mudstones, siltstones, thin coal beds, and medium-grained sandstones. The upper unit in the areas of the Square Butte to Fryburg fields may be divided into a lower subunit, dominated by dark gray to grayish-black, argillaceous limestones and calcareous shales, and an upper subunit dominated by grayish-red, anhydritic limestones, varicolored to reddish-brown, calcareous shales, and locally, thin anhydrite. In the area of the …


Glacial Geology And Stratigraphy Of Southeastern Pierce And Southwestern Benson Counties, North Dakota, Arthur W. Schnacke Jr. Jan 1982

Glacial Geology And Stratigraphy Of Southeastern Pierce And Southwestern Benson Counties, North Dakota, Arthur W. Schnacke Jr.

Theses and Dissertations

The study area includes 220 square miles in southeastern Pierce and southwestern Benson Counties, North Dakota (T. 152 N. through T. 154 N., R. 70 W. through R. 73 W.).

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Field mapping and subsequent analyses were attempted to differentiate the drifts of the Leeds and Souris lobes, to determine the sequence and duration of events during and subsequent to glaciation, and to aid in correlating the drifts. Landforms of the area include: ice marginal ridges, ground moraine, proglacial plains, abandoned river channels, and sand dunes.

In the laboratory, very coarse sand lithology percentages, till fabric, texture, and gross lithology …


Preliminary Investigation Of Ground-Water Occurrence In The Atoka Formation Of Pope And Faulkner Counties, Arkansas, Wyndal M. Goodman, Albert E. Ogden Jan 1982

Preliminary Investigation Of Ground-Water Occurrence In The Atoka Formation Of Pope And Faulkner Counties, Arkansas, Wyndal M. Goodman, Albert E. Ogden

Journal of the Arkansas Academy of Science

One hundred and twelve wells having drillers' logs were studied in Pope and Faulkner counties. Sixty-six of the wells produced water from shales and siltstones of the Atoka Formation while 46 produced from interbedded Atoka sandstones. Drillers' estimated well yields ranged from 1 to 100 gpm, but the median yield was only 9 gpm. Well depths ranged from 30 to 337 feet with a median depth of 100 feet. Ground-water is usually obtained from a series of low-producing confined aquifers of low artesian pressure. Pressure head and production were shown, statistically (a = .01), to decrease with increasing well depth. …


Stratigraphy Of A Pennsylvanian Deltaic Sequence In Russellville, Arkansas, Christopher F. Moyer, Ken Fritsche Jan 1982

Stratigraphy Of A Pennsylvanian Deltaic Sequence In Russellville, Arkansas, Christopher F. Moyer, Ken Fritsche

Journal of the Arkansas Academy of Science

No abstract provided.


Reconnaissance Of Ground-Water Resources Of Stone And Independence Counties, Arkansas, Albert E. Ogden, James R. Musgrove, Lisa Milligan Jan 1982

Reconnaissance Of Ground-Water Resources Of Stone And Independence Counties, Arkansas, Albert E. Ogden, James R. Musgrove, Lisa Milligan

Journal of the Arkansas Academy of Science

No abstract provided.


Glacial Deposits, Vol. 10, 1981-1982, Department Of Geography-Geology Jan 1982

Glacial Deposits, Vol. 10, 1981-1982, Department Of Geography-Geology

Glacial Deposits

Newsletter of the Department of Geography-Geology


Geothermal Resources Of Nebraska, W. D. Gosnold, D. A. Eversoll Jan 1982

Geothermal Resources Of Nebraska, W. D. Gosnold, D. A. Eversoll

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Thickness And Structure Maps Of The Pennsylvanian And Permian Rocks Across Southern Nebraska, R. R. Burchett Jan 1982

Thickness And Structure Maps Of The Pennsylvanian And Permian Rocks Across Southern Nebraska, R. R. Burchett

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Petrology And Alteration In The Core Of The Bear Lodge Tertiary Intrusive Complex, Bear Lodge Mountains, Crook County, Wyoming, Michael Wilkinson Jan 1982

Petrology And Alteration In The Core Of The Bear Lodge Tertiary Intrusive Complex, Bear Lodge Mountains, Crook County, Wyoming, Michael Wilkinson

Theses and Dissertations

The Bear Lodge complex is an elongate, dome-shape uplift about 8.5 km long by 4 km wide, 10 km northwest of Sundance, Wyoming. The study area is centered about Warren Peaks and includes approximately 23 km2. The igneous intrusive core of the complex is mostly alkali trachyte but latite is abundant in the southern portion of the complex. Phonolite, pseudoleucite trachyte porphyry, and carbonatite dikes cut across the core. Precambrian granitic rocks and lower Paleozoic sedi mentary rocks flank the intrusion and occur as xenoliths.

The latite is relatively unaltered and consists mostly of oligo clase, andesine, alkali feldspar, salite, …


Analysis Of Petroleum Source Rocks Of The Bakken Formation (Devonian And Mississippian) In North Dakota, Rick L. Webster Jan 1982

Analysis Of Petroleum Source Rocks Of The Bakken Formation (Devonian And Mississippian) In North Dakota, Rick L. Webster

Theses and Dissertations

The Bakken Formation of North Dakota consists of upper and lower, black, organic-rich shales separated by a calcareous siltstone middle member. The formation is a relatively thin unit (maximum thickness of 145 feet) with the lower shale .attaining a maximum thickness of 50 feet and the upper shale a maximum thickness of 23 feet. The shales are hard, siliceous, pyritic, fissile, and noncalcareous. They contain abundant conodonts and tasmanites and have planar laminations accented by pyrite. The upper and lower shales were apparently deposited in an offshore, marine, anoxic environment where anoxic conditions may have been caused by silling of …


Mineralogical, Textural, And Paragenetic Studies Of Selected Ore Deposits Of The Southeast Missouri Lead-Zinc-Copper District And Their Genetic Implications, Kenneth Bruce Horrall Jan 1982

Mineralogical, Textural, And Paragenetic Studies Of Selected Ore Deposits Of The Southeast Missouri Lead-Zinc-Copper District And Their Genetic Implications, Kenneth Bruce Horrall

Doctoral Dissertations

“A detailed paragenetic study of Pb-Zn-Cu ores from the Viburnum Number 28, Brushy Creek, and Goose Creek mines in the Southeast Missouri lead district indicates a complicated paragenesis characterized by repeated periods of mineral deposition. The sequence is composed of nineteen minerals including abundant galena, sphalerite, chalcopyrite, pyrite, marcasite, dolomite, calcite, and quartz and minor siegenite, bornite, bravoite, blaubleibender covellite, covellite, gersdorffite, digenite, enargite, tennantite, dickite, and malachite.

The paragenesis indicates that the ore solutions evolved in the following order: (1) Cu-rich, (2) Co-Ni-rich, (3) Pb-Zn-rich, and (4) Fe-rich. Subsequent repeated generations include cubic galena, later sphalerite, and minor crystalline …


Hydrology Of The Sinking Creek System, Logan And Simpson Counties, Kentucky, James C. Cubbage Dec 1981

Hydrology Of The Sinking Creek System, Logan And Simpson Counties, Kentucky, James C. Cubbage

Masters Theses & Specialist Projects

Southwest of Bowling Green, Kentucky, is the Western Pennyroyal, is a karstified area which has been neglected in the study of its ground water. About 100 square miles near Adairville were chosen for analysis to help rectify this lack of knowledge. The area is dominated by Sinking Creek, a surface-subsurface drainage system.

The main purpose of the study was to map the underground flow in the Sinking Creek area. The drainage system seemed to be typical for the Western Pennyroyal and exhibited many similarities to flow paths known in the Central Kentucky Karst.

The investigation proved to be of basic …


Geology Newsletter- 1981, Department Of Geology Dec 1981

Geology Newsletter- 1981, Department Of Geology

Geological and Environmental Sciences News

Vol. 1 No. 6

  • Dear Alumni and Friends
  • Faculty News
  • Alumni News
  • Geology Club News


Petrology Of Fluvial And Shoreline Sands In A Modern Arc-Trench Gap, Guatemala, James Robert Bartel Dec 1981

Petrology Of Fluvial And Shoreline Sands In A Modern Arc-Trench Gap, Guatemala, James Robert Bartel

Masters Theses

Petrographic studies of modern sands, derived from areas with known source rocks, climate, relief, environments of deposition, and tectonic setting, are essential for compiling compositional models for ancient sandstones. The Pacific coastal plain of Guatemala is terminated 25-60 km inland by the steep slopes of a row of active Quaternary volcanic and granitic rocks.

Sands being deposited on the coastal plain by the Rio Nahulate, which drains the older volcanic and granitic terrane, show significant compositional differences with those supplied by the Rio Samala, which drains an area dominated by active volcanism: Q9F35L56 vs. Q …


An Analysis Of Nitrate Concentrations In The Ground-Water Of Antwerp Township, Van Buren County, Michigan, John Emil Klanke Dec 1981

An Analysis Of Nitrate Concentrations In The Ground-Water Of Antwerp Township, Van Buren County, Michigan, John Emil Klanke

Masters Theses

Private wells were tested for nitrate during the spring of 1979 throughout sections of Antwerp Township, Van Buren County, southwestern Michigan (sections 1-5, 7-22, 24-26, 28-31, 33-36). Water samples were collected from 159 private wells and analyzed for nitrate. Nitrate concentrations ranged from less than 1 mg/1 NO3-N to 14.6 mg/1 NO3-N. Seven wells were found to have nitrate concentrations equaling or exceeding the National Interim Primary Drinking Water Standard of 10 mg/1 NO3-N. Nitrate concentrations were related to age of septic system, well depth below static water level, land use, and soil type. …


Structural Analysis Of Precambrian Metasedimentary Rocks Of The Swede Gulch Formation, Nahant, South Dakota, Richard G. Cookman Dec 1981

Structural Analysis Of Precambrian Metasedimentary Rocks Of The Swede Gulch Formation, Nahant, South Dakota, Richard G. Cookman

Masters Theses

Precambrian X tectonites deformed between thermal domes in the northern Black Hills 1.7 B.Y.B.P. display variably trending isoclinal folds cross-cut by southeast trending slip-folds developed in discrete shear zones. Eugeosynclinal sedimentary rocks consisting of shale, quartzarenite , sublitharenite, and graywacke were metamorphosed to phyllite, quartzite, and metagraywacke during two syntectonic phases and one post-tectonic phase. The earliest syntectonic metamorphism was associated with development of isoclinal folds and may have produced amphibolite or greenschist facies. It was succeeded by retrograde metamorphism of greenschist facies syntectonic with and post-tectonic to development of southeast trending folds.

Mica, chlorite, iron oxides, and graphite are …


Gravity And Ground Magnetic Investigations In Eastern Nebraska, Robert F. Diffendal Jr., R. R. Burchett Nov 1981

Gravity And Ground Magnetic Investigations In Eastern Nebraska, Robert F. Diffendal Jr., R. R. Burchett

Robert F. Diffendal, Jr., Publications

The purpose of this investigation was to extend the area covered by gravity and ground magnetic data related to the Nemaha Uplift and associated structures in eastern Nebraska. Gravity data were collected from Clay, Fillmore, Hamilton, Nuckolls, Polk, Thayer, and York Counties. Additional ground magnetic data and gravity data were collected for central Otoe County.


Regional Tectonics And Seismicity Of Eastern Nebraska, Annual Report, July 1980–June 1981, R. R. Burchett Nov 1981

Regional Tectonics And Seismicity Of Eastern Nebraska, Annual Report, July 1980–June 1981, R. R. Burchett

Conservation and Survey Division: Faculty and Staff Publications

This annual report presents and interprets the information obtained by the Conservation and Survey Division (Nebraska Geological Survey) during contract year July 1, 1980, to June 30, 1981, under contract NRC-04-76-3l5 with the U.S. Nuclear Regulatory Commission. The information pertains to the geology, structure, tectonics, and seismicity of eastern Nebraska with emphasis on central Otoe County. Some of the information presented here results from a combination of studies begun in earlier years but the greater part results from studies begun during the contract year.

The scope of the studies is summarized as follows:

1. Rock outcrops in Otoe County were …


Selected Shallow Electrical Resistivity Surveys At Volcano Cliffs, Bernalillo County, And Warm Springs, Sandoval County, New Mexico, Sidney S. Brandwein Oct 1981

Selected Shallow Electrical Resistivity Surveys At Volcano Cliffs, Bernalillo County, And Warm Springs, Sandoval County, New Mexico, Sidney S. Brandwein

Earth and Planetary Sciences ETDs

To help assess the applicability of shallow electrical resistivity measurements in New Mexico, two diverse areas in northwestern New Mexico were chosen as electrical resistivity survey sites: Volcano Cliffs and Warm Springs.

Volcano Cliffs, 15 km northwest of Albuquerque, is an area of Pleistocene volcanic activity which manifested itself in cinder cones and basalt flows. At Volcano Cliffs five different electrode configurations were employed to test the horizontality and derive the thicknesses and resistivities of the three geoelectric units present. All electrode configurations yielded reliable results. The ambiguities presented by the principle of equivalence were successfully treated. The first geoelectric …


The Influence Of Halloysite Content On The Shear Strength Of Kaolinite, Reka Katalin Gabor Oct 1981

The Influence Of Halloysite Content On The Shear Strength Of Kaolinite, Reka Katalin Gabor

Dissertations and Theses

The objective of this thesis is to determine the relative shear strengths of halloysite, kaolinite, synthetic mixtures, and local soils, to investigate the influence of halloysite content on the shear strength of kaolinite, and to explore the possibility that the strength properties of soil clays might be controlled by the relative content of their component minerals.


Gravity And Ground Magnetic Investigations In Eastern Nebraska, Robert F. Diffendal Jr., R. R. Burchett Sep 1981

Gravity And Ground Magnetic Investigations In Eastern Nebraska, Robert F. Diffendal Jr., R. R. Burchett

Robert F. Diffendal, Jr., Publications

The purpose of this investigation was to extend the area covered by gravity and ground magnetic data related to the Nemaha Uplift and associated structures in eastern Nebraska. Gravity data were collected from Butler, Jefferson, Saline, and Seward counties. Additional ground magnetic data and gravity data were collected for eastern Sarpy and northeastern Cass counties in Nebraska and gravity data were collected from parts of Mills and Fremont counties in Iowa.


Regional Tectonics And Seismicity Of Eastern Nebraska, Annual Report, July 1979–June 1980, R. R. Burchett Sep 1981

Regional Tectonics And Seismicity Of Eastern Nebraska, Annual Report, July 1979–June 1980, R. R. Burchett

Conservation and Survey Division: Faculty and Staff Publications

This annual report presents and interprets the information obtained by the Conservation and Survey Division (Nebraska Geological Survey) during contract year July 1, 1979, to June 30, 1980, under contract NRC-04-76-3l5 with the U.S. Nuclear Regulatory Commission. The information pertains to the geology, structure, tectonics, and seismicity of eastern Nebraska with emphasis on the vicinity south of Omaha, Nebraska. Some of the information presented here results from a combination of studies begun in earlier years but the greater part results from studies begun during the contract year.

The scope of the studies is summarized as follows:

1. Rock outcrops in …


The Reclamation Of The Victory Mine Site, Vigo County, Indiana, Carla J. Badger Aug 1981

The Reclamation Of The Victory Mine Site, Vigo County, Indiana, Carla J. Badger

All-Inclusive List of Electronic Theses and Dissertations

This study was involved with the physical and socioeconomic aspects related to the reclamation of the Victory Mine located in Vigo County, Indiana. The Victory Mine is an abandoned slope mine which includes 165 acres of gob and slurry. During the past ten years the site has been used as a sanitary landfill utilizing the gob as a covering agent. Pollution of Honey Creek, a tributary to the Wabash River, has been caused by sediment and acid mine drainage from the Victory Mine. Possible reclamation procedures were outlined for the Victory Mine site. Physical aspects included soils, surface and ground …


Lithologic And Structural Controls On Karst Landforms Of The Mitchell Plain, Indiana, And Pennyroyal Plateau, Kentucky, Frederick Jennings Woodson Aug 1981

Lithologic And Structural Controls On Karst Landforms Of The Mitchell Plain, Indiana, And Pennyroyal Plateau, Kentucky, Frederick Jennings Woodson

All-Inclusive List of Electronic Theses and Dissertations

Karst features in Harrison County, Indiana, and the Mammoth Cave region, Kentucky, are profoundly influenced by lithology and structure. In the Sinkhole Plain two classes of sinkholes, shallow solutional and deeper subsidence, differ in morphology, origin, age, distribution, and density. Distributions of the two kinds of sinkholes reflect the outcrop pattern of specific lithostratigraphic units. Broad shallow dolines (Ste. Genevieve-type sinks) develop on the Horse Cave Member of the St. Louis Limestone and on the Ste. Genevieve, Girkin, and Paoli Limestones. Innumerable steeper-sided subsidence and collapse depressions (St. Louis-type sinkholes) form on the Corydon Chert Member, lower St. Louis Limestone, …


The Petrology And Geochemistry Of Keweenawan Diabase Dikes In Ontonagon, Gogebic, Iron And Dickinson Counties, Michigan, James J. Hahnenberg Aug 1981

The Petrology And Geochemistry Of Keweenawan Diabase Dikes In Ontonagon, Gogebic, Iron And Dickinson Counties, Michigan, James J. Hahnenberg

Masters Theses

Petrographic and chemical studies of Keeweenawan-age diabase dikes in Michigan's Upper Peninsula show two major groupings, Porcupine Mountain dikes and Lower Keweenawan dikes consist of two major rock types, fine-grained smaller dikes and the coarse-grained central portions of larger dikes. Major minerals are subophitic plagioclase and pyroxene. The rocks, as compared to the "average" basalts, are low in Al203, high in Ti02, K20, P205 and contain moderate amounts of Fe0t. They are classified as quartz tholeiites. Several parental magma sources that would account for these and other …


Dolomitization Of The Brassfield Formation (Lower Silurian) In Adams County, Ohio, Lisa L. Varga Aug 1981

Dolomitization Of The Brassfield Formation (Lower Silurian) In Adams County, Ohio, Lisa L. Varga

Masters Theses

The Lower Silurian Brassfield Formation which outcrops in the Tri-state area of Ohio, Indiana and Kentucky is a transgressive sequence consisting of a series of interbedded shales, limestones and dolostones. Evidence from depositional environments, petrography and spatial relationships of dolomitized and undolomitized rock suggests dolomitization in southwestern Ohio was a two-stage process. Initial dolomitization was restricted to the basal Belfast Member and probably occurred penecontemporaneously on small supratidal islands in a manner analagous to that which occurs in the modern sabkha environment of the Persian Gulf. Regional dolomitization was a later diagenetic event related to the formation of a fresh-seawater …


U-Pb Studies Of Zircon Cores And Overgrowths, And Monazite: Implications For Age And Petrogenesis Of The Northeastern Idaho Batholith, M. E. Bickford, R. B. Chase, B. K. Nelson, Robert Duncan Shuster, E. C. Arruda Jul 1981

U-Pb Studies Of Zircon Cores And Overgrowths, And Monazite: Implications For Age And Petrogenesis Of The Northeastern Idaho Batholith, M. E. Bickford, R. B. Chase, B. K. Nelson, Robert Duncan Shuster, E. C. Arruda

Geography and Geology Faculty Publications

U/Pb isotopic studies of zircons, many containing xenocrystic cores with euhedral overgrowths, and monazite from igneous rocks and metasedimentary inclusions of the northeastern Idaho batholith yield linear arrays on concordia diagrams. We interpret these as mixing lines between an old component (cores) and a young component (overgrowths and zircons without cores). The lower intercept of such arrays with concordia may yield the minimum age of the rocks if the overgrowths and zircons without cores are discordant, or the crystallization age if they are concordant. Monazites yield apparently concordant ages either equal or less than the lower intercept zircon ages. The …


Groundwater Levels In Nebraska, 1980, Martin S. Johnson, Darryll T. Pederson Jul 1981

Groundwater Levels In Nebraska, 1980, Martin S. Johnson, Darryll T. Pederson

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Geology Of A Volcanic Complex On The South Flank Of Mount Jefferson, Oregon, Brian Lee Gannon Jun 1981

Geology Of A Volcanic Complex On The South Flank Of Mount Jefferson, Oregon, Brian Lee Gannon

Dissertations and Theses

The volcanic stratigraphy and petrography is described for a 46 km2 area on the southern flank of Mount Jefferson in the north-central part of the Oregon High Cascades. Here, volcanic processes have been active throughout Quaternary time, resulting in complex stratigraphic relationships. In addition, three formerly recognized glaciations and a two-phase period of neoglaciation have eroded the terrain, depositing tills in contact or interstratified with the volcanic units. Collectively, these processes and the resulting deposits are characteristic of High Cascades development.


Growth-Form Analysis And Paleoecology Of The Corals Of The Late Ordovician Through Mid-Silurian Fish Haven And Laketown Formations, Bear River Range, North-Central Utah, Thomas B. Rich May 1981

Growth-Form Analysis And Paleoecology Of The Corals Of The Late Ordovician Through Mid-Silurian Fish Haven And Laketown Formations, Bear River Range, North-Central Utah, Thomas B. Rich

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Morphology of corals of the Late Ordovician through mid-Silurian Fish Haven and Laketown Formations were analyzed to document adaptations to inferred enviromental conditions, i.e., (bathymetry, illumination, sedimentation, currents, and energy), under which their enclosing sediment was deposited. Specimens and data were collected from six sites. Insoluble-residue tests were performed on the corals' matrices.

Individual corallites of radial-lensoidal corals radiate in all directions. Vertical growth, however, was restricted in turbulent conditions. Umbrellic, radial-lensoidal corals feature downward facing corallites, considered to be an adaptation to a well illuminated environment.

On tabular lensoidal corals, constituent corallites faces exclusively upward, an orientation needed under …