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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 …

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 …

Depositional Environments Of Siliceous Laminites In The Laney Member Of The Green River Formation, Sublette County, Wyoming, Michael G. Rasmussen

Loma Linda University Electronic Theses, Dissertations & Projects

Siliceous shales of the Laney Member of the Green River Formation are exposed in outcrops around Fontenelle Reservoir in the northwest corner of the Green River Basin, Wyoming. An analysis of these shales is important to an understanding of the origin of laminites in the Green River formation. The shales are rhythmic, varve -like laminites, composed of quartz, authigenic potassium feldspar , dolomite, and zeolite minerals. The association of these minerals suggest that the original sediment contained significant amounts of volcanic ash, and were deposited in a shallow, near-shore, oxygenated saline - alkaline lake environment, as inferred from (1) the …

Palynostratigraphy Of The Eocene Little River Section, Grays Harbor County, Washington, Roy E. Jensen

Loma Linda University Electronic Theses, Dissertations & Projects

A total of 27 samples from Eocene marine rocks exposed along the Little River, Grays Harbor County, southwestern Washington were analyzed for palynomorphs. Strata studied included the Crescent Formation, "Sedimentary Rocks of Late Eocene Age", and the Lincoln Creek Formation. A total of 77 micro fossil types were identified of which 32 were pollen and spores, 24 fungal remains, 18 dinoflagellate cysts, and 3 miscellaneous micro fossils.

Based upon the stratigraphic distribution of 21 palynomorphs, three informal palynologic assemblage biozones were recognized. The oldest zone, Zone 1, of late early or early middle Eocene age, contains Platycaryapollenites, Platanoidites, Laevigatosporites type-2, …

Depositional Environments Of The Miocene Esmeralda Formation, Stewart Basin, Stewart Valley, Nevada, Kevin E. Nick

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine specific depositional environments of the Miocene Esmeralda Formation in Stewart Basin (Stewart Valley), Mineral County, Nevada. Previous workers have concentrated on paleontological aspects of the basin and have described in detail the molluscs, mammals and macroflora. Less work has been done on the diatoms and spores and none on the fish, algae, wood or ostracodes. Recently, seven lithostratigraphics units of the Esmeralda Formation have been mapped in Stewart Valley (Clausen, 1983).

Detailed lithofacies are described in each of the seven lithostratigraphic units. Lithofacies 1 is composed of porcelanite and diatomite containing plant …

Depositional Model Of The Antelope Coal Field, Wyoming, Christine M. Budai

Dissertations and Theses

The coal-bearing sediments of the Antelope coal field in the southcentral Powder River Basin, Wyoming were deposited in paludal and tributary subsystems of the fluvial system that existed in the basin during the early Tertiary. A depositional model for the Antelope coal field was constructed from data collected from approximately 500 drill holes that penetrated the upper 90 meters (300 feet) of the Fort Union Formation. The depositional environments were interpreted from lithologic descriptions and guidelines established in the literature.

The two main coal seams at the Antelope coal field are the Anderson and stratigraphically lower Canyon coal seams. They …

Palynology And Paleoecology Of The Fossil Butte Member Of The Eocene Green River Formation In Fossil Basin, Lincoln County, Wyoming, Robert A. Cushman Jr.

Loma Linda University Electronic Theses, Dissertations & Projects

The palynoflora of the Fossil Butte Member of Green River Formation was studied to enhance our understanding of the depositional environment of ancient Fossil Lake. Forty-nine outcrop samples were collected from three measured sections representing the center, the margin, and intermediate areas of Fossil Lake. Of the 49 samples, 12 yielded a fairly well preserved palynomorph assemblage.

A late early Eocene to early middle Eocene age for the Fossil Butte palynoflora is indicated by the presence of Bombacaceae, Eucommia, Ilex, Juglans, Pistillipollenites, Platycarya, Pterocarya, Tilia, and Taxodium. Additional evidence for the early to middle Eocene age of the Fossil Butte …

Stratigraphy And Structure Of The Miocene "Esmeralda" Formation In Stewart Valley, Mineral County, Nevada, Benjamin L. Clausen

Loma Linda University Electronic Theses, Dissertations & Projects

The Miocene rocks of Stewart Valley, eastern Mineral County, Nevada, consist of volcanic flows and breccias and fluvio-lacustrine sedimentary rocks. They are called the Esmeralda Formation because they contain lithologies similar to those of the Esmeralda type section 100km south; however, the rocks in Stewart Valley were probably deposited in a separate local basin. The lower part of this formation contains small lacustrine claystone deposits (unit 1) that interfinger with volcanic breccias and flows (unit 2). The main fluvio-lacustrine sequence is above the flows and·is divided by the author into five units based on lithology: sandstone and claystone in unit …

Geology And Petrochemistry Of Ultramafic And Orbicular Rocks, Zuni Mountains, Cibola County, New Mexico, Ellen E. Lambert

Earth and Planetary Sciences ETDs

Field mapping, petrography, mineral and whole-rock chemistries have been completed on Precambrian ultramafic and orbicular rocks occurring in the Zuni Mountains, New Mexico. These rock types are surrounded by felsic igneous and metasedimentary rocks, including quartz-feldspar gneiss, quartz monzonite aplite, gneissic quartz monzonite and metarhyolite.

Two small orbicular rock outcrops occur along the contact between quartz-feldspar gneiss and gneissic quartz monzonite. Dark-green, hornblende-actinolite orbicules, having curving crystals of amphibole concentrically arranged about a central point, are set in a pink, quartz monzonite matrix. Many orbicules have been broken or deformed into irregular ellipsoids.

Metamorphosed ultramafic rocks, exhibiting original igneous textures, …

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- …

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 …

Geological And Thermal Aspects Of The Southern San Joaquin Basin, California: Application Of The 40ar/39ar Stepwise Heating Technique To Detrital Microclines, Kenneth Bé

Geology Theses and Dissertations

The depositional history of the southernmost region of the trough-shaped San Joaquin Basin spans from Upper Eocene to Recent time. The stratigraphy reveals both a predominantly marine environment which persisted until the Upper Pliocene, as well as nonmarine environments along the basin's margins. Folds and faults within the basin have resulted directly from movements along the San Andreas fault. Although the exact time of origin of the Big Bend is unclear, this major feature in the San Andreas fault's geometry has played an important role in recent crustal tectonics of southern California. Significantly, the southern San Joaquin's depocenter has undergone …

Geology Of The Fondo Negro Region, Dominican Republic, J. Calvin Cooper

Geology Theses and Dissertations

Detailed geologic mapping of the Fondo Negro-Sierra de Martin Garcia region of the Southwestern Dominican Republic establishes that this area is part of a broad and diffuse Northern Caribbean plate boundary zone (PBZ). Faulting in the study area is predominantly left lateral strike-slip, with secondary compression (thrusting) causing both substantial, and rapid, uplift of the region. Folding associated with the wrench faulting affects rocks of all ages in the field area from Paleocene limestones to Quaternary alluvial fans.
New stratigraphic designations are proposed for mappable litho-units in the area, and these are correlated with Hispaniola stratigraphy in general based on …

The Pre-Tertiary Geology And Mesozoic Tectonic Evolution Of Eastern China, Southeast Asia And Adjacent Regions, Michael P. Klimetz

Geology Theses and Dissertations

Several orogenic belts transecting south-eastern Asia are the sites of former convergent plate margins although there have been varying interpretations of the collisional framework of individual continental blocks, styles of convergence at these zones and the timing of respective collisions. A comprehensive tectonic study of eastern China, Mongolia and the southern Soviet Far East indicates the collision of the South China Block with a combined North China-Northeast China Fold Zone Block in the late Triassic-early Jurassic, their collective suturing to Eurasia in the late Jurassic-early Cretaceous, followed by the Sikhote Alin-Japan Block in the mid to late Cretaceous. The evidence …

Structure And Stratigraphy Of West Haven, Vermont, Christoph K. Steinhardt

Geology Theses and Dissertations

Mapping and structural investigations in an area bounded to to the west by by Grenvillian basement and to the east by allochthonous rocks emplaced during the medial Ordovician Taconic Orogeny led to division of the area into a Western Undeformed Zone and an Eastern Deformed Zone. The former consists of a thin, undeformed shelf sequence of upper Cambrian to lower Ordovician (Canadian) clastics and carbonates, which unconformably overlie Grenvillian basement and dip gently to the east.
The Eastern Deformed Zone consists of early to medial Ordovician carbonates folded about northnortheast trending axes with east to southeast dipping axial surfaces, overlain …

Geology Of The Western Boundary Of The Taconic Allochthon Near Troy And The Anastomosing Cleavage In The Taconic Melange, Zong-Guo Xia

Geology Theses and Dissertations

The Taconic Allochthon is located in eastern New York, western Vermont, western Massachusetts, and western Connecticut and extends about 200 kilometers north-south and east-west for about 25 kilometers. It contains rocks of Late Proterozoic, Cambrian and Ordovician age. The rocks are predominantly slates with lesser amounts of arenites, wackes, limestone, chert, and conglomerates. All rocks have been subjected to chlorite or biotite grade metamorphism and at least two generations of deformation. The emplacement of the Taconic Allochthon onto the coeval shelf took place during the Middle Ordovician Taconic Orogeny.
The study area lies at the western margin of the Taconic …

Structure And Tectonics Of The Keban Metamorphics In The Northern Margin Of The Bitlis Suture Zone, Southeastern Turkey, Gültekin Savci

Geology Theses and Dissertations

The study area near Keban consists of the allochthonous Keban division of the Keban-Malatya crystalline complex and the Yuksekova island-arc rocks of the Bitlis-Puturge Complex in the northern margin of the Bitlis Suture Zone. Detailed mapping shows that the Palaeozoic-Triassic Keban Metamorphics are composed of the following formations: (1) white, massive, karstic Kirklar Marble; (2) phyllitic psammite with calcschist interlayers Calik Formation; and (3) semi-crystallized gray Koyunatlayan Limestone. These formations define a tectonostratigraphy with the Kirklar Marble at the base and the Koyunatlayan Limestone at the top. The detailed lithological description of the Keban Metamorphic rock assemblages suggest that they …

Stratigraphic Relationships Of The Tillamook Volcanics And The Cowlitz Formation In The Upper Nehalem River-Wolf Creek Area, Northwestern Oregon, Michael Keith Jackson

Dissertations and Theses

The upper Nehalem River-Wolf Creek area is located on the northeastern flank of the Tillamook Highlands in the northern Oregon Coast Range. Three rock stratigraphic units underlie the thesis area, and these units range from late Eocene to Oligocene in age.

Formation And Zonation Of Ferruginous Bauxite Deposits Of The Chapman Quadrangle, Oregon, Richard Charles Marty

Dissertations and Theses

Two major theories have been advanced to account for the scattered distribution of ferruginous bauxite deposits. Original workers proposed that ferruginous bauxite originally developed over all exposed Columbia River Basalt in western Oregon and was subsequently removed by erosion. Studies which followed have suggested that it may be locally favorable conditions, especially of drainage, which are responsible for deposit distribution. Field mapping in the Chapman Quadrangle shows a possible correlation between a series of sheared zones, which may have improved drainage, and the distribution of ferruginous bauxite deposits. Examination of the pisolitic zone ferruginous bauxite of the Chapman Quadrangle failed …

A Study Of The Diagenesis Of The Overburden Between The Badger And School Coal Seams, Dave Johnston Coal Field, Converse County, Wyoming, Rebecca K. Jaffer

Dissertations and Theses

Low pH zones in portions of the overburden at the Dave Johnston Coal Field, Converse County, Wyoming are the subject of this study. The low pH zones are restricted to limonite stained sandstones which grade downdip into normal pH gray sandstones. Changes in color, clay mineralogy, cementation and feldspar surface textures are noted between the two sandstone units. These changes appear to be the result of post depositional alteration that was responsible for oxidation of pyrite and chlorite, dissoluion of calcite, and the etching of feldspar grains. The parameters for the diagenesis fit those of uranium roll front models proposed …

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 …

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 …

Holocene Geologic History Of The Clatsop Plains Foredune Ridge Complex, David Karl Rankin

Dissertations and Theses

This research formulated a recent geologic history of the Clatsop Plains dating from 3500 years BP to present. Research consisted of geomorphic mapping, near-surface stratigraphic evaluation, carbon dating and subsurface interpretation of available data.

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 …

The Precambrian Volcanic Stratigraphy And Petrology Of The Des Arc Ne 7 1/2 Minute Quadrangle, South Central St. Francois Mountains, Missouri, Vernon Max Brown

Doctoral Dissertations

"The Precambrian volcanics in the Des Arc NE 7½ minute quadrangle are composed predominantly of rhyolitic ash-flow tuffs with minor rhyolitic, trachytic, and andesitic lavas, and basaltic dikes. Thirty-seven volcanic units were identified, mapped, and informally named. A minimum of 1,000 meters of volcanic section is present. The rhyolites consist of phenocrysts of albitized alkali feldspar, albitic plagioclase, quartz, opaques, and ferromagnesium relicts set in a devitrified and locally recrystallized felsitic matrix. Pumice and lithophysal structures are common in the ash flows.

Chemically, the rhyolites are quite similar. The potassium to sodium ratio in individual units, however, tends to vary …

Genesis Of Gold Deposits At The Little Squaw Mines, Chandalar Mining District, Alaska, Kathryn King Ashworth

WWU Graduate School Collection

The Little Squaw gold mines are located in the Chandalar Mining District, which is in the Brooks Range, 200 miles north of Fairbanks, Alaska. Country rock in the Little Squaw area consists of Devonian clastic and volcanic rocks which were subjected to two periods of upper greenschist facies metamorphism during the Cretaceous. A penetrative schistosity developed during the first metamorphic event, and thrust faulting and the development of a non-penetrative cleavage occurred during the second.

Gold-bearing quartz veins in the Little Squaw area crystallized along high angle normal faults which post date thrust faulting and cross-cut the non-penetrative cleavage. Data …

Diatoms And Magnetic Anisotropy As Means Of Distinguishing Glacial Till From Glaciomarine Drift, Robert Crandall

WWU Graduate School Collection

Fossil diatom occurrence and anistropy of magnetic susceptibility are evaluated for their usefulness in differentiating glaclomarlne drift from till.

Fossil diatoms in Everson glaciomarine drift occur abundantly enough to be of paleoenvironmental significance only in association with in situ Serpula vermlcularia (Linne). Diatoms are generally a poor discriminator between till and glaciomarine drift. Paleoecological data suggest that, berg ice in marine water was the dominant agent of transportation for clastic particlesin Everson glaciomarine drift.

Anisotropy of magnetic susceptibility investigations generated a characteristic magnetic signature for each diamicton, demonstrating intrinsic differences in the petrofabrics of the two sediment types.

Net Shore-Drift Of Mason County, Washington, Dana G. (Dana Genre) Blankenship

WWU Graduate School Collection

Winds from various directions cause waves which transport sediment along the shore. Over a relatively long time interval, sediment is moved in one predominant direction, which is the direction of net shore-drift. Variations in shoreline orientation cause shore drift to occur in discrete, essentially independent, drift cells.

By the specific identification of a number of established geomorphic and sedimentological shore drift indicators, drift cell boundaries can be delineated and the directions of net shore-drift determined. These indicators include changes in bluff morphology, beach width and slope, sediment-size gradation, identifiable sediment, deposition and/or erosion at shore drift obstructions, direction of spit …

A Paleomagnetic Age Investigation Of Pre-Salmon Springs Drift Pleistocene Deposits In The Southern Puget Lowland, Washington, John L. (John Leo) Roland

WWU Graduate School Collection

The Pleistocene history of the southern Puget Lowland is marked by repeated invasions by the Puget Lobe of the Cordilleran ice sheet. The present stratigraphic sequence is represented by four glaciations (Orting, Stuck, Salmon Springs, and Fraser) of northern provenance, separated by unconformities and two nonglacial formations (Alderton and Puyallup) of central Cascade and Mount Rainier provenances. Paleomagnetic work conducted on pre-Salmon Springs sediments at their type localities and correlative exposures in the Puyallup Valley provide evidence for the ages of the Orting Drift, Alderton Formation, Stuck Drift, and Puyallup Formation.

The silts sampled demonstrate an array of soft (unconsolidated) …