http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Structure and seismic stratigraphy of the Brazos, Galveston, and High Island OCS area, Gulf of Mexico and palinspastic reconstruction of the Corsair fault
xvii, 259 leaves : illustrations, maps ; 28 cm.
The study area in the central northern offshore Texas is probably the best location in the world to study the mechanics of large, linear, very long growth fault systems. The area also contains both overpressured shale and salt which interact with each other to form growth faults, and to create shale- and/or salt-withdrawal basins. The integration of extensive seismic, well log, and biostratigraphic data makes possible the reconstruction of the evolution of salt-or shale-based growth fault systems and basin evolution of the northern Gulf of Mexico. To better understand the stratigraphic, depositional, and structural evolution of region, I developed new computer programs and numerical methods on the Landmark seismic interpretation workstation for calculating fault trajectory, geohistory and backstripping analyses, total or tectonic subsidence and aleotemperature distribution, and palinspastic reconstruction. Deep parallel structures (Brazos and Sabine transfer faults) control the distribution of Paleogene salt and position of the major delta systems. The Clemente-Tomas fault system detached onto the basinward flank of a broad, deeply-buried, shale-cored anticline in the absence of salt. The Corsair and Wanda faults soled deeply onto a detachment surface that formed on a now-evacuated Paleogene allochthonous salt canopy. Analysis of timestructure and isochron maps for 10 paleohorizons indicated that depocenters during the early Miocene were mainly dip-elongated basins formed by the delta system across the Clemente-Tomas faults. Long strike-oriented strandplain and barrier island depositional systems supplied large amounts of sediments to the shelf or slope, which resulted in the long fault systems. From I I condensed sections that I identified during the Miocene and PliocenePleistocene based on the correlation of the nannofossil data with well logs and seismic data, I present a sequence stratigraphic model appropriate to overpressured shale and salt tectonics being to explain the structural and stratigraphic evolution of the study area. Thick submarine fans and channels characterized the study area during the Miocene and PliocenePleistocene, which were deposited in the outer shelf and slope downdip of the major fault trends. Results of numerical analyses of the fault tra ectory, basin history, and palinspastic reconstruction demonstrated that movement of shale and/or salt, faulting, and sediment loading were closely interrelated. Shale ridge development initiated incipient growth fault on seaward flank in the early Miocene. Differential sediment loading and gravity spreading caused salt-withdrawal to mature growth fault. Overpressured shale mobilization provided sediment accommodation space in the Clemente-Tomas fault zone, hence forming the Brazos ridge. Sediment loading, in turn, enhanced primary salt-withdrawal and further growth faulting of the Corsair fault in the middle Miocene. As the salt withdrew, it provided much of the sediment accommodation space basinward of the Corsair fault. Subsidence caused by the weight of the sediment has provided a significant amount of the sediment accommodation space. Continued deposition caused additional faulting, folding, and displacement of sedimentary sequences as the secondary salt-withdrawal in the Wanda fault. This process progressively shifted paleoshelf breaks seaward.
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