Geology Commons^™

The Depositional History Of The Point Pleasant Member Of The Cynthiana Formation In Northern Kentucky, Gary J. Stefaniak

Masters Theses

Bioclastic limestones, siltstones, and shales of the Point Pleasant Member were deposited in a shallow marine environment immediately below normal effective wave base. High-energy conditions produced by storms lowered the effective wave base and stirred the bottom sediments and redistributed them into bedforms. The different types of contacts, distribution of the faunal groups, and fabrics permit inferences regarding energy levels and assignment of samples to a mode of deposition. Vertical and lateral trends were then deduced. High-energy conditions are believed to have occurred during Early and Late Point Pleasant time, whereas, low-energy conditions prevailed during deposition of the middle Point …

Geology Of A Section Of The Northwest Tobacco Root Mountains, Madison County, Southwest Montana, Kiff James Samuelson

Masters Theses

The northwest Tobacco Root Mountains are located on the boundary between two major tectonic provinces: the fold and thrust belt and the Rocky Mountain foreland. Deformation typical of the Rocky Mountain foreland is present in the form of two major northwest trending faults with associated folds. Paleozoic rocks were passively draped over at least one of the elevated Precambrian blocks. Foliation of the Precambrian rocks also appears to have been gently folded in the process.

Folds and thrusts occur within the Precambrian and Paleozoic rocks, on the westernmost flank of the range, appearing to follow the general trend of the …

Hydrogeologic And Geochemical Factors Influencing The Impact Of A Chromium-Arsenic-Copper Wastewater Discharge On A Glacial Outwash Aquifer, Michael J. Gallagher

Masters Theses

A discharge of chromium-arsenic-copper laden wastewater occurred periodically from 1970 to 1980 at a wood preserving company located in southwestern Kalamazoo County, Michigan. As a result of this discharge, soils at the company site became contaminated with chromium, arsenic, and copper, and a local glacial outwash aquifer became contaminated with hexavalent chromium.

Soil samples collected from the discharge site were analyzed for clay-silt-sand-gravel content, organic matter, pH, clay mineralogy, and chromium, arsenic, copper, iron, and manganese content. Background soil samples were analyzed for most of the above catagories. Pearson r coefficients of correlation were calculated to determine the correlation of …

Structural Geology Of The Northern Snowcrest Range, Beaverhead And Madison Counties, Montana, Mark Kenneth Sheedlo

Masters Theses

The Snowcrest Range was uplifted in Late Cretaceous and Early Tertiary time as a consequence of thrusting in Precambrian basement and Phanerozoic cover rocks.

The Snowcrest-Greenhorn thrust system is associated with largescale overturned, eastward verging folds. Mean orientation of the thrust system is N.40°E., 35°N.W.. The trend of the thrust system and associated transverse faults appear to be controlled by earlier structures. Mesoscopic and microscopic analyses indicate that metamorphic basement rocks accommodated congressional strain largely by brittle faulting and cataclastic shearing. Kinematic indicators suggest that local stresses were directed east-southeastward.

Northeast-trending Neogene faults along the western flank of the range …

Lithology And Sedimentology Of The Graydon Springs Channel, Pennsylvanian Of Southwestern Missouri, Gregory Lee Easson

Masters Theses

"The Graydon Springs Member of Southwest Missouri, here assigned to the Warner Formation of Pennsylvanian age was sampled and examined in order to document the lithology, sedimentology, source area, stratigraphic position, and overall geologic history of these channel-like bodies. The member is composed of an upper sandstone unit and a lower conglomerate unit.

Laboratory investigations of thin sections indicate that the sandstone unit is composed of well sorted, well rounded quartz and minor amounts of accessory minerals cemented with iron oxide, commonly hematite. Field observations indicate that the conglomerate unit is composed of very poorly sorted, very well rounded chert …

Relation Of Bitumen To Ore In The Magmont West Orebody, Southeast Missouri, Mark Alan Marikos

Masters Theses

"Bitumen in the form of oil blebs from the Magmont West orebody of the Viburnum Trend was examined and analysed in an attempt to relate hydrocarbon distribution and origin to ore genesis. Hydrogen, carbon, nitrogen, sulfur and oxygen percentages were determined by elemental analyses. Trace element composition was determined by emmission spectroscopy and the composition of the bitumen was calculated with respect to aromatic hydrocarbons, saturated hydrocarbons and NSO (nitrogen-sulfur-oxygen) components. The bitumen and kerogen from associated shale samples were evaluated by Rock-Eval pyrolysis and pyrolysis-gas chromatography.

The bitumen was calculated to be approximately 40 to 50 percent aromatic and …

Oil Producing Upper Cherokee And Lower Marmaton (Pennsylvanian) Channel Sandstones Of Jackson And Cass Counties, Missouri, Stephen Thomas Carroll

Masters Theses

"Approximately 240 gamma ray-neutron logs were interpreted and correlated in an attempt to isolate separate channels collectively referred to as "Squirrel" sands in the upper Cherokee and lower Marmaton (Pennsylvanian) rocks of Jackson and Cass counties, Missouri. Isopach maps were prepared for two of the identifiable fluvial sandstones and a structure map was drawn on the laterally extensive Anna Shale.

The term "Squirrel" has been applied to as many as five different sandstone packages, and thus, has been the source of a great deal of confusion. In an attempt to sort out the confusion this thesis recognizes and defines three …

Environment Of Deposition Of The A-1 Carbonate, Salina Group, Michigan Basin, Barbara June Leonard

Masters Theses

The lower Salina Group of the Michigan Basin is composed of a cyclic succession of carbonate and evaporite units. The lowermost Salina unit is the A-1 unit which consists of a lower A-1 evaporite and an upper A-1 carbonate. The A-1 unit is underlain by Niagara Group carbonates. The transition from Niagaran carbonates to A-1 evaporite to A-1 carbonate has not been thoroughly understood and previous models have not satisfied some of the evidence. This paper sets forth the hypothesis that the A-1 carbonate was deposited in a non-marine lake environment rather than an isolated marine environment. Findings supporting this …

The Geology Of The Southern Bull Mountain Area, Jefferson County, Montana, Michael Edward Streeter

Masters Theses

The Late Cretaceous-Early Tertiary Laramide orogeny was responsible for the northward tilting of the pre-Eocene rocks of the area. The Late Cretaceous deposition of the Elkhorn Mountains Volcanics resulted in the volcanic-Madison Group unconformity. Late Cretaceous faulting took place probably in response to caldera subsidence. Laramide uplift erosion and downstream transport resulted in the deposition of the Conrow Creek conglomerate and debris flows over the Lodgepole Limestone. Block faulting took place in response to regional extension probably during Late Oligocene-Early Miocene time resulting in the formation of the St. Paul's Gulch, Golden Sunlight, and Boulder basin faults. The Oligocene Dunbar …

Sedimentation Rate Of Salt Determined By Micrometeorite Analysis, James Matthew Barnett

Masters Theses

The sedimentation rate of the A-l Evaporite of Michigan was determined by analysis of micrometeorites found as inclusions in the halite deposit. The samples were obtained from the Dow Chemical Company salt well number eight. The residue from the dissolved salt was magnetically separated and later analyzed by Particle Induced X-ray Emission (PIXE), X-ray diffraction , and microprobe techniques. The amount of extraterrestrial material was determined from the quantity of nickel present.

A sedimentation rate of .01 to .4 centimeters per year was calculated for the salt based on a constant influx rate of meteoritic material of 1 x 10 …

The Geology And Geochemistry Of The Summit Creek Molybdenum Prospect, Custer County, Idaho, Thomas Murray Hanna

Masters Theses

The Summit Creek stock, a molybdenum prospect located in the Pioneer Mountains of central Idaho, is a 46.7 m.y. old medium grained, slightly porphyritic quartz monzonite, which has intruded the late Ordovician Phi Kappa formation. Trend surface analysis shows that the stock is the product of one intrusive event. Pervasive mineral alteration usually associated with such porphyry (stockwork) molybdenum deposits is not present in this pluton, and the alteration that is present is confined to local faults and fractures.

Geochemical and petrographic evidence suggest that the pluton is a felsic differentiate from a melt which originated at a depth of …

The Geology Of Burnt Ridge Quadrangle And Vicinity Ravalli County, Montana, Randall Reichert

Masters Theses

Peltitic schist, quartzofeldspathic gneiss, and calc-silicate rocks of the Precambrian Belt Supergroup hav ebeen intruded by granatic plutons of the northeastern Idaho batholith within the vicinity of the southern Bitterroot Range, Montana. These units were mylonitized along the eastern margin of the intrusive complex, with shear surfaces presently dipping approximately 20° to the east. Rhyolitic ash flows and associated mafic to felsic dikes developed on and within the granitic-metamorphic terrance during Tertiary time. Numerous northeast- trending and northwest-trending faults and joints are present throughout the mapped region.

The following events play a major role in the geologic history: 1) amphibolite- …

Lead-Zinc Metallotects Of The Ozark Dome, Linda Leigh Mallery

Masters Theses

"This is a regional study of the relationship between Mississippi Valley-type mineral deposits and structural features of the Ozark dome which resulted in the description and classification of lead-zinc "metallotects". A more accurate delineation of the Ozark dome was accomplished by examining the gradient and structural contour lines of its Precambrian basement. A general background on the geology, structure, and evaluation of the Ozark dome was discussed along with the stratigraphy, structure, and ore deposits of the major lead-zinc districts of the Ozark dome in order to develop the background data for the application of the "metallotect" concept. The major …

Geochemistry And Petrology Of The Cold Springs Breccia Formation, Wichita Mountains, Oklahoma, Dana Marie Vidrine

Masters Theses

"In the Wichita province of southwestern Oklahoma the Cold Springs Breccia Formation, exposed in a 15 km² area in Kiowa County, is characterized by blocks and pillows of microdiorite surrounded by pink granite. Intimately associated with this mixed zone are sill-like bodies of intermediate rocks, granodiorites and tonalites. The intermediate rocks have been interpreted as hybrids produced by assimilation of microdiorite by granitic magma, and the mixed zone has been interpreted as an intrusion breccia formed at the margins of the hybrid sills.

Major, minor and trace element data have been obtained on a suite of granites, intermediates, and …

Mineralogy And Chemistry Of The Tuff On Pritchards Station, East-Central Nevada, Stanley Christopher Hatfield

Masters Theses

"The Tuff of Pritchards Station in east-central Nevada is a little-known ash-flow tuff of limited areal extent. A detailed study of this tuff was conducted to determine if it is a distinctive unit which can be correlated from one locality to another.

Mineralogical and chemical data indicate that the Tuff of Pritchards Station displays significant lateral variability. Lateral variations in mineralogy include changes in total crystal content and the amount and grain size of individual minerals present over the area studied. Chemically, the tuff is a quartz latite to rhyodacite in composition. However, certain elements, most noteably titanium, show considerable …

Lithofacies Analysis Of The Roubidoux Formation, South Central Missouri, Michael William Harbaugh

Masters Theses

"Lithologic and thickness data of the Lower Ordovician rocks of the Roubidoux Formation, south central Missouri, were interpreted from sample logs. Maps included are based on structure, thickness and lateral and vertical lithologic variability. Sand distribution in the Roubidoux is represented by a "sand percentage" map, a "sand isolith" map, and a "tripartite sand distribution" map. The Roubidoux Formation consists of a sequence of dolomite, sandy dolomite, sand and chert. It is believed that the Roubidoux was deposited on a stable marine platform receiving a supply of elastics from the north and northeast. The sands were deposited by longshore or …

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

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 …

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; …

The Features And Significance Of Layering And Shearing Within The Zone Of Mylonitization, Northeastern Idaho Batholith, Jon Michael Hermann

Masters Theses

The northeastern border zone of the Idaho batholith contains a north-south trending zone of myionitized gneiss, schist, and granite-granodiorite. The schist and gneiss contain plagioclase augen surrounded by crushed and recrystallized biotite, quartz, feldspar, + muscovite, + hornblende. The granite grades upward from porphyritic rock into augen-bearing mylonitic rocks interlayered with schist and gneiss.

Radiometric And Petrochemical Characteristics Of The Dells Granite, Yavapai County, Arizona, Kenneth Stewart Fleck

Masters Theses

"The Dells granite of central Arizona, an alkaline granite containing accessory fluorite and tourmaline, contains anomalously high amounts of uranium. Gamma-ray spectrometry, x-ray fluorescence, petrographic, and autoradiographic methods were used to determine the contents and distribution of equivalent U, Th, K, and ten major element oxides within the granite pluton. The range of uranium content is 0 to 39.7 parts per million (ppm) with the mean equivalent U content 8.8 ppm; eTh, 26.8 ppm; and K, 4.8%. The average uranium content is about twice the average of western United States granites, the thorium content slightly less than average. The Th/U …

Petrology Of Fluvial And Shoreline Sands In A Modern Arc-Trench Gap, Guatemala, James Robert Bartel

Masters Theses

Petrographic studies of modern sands, derived from areas with known source rocks, climate, relief, environments of deposition, and tectonic setting, are essential for compiling compositional models for ancient sandstones. The Pacific coastal plain of Guatemala is terminated 25-60 km inland by the steep slopes of a row of active Quaternary volcanic and granitic rocks.

Sands being deposited on the coastal plain by the Rio Nahulate, which drains the older volcanic and granitic terrane, show significant compositional differences with those supplied by the Rio Samala, which drains an area dominated by active volcanism: Q₉F₃₅L₅₆ vs. Q …

An Analysis Of Nitrate Concentrations In The Ground-Water Of Antwerp Township, Van Buren County, Michigan, John Emil Klanke

Masters Theses

Private wells were tested for nitrate during the spring of 1979 throughout sections of Antwerp Township, Van Buren County, southwestern Michigan (sections 1-5, 7-22, 24-26, 28-31, 33-36). Water samples were collected from 159 private wells and analyzed for nitrate. Nitrate concentrations ranged from less than 1 mg/1 NO₃-N to 14.6 mg/1 NO₃-N. Seven wells were found to have nitrate concentrations equaling or exceeding the National Interim Primary Drinking Water Standard of 10 mg/1 NO₃-N. Nitrate concentrations were related to age of septic system, well depth below static water level, land use, and soil type. …

Structural Analysis Of Precambrian Metasedimentary Rocks Of The Swede Gulch Formation, Nahant, South Dakota, Richard G. Cookman

Masters Theses

Precambrian X tectonites deformed between thermal domes in the northern Black Hills 1.7 B.Y.B.P. display variably trending isoclinal folds cross-cut by southeast trending slip-folds developed in discrete shear zones. Eugeosynclinal sedimentary rocks consisting of shale, quartzarenite , sublitharenite, and graywacke were metamorphosed to phyllite, quartzite, and metagraywacke during two syntectonic phases and one post-tectonic phase. The earliest syntectonic metamorphism was associated with development of isoclinal folds and may have produced amphibolite or greenschist facies. It was succeeded by retrograde metamorphism of greenschist facies syntectonic with and post-tectonic to development of southeast trending folds.

Mica, chlorite, iron oxides, and graphite are …

The Petrology And Geochemistry Of Keweenawan Diabase Dikes In Ontonagon, Gogebic, Iron And Dickinson Counties, Michigan, James J. Hahnenberg

Masters Theses

Petrographic and chemical studies of Keeweenawan-age diabase dikes in Michigan's Upper Peninsula show two major groupings, Porcupine Mountain dikes and Lower Keweenawan dikes consist of two major rock types, fine-grained smaller dikes and the coarse-grained central portions of larger dikes. Major minerals are subophitic plagioclase and pyroxene. The rocks, as compared to the "average" basalts, are low in Al₂0₃, high in Ti0₂, K₂0, P₂0₅ and contain moderate amounts of Fe0_t. They are classified as quartz tholeiites. Several parental magma sources that would account for these and other …

Dolomitization Of The Brassfield Formation (Lower Silurian) In Adams County, Ohio, Lisa L. Varga

Masters Theses

The Lower Silurian Brassfield Formation which outcrops in the Tri-state area of Ohio, Indiana and Kentucky is a transgressive sequence consisting of a series of interbedded shales, limestones and dolostones. Evidence from depositional environments, petrography and spatial relationships of dolomitized and undolomitized rock suggests dolomitization in southwestern Ohio was a two-stage process. Initial dolomitization was restricted to the basal Belfast Member and probably occurred penecontemporaneously on small supratidal islands in a manner analagous to that which occurs in the modern sabkha environment of the Persian Gulf. Regional dolomitization was a later diagenetic event related to the formation of a fresh-seawater …

U-Pb Systematics And Ages Of Rocks From The Zone Of Cataclasis, Bitterroot Dome, Southwestern Montana, Edward Charles Arruda

Masters Theses

The eastern flank of the Bitterroot range, western Montana, consists of a 100 km-long zone of cataclasis which dips to the east. Zircons in sheared granitic plutons from three localities within this zone were dated using U-Pb methods. These zircons, which consist of anhedral cores and euhedral overgrowths, yield concordia lower-intercept ages of 48-52 million years before the present, dates which likely represent crystallization ages of the plutons. Shearing which affected these plutons, therefore, is significantly younger than the 72-76 million year age assigned for eastward movement of the Sapphire tectonic block whose detachment zone has been interpreted as 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 …

Variations In The Depositional Environment Of The Lower Cincinnatian Kope Formation, Thomas K. Mahan

Masters Theses

In northern Kentucky, the Upper Ordovician (Lower Cincinnatian) Kope Formation outcrops as a series of interbedded, laterally discontinuous limestone lenses and beds enclosed in a silty shale unit. Six stratigraphic sections within a 20-mile radius were sampled and measured and two of these were described in detail to characterize the variations in the environmental setting wherein the Kope Formation was deposited.

The shale lithology is homogeneous throughout this formation whereas the bioclastic limestones vary widely in faunal composition, texture, cross-sectional shape, and thickness. Apparently, the depositional style for the fine-grained, terrigenous sediment remained almost constant through Early Cincinnatian time, whereas …

Fossil Algae In The St. Louis Limestone, Near St. Louis, Missouri, Sherris Ragsdale Myers

Masters Theses

"Although Mississippian algae research is fairly extensive, little has been published on algae from the Mississippian type locality, the Upper Mississippi River Valley. For this study, portions of sixteen St. Louis Limestone stratigraphic sections containing units with oncolites, domal stromatolites, laminations, or mottled (possibly algal) textures, were measured, described, and sampled to determine: (1) to what extent algae are preserved in the St. Louis Limestone, (2) if enough of the delicate structure was fossilized to determine morphology, (3) depositional environment of the algae, and (4) if the algae are related to a lithologic pattern. Thin sections of the sampled units …