Physical Sciences and Mathematics Commons^™

Holocene Sedimentology And Stratigraphy Of Coastal Sediments In An Arid Climate, Al Qahmah, Southern Red Sea, Saudi Arabia, Abdullah Ibrahim Nabhan

Doctoral Dissertations

"Holocene sedimentary deposits in Al Qahmah coast, southern Red Sea, in Saudi Arabia have been accumulated on an arid siliciclastic coast in a rift tectonic setting. This study provides a detail interpretation and analysis of sedimentary facies, stratigraphy, depositional environment, and major geological processes. Two studies have been undertaken. First, petrological study of composition and texture of modern sediments and facies mapping delineate facies distribution and mechanisms of sediment transport and deposition. A unique suite of complex riverine, wave, tidal, wind, and chemical and biological processes affect the composition, texture, and distribution of the facies. Second, the depositional environments of …

Crustal Thickness And Vp/Vs Beneath The Western United States: Constraints From Stacking Of Receiver Functions, Uranbaigal Purevsuren

Doctoral Dissertations

"This study investigates crustal characteristics beneath the western United States. Crustal parameters, including crustal thickness (H), mean Vp/Vs, and the sharpness of the Moho as quantified by the amplitude of the P-to-S converted phases from the Moho, are measured at a total of 1000 permanent and portable broadband seismic stations using over 150,000 receiver functions recorded between 1988 and 2012. The study area is composed of a diverse set of tectonic provinces formed by a series of tectonic events, and is thus ideal for investigating crustal formation and modification by different tectonic processes. The resulting crustal thickness varies from …

Precambrian Evolution Of The Salalah Crystalline Basement From Structural Analysis And 40Ar/39Ar Geochronology, Hanadi Abulateef Al-Doukhi

Doctoral Dissertations

"The Salalah Crystalline Basement (SCB) is the largest Precambrian exposure in Oman located on the southern margin of the Arabian Plate at the Arabian Sea shore. This work used remote sensing, detailed structural analysis and the analysis of ten samples using ⁴⁰Ar/³⁹Ar age dating to establish the Precambrian evolution of the SCB by focusing on its central and southwestern parts. This work found that the SCB evolved through four deformational events that shaped its final architecture: (1) Folding and thrusting event that resulted in the emplacement of the Sadh complex atop the Juffa complex. This event resulted …

The Paleontology And Biostratigraphy Of The Lower Ordovician Gasconade Formation Of Missouri, Bruce L. Stinchcomb

Doctoral Dissertations

"The biostratigraphy, paleoecology and paleontology of the Lower Ordovician Gasconade Formation in Missouri is reinvestigated in an attempt to solve problems that have arisen since the classic earlier studies by Ulrich, Bridge and others. Twelve faunal zones are established, many based on primitive mollusks which dominate the formation. The oldest of these, in the Van Buren Member, is the Hypseloaonus Zone. This is followed by a zone characterized by the primitive cephalopod Dakeoaeras then a zone dominated by the gastropod Sinuopea. These zones are succeeded by the Euomphalopsis, Matthevia and Ozarkina Zones which lie stratigraphically below the Cryptozoon Zone, …

Lower Mississippian Sedimentation In Northwestern Montana, Forest E. Haines

Doctoral Dissertations

"Thirty-three measured sections, nine with thin sections and insoluble residues, were studied to determine the depositional history of the Allan Mountain Limestone and the lower member of the Castle Reef Dolomite of the Madison Group in northwestern Montana.

The Allan Mountain base is a fossiliferous limestone, herein named the Brownback Gulch Member, which thickens and becomes cherty to the southwest where the section at Lone Butte resembles that of the Bridger Range Waulsortian-type reefs. A crinoidal lag deposit marks a dis- conformity at the top. In the overlying silty limestone member a thin black shale (Unit 1) grades into normal …

Petrography, Diagenesis And Environment Of Deposition Of The Gasconade Formation, Lower Ordovician, Southern Missouri, Abd El-Aziz El-Hady A. Borahay

Doctoral Dissertations

"The Gasconade Formation (Lower Ordovician) has been studied in the surface and subsurface in the Ozarks of Missouri and northeastern Oklahoma. The formation is mostly dolomite with a sandstone member at the base (Gunter) and frequent occurrences of chert bodies of different shapes particularly in the middle part.

The dolomite crystals in the lower and upper parts are subhedral to euhedral of equicrystalline to two-size fabric and range in size from 300-600 microns, and subhedral to anhedral of variable fabric and smaller size in the middle part. A sequence of cloudy and clear areas, named zoning, characterizes the euhedral crystals. …

Paleozoic Stratigraphy As An Ore Control Of Hydrothermal, Base-Metal, Sulfide Deposits In New Mexico, John Samuel Sullivan Jr.

Doctoral Dissertations

"Until now the concept or regional stratigraphic control of hydrothermal ore deposits has not received much attention in the literature as a possible exploration guide for locating additional ore bodies. This concept is applied on a regional scale to Paleozoic strata in thirteen mining districts with hydrothermal base-metal deposits in a 35,300 square mile area or southwest New Mexico.

The rocks at the stratigraphic position of the ore-zones are characterized as massive- to thick-bedded with less than 5 percent chert present. The rocks are abundantly to moderately fractured. Fine- to medium-grained dolomite is the dominant host-rock in the lower Paleozoic …

The Technique Of Lineaments And Linears Analysis And Its Application In The Minerogenic Province Of Southeast Missouri, Hassan A. Etr

Doctoral Dissertations

"Current terminology in the field of lineaments and linears (lineations) analysis was reviewed and quantitative definitions of the common terms offered. A general classification of lineations is herein proposed. Characteristics of drainage and airphoto lineations were reviewed and the procedure used in their analysis discussed.

An area about 1880 square miles was analyzed for lineations based on drainage networks and the resulting patterns showed preferred orientation. These drainage lineations were later compared with the airphoto lineations of the same area and a limited degree of similarity was observed.

The airphoto lineations of an area approximately 7000 sq. mi. covering the …

Some Geological And Magnetic Characteristics Of Buried And Resurrected Precambrian Hills Of Southeastern Missouri, James Edward Palmer

Doctoral Dissertations

"PURPOSE AND SCOPE OF INVESTIGATION The major purpose of this investigation was to determine by a comprehensive study various geological and magnetic characteristics of buried and resurrected Precambrian hills of the Central Ozarks. A second important objective was the determination of characteristics which might aid in the location of buried Precambrian hills. A final objective was the testing of the magnetic surface integration method for identification and determination of depth of buried Precambrian hills.

This investigation is limited to buried and resurrected Precambrian hills of the Central Ozarks. It is concerned primarily with the structure and stratigraphy of sediments adjacent …

Stratigraphy Sedimentation And Petroleum Possibilities Of The Middle Ordovician (Kimmswick-Galena) Rocks Of Missouri, Illinois And Iowa, Krishna Kant Misra

Doctoral Dissertations

"Detailed surface and subsurface studies of the Kimmswick Limestone and the Galena Formation of Middle Ordovician age in eastern Missouri, western Illinois, and southeastern Iowa were conducted in order to examine their stratigraphic relations, geological history, environment of deposition, and petroleum possibilities.

The main objective of this study was to seek a stratigraphic subdivision of the Kimmswick Limestone in Missouri, based on its gross lithology and thin section study, and its correlation with the Galena Formation in Illinois and Iowa. As a result of this study, based on the examination of twelve surface sections and 92 thin sections a three-fold …