Geology Commons^™

Dunes And Vegetation: Natural Recovery On A Damaged Barrier Island, C. John Burk, H. Allen Curran, Teresa M. Czerniak

Geosciences: Faculty Publications

No abstract provided.

Rheological Properties Of Mudflows Associated With The May 1980 Eruptions Of Mount St. Helens Volcano, Washington, Jonathan H. Fink, Michael C. Malin, Richard E. D'Alli, Ronald Greeley

Geology Faculty Publications and Presentations

Rheological properties of three recent mudflows at Mount St. Helens were estimated using techniques developed for determining the properties of debris flows based on the geometry of their deposits. Calculated yield strengths of 1100, 1000, and 400 Pa, maximum flow velocities of 10 to 31 m/s, volumetric flow rates of 300 to 3400 m³/s, and plastic viscosities of 20 to 320 Pa-s all compare favorably with measured and estimated values cited in the literature. A method for determining likely sites of future mudflow initiation based on these data is outlined.

Nebraska Mineral Operations Review, 1980, Raymonds R. Burchett, Duane A. Eversoll

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Quality Of Surface Water In Bell County, Kentucky, Robert B. Cook Jr., Reese E. Mallette

Information Circular--KGS

Reconnaissance data for surface waters in Bell County, Kentucky, have been gathered in response to the anticipated need for baseline information related to Federal and State surface-mining regulations. Bell County is particularly well suited for such a study due to past and current coal mining, the widespread distribution of mining and diversity of stratigraphic units affected, the diverse array of both disturbed and undisturbed drainage basins, and the relative ease of access within the county.

Estimated flow rate, temperature, pH, conductivity, and concentration of iron, manganese, and suspended solids were determined for flowing waters collected at 71 scattered sites. Sample …

Fluid Inclusion Evidence For Ore-Forming Solutions: Phoenixville, Audubon And New Galena Mine Districts, Pa, Jeanne Passante Lawler

Bryn Mawr College Dissertations and Theses

The Audubon, Phoenixville and New Galena Pb-Zn-Cu vein deposits of southeastern Pennsylvania have been investigated by microthermometric analysis of fluid inclusions in sphelerite, dolomite and quartz. The results obtained from primary and pseudosecondary inclusions in spherelite indicate that the ore was deposited by a sodium rich brine of moderate salinity (11-14 equivalent wt. % NaCl) at temperatures probably near 200 degrees C. The Na-rich character of the fluid suggests that dissolved constituents in the fluids were derived from Na-rich sedimentary rocks of the Newark basin. Local fluid-wallrock interaction may have produced slightly higher salinity fluids (15-16 equivalent Wt. % NaCl) …

Stratigraphy And Depositional Environments Of The Wilcox Group (Paleocene) At The Oxbow Mine Site, Northwestern Louisiana, Richard E. Halle

Theses and Dissertations

The stratigraphy, structure, and depositional environments of the Naborton, Do let Hills, and part of the Cow Bayou Formations (Wilcox Group, Paleocene) at the Oxbow Mine site, Red River, De Soto, and Natchitoches Parishes,. Louisiana, were evaluated from a study of four continuous cores and 466 geophysical logs.

Overlying 40 feet {12 m) of silty Porters Creek shale is the Naborton Formation composed of 130-195 feet (40-59 m) of sand, silt, clay, and lignite. There are three lignites in this formation and their average total thickness is 13.5 feet (4. l m), or about 10% of the formation thickness. The …

Stratigraphy And Sedimentology Of The Sentinel Butte Formation (Paleocene) Near Lost Bridge, Dunn County, West-Central North Dakota, Bradley D. Nesemeier

Theses and Dissertations

The Sentinel Butte Formation (Paleocene) near Lost Bridge, Dunn County, west-central North Dakota, is 190 meters thick, and is charac terized by four main lithologies: sand, silt, clay, and lignite. The study interval is ISO meters thick, and lies between the basal sand of the formation and the Bullion Butte lignite bed, neither of which are exposed in the immediate study area. Sand, gray to yellow, makes up about 3S% of the interval studied. It occurs in tabular beds 2-18 meters thick. It is fine to very-fine, angular, and composed largely of quartz, feldspar, rock fragments, with minor amounts of …

Permo-Triassic Reconstruction Of Western Pangea And The Evolution Of The Gulf Of Mexico-Caribbean Region, James Lawrence Pindell

Geology Theses and Dissertations

A Permo-Triassic reconstruction of western Pangea (North America, South America, Africa) is proposed that is characterized by: 1) definition of the North Atlantic fit by matching of marginal offsets (fracture zones) along the opposing margins, 2) a South Atlantic fit that is tighter than the Bullard fit and that is achieved by treating Africa as two plates astride the Benue Trough and related structures during the Cretaceous, 3) complete closure of the Proto-Atlantic Ocean between North and South America, accomplished by placing the Yucatan block between the Ouachita Mountains and Venezuela, 4) a proposed Hercynian suture zone that separates zones …

Geology Of The Plutonic And Hypabyssal Rocks Of The Betts Cove Ophiolite Complex, Newfoundland, Bruce D. Idleman

Geology Theses and Dissertations

The Betts Cove ophiolite complex lies within the Dunnage Zone island arc terrain of central Newfoundland. It forms the base of the lower Ordovician Snooks Arm Group, which consists of mafic igneous rocks of the ophiolite and a thick sequence of volcanic and volcaniclastic rocks which conformably overlies it. The Snooks Arm Group is unconformably overlain by sub-aerial sediments and volcanics of the presumed Silurian Cape St. John Group.
The base o£ the ophiolite complex consists predominantly of ultramafic rocks. These are interlayered on a variety of scales, and show mesoscopic igneous structures which suggest that they were produced by …

Structural Analysis Of An Area Near Middlebury, Vermont, Paul A. Washington

Geology Theses and Dissertations

Detailed mapping of an area near Middlebury, Vermont, reveals a multiple deformational scheme quite different from that previously proposed. The published stratigraphy of the middle Ordovician limestones, on which earlier structural theories are based; was found to be inaccurate, so a new system has been defined. An unreported early generation of cleavage has been discovered which indicates the existence of a decollement zone in the upper Bascom formation. The second generation of cleavage and its associated folding were well defined by earlier workers, but this study shows that it is also a thin-skinned event.
The last deformation, as exhibited by …

Structural Studies Of The Ordovician Flysch And Melange In Albany County, New York, Frederick W. Vollmer

Geology Theses and Dissertations

The middle Ordovician rocks of the Albany 15 minute quadrangle comprise interbedded graywacke and shale, and in the east, coarse cobble or olistostromic deposits. The detrital composition, westward fining and regional westward transgression of these deposits indicate that these were sediments shed off the westward thrusting Taconic Allochthon. Primary sedimentary structures show that these rocks were deposited by turbidity currents flowing into a longitudinal trough, probably formed in response to increased load during overthrusting. Although strongly dependent on lithology, deformation intensity generally increases from west to east; from essentially undeformed bedded flysch through asymmetrically folded and thrust beds to highly …

Some Chemical And Mineralogical Aspects Of Plutonic Rocks From The North Arm Mountain Massif, Bay Of Islands Ophiolite, Newfoundland, Jerry W. Sullivan

Geology Theses and Dissertations

Whole-rock major and trace element compositions of one basalt, one diabase, and 21 rocks from the magmatic-plutonic units of the North Arm Mountain massif, Bay of Islands ophiolite, Newfoundland, were determined. Mineral compositions of a subset of the plutonic rocks were also determined.
The major and trace element compositions of the basalt and diabase are similar to abyssal tholeiites, and this is consistent with the REE data of Malpas (1978) and Suen, et. al. (1979) that suggest the lavas and dikes formed from a depleted or slightly enriched abyssal tholeiitic magma. The alkaline nature of the magma proposed by several …

Geologic Investigations In The Cayman Trough And The Nature Of The Plutonic Foundation Of The Oceanic Crust, Janet B. Stroup

Geology Theses and Dissertations

A survey of the literature that deals with the gabbroic rocks believed to comprise the foundation of the oceanic crust indicates that the overwhelming majority of these rocks are recovered from escarpments associated with transform faults. The wide range of mineral and chemical compositions characterizing oceanic gabbroic rocks suggests that the lower oceanic crust is much more heterogeneous in nature than was previously suggested by the results of geophysical investigations. The examination of gabbroic rocks recovered in situ from the walls of the Mid-Cayman Rise rift valley by the submersible ALVIN not only supports the notion that oceanic gabbroic rocks …

A Pleistocene Sand Sea On The Alaskan Arctic Coastal Plain, L. David Carter

United States Geological Survey: Staff Publications

A ridge and thermokarst-basin landscape that is strikingly portrayed in Landsat winter imagery consists of large Pleistocene dunes that have been modified by younger eolian activity and thermokarst processes. This is the most extensive area of large stabilized dunes yet reported in the North American Arctic; the landscape is ofparticular interest because it has been proposed as a$rst-order analog for martian fretted terrain. Recognition of the large dunes permits a new interpretation for linear and curvilinear trends visible in Landsat summer imagery.

Emission Rates Of Co2 From Plume Measurements., D. M. Harris, M. Sato, T. J. Casadevall, William I. Rose, T. J. Bornhorst

Michigan Tech Publications, Part 1

Most of the CO2 that emanated from Mount St. Helens became part of the gas plume as it moved away from the volcano. An airborne technique was developed for continuous sampling and infrared analysis for CO2 in the plume. The CO2-emission rates were determined by measuring the area, the horizontal velocity, and the CO2 concentration anomaly in vertical cross sections of the plume The emission rate varied from 2100 t/day to about 22 000 t/day.-from Author

Development Of Irrigation Well Drilling In Nebraska, Vance Anderson

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Glacial Deposits, Vol. 9, 1980-1981, Department Of Geography-Geology

Glacial Deposits

Newsletter of the Department of Geography-Geology

Geomorphology And Dynamics Of A Sand Wave In Lower Chesapeake Bay, Virginia, Gerardo Miguel Eduardo Perillo

OES Theses and Dissertations

A single, more or less isolated, sand wave in a sand wave field recently discovered in the lower Chesapeake Bay, Virginia, was studied intensively for morphology, sedimentology and in terms of dynamic processes. The morphologic investigation consisted of bathymetric surveys of the sand wave field and the specific sand wave. Twenty-five grab samples and four box cores were obtained from different segments of the feature studied. Textural parameters of the samples were determined, and a multivariate technique was utilized to identify subenvironments on the feature. The box cores provided information on the internal structure of the sand wave.

Observations of …

Distribution Of Fenitized Crustal Xenoliths In Carbonatite Intrusions, West-Central Arkansas, John Sharp

Journal of the Arkansas Academy of Science

Crustal xenoliths from carbonatite intrusions in the Morrilton-Perryville Arkansas area display a variety of mineralogical and textural features that suggest that they are fragments of basement crystalline rock that has undergone sodic metasomatism resulting from their close proximity at depth to a carbonatite complex. With increasing degrees of fenitization, the leucocratic xenoliths range from granolite - syenite - analcite syenite, while the melanocratic xenoliths range from hornblende - biotite to aegerine-apatite. A definite increase in fenitization is observed from Morrilton in the north to Brazil Branch, 16.8 km to the south. Fenitized xenoliths from Brazil Branch are generally quite small …

Petrology Of The Cenozoic Phonolites And Related Rocks Of The Houston Creek Area, Bear Lodge Mountains, Wyoming, Frederick S. O’Toole

Theses and Dissertations

The purpose of this study was to map and study the characteristics and origin of the Cenozoic phonolites and related rocks of the Houston Creek area, located on the southwestern flank of the Bear Lodge Mountains, 10 km northwest of Sundance, Wyoming. Mapping was conducted on a 2 1:10,000 scale over a 16 km area. Microprobe, optical, and x-ray diffraction procedures were employed to observe and describe petrographic and chemical characteristics of the rocks.

The Cenozoic igneous rocks of the Houston Creek area are classified as phonolite, phonolite porphyry, trachyte porphyry, sodalite-bearing phonolite and altered felsite. These hypabyssal rock types …

Geology And Groundwater Supplies Of Southern Dawes And Northern Sheridan Counties, Nebraska, Vernon L. Souders

Conservation and Survey Division: Faculty and Staff Publications

The upland plain in southern Dawes and northern Sheridan counties of northwest Nebraska is underlain by rocks of Tertiary age. These rocks overlie those of Cretaceous and Jurassic ages in this region of about 2250 square miles . Strata of Tertiary age are a source of groundwater for most of the irrigation, municipal, stock, and rural-domestic needs of the area.

Nine stratigraphic units of Tertiary.age were defined by examination of test hole samples and logs and by examining electric logs of oil and gas tests, driller's logs of irrigation wells, and outcrops. Stratigraphic correlations are difficult in the area because …

Annual Outflow Of Water From Nebraska, 1950-1980, Conservation Survey Division

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Nebraska Groundwater Level (Decline & Rise) And Location Of Registered Wells, 1981

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Groundwater Reservoir Management Policy Issue Study: A Contract Report For The State Water Planning And Review Process-Nebraska Natural Resources Commission

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

The Geology And Environment Of Deposition Of The Kinneman Creek Interval, Sentinel Butte Formation (Paleocene), North Dakota, Katherine J. Logan

Theses and Dissertations

To date, most environmental reconstructions of lignite bearing formations in western North Dakota have been done on a formational scale. The objective of this study was to investigate one of the non-lignite intervals, the Kinneman Creek Interval, directly above the strati graphically lowest lignite in the Paleocene Sentinel Butte Formation. The Kinneman Creek Interval has been recognized in the Sentinel Butte Formation throughout most of western North Dakota.

The field area is located in west-central North Dakota in Mercer, Oliver, and McLean Counties and is bisected by the Missouri River. Excellent exposures are provided in the highwalls of Baukol-Noonan, North …

A Thermochemical Study Of The Ore Deposits Of The Milliken Mine, New Lead Belt, Missouri, Douglas L. Rickman

Doctoral Dissertations

"The ore body at the Milliken mine is a typical Mississippi Valleytype ore deposit. Mineralization is in a dolostone and structures are subtle, but very important ore controls. The major mineralogy is simple, predominately galena, luminescent hydrothermal dolomite, sphalerite and chalcopyrite. Twenty-three additional minerals have been identified in the ores, including barite and Pb-aragonite, bot h of which have not previously been recognized in the district.

Paragenetically, the ores are very complex, with four major, distinct periods of mineralization plus numerous periods of dissolution. The paragenesis provides evidence for the dynamic, evolving nature of the ore system. Galena textures, euhedral …

An Investigation Of The Nickel-Cobalt Occurrence In The Southeast Missouri Mining District, David Ray Jessey

Doctoral Dissertations

"A study of the occurrence of nickel and cobalt in the Southeast Missouri Mining District has revealed several significant geochemical trends and mineralogical relationships. Regional geochemical studies indicate that the greatest concentration of nickel and cobalt occurs in the Fredericktown area. Mines in the Viburnum Trend also have significant concentrations of these metals. Studies of the Viburnum Trend have established that both nickel and cobalt decrease in concentration southward from the Magmont mine to the Brushy Creek mine, increase at the Fletcher mine, and decrease again at the Sweetwater mine.

A detailed geochemical study of the Buick mine has shown …

Radar Observations Of Ash Eruptions, D. M. Harris, William I. Rose, R. Roe, M. R. Thompson

Michigan Tech Publications, Part 1

Radar systems located at Portland, Oreg., Seattle, Wash., and near Spokane, Wash., have been used extensively for observations of ash clouds from explosive volcanic eruptions at Mount St. Helens during 1980. Eruption clouds are composed of silicate particles and are therefore detectable by radar. Radar observations can be made at night and in overcast weather when conventional observations of eruptions are difficult.-from Authors

Quaternary Geology Of Chaco Canyon, Northwestern New Mexico, David Waxham Love

Earth and Planetary Sciences ETDs

The overall purpose of studying the Quaternary geology of Chaco Canyon is to develop an understanding of how the geomorphic system in the Chaco drainage evolved and how it presently operates. This dissertation has several subsidiary purposes; (1) to describe and relate modern sedimentary features and facies (which are likely to be preserved in the alluvial fill of the canyon) to modern geomorphic processes, (2) to use the results from the study of modern sediments to interpret exposures of alluvium in Chaco Canyon in order to reconstruct past environments, (3) to develop conceptual models of the geologic subsystems of the …

Relationship Of Gravity Anomalies To A Drift Filled Bedrock Valley System In Calhoun County Michigan, James W. Farnsworth

Masters Theses

Gravity geophysics along with well data were used to delineate and map the locations of buried river valleys in Calhoun County, Michigan. The valleys are filled with thick sequences of glacial fluvial deposits which can serve as important aquifers.

One hundred and sixty-four gravimeter observations were made at approximately one-quarter mile intervals in a 35 square mile area. Four short-interval profiles were also established perpendicular to suspected valleys. A three-dimensional trend surface polynomial was fitted to the total Bouguer anomaly to approximate the regional effect of gravity. By comparing the observed residual gravity to theoretically derived anomalies, models were developed …