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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Deposition and diagenesis of the early Permian Lower Parmeener Supergroup limestones, Tasmania

Rogala, Becky 24 April 2008 (has links)
The Lower Parmeener Supergroup consists of 500 to 900 metres of marine and terrigenous sedimentary rocks, deposited in the high-latitude Tasmania Basin during the late Carboniferous to middle Permian, at the end of the late Paleozoic ice age. Two bioclastic carbonate units, the Darlington and Berriedale limestones, are of particular interest due to their formation in this polar, cold-water environment. Both limestones contain ice-rafted debris scattered throughout, signifying numerous icebergs, and are under- and over-lain by glendonitic siltstone indicating near-freezing seawater. Despite the unusual environment, seawater in the Permian Tasmania Basin was, with the exception of an anomalously high 13C value, isotopically and chemically similar to modern seawater. These limestones consist of a high-abundance, low-diversity heterozoan assemblage, dominated by large, robust brachiopods, bryozoans, and Eurydesma bivalves. Sponge spicules and crinoids are locally important constituents. The carbonates are interpreted to have been deposited in mid-shelf environments during sea-level highstands, where the faunal communities were beyond the depths of grounding icebergs, and sufficiently outboard from terrigenous sediment influx and brackish water. Growth and preservation of biogenic carbonates were promoted by up-welling of nutrient-rich water, which sustained high levels of primary productivity in the water column and phosphate concentrations in the sediment. Lower Parmeener Supergroup carbonates were exposed to a complex series of diagenetic processes, commencing on the seafloor and continuing during rapid burial. Limestone composition was further modified by diagenetic fluids associated with the intrusion of Mesozoic igneous rocks. Alteration in the marine paleoenvironment was both destructive and constructive; although dissolution took place there was also coeval precipitation of fibrous calcite cement, phosphate, and glauconite. These processes are interpreted to have been promoted by mixing of marine waters and enabled by microbial degradation of organic matter. In contrast, meteoric diagenesis was insignificant, being confined to minor dissolution and localized cementation, although mechanical compaction was ubiquitous. Chemical compaction was instigated at burial to depths of approximately 150 m, and promoted extensive precipitation of ferroan calcite. Diagenesis may well have ended here, except for the subsequent intrusion of massive Mesozoic diabases and associated injection of silicifying fluids into the limestones. Finally, fractures associated with Cretaceous uplift were filled with late-stage non-ferroan calcite cement. / Thesis (Ph.D, Geological Sciences & Geological Engineering) -- Queen's University, 2008-04-23 11:12:58.461 / NSERC
22

The gamma member of the Kaibab Formation (Permian) in northern Arizona

Lipinski, Paul William, 1951-, Lipinski, Paul William, 1951- January 1976 (has links)
No description available.
23

Morphological variation and disparity in Lystrosaurus (Therapsida: Dicynodontia)

Camp, Jessica Amber 01 July 2010 (has links)
The dicynodont genus Lystrosaurus, a relative of the Kannemeyerids, is one of few terrestrial vertebrate genera which can be found on both sides of the Permian-Triassic (P-T) boundary (Botha and Smith, 2006); indeed, a single species, Lystrosaurus curvatus, is known from both periods. In the Permian, Lystrosaurus was of average abundance relative to other genera. Shortly following the P-T extinction, it drastically increased in abundance until it dominated the faunas it was present in (Botha and Smith, 2006). To date, Lystrosaurus fossils have been found in South Africa, India, Antarctica, China, and Russia (Grine et al., 2006). Abundance, survivorship, and expansive geographic presence give Lystrosaurus extreme potential as a model organism for multiple questions involving ideas such as extinction survivorship, biogeography, and ecology; however, Lystrosaurus has been subject to the practice of an extreme version of "splitter" taxonomy in the past. Here I quantify Lystrosaurus morphology using geometric morphometrics. Chinese Lystrosaurus taxonomy has not been analyzed in light of this. My results show that they are different from Gondwanan Lystrosaurus and represent at least one if not two unique species.
24

A Paleopedological and Ichnological Approach to Spatial and Temporal Variability in Pennsylvanian-Permian Strata of the Lower Dunkard Group

Blair, Michael G. 17 September 2015 (has links)
No description available.
25

MIDDLE GUADALUPIAN (PERMIAN) BENTONITE BEDS, MANZANITA MEMBER, CHERRY CANYON FORMATION, WEST TEXAS: STRATIGRAPHIC AND TECTONOMAGMATIC APPLICATIONS

NICKLEN, BRIAN LEE 02 September 2003 (has links)
No description available.
26

Stratigraphy and environment of the Toroweap Formation (Permian) north of Ashfork, Arizona

Mullens, Rockne Lyle, 1944- January 1967 (has links)
No description available.
27

The Historical Development of the University of Texas of the Permian Basin, Odessa, Texas

Kern, Stephanie P. 08 1900 (has links)
The University of Texas of the Permian Basin (UTPB) is a public university that serves over 4,500 undergraduate and graduate students as a branch of the University of Texas system located in Odessa, Ector County, Texas. The UTPB was established as an upper-division and graduate school on February 4, 1969, and first opened its doors to students in September, 1973. This historical study focuses on the development and progress of the UTPB from its inception until it was elevated from an upper-level institution to a four-year university twenty-two years later. The formation, mission, and curriculum are examined as well as are faculty and student characteristics and support. This study addresses the background history of higher education in the region, the role of community and college leaders in the UTPB's creation and struggle for four-year status, and the UTPB's unique features. The study was conducted by collecting data from available primary and secondary sources. The written data were then subjected to both external and internal criticism to determine the authorship and meaning of the documents. To explain events and put the written documents in context, oral histories, given by participants, were used. The educational opportunities offered by the UTPB have enriched the lives of Ector County citizens as well as the lives of many students from surrounding counties in the region of Texas known as the Permian Basin. Additional research topics related to the UTPB as well as other educational institutions are suggested.
28

Petrology and stratigraphy of the Colina limestone (Permian) in Cochise County, Arizona

Wilt, Jan Carol January 1969 (has links)
No description available.
29

Subsurface stratigraphy of the Supai Formation in east central Arizona

Passmore, Virginia Louise, 1942- January 1969 (has links)
No description available.
30

A stratigraphic study of the Toroweap Formation (Permian) between Sycamore and Oak Creek Canyons, Arizona

Evans, Thomas J., 1946- January 1971 (has links)
No description available.

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