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Articles 27871 - 27900 of 29955

Full-Text Articles in Geology

The Precambrian Volcanic Stratigraphy And Petrology Of The Des Arc Ne 7 1/2 Minute Quadrangle, South Central St. Francois Mountains, Missouri, Vernon Max Brown Jan 1983

The Precambrian Volcanic Stratigraphy And Petrology Of The Des Arc Ne 7 1/2 Minute Quadrangle, South Central St. Francois Mountains, Missouri, Vernon Max Brown

Doctoral Dissertations

"The Precambrian volcanics in the Des Arc NE 7½ minute quadrangle are composed predominantly of rhyolitic ash-flow tuffs with minor rhyolitic, trachytic, and andesitic lavas, and basaltic dikes. Thirty-seven volcanic units were identified, mapped, and informally named. A minimum of 1,000 meters of volcanic section is present. The rhyolites consist of phenocrysts of albitized alkali feldspar, albitic plagioclase, quartz, opaques, and ferromagnesium relicts set in a devitrified and locally recrystallized felsitic matrix. Pumice and lithophysal structures are common in the ash flows.

Chemically, the rhyolites are quite similar. The potassium to sodium ratio in individual units, however, tends to vary …


Nebraska Groundwater Level (Decline & Rise) And Location Of Registered Wells, 1983 Dec 1982

Nebraska Groundwater Level (Decline & Rise) And Location Of Registered Wells, 1983

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


The Geology Of The Floras Creek Area, Curry County, Oregon, Jon Dudley Bounds Dec 1982

The Geology Of The Floras Creek Area, Curry County, Oregon, Jon Dudley Bounds

Dissertations and Theses

The Floras Creek area, east of the town of Langlois, near the southwest Oregon coast, includes Colebrooke Schist (a klippe of metamorphosed pelitic sediments of Jurassic age), Jurassic Otter Point Formation (a melange complex), and lower the middle Eocene Roseburg and Lookingglass Formations, part of a sandstone-shale sequence occurring more extensively in other areas. The Colebrooke Schist occurs in the south-central part of the area, bounded on the Otter Point and Roseburg. The Lookingglass is exposed as a small (1.5 sq. km) block in the north-north-west part of the area. Two major structural trends are found in the Floras Creek …


A Geophysical Study Of The North Scappoose Creek, Alder Creek, Clatskanie River Lineament, Along The Trend Of The Portland Hills Fault, Columbia County, Oregon, Nina Haas Dec 1982

A Geophysical Study Of The North Scappoose Creek, Alder Creek, Clatskanie River Lineament, Along The Trend Of The Portland Hills Fault, Columbia County, Oregon, Nina Haas

Dissertations and Theses

The Portland Hills fault forms a strong northwest trending lineament along the east side of the Tualatin Mountains. An en echelon lineament follows North Scappoose Creek, Alder Creek, and the Clatskanie River along the same trend, through Columbia County, Oregon. The possibility that this lineament follows a fault or fault zone was investigated in this study. Geophysical methods were used, with seismic refraction, magnetic and gravity lines run perpendicular to the lineament. The seismic refraction models indicate the near surface basalt is broken in many places, with 15 - 30 meters (50 - 100 feet) vertical displacement, down to the …


The Michigan Basin, L. L. Sloss Dec 1982

The Michigan Basin, L. L. Sloss

UMR Journal -- V. H. McNutt Colloquium Series

The Michigan basin is widely acknowledged to be the archetype among those basins of cratonic interiors whose subsidence is dominated by flexure rather than faulting. Broadly ovate in plan over an area of some hundreds of thousands of square kilometers, with a preserved Phanerozoic sediment thickness exceeding 4 km accumulated during distinct episodes of subsidence over a 500-million year span, the basin is endowed with significant fossil-fuel resources.

The basin area is crossed, from north-northwest, by a rift zone filled with mafic igneous rock and great thickness of sedimentary rock resting on Archean and Middle Proterozoic crystallines. Rifting is presumably …


Geology And Energy Resources Of The Arkoma Basin, Oklahoma And Arkansas, Boyd R. Haley Dec 1982

Geology And Energy Resources Of The Arkoma Basin, Oklahoma And Arkansas, Boyd R. Haley

UMR Journal -- V. H. McNutt Colloquium Series

The Arkoma basin is a structurally defined basin that underlies an area of about 13,000 sq. mi. It extends from Little Rock, Arkansas, to Atoka, Oklahoma. The rocks in the basin grade upward from dolomite, some limestone, sandstone (Upper Cambrian to Upper Devonian) to shale and limestone (Upper Devonian to Lower Pennsylvanian) to shale, limestone, and sandstone (Lower Pennsylvanian) to shale and sandstone (Middle Pennsylvanian). The sediments that formed rocks in the lower part of the Atoka formation on the south side of the basin were deposited in a deep-water environment. All other sediments in the basin were deposited in …


Basement Rocks Of The Main Interior Basins Of The Midcontinent, Edward C. Lidiak Dec 1982

Basement Rocks Of The Main Interior Basins Of The Midcontinent, Edward C. Lidiak

UMR Journal -- V. H. McNutt Colloquium Series

The basement underlying the deeper basins in the Midcontinent is not well known because of the considerable thickness of overlying sedimentary rocks. However, gravity and magnetic surveys and sparse wells to basement suggest that deeper intracratonic basins are characteristically underlain by denser and more magnetic rocks than in adjacent areas. This correlation has important bearing on understanding the tectonic development and geologic history of Midcontinent basins.

The Michigan basin is underlain by prominent, linear gravity and magnetic highs that extend across the southern peninsula. A recent deep well to basement encountered basalt overlain by red clastic sedimentary rock. The combined …


Umr Journal: Selected Structural Basins Of The Mid-Continent, U.S.A., University Of Missouri--Rolla Dec 1982

Umr Journal: Selected Structural Basins Of The Mid-Continent, U.S.A., University Of Missouri--Rolla

UMR Journal -- V. H. McNutt Colloquium Series

No abstract provided.


Geologic-Tectonic History Of The Area Surrounding The Northern End Of The Mississippi Embayment, H. R. Schwalb Dec 1982

Geologic-Tectonic History Of The Area Surrounding The Northern End Of The Mississippi Embayment, H. R. Schwalb

UMR Journal -- V. H. McNutt Colloquium Series

Since Precambrian time, zones of weakness have been repeatedly but infrequently reactivated in the Mississippi Embayment area. All of the major folds and many of the minor anticlines caused by this activity are associated with faults in the basement rocks. The latest occurrence of major tectonic activity (perhaps Early Cretaceous), however, not only affected the old fault zones but also created a vast new feature, the Pascola arch, which has no Paleozoic antecedent. Severe erosion and subsequent Tertiary subsidence associated with the Pascola arch indicate that this structure alone is the locus of present-day major earthquake activity. Until the time …


Structure Of The Salina-Forest City Interbasin Boundary From Seismic Studies, Don W. Steeples Dec 1982

Structure Of The Salina-Forest City Interbasin Boundary From Seismic Studies, Don W. Steeples

UMR Journal -- V. H. McNutt Colloquium Series

As petroleum exploration efforts in the Midcontinent become directed toward smaller fields and the search for minerals is extended into new areas, the edges of the Salina and Forest City basins will become of increased interest to industry. The principal boundary feature between the two basins is the Nemaha ridge, a linear feature that extends from near Omaha, Nebraska, to near Oklahoma City, Oklahoma. Recent seismic studies at the Kansas Geological Survey have revealed a complex array of faulted and folded structures in the vicinity of the Humboldt fault zone (the eastern flank of the Nemaha ridge). Faulting of both …


Geological Evolution And Energy Resources Of The Williston Basin, Lee C. Gerhard Dec 1982

Geological Evolution And Energy Resources Of The Williston Basin, Lee C. Gerhard

UMR Journal -- V. H. McNutt Colloquium Series

The Williston basin of North Dakota, Montana, South Dakota, and south-central Canada (Manitoba and Saskatchewan) is a major producer of oil and gas, lignite, and potash. Located on the western periphery of the Phanerozoic North American craton, the Williston basin has undergone only relatively mild tectonic distortion during Phanerozoic time. This distortion is largely related to movement of Precambrian basement blocks.

Sedimentary rocks of cratonic sequences Sauk through Tejas are present in the basin. Sauk, Tippecanoe, and Kaskaskia Sequence rocks are largely carbonate, as are the major oil and gas producing formations. Absaroka and Zuni rocks have more clastic content, …


Important Geological Features And Localities Of Maine, Maine Geological Survey Dec 1982

Important Geological Features And Localities Of Maine, Maine Geological Survey

Maine Collection

Important Geological Features and Localities of Maine

Executive Department, Maine Geological Survey : Maine State Planning Office

(December, 1982).

Contents: Introduction / Purpose of this Study / The Geology of Maine / Important Publications / Catalogue of the Critical Geologic Features of Maine / Recommendations for Further Research / Publications / Conclusions / Acknowledgements / References Cited / Critical Areas Program List of Geological Planning Reports


Preface, Paul Dean Proctor, John W. Koenig Dec 1982

Preface, Paul Dean Proctor, John W. Koenig

UMR Journal -- V. H. McNutt Colloquium Series

The UMR Journal has had an interesting but somewhat sporadic history. The topics of papers that appeared in UMR Journal 1 in 1968 under the general title of “A Coast to Coast Tectonic Study of the United States” covered the major tectonic features of the contiguous United States from the margin of the Atlantic continental shelf to the Pacific coast. Each paper was authored by a recognized expert for the specific province reviewed. UMR Journal 2, which was published in 1971, related to “Alaska—Its Mineral Potentials and Environmental Challenges”. This UMR Journal 3 emphasizes the geology, genesis, and energy resources …


Geology Newsletter- 1982, Department Of Geology Dec 1982

Geology Newsletter- 1982, Department Of Geology

Geological and Environmental Sciences News

Vol. 1 No. 7

  • Dear Alumni and Friends
  • Capital Fund Drive
  • Geology/ Earth Science Club News
  • Faculty News
  • Alumni News


Pennsylvanian Deltaic Sedimentation In Grand Ledge, Michigan, Jeffrey R. Martin Dec 1982

Pennsylvanian Deltaic Sedimentation In Grand Ledge, Michigan, Jeffrey R. Martin

Masters Theses

Pennsylvanian outcrops along the Michigan Basin's southern/margin are composed of fluvial-deltaic and marine shelf sediments. Constructive deltaic facies include point-bar sandstones displaying erosional bases, channel lag, and upward decreasing grain size and sedimentary structures. Cross-stratification data indicate a unimodal, highly variant, northward-trending, paleocurrent pattern that deviates from regional paleoslope. Point-bar sandstones record delta plain deposition by meandering distributary channels. Channel margin facies include Lingula-bearing, interdistributary bay shales; overlain gradationally by laminated, flaser-bedded and rooted marsh shales and siltstones; and subbituminous swamp coal. Bay-fill facies are interrupted by lens-shaped, quartz-poor, fine-grained, crevasse-- splay sandstones.

Delta destructive facies--quartz -rich bioturbated sandstone-- suggest …


The Origin Of Carbonate Cements In Bahama Escarpment Limestones, Katharine D. Fulker Dec 1982

The Origin Of Carbonate Cements In Bahama Escarpment Limestones, Katharine D. Fulker

Masters Theses

Limestones recovered from Bahama Escarpment dives (DSRV Alvin, 1978) were expected to contain shallow marine, freshwater, and deep marine cementation since the limestones had been fractured, bored, and cemented at depth. Magnesium and trace element concentrations, carbon-oxygen composition, cathodoluminescence, and petrographic study indicated the presence of all three cement types.

Lithification may have proceeded by allochem deposition, major shallow marine cementation, sparse freshwater cementation leaving porosity, fracturing, and final deep marine cementation leaving minor porosity. According to this interpretation, the pore space remained open for an unlikely 75-115 million years. In an alternative interpretation, pore space is occluded after freshwater …


Gully, Scour Hole, And Pothole Development At The Base Of The Gering Formation (Miocene?), Southeastern Banner County, Nebraska, Robert F. Diffendal Jr. Sep 1982

Gully, Scour Hole, And Pothole Development At The Base Of The Gering Formation (Miocene?), Southeastern Banner County, Nebraska, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Several sediment-filled paleovalleys belonging to the Arikaree Group of Miocene (?) age occur in southeastern Banner County, Nebraska. One gully and a main paleovalley exhibit, respectively, erosional features like those in modern gullies in the area and like those on the bedrock floors of modern straight streams carrying an appreciable sediment load. Scour holes and a pothole on the valley floor of the main paleovalley are similar to those produced experimentally on the bed of a straight stream.


Research On Atmospheric Volcanic Emissions: An Overview, James P. Friend, Alan R. Bandy, Jarvis L. Moyers, William H. Zoller, Richard E. Stoiber, Arnold L. Torres, William I. Rose, M. Patrick Mccormick, David C. Woods Sep 1982

Research On Atmospheric Volcanic Emissions: An Overview, James P. Friend, Alan R. Bandy, Jarvis L. Moyers, William H. Zoller, Richard E. Stoiber, Arnold L. Torres, William I. Rose, M. Patrick Mccormick, David C. Woods

Department of Geological and Mining Engineering and Sciences Publications

The project "Research on Atmospheric Volcanic Emissions" is a unique effort by NASA and university scientists to investigate the detailed chemical nature of plumes from volcanic eruptions. The major goals of the project are to: 1) understand the impact major eruptions will have on atmospheric chemistry processes, 2) understand the importance of volcanic emissions in the atmospheric geochemical cycles of selected species, 3) use knowledge of the plume chemical composition to diagnose and predict magmatic processes. Project RAVE'S first mission used the NASA Lockheed Orion P-3 outfitted with equipment to measure concentrations of the gases SO2, OCS, H …


Nitrate Levels In The Groundwater Of Kalamazoo County, Michigan, William Robert Norman Aug 1982

Nitrate Levels In The Groundwater Of Kalamazoo County, Michigan, William Robert Norman

Masters Theses

Nitrate levels from 1,978 wells were compiled and analyzed to identify areas having levels above the Federal and State Drinking Water Standards of 10 ppm, identify possible sources of nitrate in each area and determine factors that produce high concentrations of nitrate in groundwater.

Eighteen areas in which nitrate concentrations exceeded 10 ppm were identified. County-wide, 465 (23 percent) of the wells for which data were available produced water with nitrate concentrations above drinking water standards.

Septic tank effluent is thought to be the most common source of nitrate in the problem areas. Agricultural practices are also likely nitrate contrbutors; …


Impact Of Urban Stormwater Runoff On The Water Quality Of The Subsurface Lost River, Bowling Green, Kentucky, Donald Rice Jul 1982

Impact Of Urban Stormwater Runoff On The Water Quality Of The Subsurface Lost River, Bowling Green, Kentucky, Donald Rice

Masters Theses & Specialist Projects

Bowling Green, Kentucky is located in a distinctive karst region, characterized by subsurface drainage. The Lost River is a large subsurface stream which flows beneath the city. It receives much of the stormwater runoff from Bowling Green, since most of the city's runoff is directed underground. Significant pollutants in Bowling Green's stormwater runoff were identified from water quality test results of storm event grab samples, and a composite sample, of runoff entering the urban By-Pass Cave. Water quality test results were also obtained from storm event grab samples, and a composite sample, of the Lost River at the Blue Hole …


Nebraska's Platte River: A Graphic Analysis Of Flows, Ray Bentall Jul 1982

Nebraska's Platte River: A Graphic Analysis Of Flows, Ray Bentall

Conservation and Survey Division: Faculty and Staff Publications

WSP-53


Stratigraphy And Depositional Environments Of A Late Pleistocene Barrier Island Complex, Southeastern Virginia, Alan K. Jasper Jul 1982

Stratigraphy And Depositional Environments Of A Late Pleistocene Barrier Island Complex, Southeastern Virginia, Alan K. Jasper

OES Theses and Dissertations

The Norfolk, Kempsville, and Sand Bridge Formations beneath the HIckory Scarp of southeastern Virginia are reinterpreted as representing one glacio-eustatic transgressive cycle. The timing of this transgressive event is set during the earliest Wisconsinan. The formations were previously interpreted as unconformable overlying one another. The Norfolk-Kempsville unconformity is actually a diagenetic boundary. Evidence is presented which indicates that the Kempsville Scarp area should be reduced to member status or dropped entirely.


Water-Soluble Material On Aerosols Collected Within Volcanic Eruption Clouds, David B. Smith, Robert A. Zielinski, William I. Rose, B. J. Huebert Jun 1982

Water-Soluble Material On Aerosols Collected Within Volcanic Eruption Clouds, David B. Smith, Robert A. Zielinski, William I. Rose, B. J. Huebert

Department of Geological and Mining Engineering and Sciences Publications

In February and March of 1978, filter samplers mounted on an aircraft were used to collect the aerosol fraction of the eruption clouds from three active Guatemalan volcanoes (Fuego, Pacaya, and Santiaguito). The samples were collected on Teflon (Fluoropore) filters with a nominal pore diameter of 0.5μm. The mass of air sampled by the filters ranged from 0.15 to 6.6 kg. The particulate material collected consisted of fragments of angular silicate ash and droplets of what is interpreted as dilute H2SO4 and HCl. After collection of the samples, each filter was rinsed with 60 ml of distilled-deionized …


Small Particles In Plumes Of Mount St. Helens, William I. Rose, Raymond L. Chuan, D. C. Woods Jun 1982

Small Particles In Plumes Of Mount St. Helens, William I. Rose, Raymond L. Chuan, D. C. Woods

Department of Geological and Mining Engineering and Sciences Publications

Particles in the size range of 0.1–25 micrometers were sampled by aircraft carrying a quartz crystal microcascade in the Mount St. Helens plume on three dates in August and September 1980. Two of the sampling dates represented ‘typical’ emissions of the volcano between plinian eruptions. One sampling flight was made 1–4 hours before the small plinian eruption of August 7, 1980, when the plume had become discontinuous and visibly darker. Size distributions were determined, and individual particles were studied by using scanning electron microscopy. The plume sampled on August 7, before the eruption, contained mainly approximately 2 micrometer diameter silicic …


Nonpoint Agricultural Pollution In A Karst Aquifer: Lost River Groundwater Drainage Basin, Warren County, Kentucky, Nancy Tucker Jun 1982

Nonpoint Agricultural Pollution In A Karst Aquifer: Lost River Groundwater Drainage Basin, Warren County, Kentucky, Nancy Tucker

Masters Theses & Specialist Projects

Chemical analysis of samples collected from subsurface streams and wells were analyzed to identify nonpoint pollutants in karst aquifers resulting from agricultural land use. Major flow paths and travel times taken by nonpoint pollutants were identified. A land use limitation map showing areas where agricultural activities may results in nonpoint pollution of the karst aquifer was prepared. A groundwater susceptibility map was prepared to show areas of the karst aquifer most susceptible to groundwater contamination by nonpoint pollution resulting from agricultural land use.

Research findings revealed that pollutant concentrations may reach levels thousands of times greater during high discharge events …


Groundwater Levels In Nebraska, 1981, Martin S. Johnson, Darryll T. Pederson Jun 1982

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

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Geology And Hydrothermal Alteration, Glass Buttes, Southeast Oregon, Dulcy Annette Berri May 1982

Geology And Hydrothermal Alteration, Glass Buttes, Southeast Oregon, Dulcy Annette Berri

Dissertations and Theses

The Glass Buttes volcanic complex consists of many domes and individual vents that erupted both rhyolitic and basaltic lavas during the late Miocene to early Pliocene. The east half of the complex, in the vicinity of Little Glass Butte, contains interfingering, finely flow-banded rhyolite and black obsidian flows. The youngest unit, an obsidian, has been dated at 4.9 m.y. East of Little Glass Butte lie two northwest-trending ridges, Antelope and Cascade Ridges, composed of two or more overlapping exogenous domes that formed along northwest-trending faults.


Therometry And Barometry Of Precambrian Orthogneisses And Related Rocks From The Minnesota River Valley, Southwestern Minnesota, Paula J. Leier May 1982

Therometry And Barometry Of Precambrian Orthogneisses And Related Rocks From The Minnesota River Valley, Southwestern Minnesota, Paula J. Leier

Undergraduate Theses and Senior Projects

Granulite facies metamorphism is reported to have occurred in the Granite Falls-Montivideo area of the Minnesota River Valley and a broader view of the valley is taken to determine the extent of granulite facies metamorphism. Pressures and temperatures of metamorphism were determined using two geothermometers and one geobarometer. Based upon two-feldspar and garnet-biotite thermometers, temperature of metamorphism is approximated at 600 °c. Metamorphic pressures based on the reaction cordierite= garnet+ quartz + sillimanite were probably between 4 and 6 Kbars. Based on barometry and thermometry, it is suggested the Algoman o rogeny (2600 m.y. ago) was at least upper amphibolite …


Petrology Of The Middle Cambrian Blacksmith Formation, North-Central Utah, Howard William Hay Jr. May 1982

Petrology Of The Middle Cambrian Blacksmith Formation, North-Central Utah, Howard William Hay Jr.

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The dolostones and dolomitic limestones of the Middle Cambrian Blacksmith Formation were studied in the Bear River and Malad Ranges and the Wellsville Mountains of north-central Utah. The depositional textures and sedimentary structures retained within the rocks form the basis of subdivisions of measured sections, interpretation of depositional paleogeography, and reconstruction of environments.

Other studies of modern carbonate environments and their ancient analogues provided the basis for interpretation of the depositional textures found within the rocks of the Blacksmith Formation. Four identifiable lithofacies were recognized within the study area. These facies include: (1) oolite shoal; (2) restricted lagoon; (3) low- …


Petrology Of The Lower Middle Cambrian Langston Formation, North-Central Utah And Southeastern Idaho, Gary Jay Buterbaugh May 1982

Petrology Of The Lower Middle Cambrian Langston Formation, North-Central Utah And Southeastern Idaho, Gary Jay Buterbaugh

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Lower Middle Cambrian Langston Formation was studied in the Bear River Range of north-central Utah and southeasternmost Idaho and the Wellsville Mountains of north-central Utah. The depositional textures and sedimentary structures preserved within the rocks were compared with characteristics of similar modern sediments and ancient rock to determine environments of deposition, paleogeography, diagenetic alteration and pattern of dolomitization.

The rocks of the Langston Formation were divided into eleven different rock types. These eleven rock types were formed within four recognizable lithofacies: 1) upper peritidal; 2) inner carbonate shelf; 3) inner clastic shelf; and 4) outer clastic shelf.

The general …