No description available.

No description available.

In this thesis, I present new results based on 2D multi-channel seismic data of the Song Hong-Yinggehai and Qiongdongnan Basins, geochemical data derived from ODP Site 1148, and sediment provenance analysis of modern sediment and Cenozoic sedimentary rocks collected along the Red River system. The Song Hong-Yinggehai Basin started opening after ~50 Ma but strong subsidence, triggered by motion on the Red River Fault, only occurred after ~34 Ma.  This process was followed by thermal subsidence after ~21 Ma.  In contrast, the formation the Qiongdongnan Basin is believed to be related to the development of the northern rifted margin of the South China Sea. Sediment budget estimates, coupled with geochemical data show that chemical weathering gradually decreased after ~25 Ma, while physical erosion became stronger.  These data also suggest a period of the monsoon enhancement (~15-10 Ma), although with a likely initial East Asia monsoon strengthening ~23 Ma. U-Pb zircon dating coupled with Hf isotopes, muscovite Ar-Ar dating, bulk sediment Nd isotope and heavy mineral analysis allow me to draw the following points: (1) if the headwaters of the modern Yangtze, Mekong and Salween Rivers were ever connected to the palaeo-Red River then they were disconnected from the Red River no later than the Middle Miocene; (2) The palaeo-Red River flowed northeast of the Day Nui Con Voi during the Miocene and did not flow via Lao Cai and southwest of the range as it is observed today; (3) the Yangtze Craton and the Songpan Garze Block are the most important source regions to the Red River; (4) apart from the main Red River trunk, the Lo River is the most important sediment contributor to the Red River system, while the Da River is only a minor contributor.

No description available.

Thesis advisor: Kenneth G. Galli / Thesis advisor: Noah P. Snyder / The Brushy Basin Member of the Morrison Formation records a time of increased volcanic activity in the North American Cordillera during the Late Jurassic. Sedimentological and petrographic observations in the Brushy Basin, in conjunction with findings of widespread plutonic intrusion in the source areas, point to a volcanic pulse within the Cordilleran magmatic arc. This study investigated the subjacent Salt Wash Member, for the purpose of better constraining the timing of the volcanic pulse. Petrographic and statistical analyses of the Salt Wash sandstone identified statistically significant upsection trends in volcanic rock fragment and plagioclase feldspar at one of the four study areas. The remaining three study areas showed no upsection trends in sandstone composition that would reflect a pulse in volcanism during Salt Wash Member time. It is more likely that the Salt Wash was deposited during a time of volcanic quiescence leading up to the post-Nevadan Orogeny volcanic reactivation. Sedimentology and cementation patterns of the Salt Wash Member were also studied. Cathodoluminescence indicates that the member was well-flushed with shallow formation waters, thus preventing any calcite optical zoning. Luminescence intensity suggests that the Salt Wash Member sediments were cemented at varying depths and within differing Eh-pH regimes. Field-based sedimentological observations support a model of braided stream channel deposition across a semi-arid landscape with streamflow entering the basin from both the south and west. / Thesis (MS) — Boston College, 2009. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Geology and Geophysics.

<p> The United States Bureau of Ocean Energy Management (BOEM)&rsquo;s Sandy Needs Assessment collected geophysical and geotechnical data, related to beach nourishment activities, along the continental shelf south of Long Island between 2015&ndash;2017 in an area offshore the Fire Island National Sea Shore, near Watch Hill, NY. This new geological and geophysical data provides evidence of continuous and ongoing sand transport offshore of Fire Island National Sea Shore. New stratigraphic evidence shows the evolution, migration and erosion of shore-oblique sand ridges formed from the reworking of glacial outwash sand consistent with a conceptual process model. Three separate ridge features are related to each other with evidence of direct ridge migration in the region. Outwash fans and deltas likely provided the cores of mesoscale submarine ridges n the study area. Subsequent episodes of ridge erosion remobilized sand to feed the growth of ridges further west. The possibility of natural transport process actively delivering sand to the shore remains, but is not identified, and will require further work before these ridges can be sustainably utilized in nourishment activities.</p><p>

Stratigraphy and source rock analyses of the Heath Formation in Fergus, Garfield, Golden Valley, Musselshell, Petroleum, and Rosebud counties, central Montana

Thesis (doctoral)--Freie Universität Berlin, 2004. / "April 2004"--P. [2] of cover. Lebenslauf. Includes bibliographical references (p. 182-[199]). Also available on the World Wide Web.

The formation and evolution of sedimentary basins are best understood within the context of prevailing tectonic conditions. This dissertation presents an integrated geologic and geophysical study of the southeast Caribbean–northeast South American margin which is characterized by a 300-km-long curved transition from subduction to strike-slip plate boundary interaction. Tomography models are generated to image the geometry and orientation of the subducting slab and associated upper mantle structures, and integrated with observations made from gravity, magnetic and seismicity data. The plate boundary interaction changes laterally from: (1) direct subduction where oceanic South American lithosphere dips towards the west at up to 65° beneath the Caribbean plate; to (2) collision where South American transitional-continental type lithosphere dips 44°–24° beneath the Caribbean plate; to (3) east-west oriented strike-slip interaction where the slab is detached from the South American continent. A tectonostratigraphic framework based on the interpretation of ~10,000 km of 2-D seismic and abundant well data is used to study the evolution of the structures and basin fill of the margin. The basins are characterized by composite and superimposed structural styles which differ from basins formed in pure strike-slip or convergent margins. A NW–SE oriented tear fault aligned with the South American continent-ocean-boundary defines the boundary between different contractional styles in the sedimentary succession of the subduction and collision provinces. An examination of bathymetric conditions and the upper Pleistocene succession of the continental shelf suggest a bimodal sediment transport process, linked to shoreline changes. Current-driven, strike-parallel sediment distribution systems dominate during highstand, generating unique shelf-bound channels and fills. Lowstand across the area is characterized by dip-directed, sediment distribution systems with SW–NE oriented channels that direct sediments to the shelf edge and deep basin environments. The results of this study illustrate that plate boundary conditions and associated lithospheric arrangement at depth, play a significant role in influencing the form of shallow structures, basins and surface geomorphology. Crustal-scale structures; influenced by deeper lithospheric-scale configuration, act over longer time-scales to create and deform depocenters; while sea-level stand exerts significant control on the timing and location of sedimentation over shorter time periods. / text

<p> Three-dimensional fluid-flow simulation models provide attractive tools for understanding the potential behavior of the subsurface. Retention of high-resolution geologic heterogeneity in the characterization of large volumes presents significant challenges to this modeling. </p><p> A 2D dataset donated by Industry constrains a hierarchical stratigraphic framework based on 30,000 wells with log curves, 60 surfaces crossing the 70,000 cubic-kilometer Powder River Basin from Precambrian basement to top of the Cretaceous Lewis Shale. Five sedimentary systems subdivided into 25 stratigraphic intervals make up the 3D representation of 70 discrete modeling areas. These sedimentation regions group distinct sedimentary attributes (e.g., porosity, thickness, sedimentary architecture). These attributes relate to suites of rock properties, such as porosity, percentage of thickness with porosity and well log shape, which were compiled from 4000 wells with donated/purchased log ascii files, 15 cores, 300 wells with public core plug data, 115 published oil field reports, and basin rimming outcrops. </p><p> Sedimentary system analysis considered regional controls on the depositional setting from the craton-scale to the pore-scale and it employed techniques to group information and replicate the effect of fine-scale geologic heterogeneity in a static reservoir model. This process highlights the importance of understanding the role of tectonic anisotropy on the preservation of stratigraphic sequences when interpreting the depositional environment. Subdivision into the 70 sedimentation regions permitted calculation of the gross pore volume in each sedimentary system, using total porosity and a percentage of the vertical thickness for each modeling volume. The total volume calculated depended on the method; stratigraphic layering and sedimentation regions provided 600 cubic kilometers and equating to storage capability of over 250 gigatons of supercritical carbon dioxide, whereas using factors and no stratigraphy, the total volume was calculated at 460 cubic kilometers. </p><p> Pore volume distribution in the subsurface is more accurately characterized with high-resolution stratigraphic and sedimentation region analysis. Integrated tectonic analysis provides context that better constrains the application of outcrop analogs and depositional models, which guide sedimentation region analysis. This dissertation addresses the impact of geologic heterogeneity from crustal anisotropy to distributions of porosity and permeability and provides a tool to assess feasibility of gigaton-scale carbon dioxide sequestration. </p>