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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.
1

Distribution and development of Middle Miocene submarine fans, Taranaki Basin, New Zealand

Mohammed, Renas Ismael 04 October 2011 (has links)
The Taranaki Basin was formed as a consequence of multiple geologic events. From the Cretaceous period until present, it went through rifted margin, passive margin, foreland basin, and back-arc phases. A dominantly sandy unit, the Moki Formation, was deposited during the Middle Miocene within the Taranaki Basin offshore the west coast of the North Island of New Zealand. The study area covers about 1600 km2 of the southern part of the north Taranaki graben, an area covered by a 3D seismic volume. The Moki Formation is interpreted as a basin floor fan deposit that accumulated during basinward migration of the shelf edge with supplied sediments sourced from the SSE. Seismic profiles revealed that the mound-shape reflectors of Moki fan deposits situated between continuous reflectors of underlying Oligocene carbonates and hemipelagic muds of the overlying Manganui Formation. The reflections of the Moki sandy fan deposits locally grade laterally into interlobal deposits of hemipelagic muds. Correlation between wells Witiora-1, Taimana-1, and Arawa-1 verified the seismic interpretation, which shows an overall thickness variation of fan deposits that range from a greater thickness in the middle part of the sand lobe accumulation towards diminished thicknesses on the flanks. Gamma ray facies show clear progradation then aggradation motif that confirm the results from the seismic analyses. Depending on seismic attribute maps, paleochannels associated with the sand bodies sharing a SE to NW flow direction can be distinguished. Due to the volcanic activity in the eastern mobile belt, no paleochannels or significant stratigraphic features were recognized within the studied interval of the seismic data. Generally, in the study area, the fan deposits represent sand rich deposits that developed and prograded from south to north with variations in lateral extent driven by three major shifts in sediment pathways as the feeder channel orientations changed. / text
2

Sedimentology, Stratigraphy, Architecture and Origin of Deep-water, Basin-floor Deposits: Middle and Upper Kaza Group, Windermere Supergroup, B.C., Canada

Terlaky, Viktor 08 January 2014 (has links)
Ancient basin-floor strata are exceptionally well exposed in the Neoproterozoic Windermere Supergroup in the southern Canadian Cordillera. Data from the Castle Creek outcrop, where strata of the upper Kaza Group crop out, and the Mt. Quanstrom outcrop, where the middle Kaza is exposed, form the main dataset for this study. The aim of this study is to describe and interpret the strata starting at the bed scale, followed by stratal element scale, lobe scale and ultimately fan scale. Strata of the Kaza Group comprise six sedimentary facies representing deposition from a variety of fluid and cohesive sediment gravity flows. These, in turn, populate seven stratal elements that are defined by their basal contact, cross-sectional geometry and internal facies distribution. The lithological characteristics of stratal elements vary little from proximal to more distal settings, but their relative abundance and stacking pattern do, which, then, forms the basis for modeling the internal architecture of lobes. Lobes typically comprise an assemblage of stratal elements, which then are systematically and predictably arranged in both space (along a single depositional transect) and time (stratigraphically upward). Lobes typically became initiated by channel avulsion. In the proximal part of the system scours up to several meters deep, several tens of meters wide are interpreted to have formed by erosion downflow of the avulsion node. Erosion also charged the flow with fine-grained sediment and on the lateral margins and downflow avulsion splays were deposited. Later flows then exploited the basin-floor topography and on the proximal basin-floor carved a feeder channel, which then fed a downflow depositional lobe. At the mouths of feeder channels flows became dispersed through a network of distributary channels that further downflow shallow and widen until eventually merging laterally in sandstone-rich terminal splays. During the lifespan of a single lobe the feeder channel remains fixed, but the distributary channel network and its associated terminal splays wander, causing them to stack and be intercalated laterally and vertically. Eventually an upstream avulsion terminates local sediment supply, causing a new lobe to be initiated elsewhere on the fan, and the process repeats.
3

Sedimentology, Stratigraphy, Architecture and Origin of Deep-water, Basin-floor Deposits: Middle and Upper Kaza Group, Windermere Supergroup, B.C., Canada

Terlaky, Viktor January 2014 (has links)
Ancient basin-floor strata are exceptionally well exposed in the Neoproterozoic Windermere Supergroup in the southern Canadian Cordillera. Data from the Castle Creek outcrop, where strata of the upper Kaza Group crop out, and the Mt. Quanstrom outcrop, where the middle Kaza is exposed, form the main dataset for this study. The aim of this study is to describe and interpret the strata starting at the bed scale, followed by stratal element scale, lobe scale and ultimately fan scale. Strata of the Kaza Group comprise six sedimentary facies representing deposition from a variety of fluid and cohesive sediment gravity flows. These, in turn, populate seven stratal elements that are defined by their basal contact, cross-sectional geometry and internal facies distribution. The lithological characteristics of stratal elements vary little from proximal to more distal settings, but their relative abundance and stacking pattern do, which, then, forms the basis for modeling the internal architecture of lobes. Lobes typically comprise an assemblage of stratal elements, which then are systematically and predictably arranged in both space (along a single depositional transect) and time (stratigraphically upward). Lobes typically became initiated by channel avulsion. In the proximal part of the system scours up to several meters deep, several tens of meters wide are interpreted to have formed by erosion downflow of the avulsion node. Erosion also charged the flow with fine-grained sediment and on the lateral margins and downflow avulsion splays were deposited. Later flows then exploited the basin-floor topography and on the proximal basin-floor carved a feeder channel, which then fed a downflow depositional lobe. At the mouths of feeder channels flows became dispersed through a network of distributary channels that further downflow shallow and widen until eventually merging laterally in sandstone-rich terminal splays. During the lifespan of a single lobe the feeder channel remains fixed, but the distributary channel network and its associated terminal splays wander, causing them to stack and be intercalated laterally and vertically. Eventually an upstream avulsion terminates local sediment supply, causing a new lobe to be initiated elsewhere on the fan, and the process repeats.
4

Subsurface Framework and Fault Timing in the Missourian Granite Wash Interval, Stiles Ranch and Mills Ranch Fields, Wheeler County, Texas

Lomago, Brendan Michael 14 December 2018 (has links)
The recent and rapid growth of horizontal drilling in the Anadarko basin necessitates newer studies to characterize reservoir and source rock quality in the region. Most oil production in the basin comes from the Granite Wash reservoirs, which are composed of stacked tight sandstones and conglomerates that range from Virgillian (305-299 Ma) to Atokan (311-309.4 Ma) in age. By utilizing geophysical well logging data available in raster format, the Granite Wash reservoirs and their respective marine flooding surfaces were stratigraphically mapped across the regional fault systems. Additionally, well log trends were calibrated with coincident core data to minimize uncertainty regarding facies variability and lateral continuity of these intervals. In this thesis, inferred lithofacies were grouped into medium submarine fan lobe, distal fan lobe, and offshore facies (the interpreted depositional environments). By creating isopach and net sand maps in Petra, faulting in the Missourian was determined to have occurred syndepositionally at the fifth order scale of stratigraphic hierarchy.
5

Sedimentology and Stratigraphy of Super-Critical Sediment Gravity Flow Deposits Within the Upper Cretaceous Mancos Shale, Eastern Utah

Rice, Trezevant Adair 21 April 2023 (has links)
No description available.

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