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Articles 27511 - 27540 of 29955

Full-Text Articles in Geology

A Gravity And Magnetic Study Of The Crooked Creek Cryptoexplosion Structure, Crawford County, Missouri, Charles Edward Woodbury Jan 1987

A Gravity And Magnetic Study Of The Crooked Creek Cryptoexplosion Structure, Crawford County, Missouri, Charles Edward Woodbury

Masters Theses

"The pre-Pennsylvanian structure at Crooked Creek consists of a complex, vertically faulted ring of Cambrian and Ordovician sediments with a central uplifted core. The center of the structure is strongly deformed and contains shatter cones, brecciation, and other signs of extreme shock.

A magnetic low over the center of the structure suggests that igneous material was not involved in the formation of the structure, and this is corroborated by core analysis. Gravity data indicates several small gravity lows, possibly associated with areas of brecciation, circling the flanks of the structure. As in the magnetic data, there is no indication that …


Analysis Of Coal Samples From The Southwestern District, Kentucky (Clay, Jackson, Knox, Laurel, Lee, Mccreary, Owsley, Whitley, And Parts Of Bell, Clinton, Estill, Madison, Pulaski, Rockcastle, And Wayne Counties), James C. Currens, Linda Jean Bragg, James C. Hower Jan 1987

Analysis Of Coal Samples From The Southwestern District, Kentucky (Clay, Jackson, Knox, Laurel, Lee, Mccreary, Owsley, Whitley, And Parts Of Bell, Clinton, Estill, Madison, Pulaski, Rockcastle, And Wayne Counties), James C. Currens, Linda Jean Bragg, James C. Hower

Information Circular--KGS

Chemical and petrographic data ore presented for 119 samples of cool collected in the Southwestern District, eastern Kentucky. The data include sample-site locations, sampling conditions, stratigraphic position, megoscopic description of the cool, air-drying loss, proximate and ultimate analyses, Btu content, forms of sulfur, initial deformation temperature, softening temperature, fluid temperature, free-swelling index, concentration of major- and minor-oxides and trace elements, and petrographic analyses.


Analysis Of Coal Samples From The Upper Cumberland District, Kentucky (Parts Of Bell, Harlan, Letcher, And Whitley Counties), James C. Currens, Linda Jean Bragg, James C. Hower Jan 1987

Analysis Of Coal Samples From The Upper Cumberland District, Kentucky (Parts Of Bell, Harlan, Letcher, And Whitley Counties), James C. Currens, Linda Jean Bragg, James C. Hower

Information Circular--KGS

Chemical and petrographic data ore presented for 57 samples of cool collected in the Upper Cumberland District, eastern Kentucky. These data include sample-site locations, sampling conditions, stratigraphic position, megoscopic description of the cool, air-drying loss, proximate and ultimate analyses, Btu content, forms of sulfur, initial deformation temperature, softening temperature, fluid temperature, free-swelling index, concentration of major- and minor-oxides and trace elements, and petrographic analyses.


Analysis Of Coal Samples From The Big Sandy District, Kentucky (Floyd, Johnson, Martin, And Pike Counties), James C. Currens, Linda Jean Bragg, James C. Hower Jan 1987

Analysis Of Coal Samples From The Big Sandy District, Kentucky (Floyd, Johnson, Martin, And Pike Counties), James C. Currens, Linda Jean Bragg, James C. Hower

Information Circular--KGS

Chemical and petrographic data ore presented for 146 samples of cool collected in the Big Sandy District, eastern Kentucky. The data include sample-site locations, sampling conditions, stratigraphic position, megoscopic description of the cool, air-drying loss, proximate and ultimate analyses, Btu content, forms of sulfur, initial deformation temperature, softening temperature, fluid temperature, free-swelling index, concentration of major- and minor-oxides and trace elements, and petrographic analyses.


Nebraska Mineral Operations Review, 1986, Raymond R. Burchett, Duane A. Eversoll Jan 1987

Nebraska Mineral Operations Review, 1986, Raymond R. Burchett, Duane A. Eversoll

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Depositional Environments And Diagenesis, Winnipegosis Formation (Middle Devonian), Williston Basin, North Dakota, Nancy A. Perrin Jan 1987

Depositional Environments And Diagenesis, Winnipegosis Formation (Middle Devonian), Williston Basin, North Dakota, Nancy A. Perrin

Theses and Dissertations

In the Williston Basin, the Winnipegosis Formation is the major carbonate unit of the initial transgressive-regressive pulse of the Kaskaskia sequence. Twenty-two lithofacies were identified by well-log, core, and thin-section studies of Winnipegosis rocks; these belong to seven environments of deposition which include deep basin, deep shelf, shallow shelf, reef, lagoon, tidal flat, and evaporite basin. The deposition of the Winnipegosis and Prairie Formations were inter-related and occurred during six episodes. Following a brief hiatus separating the underlying Ashern Formation from the Winnipegosis, a clear, quiet, shallow-marine environment became established in the North Dakota portion of the Elk Point Basin. …


Glacial Deposits, Vol. 15, 1986-1987, Department Of Geography-Geology Jan 1987

Glacial Deposits, Vol. 15, 1986-1987, Department Of Geography-Geology

Glacial Deposits

Newsletter of the Department of Geography-Geology


Evaluation Of The Interaction Between Seepage From A Municipal Waste Stabilization Lagoon, Mcville, North Dakota, And A Shallow Unconfined Aquifer, Paul R. Bulger Jan 1987

Evaluation Of The Interaction Between Seepage From A Municipal Waste Stabilization Lagoon, Mcville, North Dakota, And A Shallow Unconfined Aquifer, Paul R. Bulger

Theses and Dissertations

The McVille, North Dakota, Municipal Waste Stabilization Lagoon is situated above the McVille Aquifer, an unconfined glaciofluvial aquifer capable of significant water yields. The site contains a 3-D network of 29 monitoring wells. Standing waste-water is maintained in the clay-lined, primary-operating cell. Operating practices at the site entail periodic discharges of waste-water from the lined cell to an unlined cell, a procedure which results in rapid infiltration.

The shape and extent of the groundwater contaminant plume caused by the waste-stabilization process is best delineated by the distribution of chloride. Background wells contain less than 10 mg/L chloride. The area up …


Diagenesis And Porosity Development Of The Mission Canyon And Charles Formations (Mississippian), Treetop And Whiskey Joe Fields, North Dakota, Rebecca L. Durall Jan 1987

Diagenesis And Porosity Development Of The Mission Canyon And Charles Formations (Mississippian), Treetop And Whiskey Joe Fields, North Dakota, Rebecca L. Durall

Theses and Dissertations

Rocks of the upper Mission Canyon and lower Charles Formations (Mississippian) in central Billings County, North Dakota consist of interbedded limestones, dolostones, and anhydrites which were deposited in a shallow epeiric sea. This study was limited to the upper Mission Canyon and lower Charles Formations of Treetop and Whiskey Joe fields, located along the Billings anticline in central Billings County, North Dakota. Close examination of ap~roximately 260 metres (850 feet) of upper Mission Canyon and lower Charles Formations core in the study area resulted in the separation of rocks into six lithotypes: 1) echinoderm wackestone, 2) dolomudstone, 3) neomorphic wackestone, …


A Mineralogical Study Of The Harmon Lignite Bed, Bullion Creek Formation (Paleocene), Bowman County, North Dakota, Christopher J. Zygarlicke Jan 1987

A Mineralogical Study Of The Harmon Lignite Bed, Bullion Creek Formation (Paleocene), Bowman County, North Dakota, Christopher J. Zygarlicke

Theses and Dissertations

Study of the Harmon lignite bed at the Gascoyne Mine in Bowman County, North Dakota showed that most of the minerals in the coal lithobodies were detrital in origin and that variable ash deposition during combustion may be caused by variations in types and quantities of mineral phases.

The Harmon bed is part of the Bullion Creek Formation (Paleocene). Objectives of this study included: to develop scanning electron microscope/microprobe techniques for the study of minerals in coal; to determine the origins of the mineral phases; to postulate a depositional environment for the Harmon lignite; and to ascertain whether variable ash …


Stratigraphic Model Of The Southern Portion Of The Jim Bridger Coal Field, Sweetwater County, Wyoming, Paul S. Maywood Jan 1987

Stratigraphic Model Of The Southern Portion Of The Jim Bridger Coal Field, Sweetwater County, Wyoming, Paul S. Maywood

Dissertations and Theses

Uppermost Lance and lowermost Fort Union Formation sediments are found in outcrop in the southern portion of the Jim Bridger coal field, located on the northeast flank of the Rock Springs Uplift in Sweetwater County, Wyoming. Twenty-nine surface sections and 581 subsurface (borehole) sections were evaluated and used to construct a stratigraphic model.

Stratigraphic correlations with economically mineable coal seams in the Fort Union Formation north and south of the study area combined with definition of questionable local formational boundary locations are significant objectives in this investigation.


Development And Application Of Some Quantitative Stratigraphic Techniques To The Coos Bay Coalfield, A Tertiary Fluvio-Deltaic Complex In Southwestern Oregon, Willard Sidney Titus Iii Jan 1987

Development And Application Of Some Quantitative Stratigraphic Techniques To The Coos Bay Coalfield, A Tertiary Fluvio-Deltaic Complex In Southwestern Oregon, Willard Sidney Titus Iii

Dissertations and Theses

A computer technique for interpreting geophysical logs of drill-holes in quantitative lithologic terms has been developed and tested on the deposits of the late Eocene Coaledo Formation, a well-studied fluvio-deltaic complex in southwestern Oregon. The technique involves the use of induced and natural gamma logs for separation of coal and claystone from coarse-grained detrital rocks and the use of the ratio of resistivity and natural gamma responses (defined here as the "grain size index") to divide the coarse elastic rocks into a series of textural classes corresponding to the Wentworth-Odden particle size scale.


Stratigraphic And Geochemical Evolution Of The Glass Buttes Complex, Oregon, Richard Louis Roche Jan 1987

Stratigraphic And Geochemical Evolution Of The Glass Buttes Complex, Oregon, Richard Louis Roche

Dissertations and Theses

Glass Buttes complex lies at the northern margin of the Basin and Range province in central Oregon and is cut by the northwest-trending Brothers fault zone. An older acrystalline volcanic sequence of high-silica rhyolites (>75% SiO2) forms a broad platform composed of domes and flows with minor pyroclastic deposits. The high-silica rhyolite sequence is divided on the basis of texture into 1) zoned flows and domes, 2) obsidian flows, 3) felsite flows, and 4) biotite-phyric flows and domes.


Stratigraphy Of The Ohanapecosh Formation North Of Hamilton Buttes, Southcentral Washington, Cynthia Marie Stine Jan 1987

Stratigraphy Of The Ohanapecosh Formation North Of Hamilton Buttes, Southcentral Washington, Cynthia Marie Stine

Dissertations and Theses

Over 1055 m of early Oligocene andesitic-dacitic volcaniclastic rocks and minor interbedded andesitic lava flows of the Ohanapecosh Formation are exposed in a dissected structural high in the southern Washington Cascade Range, about 22 km southwest of Packwood, Washington.

The exposed sequence of rocks in the study area are located approximately 250 m above the base of the Ohanapecosh Formation. A lower sequence of deposits, about 350 m in thickness, are dominated by primary and reworked lithic lapilli-tuff and epiclastic channelized volcanic sandstone and conglomerate. These sediments are interpreted as pyroclastic flows and stream deposits, respectively. The upper sequence, about …


An Analysis Of The Eastern Margin Of The Portland Basin Using Gravity Surveys, Steven Allen Davis Jan 1987

An Analysis Of The Eastern Margin Of The Portland Basin Using Gravity Surveys, Steven Allen Davis

Dissertations and Theses

The recent contributions of several investigators has indicated the Portland basin may be a pull-apart structure associated with wrench tectonism. Because of the large density contrast between sedimentary and volcanic units and because of their reasonably uniform and continuous nature, gravity survey methods can be used to identify covered structures with considerable success. The study utilized gravity modeling techniques to investigate the structure and genesis of the Portland basin's eastern margin.


Coral Reef To Eolianite Transition In The Pleistocene Rocks Of Great Inagua, Bahamas, Brian White, H. Allen Curran Jan 1987

Coral Reef To Eolianite Transition In The Pleistocene Rocks Of Great Inagua, Bahamas, Brian White, H. Allen Curran

Geosciences: Faculty Publications

Great Inagua Island, the southernmost of the chain of Bahamian islands, lies approximately 100 km northeast of the eastern tip of Cuba. This paper reports the results of reconnaissance geologic field work conducted on Great Inagua Island in January, 1985, and of more detailed observations made in January, 1986, near Matthew Town, between South West Point and Devil's Point.


Geohydrologic Evaluation Of A Proposed Coal-Ash Disposal Site Near Mandan, North Dakota, David M. Ronnei Jan 1987

Geohydrologic Evaluation Of A Proposed Coal-Ash Disposal Site Near Mandan, North Dakota, David M. Ronnei

Theses and Dissertations

Montana-Dakota Utilities Company (MDU) operates Heskett Station, a 100 megawatt coal-fired power plant, located near Mandan, North Dakota. In the process of generating electricity, MDU's Heskett Station produces approximately 62,000 tons of coal-ash annually. The ash has been disposed of by above-ground stockpiling on the plant site for the past 35 years. Limited storage space and new solid waste regulatory restrictions have necessitated the search for a new ash disposal site.

This investigation focused on selecting a disposal site that would be suitable for long-term disposal of coal-ash generated at Heskett Station. Specifically, the objective was to locate a site …


The Hydrogeology Of Nags Head Woods, Dare County, North Carolina, Janet Salyer Emry Jan 1987

The Hydrogeology Of Nags Head Woods, Dare County, North Carolina, Janet Salyer Emry

OES Theses and Dissertations

Nags Head Woods, a coastal maritime forest located on a barrier island in eastern North Carolina, stabilizes a back-barrier dune system bordering a tidal marsh. The purpose of this study is to provide basic information about the groundwater geology in Nags Head Woods and to predict the effects upon water levels due to municipal pumping of Fresh Pond, a large lake near the center of the island.

Clean, fine-to-medium sands dominate the top of the surficial (water table) aquifer, underlain by silty fine-to-coarse sands at -4 m elevation. A silty clay bed of very low permeability is present at -12 …


Depositional And Diagenetic History Of The Middle Ordovician Carbonates Of The Shenandoah Valley, Northern Virginia, Lynn Ellen Weyenberg Jan 1987

Depositional And Diagenetic History Of The Middle Ordovician Carbonates Of The Shenandoah Valley, Northern Virginia, Lynn Ellen Weyenberg

OES Theses and Dissertations

An examination of the Middle Ordovician carbonates in northwest Virginia has revealed a particularly sensitive record of deposition and subsidence. Two-hundred acetate peels from six measured stratigraphic sections in Shenandoah County, Virginia were examined to interpret the depositional and diagenetic history. Two major lithofacies have been recognized within the New Market Limestone and three have been recognized in the Lincolnshire Formation. These five lithofacies represent an overall transgressive sequence. This transgression was not uniform but paused several times to allow carbonate deposition to reach sea-level. These shoaling events suggest a slowly subsiding basin in this region. The carbonate rocks within …


Petrographic Criteria For The Recognition Of 'Magadi-Type' Cherts, Kathryn A. Schubel Jan 1987

Petrographic Criteria For The Recognition Of 'Magadi-Type' Cherts, Kathryn A. Schubel

Honors Papers

The Magadi cherts, inorganic lacustrine deposits from the Lake Magadi area, Kenya, are widely used as a modern analog to explain the origin of ancient inorganic cherts. Formed in a highly alkaline lake, as the result of a transformation from the sodium silicates minerals, magadiite and/or kenyaite, to quartz, the Magadi cherts possess a distinctive set of textural characteristics that allow them to be distinguished from cherts of different origin with only a limited number of samples. Textural characteristics that are diagnostic of the Magadi cherts and that can be used as a test for the occurrence of ancient 'Magadi-type' …


Botanical Evidence For Holocene Movement Of Rock Streams In Arkansas, S. Marie Lookingbill, Malcolm K. Cleaveland, Margaret J. Guccione Jan 1987

Botanical Evidence For Holocene Movement Of Rock Streams In Arkansas, S. Marie Lookingbill, Malcolm K. Cleaveland, Margaret J. Guccione

Journal of the Arkansas Academy of Science

Botanical studies of rock streams on the western half of Rich Mountain and on the north slope of Mt. Magazine in Arkansas question the common presumption that such streams require periglacial conditions to form, and are now inactive relict features in this area. Trees along the margins of the streams examined show abundant evidence of trauma resulting from Late Holocene movement, in the form of bent and tilted stems. Cross sections of trees demonstrate marked eccentric growth associated with tilting and cambial trauma associated with corrasion by rocks. That this damage is not the result of excessive snow loading is …


Textural And Lithologic Differences Of Cretaceous, Tertiary, And Quaternary Gravels Of South Arkansas, Lesli Wood Jan 1987

Textural And Lithologic Differences Of Cretaceous, Tertiary, And Quaternary Gravels Of South Arkansas, Lesli Wood

Journal of the Arkansas Academy of Science

Stream gravels have been derived from the Ouachita Mountains since at least Cretaceous times. Past studies have assigned ages to gravel deposits in the basins of the Saline and Little Missouri Rivers on the basis of altitude above local floodplains. This study examines the lithologies and textures of seven gravel outcrops ranging in age from Cretaceous to Quaternary to determine whether any patterns of variation based on assigned ages, variable sources, or precise depositional setting can be discerned. No variation patterns could be found for size distributions of sand-sized and larger fractions. However, the amount of silt-clay matrix decreases through …


Lithofacies Analysis Of The Lamotte Sandstone In South Central Missouri, Michael Gerard Kraenzle Jan 1987

Lithofacies Analysis Of The Lamotte Sandstone In South Central Missouri, Michael Gerard Kraenzle

Masters Theses

"Based on the analysis of thirty-one cores obtained from the Missouri Department of Natural Resources in Rolla, the upper Cambrian Lamotte Sandstone in South Central Missouri has been divided into six sedimentary facies ranging from alluvial fan and braided stream to open marine.

The Lamotte Sandstone is the basal Cambrian sandstone found throughout most of the state of Missouri. It directly overlies late Precambrian (1.4 to 1.5 billion year old) granites and metasediments. The Lamotte and overlying Bonneterre Formations are generally considered to have been deposited by a transgression which occurred during the Late Cambrian Period (Croixian Epoch).

The Lamotte …


A Paleoenvironmental Study Of The Salem Limestone In The Vicinity Of St. Louis, Missouri, Douglas J. Van Brunt Jan 1987

A Paleoenvironmental Study Of The Salem Limestone In The Vicinity Of St. Louis, Missouri, Douglas J. Van Brunt

Masters Theses

“The Salem Limestone (Meramecian) of Mississippian age in the vicinity of St. Louis, Missouri is composed of a variable sequence of limestones deposited in shallow waters adjacent to scattered positive elements. This unit varies in thickness from zero up to 160 feet.

A medium to coarse-grained calcarenite is the dominant rock-type of the thesis area and is most abundant in the central and southwest regions. Stratigraphic sections in the northern region are more dolomitic, increasingly brecciated, and contains numerous secondary features. The southeast region is thinly bedded and composed of greater amounts of micrite formed by algal activity or direct …


A Petrographic Investigation Of The Rhythmically Bedded Upper Fayetteville Formation (Mississippian) In Northern Arkansas, Edith Ann Starbuck Jan 1987

A Petrographic Investigation Of The Rhythmically Bedded Upper Fayetteville Formation (Mississippian) In Northern Arkansas, Edith Ann Starbuck

Masters Theses

"The upper Mississippian Fayetteville Formation in northern Arkansas is primarily a calcareous black shale, but in some localities the upper one third to one half of the formation is made up of alternating black shales and limestones. Comparable lithologies have been suggested by some (Hallam, Ricken, Kent, and Sujkowski) to have been created by the diagenetic segregation of carbonate from calcareous shale.

Petrographic thin section analysis reveals that the lowest limestone beds of the rhythmic upper Fayetteville are made up almost entirely of microspar and all fossil material is recrystallized, even to the point of obliteration in some cases. The …


Coarsening Of Fine-Scale Exsolution Lamellae, John B. Brady Jan 1987

Coarsening Of Fine-Scale Exsolution Lamellae, John B. Brady

Geosciences: Faculty Publications

Diffusional exchange between the wedge-shaped terminations of fine-scale, coherent exsolution lamellae and the large flat sides of adjacent like lamellae is proposed as the principal mechanism for the coarsening of lamellar exsolution textures in silicate minerals. Following the methods of Gibbs (1906), a formula is derived for the chemical potential gradients due to interfacial energy effects that drive the proposed diffusion and coarsening....


Conservation And Survey Division. 1987. Significant Rises And Declines In Nebraska Groundwater Levels (From Pre-Development As Of Fall 1985)/Registered Irrigation Wells In Nebraska (As Of January 1, 1986), Conservation Survey Division, U.S. Geological Survey Jan 1987

Conservation And Survey Division. 1987. Significant Rises And Declines In Nebraska Groundwater Levels (From Pre-Development As Of Fall 1985)/Registered Irrigation Wells In Nebraska (As Of January 1, 1986), Conservation Survey Division, U.S. Geological Survey

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Resource Notes-Spring/Summer 1987 Jan 1987

Resource Notes-Spring/Summer 1987

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Genesis Of Marine Terrace Soils, Barbados, West Indies: Evidence From Mineralogy And Geochemistry, Daniel R. Muhs, Russell C. Crittenden, John N. Rosholt, Charles A. Bush, Kathleen C. Stewart Jan 1987

Genesis Of Marine Terrace Soils, Barbados, West Indies: Evidence From Mineralogy And Geochemistry, Daniel R. Muhs, Russell C. Crittenden, John N. Rosholt, Charles A. Bush, Kathleen C. Stewart

United States Geological Survey: Staff Publications

Well-developed, clay-rich soils dominated by interstratified kaolinite-smectite are found on the uplifted coral reef terraces on the island of Barbados. The reef limestone is unlikely to have been the soil parent material however, because it is 98 per cent CaCO, and geomorphic evidence argues against the 20 m of reef solution required to produce the soils by this process. The mineralogy of the sand, silt, and clay fractions of the soils, and trace element geochemistry, suggest that aeolian materials carried on the trade winds from Africa, volcanic ash from the island of St. Vincent, and quartz from Tertiary bedrock on …


Depositional Environments Of A Portion Of The Bullion Creek Formation (Paleocene), Western Billings County, North Dakota, Rodney K. Perkins Jan 1987

Depositional Environments Of A Portion Of The Bullion Creek Formation (Paleocene), Western Billings County, North Dakota, Rodney K. Perkins

Theses and Dissertations

The Bullion Creek Formation (Paleocene) in North Dakota is part of an Upper Cretaceous to Eocene wedge of siliciclastic rocks formed during uplift associated with the Laramide Orogeny. The Bullion Creek Formation consists predominantly of mudrocks , with fine-grained sandstone, lignite, and rare limestone lenses . Previous workers have postulated combinations of fluvial and lacustrine depositional environments for the rocks.

The study area covers 15 square kilometres in the badlands of the Little Missouri River in western Billings County, North Dakota, where approximately the upper 75 metres of the Bullion Creek Formation ls exposed. Twenty nine stratigraphic sections were measured …