Physical Sciences and Mathematics Commons^™

The Virginius Vein Ore Deposit, Northwestern San Juan Mountains, Colorado: A Study Of The Mineralogy, Structure, And Fluid Inclusions Of An Epithermal Base-Metal And Silver Vein In A Volcanic Environment, Berton Woodward Coxe

Earth and Planetary Sciences ETDs

The Virginius ore deposit, Ouray and San Miguel Counties, Colorado, yielded 14.5 million oz of silver between 1880 and 1912. The deposit consists of several quartz, base-metal, and silver mineralized fissures which is hosted by Tertiary volcanic rocks of the San Juan volcanic field and was deposited in fractures radial to the northwest margin of the Silverton caldera.

Four stages of mineralization have been recognized: (I) quartz, galena, sphalerite, chalcopyrite, and argentiferous tetrahedrite; this stage comprises a bulk of the total vein material and all of the silver; (II) rhodonite, rhodochrosite, quartz, magnetit, galena, chalcopyrite, and pyrite; this stage is …

Geology Newsletter- 1985, Department Of Geology

Geological and Environmental Sciences News

Vol 1 No. 10

• Dear Alumni and Friends
• Geology Development Fund
• Advisory Council
• Faculty News
• W. David Kuenzi Scholarship Fund
• Awards and Scholarships
• Geology and Earth Science Club

Geophysical And Hydrogeological Effects Of Astorm-Water Retention Pond On The Floridan Aquifer, Hillsborough County, Florida, Abdullah M. Alamri

USF Tampa Graduate Theses and Dissertations

An integrated geologic, hydrologic, and geophysical investigation was conducted to determine the effect of a storm-water retention pond on the Floridan aquifer. Surface DC resistivity surveys were used to delineate the hydrostratigraphy. There are four distinct geoelectric layers: (1) Layer 1, high resistivity, 3 meters thick, fine to very fine unsaturated sand; (2) Layer 2, moderate resistivity, 1 to 2.5 meters thick, saturated sands and silts; (3) Layer 3, lower resistivity, 4 to 10 meters thick, silt and clay; (4) Layer 4, moderate resistivity, argillaceous limestone. Two fracture zones are defined by resistivity lows and marked by deep, V-shaped depressions …

Kinematics Of Great Basin Intraplate Extension From Earthquake, Geodetic And Geologic Information, Paul Kendall Eddington

All U.S. Government Documents (Utah Regional Depository)

Strain rates assessed from brittle fracture, associated with earthquakes, and total brittle-ductile deformation measured from geodetic data have been compared to paleostrain from Quaternary geology for the intraplate Great Basin of the western United States. These data provide an assessment of the kinematics and mode of lithospheric extension that the western U.S. Cordillera has experienced in the last 5-10 million years. Strain and deformation rates were determined by the seismic moment tensor method using historic seismicity and fault plane solutions. By subdividing the Great Basin into areas of homogeneous strain it was possible to examine regional variations in the strain …

The Response Of The Kentucky River Drainage Basin To A Lowering Of Base Level Control, David B. Warwick

Masters Theses

The Kentucky River has responded to a lowering of base level control by: 1) deepening the course of its channel; 2) cutting off meanders as incision proceeded; 3) developing knickpoints on tributaries; 4) widening its valley; and 5) dissecting the upland surface.

Field work involved surveying streams to obtain profiles. Twenty streams covering 125 miles of river from Carrollton to Camp Nelson, Kentucky were surveyed. Knickpoints were defined from these profiles. Data from stream profiles showed knickpoint distances decreasing with increasing distance up river. Map work involved obtaining data for hypsometric curves. Hypsometric integrals were determined from these curves. Data …

Lithofacies And Geochemistry Of Interreef Carbonates, Middle Silurian, Michigan Basin, Eric N. Porcher

Masters Theses

The Niagara Group of the Michigan Basin is composed of reef, interreef, and basinal carbonates. The Niagara Group interreef has herein been divided into several litho facies: algal-laminated dolomicrite, bioturbated dolomicrite, intraclastic dolomicrite, wispy-laminated dolomicrite, crinoidal micrite, and nodular micrite. These interreef carbonates show a shallowing upward sequence.

The geochemistry of the Niagara Group interreef was examined in an attempt to delineate any geochemical gradients with respect to reefs. The geochemistry of the inter reef was determined by Particle Induced X-Ray Emission (PIXE) analysis. No significant geochemical gradients were found to be associated with reefs. Reasons for this may include: …

The Geology, Geochemistry, And Alteration Of Red Butte, Oregon: A Precious Metal-Bearing Paleo Hot Spring System, Carol Susan Evans

Dissertations and Theses

Red Butte is located 60 km south of Vale, Oregon, about 20 km west of the Oregon/Idaho border. The butte is within the Owyhee Upland physiographic province of eastern Oregon which lies at the intersection of the Western Snake River Plain, the High Lava Plains, and the Northern Basin and Range provinces.

The butte is composed of Miocene to Pliocene lacustrine and fluvial volcaniclastic sediments. The topography of the butte is controlled by silicification of the sandstones and mudstones which cap it. Silicification and hydrothermal alteration are both structurally and stratigraphically controlled. North-trending normal faults dominate the area, and show …

Geometry Of Silicic Dikes Beneath The Inyo Domes, California, Jonathan H. Fink

Geology Faculty Publications and Presentations

Structural geologic evidence in the vicinity of the Inyo Domes indicates that the youngest extrusive products were erupted from a silicic dike that divided into at least three segments which underwent up to 30° of clockwise rotation as they neared the surface. The geometry of ground cracks, explosion craters, and surface structures on the domes suggest that the dike may have propagated laterally from a source beneath Mammoth Mountain, with both the overall-dike and the individual segments rising as they moved northward. Structural evidence and tephrochronology also imply that the actual vents may have migrated northward along individual dike segments …

Seismic Modelling And Paleoceanography At Dsdp Site 574, Larry A. Mayer, Tom H. Shipley, Fritz Theyer, Roy H. Wilkens, Edward L. Winterer

Affiliate Scholarship

The analysis of high-resolution watergun seismic profiles collected in support of DSDP Leg 85 drilling reveals sev eral major, regionally traceable reflectors that can be correlated over more than 360,000 km2 in the central equatorial Pacific. Synthetic seismograms generated from shipboard physical property measurements (carefully corrected to in situ values) for DSDP Site 574 show excellent agreement with the field records; the agreement suggests that the traveltime to-depth conversion is accurate and permits the precise (± 5 m) location of reflectors in the cored section. The reflectors can be dated (±0.5 Ma) as follows: Orange, 21.5 to 22.5 Ma; Yellow, …

Depositional Environments Of Late Precambrian Sediments From Liberia, Sierra Leone, And Senegal, West Africa, Alfred W. Magee Iii

OES Theses and Dissertations

Field and hand sample descriptions were supplemented with petrographic and textural analyses derived from thin sections, and scanning electron microscopy (SEM) to determine environments of deposition for the late Precambrian Gibi Mountain Formation, Liberia, Tabe

Formation, Sierra Leone, and the basal Mali Group, Senegal, West Africa.

The Gibi Mountain Formation consists of a glaciomarine tillite, marine laminites with dropgrains, and shallow water arkoses. A shale facies remains unresolved in origin.

The Tabe Formation is composed of three members: Tibai, Dodo, and Taban. The Tibai Member contains a glaciomarine tillite deposited in a shallow shelf marine environment, marine laminites, and shallow …

Conodont Biostratigraphy Of The Cambrian-Ordovician Boundary Interval In The Northern Shenandoah Valley Of Virginia, U.S.A., Randall C. Orndorff

OES Theses and Dissertations

Conodonts collected from two measured sections in the northern Shenandoah Valley of Virginia indicate that locally the Cambrian-Ordovician boundary is within the upper part of the Conococheague Formation and that the Conococheague-Stonehenge formational contact as defined in this study, is diachronous in relation to the boundary. Using the generally accepted definition of the CambrianOrdovician boundary as at the base of the trilobite Missisguoia Zone or within the conodont Hirsutodontus hirsutus Subzone of the Cordylodus proavus Zone, it is found here that the boundary is 230 ft (70 m) below the formational contact at the Narrow Passage Creek section. Several North …

Lineament Analysis And Tectonic Interpretation For The Central Tharsis Region, Mars, Robert C. Anderson

OES Theses and Dissertations

Lineament studies conducted for the Central Tharsis Region of Mars (JOON and JOOS latitude; 450w to 157.50W longitude) indicate two major events controlled the formation of the Tharsis Dome: 1) a pre-Tharsis fracture system consisting of North-West (3150) trending fractures; and 2) a Tharsian fracture system containing North-South (355°) and East-West (275°) trending fractures. The North-West (3150) trending fractures represent a crustal weakness zone which controlled the early formation of the Tharsis Dome. Analytical studies suggest four centers of uplift: 1) 6°N, 124°W; 2) 0.5°N, 114°W; 3) 5°S, 105°W; and 4) 7°S, 104°W. Each of these uplifting centers is associated …

Depositional Model For The Auriferous Gravels In The Payan Mining District Department Of Narino, Columbia, South America, Jim R. Garrett

OES Theses and Dissertations

Unlike placer deposits in arid and semi-arid environments where gold concentration is closely tied to the position of the bedrock, Payan placer deposits have no association with bedrock. Gold concentration values show highest gold concentrations occur at the contact of a coarse sand unit and its underlying gravel unit. Comparisons of the size and shape distributions of gold grain populations with their associated black sand populations indicate the gold and black sand were not deposited in hydraulic equilibrium. The mean size of each gold population is consistently coarser than the mean size of its associated black sand population despite the …

Leachate Monitoring In Naturally Saline Groundwater Chesapeake Landfill Chesapeake Virginia, T. Britt Mcmillan

OES Theses and Dissertations

Groundwater chemistry around the Chesapeake municipal landfill was monitored over a one year period. Ten sample sites as well as two surface water sites were used to monitor water quality. Two wells, one at 3 m and the other at 10 m were located at each site. Surface water samples were taken from the Elizabeth River, north of the landfill, and a tidal channel, west of the landfill. Seven groundwater sites were downgradient of the landfill and three sites were upgradient (control sites).

The landfill overlies a tidal marsh, approximately 100 m south of the intracoastal waterway (Elizabeth River). Dredge …

Geology Of The Tekman (Erzurum) Basin And Petroleum Possibilities, Abdullah Gedi̇k

Bulletin of the Mineral Research and Exploration

No abstract provided.

Subsurface Stratigrapy And Sedimentologic Control On The Productive Middle Devonian Age Richfield Member Of The Lucas Formation In The Michigan Basin, Sukru Nail Apak

Masters Theses

The depositional system of the Middle Devonian Richfield Member of Lucas Formation in the Michigan Basin was delineated using well logs, cores, drillers' records, and the literature. The Richfield Member was deposited in Sabkha and lagoonal environments characterized by cycles of anhydrite, dolomite, and limestone. Seven significant productive dolomitic zones, interbedded with anhydrite and limestone can be correlated throughout the study area. These zones change laterally to anhydrite towards the west flank and to dense limestone towards the east flank of the basin. Post-depositional diagenetic history of the Richfield was established with the aid of scanning electron microscopy and electron …

A Seismic Study Of An Impact Feature In Cass County, Michigan, Mancheol Suh

Masters Theses

A geophysical investigation, including a seismic study, of the subsurface structure of the Calvin-28 oil field, Cass County, Michigan, indicates that the structure's origin may be related to an impact event. The structural closures in the time structure maps and drilling results both show a central uplift. The fault system in the Trempealeau Formation shows a structure similar to other proven astroblemes. Undisturbed layers just beneath the central uplift also provide evidence of an impact structure. The result of mathematical modeling of the central uplift under the assumption that the structure is an impact structure corresponds well with the drilling …

A Gravity Investigation Of Mountain Flank Thrusting And Normal Faulting, Madison And Tobacco Root Ranges, Montana, Stephen Thomas Wigger

Masters Theses

Gravity modeling of west-dipping, Laramide mountain flank thrusts which involve Archean metamorphic rocks in the western Tobacco Root and northern Madison Ranges supports the idea that these thrusts are gently dipping.

The thrusts provided a favorable location for normal faulting during Neogene extension. The Neogene faults on the eastern portions of the Madison and Jefferson Basins are interpreted to be listric, and merge with the Laramide thrusts. Basin development occurred along a series of such faults, which dropped hanging wall blocks of the thrust sheets to progressively greater depths. The maximum depth of the Madison basin, near Ennis, was found …

The Amphibians And Reptiles Of Nebraska, George E. Hudson

Conservation and Survey Division

No abstract provided.

Effects Of Urbanization On The Quantity And Quality Of Storm Water Runoff Recharging Through Caves Into The Edwards Aquifer, Bexar County, Texas, George Veni

Masters Theses & Specialist Projects

Eighty-nine caves and sinkholes were investigated in the Edwards Aquifer recharge zone in Bexar County, Texas. The study examined their hydrogeologic and topographic origins and distribution, relationships to major fracture traces, quantity of recharge into the aquifer and degree of sensitivity towards degradation of the aquifer’s water quality. Groundwater traces were attempted to determine aquifer flow routes, time of groundwater travel, groundwater volume within conduits, and the aquifer’s capacity for dilution and dispersion of recharged contaminants. Trends in water quality were examined to quantify the volume and variety of contaminants recharged into the aquifer and to determine the effects of …

Dynamics Of Clastic Sedimentation And Watershed Evolution Within A Low-Relief Karst Drainage Basin, Mammoth Cave Region, Kentucky, John D. Pickle

Earth and Planetary Sciences ETDs

The hydrology and sedimentology of the Mill Hole drainage basin, a low-relief karst system in the Mammoth Cave Region, Kentucky, depend upon the interactions of surface and groundwater drainages and the distribution of lithologies within the basin. This basin is characterized by sinking streams in the headwaters (Glasgow Uplands) draining into cave rivers beneath the sinkhole-pocked plain (sinkhole plain), which, in turn, flow beneath a sandstone-capped upland (Chester Cuesta) and emerge at base-level springs. Karst windows expose the subterranean drainage within the Chester Cuesta.

Geochemistry Of Alteration And Mineralization Of The Wind River Gold Prospect, Skamania County, Washington, Krista I. Mcgowan

Dissertations and Theses

The Wind River gold prospect is located in TSN, R7E of Skamania County, Washington, and is an epithermal gold-quartz vein system hosted in volcanic rocks of the Ohanapecosh Formation, a late Eocene to middle Oligocene unit of calcalkaline chemical composition. Andesitic pyroclastic rocks of the Ohanapecosh Formation are the host of mineralization in the study area, and form the lowest of several stratigraphic subunits. These pyroclastic rocks are overlain by two sequences of lava flows which cap the ridges and are folded by an anticlinal warp over the length of Paradise Ridge, plunging gently to the southeast. Toward the west, …

Geology And Geochemistry Of Hydrothermal Alteration, Eastern Portion Of The North Santiam Mining Area, J. Michael Pollock

Dissertations and Theses

The Ruth Mine is a base-metal vein deposit near the eastern margin of a reported porphyry copper deposit in the Western Cascade Range in Oregon. Uplift of the Western Cascade Range has resulted in a deeply dissected terrain in which more than a kilometer of the stratigraphy overlying the porphyry-style mineralization is preserved and exposed. The stratigraphic units, which are middle Tertiary in age, have been given arbitrary letter designations beginning with the lowest unit (Unit A) through the uppermost unit (Unit D).

Unit A is composed of fragmental rocks of andesitic composition. Overlying and interlayered with Unit A are …

Overview Of Nebraska And The Regional Aquifer From Proceedings Of The 1985 Water Resources Seminar Series, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

During each spring semester, the Nebraska Water Resources Center sponsors a Water Resources Seminar Series at the University of Nebraska-Lincoln. The 1985 seminar series was entitled "Aspects of Groundwater Quality." This article appeared in the proceedings.

Fluvial, Tidal And Storm Sedimentation In The Chilhowee Group (Lower Cambrian), Northeastern Tennessee, Mary R. Cudzil

Masters Theses

The Lower Cambrian Chilhowee Group of northeastern Tennessee consists of the Unicoi, Hampton and Erwin Formations and is divided into four facies. Facies G occurs only within the lower 200 m of measured section (the Unicoi Formation) and consists of fine-grained to pebbly quartz wacke with rare thin beds of laminated siltstone. Subfacies Gh consist of low-angle to horizontally laminated, fine-grained sandstone with laminae and lenses of granules and pebbles. Subfacies Gh represents upper flow-regime, overbank deposition within a braided stream system that was proximal to a coastline. Subfacies Gmr consists of medium-scale, planar-tabular cross-stratified conglomerate in which megaripple bedforms …

Groundwater Levels In Nebraska 1984, Michael J. Ellis, Darryll T. Pederson

Conservation and Survey Division

No abstract provided.

Groundwater Levels In Nebraska, 1984, Michael J. Ellis, Darryll T. Pederson

Conservation and Survey Division

No abstract provided.

Aspects Of Groundwater Quality Proceedings 1985 Water Resources Seminar Series

Conservation and Survey Division

During each spring semester, the Nebraska Water Resources Center sponsors a Water Resources Seminar Series at the University of Nebraska - Lincoln. The 1985 seminar series was entitled "Aspects of Groundwater Quality".

Parameters Controlling Sediment Composition Of Modern And Pleistocene Jamaican Reefs, Stephen K. Boss

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Recent carbonate sediments from Jamaican north coast fringing reefs display variation in constituent composition, texture, and mineralogy related to their location on the reef. Samples were collected along lines which traversed the back reef and fore reef (0.5m to 70m).

The sediment is dominated by highly comminuted coral fragments, plates of the calcareous green alga, Halimeda, coralline algae, and the encrusting Foraminifera, Homotrema rubrum, with lesser amounts of other taxonomic groups (Foraminifera; molluscs; echinoderms). Relative abundances of these biotic components vary between sites. Q-mode cluster analysis indicates that constituent composition can be used to delineate the different reef …

Structural Geology Of Eastern Part Of Dairy Ridge Quadrangle And Western Part Of Meachum Ridge Quadrangle, Utah, Val A. Kienast

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A detailed geologic investigation was made of the eastern part of the Dairy Ridge Quadrangle and the western part of the Meachum Ridge Quadrangle, Utah. The area is located in north-central Utah in Rich County. It lies between lat. 41°22'30" N. and lat. 41°28'50" N. and between long. 111°21'40" W. and long. 111°25'15" W. The area measures 13.8 km in the north-south direction and 5.5 km in the east-west direction. It is on the eastern side of the Wasatch Range about 20 km west-southwest of Randolph, Utah.

Stratigraphic units of Precambrian to Cambrian age crop out in the western part …