Geology Commons^™

Thermal-Mechanical Response To An Intruding Magma Chamber, Christoph Arz

Geology Theses and Dissertations

The thermal-mechanical response of rock at shallow to medium depth beneath the earth's surface has been modeled as a magma body ascends toward it. The overall stress field is calculated by considering the country rock as a viscous fluid, a thermal-elastic material, or as an elasto-plastic material that fractures when its strength is overcome.
The stress field within and around a spherical magma body surrounded by a homogeneous, Newtonian fluid has been evaluated and can be used at deeper levels in the earth's crust where the viscosity of the country rock is relatively low. With decreasing depth wall rock material …

A Kinematic Study Of The Summit Valley Plutonic Complex, Klamath Mountains, California, Nancy E. Griesau

Geology Theses and Dissertations

The Summit Valley plutonic complex (SVPC) is a multi-phase intrusive body of Late Jurassic age. Crystallization age for a zircon of 150±1 Ma and a cooling age for a hornblende of 144±1 Ma indicate a protracted period of high temperature. The SVPC is irregularly shaped, covers <15 km², and is believed to be in the western limb of a post-Nevadan syncline, with an easterly dip estimated at about 45°. The SVPC penetrated the Orleans Fault and intruded and contact metamorphosed the upper and lower plates of the thrust. The Orleans Fault is a major tectonic boundary separating the Western Paleozoic …

The Geology Of The Vermont Valley And The Western Flank Of The Green Mountains Between Dorset Mountain And Wallingford, Vermont, Rolf Herrmann

Geology Theses and Dissertations

The carbonate sequence of the Vermont Valley has been generally believed to lie on the east limb of a major unfaulted syncline ("Middlebury Synclinorium"), and the exposed Precambrian basement and overlying cover rocks of the Green Mountain massif on the west limb of the adjacent major unfaulted anticline ("Green Mountain Anticlinorium"). Except for the Basal Thrust of the Taconic Allochthon, all faults shown on previous maps die out north of Dorset Mountain.
In contrast, detailed mapping for this thesis in the Vermont Valley and the western flank of the Green Mountain massif has revealed several major north/south trending thrust faults, …

The Last Interglacial-Glacial Transition In North America: Evidence From Uranium-Series Dating Of Coastal Deposits, Daniel R. Muhs

United States Geological Survey: Staff Publications

Considerable uncertainty exists as to whether the last interglacial was relatively "short" (~10 ka) or "long" (-20-60 ka), although most investigators generally agree that the last interglacial correlates with all or part of deep-sea oxygen-isotope stage 5. A compilation of reliable U-series ages of marine terrace corals from deposits that have been correlated with isotope stage 5 indicates that there were three relatively high sea-level stands at ca 125-120 ka, ca. 105 ka, and ca. 85-80 ka, and these ages agree with the times of high sea level predicted by the Milankovitch orbital-forcing theory. At a number of localities, however, …

Geologic Highway Cross Sections: Interstate Highway 64 Farmers To Catlettsburg, Kentucky, Donald R. Chesnut Jr.

Map and Chart--KGS

Highway roadcuts along Interstate Highway 64 from Farmers to Catlettsburg, Kentucky, provide scientifically significant exposures of rocks of Devonian, Mississippian, and Pennsylvanian ages in northeastern Kentucky. The roadcut exposures offer easy access to a variety of stratigraphic units and are ideal for educational field trips. However, Kentucky law prohibits vehicles from stopping on the shoulders of limited- access highways except in case of emergency, so any planned field trips must be coordinated with State authorities. Several national and international field trips, as well as many out-of-State university field trips, have examined these exposures. In addition, scientific studies involving carbonate sedimentology, …

Stratigraphic And Structural Framework Of The Carboniferous Rocks Of The Central Appalachian Basin In Kentucky, Donald R. Chesnut Jr.

Bulletin--KGS

A series of seven cross sections across the Central Appalachian Basin in Kentucky, Tennessee, Virginia, West Virginia, and Ohio was constructed in order to determine a stratigraphic and structural framework of the Carboniferous rocks for the basin. Oil and gas well logs, coal-company core descriptions, measured sections, and mapping of surface geology were used to construct these sections. New surface and subsurface faults, folds, and flexures were identified.

New, formal and informal lithostratigraphic nomenclature was introduced to clarify the stratigraphic framework. Formalized nomenclatural changes are (1) elevating Breathitt Formation to Breathitt Group, (2) dropping the Lee Formation, (3) elevating four …

Available Coal Resources Of The Booneville 7.5–Minute Quadrangle, Owsley County, Kentucky, Gerald A. Weisenfluh, R. E. Andrews, John K. Hiett, Stephen F. Greb, Richard E. Sergeant, Donald R. Chesnut Jr.

Information Circular--KGS

The Booneville Quadrangle lies within the Southwestern Reserve District of the Eastern Kentucky Coal Field. Six coal beds in the quadrangle have been commercially developed, mainly by surface mining methods, and comprise the basis of this Coal Availability Study. These beds are, in descending stratigraphic order, Copland, Whitesburg, Amburgy, Upper Elkhorn No. 3, Jellico and Manchester. A computerized Geographic Information System (GRASS) was used to calculate estimates of original, mined-out and remaining resources, restrictions to mining and available resources.

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

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Groundwater-Level Changes In Nebraska, Predevelopment To Fall 1992, Conservation Survey Division, U.S. Geological Survey

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Effect Of Sinkholes On Soil Moisture And Ground Water Recharge At An Abandoned Underground Coal Mine Near Wilton, North Dakota, Michael M. Sonderman

Theses and Dissertations

Subsidence at abandoned underground mines in south-central and southwest North Dakota has produced numerous sinkholes. Previous studies in the Northern Great Plains have suggested depression-focused recharge may be a significant ground water recharge mechanism in this region. Thus, sinkholes may increase soil moisture and ground water recharge. Current reclamation practices include filling sinkholes with non-topsoil fill material. However, the benefits of increases in soil moisture and ground water supplies may outweigh the benefits of expensive reclamation. The purpose of this study was to determine whether soil moisture and, hence, the potential for ground water recharge, was greater in sinkholes than …

Mineralogy, Geochemistry, And Dispersal Of Opaque Oxides On The Continental Shelf Of The Cascadia Margin, Kommajosyula Subramanya Ravi

Dissertations and Theses

Opaque oxide minerals (ilmenite, chromite, and magnetite) in sands from the Oregon continental shelf have been studied to establish the provenance, dispersal, and grade of potential shelf placer deposits. The study area extends southward from offshore of the Columbia River in northern Oregon to the Klamath River in northern California.

Stratigraphy And Structure Of The Southeast Part Of The Portland Basin, Oregon, Kenneth E. Lite Jr.

Dissertations and Theses

The southeast part of the Portland Basin has been previously described by other investigators. However, little detailed information existed on the depositional relationships between the units, the various sedimentary fades, or the origin of many of the units.

Regional Tectonic Deformation Of The Northern Oregon Coast As Recorded By Pleistocene Marine Terraces, Richard Alan Mulder

Dissertations and Theses

Pleistocene marine terraces of the northern Oregon coast are an important factor in understanding the tectonics and paleoseismicity of the central Cascadia subduction zone. The lowest marine terrace, tentatively correlated to 80,000 year old Whiskey Run terrace of southern Oregon, is intermittently exposed in the present day sea cliff along an 80 km section of coastline between Tillamook Head and Cape Kiwanda. Terrace sediments consist largely of fine material such as clay, silt and fine sand with several locations containing large amounts of gravel derived from nearby headlands and steep bedrock hills. The terrace sediments are interpreted to be deposited …

Desorption Hysteresis In Five Ion Exchanged Montmorillonites, Jerry Paul Fairley

UNLV Theses, Dissertations, Professional Papers, and Capstones

It is generally believed that the formation of recalcitrant (slowly desorbing) fractions of volatile organic compounds (VOCs) in soils is due to diffusion of compounds to sorption sites inaccessible to bulk fluid. The exact nature of these sites, however, is not well understood. In clay minerals, researchers favor two probable areas for the storage of persistent contamination; sites between the clay lamella, or sites with clay particle aggregates.

To test the hypothesis that recalcitrant fractions are formed in interlamellar spaces, a Na/Ca Montmorillonite (Smectite) was ion exchanged with five different cations (K⁺, Na⁺, Ca⁺, …

Development Of Organic Mud Mounds In A Mixed Carbonate-Siliciclastic Depositional Environment, John M. Ryan, Doy L. Zachry

Journal of the Arkansas Academy of Science

Organic carbonate mud mounds in the Prairie Grove Member of the Hale Formation developed on a shallow shelf swept by competent tidal currents. The mounds were stabilized by crustose red algae and fostered a sheltered setting where phylloid algae and marine invertebrates could thrive. The mounds supplied skeletal sediment locally to the intermound areas as well as regionally along the stable platform. This sediment mixed with quartz sand to form a major mixed carbonate-siliciclastic system in northwestern Arkansas.

Glacial Deposits, Vol. 20, 1991-1992, Department Of Geography-Geology

Glacial Deposits

Newsletter of the Department of Geography-Geology

Metamorphic Petrology And Gravity Studies Of The Archean English River Subprovince, Western Superior Province, Manitoba And Ontario, Canada, Moira E. Campion

Theses and Dissertations

The tectonic development of the English River Subprovince (ERSP) of the Superior Province in Ontario and Manitoba, as with other Archean medium-high grade metasedimentary/gneiss terranes, is an area of active research. Geochemical and geophysical data were collected during this study to determine the metamorphic conditions of formation, and the relationship between surface and subsurface geology. The results of metamorphic studies by Henke (1984), Baumann (1985), Chipera (1985) and Roob (1987) were also integrated with those of this study. The temperatures and pressures of formation, as well as detailed gravity characteristics, constrain the postulated tectonic model for the ERSP.

Chemical data …

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

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Wheeler County Test Hole Logs, Raymond R. Burchett

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Resource Notes-Academic Year 1991-92

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Resource News-January/February 1992

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Resource News-March/April 1992

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Resource News-July/August 1992

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Mineral Resource Map Of Nebraska, R. R. Burchett

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Geologic Bedrock Map Of Nebraska, R. R. Burchett

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Description Of Rocks From A Core Drilled At A Potential Low-Low Level Radioactive Waste Site In Nemaha County, R. R. Burchett

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Sr-Isotope Record Of Quaternary Marine Terraces On The California Coast And Off Hawaii, Kenneth R. Ludwig, Daniel R. Muhs, Kathleen R. Simmons, James G. Moore

United States Geological Survey: Staff Publications

Strontium-isotopic ratios of dated corals have been obtained from submerged reefs formed during Quaternary glacial periods off the Hawaiian islands. These data, combined with data from deep-sea sediments, tightly constrain the secular variation of marine ⁸⁷Sr/⁸⁶Sr for the past 800,000 yr. Although long-term trends are apparent, no significant (>0.02‰), rapid (<100,000 yr) excursions in ⁸⁷Sr/⁸⁶Sr were resolved nor did we observe any samples with ⁸⁷Sr/⁸⁶Sr greater than that of modern seawater. Strontium in mollusks from elevated marine terraces formed during interglacial periods on the southern California coast show resolvable and consistent variations in …