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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 …

Uranium-Lead Zircon Ages And Crustal Contamination Of The Northeastern Idaho Batholith, James J. Dexter

Masters Theses

The magmas which formed the northeastern Idaho batholith were contaminated with, or derived from, old crustal material as evidenced, from previous studies, by high whole-rock ⁸⁷Sr/⁸⁶Sr ratios, relatively high ²⁰⁷Pb/²⁰⁶Pb ages, and Archean to Proterozoic upper intercept ages for batholithic zircons.

The old zircon component has been identified in this study by separating zircons into fractions based on size and morphology. Pb/U isotopic ratios are distributed on a chord with a lower concordia intercept intrusive age of 73.6+6 m.y. Zircons from a batholithic sample located one kilometer inward from the contact were separated according …

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 …

Land Use Effects On Shallow Earth Resistivity, Gary James Barton

Masters Theses

No abstract provided.

A Geophysical Investigation Of A Possible Astrobleme In Southwestern Michigan, Suhas L. Ghatge

Masters Theses

A circular pattern to the oil production in Calvin Township, Cass County, Michigan, absence of about 1200 feet of Ordovician sediments and uplift indicated by a deep drill hole in the center of the productive area and absence of anomalies on the regional gravity and magnetic maps led to detailed gravity and magnetic surveys over this structure to delineate it and provide information regarding its genesis.

The Bouguer gravity and magnetic anomaly maps show no anomaly associated with the structure. The 28-mile wavelength second harmonic residual gravity and magnetic maps show linear features in the area. Two dimensional gravity modeling …

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 …