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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

Abo Formation (early Permian) Sacramento Mountains, New Mexico : a dry alluvial fan and associated basin-fill

Speer, Stephen W. 01 July 2013 (has links)
Outcrops of the Abo Formation (Wolfcampian to early Leonardian age) in the Sacramento Mountains of south-central New Mexico record the evolution of a dry alluvial fan system as it was deposited off of the Pedernal Uplift into the Orogrande Basin. A mud-rich, upward-fining basin-fill sequence characterized by stratigraphic thickness variations of as much as 450 m (1480 ft) and contacts that range from conformable to unconformable relationships is observed in the outcrop area. Five distinctive lithologic intervals are delineated in the Sacramento Mountains, three of which are studied in detail. These three units are informally designated the lower, middle, and upper Abo intervals and are all fluvial in origin. The remaining two intervals, the Lee Ranch Tongue of the Abo Formation and the Pendejo Tongue of the Hueco Limestone, are marginal marine in origin and are restricted to the southern portion of the range. Two types of lithofacies are present in the lower, middle, and upper Abo intervals. Matrix facies represent fine-grained overbank sediments, whereas framework facies represent coarser streamflow and sheetflow deposits. Lower Abo framework facies consist of middle-fan to fan-fringe stream-channel, braided stream, and sheetflood deposits which are arranged in one or more stacked, assymetrical, upward-fining megasequences 10-50 m (33-165 ft) in thickness. Middle and upper Abo framework facies were deposited basinward of the fans and represent deposits of incised, low to moderate sinuosity ephemeral streams and associated overbank splays. Middle Abo streams exhibited an anastomosed channel pattern whereas upper Abo channels were characterized by a distributive pattern. Pedogenic and sedimentologic evidence suggests that Abo deposition was strongly influenced by a long term, semi-arid to arid climate. Lateral and vertical facies relationships indicate that the five Abo intervals were part of a northeast to southwest transverse facies tract consisting of 1) proximal alluvial fans, 2) medial anastomosed streams, and 3) distal low-gradient mud-dominated floodbasins characterized by either distributary streams or tidal flats with associated marine carbonates. The overall Abo basin-fill sequence reflects the migration of the facies tract in response to the final stages of tectonic activity and the eventual quiescence and long-term erosion, retreat (pedimentation), and onlap of the Pedernal Uplift. / text
22

A SEDIMENTOLOGICAL AND GEOMORPHICAL INVESTIGATION OF THE PARIS MORAINE IN THE GUELPH AREA, ONTARIO, CANADA

McGill, Michael 21 August 2012 (has links)
A sedimentological and geomorphologic investigation southeast of the City of Guelph, Ontario was undertaken to determine the nature, trends in distribution, and origin of subsurface sediments in the Paris moraine. Sediments were investigated by drilling five cored-holes, mapping geomorphic elements, and creating a database of existing data. Nine broadly encompassing and reoccurring lithofacies were identified, ranging from gravel to clayey silt. The general transverse trend of geomorphic elements across the moraine consists of a frontslope, hummocky, and backslope element. Sediment-landform associations were identified from the synthesis of cored-hole, geomorphic element mapping, and lithologic cross-section data. Based on these results, the Paris Moraine is thought to be the remnants of an ice-cored controlled moraine. The relief inversion process responsible for the formation of the controlled moraine creates a horizontally and vertically variable distribution of lithofacies. Hydrogeologic properties of the moraine sediments will likely be similarly spatially variable and difficult to predict. / Ontario Research Fund, NSERC, OMAFRA
23

Upper silurian carbonates of Lake Memphremagog and lime ridge areas, Quebec

Hughson, Robert Carl January 1987 (has links)
No description available.
24

Sedimentology and petroleum geochemistry of the Ouldburra Formation, eastern Officer Basin, Australia / by Mohammad Reza Kamali.

Kamali, Mohammed Reza January 1995 (has links)
Copies of author's previously published works inserted. / Bibliography: leaves 153-165. / ix, 165, [153] leaves, [10] leaves of plates : ill. (chiefly col.), maps ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, National Centre for Petroleum Geology and Geophysics, 1996
25

Sedimentology of the Ouldburra Formation (Early Cambrian), northeastern Officer Basin /

Dunster, John N. January 1987 (has links) (PDF)
Thesis (M. Sc.)--University of Adelaide, 1987. / Col. folded map in pocket of v. 1. Includes bibliographical references.
26

Lithologic evidence of the Jurassic/Cretaceous boundary within the nonmarine Cedar Mountain Formation, San Rafael Swell, Utah /

Ayers, James D. January 2004 (has links)
Thesis (M.S.)--Ohio University, August, 2004. / Includes bibliographical references (p. 152-159).
27

Conodont biofacies and carbonate lithofacies of Lower Ordovician megaconglomerates, Cow Head Group, Western Newfoundland /

Pohler, Suzanne Margarete Luise. January 1987 (has links)
Thesis (Ph.D.) -- Memorial University of Newfoundland, 1987. / Typescript. Bibliography: leaves 486-526. Also available online.
28

Lithologic evidence of the Jurassic/Cretaceous boundary within the nonmarine Cedar Mountain Formation, San Rafael Swell, Utah

Ayers, James D. January 2004 (has links)
Thesis (M.S.)--Ohio University, August, 2004. / Title from PDF t.p. Includes bibliographical references (p. 152-159)
29

Lithostratigraphy, depositional environments and sedimentology of the Permian Vryheid Formation (Karoo Supergroup), Arnot North, Witbank Coalfield, South Africa

Uys, Joanne 30 April 2009 (has links)
M.Sc. / This work documents the lithostratigraphy and interpreted depositional environments of the Permian Vryheid Formation in the most northern proximal setting yet studied in the Witbank Coalfield. Data from 924 boreholes from two mining companies (Anglo Operations Ltd. and Xstrata Coal Ltd.) drilled over 50 years, covering an area of 910km2 revealed a 35m sequence of terrigenous clastic sedimentary rocks containing two coal seams. These seams are numbered No. 1 at the base and No. 2 at the top. Delineation of facies type, facies assemblages, lateral facies distributions and computer-based three-dimensional modeling facilitated the interpretation of the palaeodepositional environments. Eleven lithofacies are defined and interpreted hydrodynamically. Facies classification is based primarily on grain size and sedimentary structures. The modeling of the borehole information uses the finite element method to interpolate the thickness, roof and floor surfaces and trend of each seam and inter-seam parting between boreholes. The spatial position of the boreholes is defined using a digital terrain model that represents the current surface topography. Lateral distributions were correlated by repositioning the boreholes using the base of the No. 2 seam as a datum. Glaciofluvial, glaciolacustrine, bed-load (braided) fluvial and constructive progradational deltaic environments are interpreted in the study area. Fluvial channel sequences are dominant and cause the thinning of the coal seams below channel axes as well as splitting of both the No. 1 and No. 2 seams. Glaciofluvial influences also affect the lower portion of the No. 1 seam. Basement palaeotopography restricts the distribution of the lower splits of the No. 1 seam. The coals either ‘pinch-out’ or are absent above basement highs but blanket the adjacent low-lying areas. In contrast to the greater Witbank Coalfield, but concurrent with other studies in the more northern proximal regions, fluvial systems dominate over deltaic systems in the study area. Glaciodeltaic, fluviodeltaic and anastomosed channel fluvial systems recognized in the remainder of the Karoo Basin were fed by the braided fluvial systems in the study area. The close proximity of the study area to the northern edge of the basin accounts for the subtle differences in lithostratigraphy and interpreted depositional environments when compared with more distal sites to the south. For example, glaciofluvial clastic sediment input in the lower portions of the No. 1 seam and post-Karoo erosion that has removed the overlying seams; the deltaic progradational sequence, above the No. 2 seam, occurs twice in succession and the bioturbation, that has become characteristic of sedimentary sequence of the Vryheid Formation above the No. 2 seam in the central and southern parts of the Karoo Basin, is not as identifiable. These differences are explained by the extreme proximal location of the study area on the northern basin margin relative to the remainder of the Karoo Basin.
30

The auriferous Middelvlei reef depositional system, West Wits Line, Witwatersrand Supergroup

Els, Barend Gerhardus 27 February 2014 (has links)
D.Phil. / Please refer to full text to view abstract

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