 M.T. Halbouty Building, Room 61 Geology & Geophysics, TAMU College Station, TX 77843-3115 dorobek@geo.tamu.edu Phone: 979-845-0635 Fax: 979-845-6162 |
 Professor and holder of the Michel T. Halbouty Chair in Geology Ph.D., Virginia Polytechnic Institute and State University, 1984 My current research focuses on sedimentology/stratigraphy and the tectonic history of sedimentary basins. Our studies have broad application to petroleum exploration/production and environmental issues.
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Tectonic controls on carbonate platform evolution. My personal research has focused in recent years on the effects of tectonic deformation on carbonate platform sedimentation. I have examined all scales of deformation, from long wavelength (>500 km horizontal distance) differential subsidence to local, fault-controlled patterns of uplift and subsidence (Figure 1). I am continually acquiring new data and entering new study areas to test my conceptual ideas in this important research area. |
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Cenozoic tectonic history and basin evolution of the South China Sea region. We have acquired extensive 2-D seismic data sets from the South China Sea (SCS) region. The data cover much of the southern SCS, from offshore Vietnam to Borneo and east-west from the Spratly Islands to the Malay Peninsula. We are examining the tectonic and depositional history of basins across the entire area and are focusing on regional patterns of sediment dispersal, styles and timing of basin inversion, interactions between siliciclastic and carbonate depositional systems, and regional long-term subsidence patterns. Basin inversion and fault reactivation is a recurrent theme in many of our regional studies of tectonically complex regions. We are also very interested in the long-term evolution of major river systems in SE Asia as recorded in the offshore stratigraphy of the South China Sea (Figure 2). The offshore record contains a wealth of information about drainage network evolution, paleoclimate change (including onset of the East Asian Monsoon), and tectonic uplift across Eastern Asia. |
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Evolution of Cenozoic carbonate buildups across the South China Sea. The South China Sea and ‘Sunda Shelf’ have been prolific areas of carbonate sedimentation throughout Cenozoic time. The data that we have accumulated over the last ten years are allowing us to constrain the evolution of individual platforms and place this into a regional tectonic and paleoclimatic framework. We are investigating the factors that affected initiation, growth, and termination of each platform, including eustatic change, local to regional tectonic deformation, subsidence patterns, wind direction, proximity to siliciclastic point sources, and other environmental factors. Analysis of regional tectonic deformation, as recorded by individual platform stratigraphies and morphologies (Figure 3), may provide us with an improved understanding of the rheological properties of continental lithosphere across this region. |
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Sequence stratigraphy, sediment transport processes, and carbonate mud mounds along an outer ramp-to-basin transition, Mississippian of south-central New Mexico. Spectacular exposures of the Lake Valley and Rancheria formations in south-central New Mexico provide an excellent opportunity to examine sediment transport processes and resultant stratigraphic development along outer parts of a Mississippian ramp. Much of the coarser-grained facies in this stratigraphic interval were deposited by sediment gravity-flows (debris flows, turbidity currents, fluidized and grain flows) and we have been investigating how these flows interacted with preexisting seafloor topographic features as they moved downslope. Numerous carbonate mud mounds are found within this stratigraphic interval and their growth history was strongly influenced by the sediment gravity flows (Figure 4). |
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Evolution of carbonate mud mounds throughout the Phanerozoic record. Carbonate mud mounds are typically associated with deeper water settings, so the factors that govern their growth are significantly different from organically constructed buildups that form in shallow-water settings. Of significant importance, but sometimes overlooked by carbonate sedimentologists, are the important physical interactions that occur between mud mounds and the depositional processes that operate around the mounds. These depositional processes might vary from fine-grained hemipelagic sedimentation to various types of sediment gravity flows. Our studies indicate that the rate of sediment accumulation and the physical processes of sediment delivery (e.g., hemipelagic settling versus erosive, high-density turbidity currents) dramatically influence the lithofacies and stratal geometries associated with mud mounds. We have focused on Devonian, Mississippian, Pennsylvanian-Permian, and Lower Cretaceous (Figure 5) mounds thus far, but many of the important factors that affect mound development are probably applicable to mound-bearing units throughout the Phanerozoic record. |
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Late Paleozoic tectonic and depositional history of the Permian Basin, West Texas. Even after nearly eighty years of petroleum exploration and production in the Permian Basin, the tectonic and stratigraphic history of this basin remains controversial. In addition to its status as one of North America’s most prolific petroleum provinces, the Permian Basin represents an important example of a complexly deformed foreland region. Major, fault-bounded basement uplifts (e.g., Central Basin Platform, Ozona Arch, and Diablo Platform) partitioned the foreland into a series of sub-basins during late Paleozoic time; the foreland deformation was coincident with shortening in the Marathon-Ouachita orogenic belt, so the deformation in both regions is somehow linked. Late Paleozoic deformation also greatly influenced synorogenic and post-orogenic depositional systems. My students and I have acquired a great deal of subsurface data (mostly well logs and 2D and 3D seismic surveys) in an attempt to characterize late Paleozoic structural styles and tectono-stratigraphic relationships across the Permian Basin. My students have compiled structural data and developed complex kinematic models for much of the Permian Basin region, which included an analysis of fault slip along the boundaries of the Central Basin Platform (Figure 6). Our studies are important for regional understanding of Permian Basin and ‘Ancestral Rocky Mountain’ tectonics. Our studies will also ultimately provide insight into mechanisms of crustal deformation across other complexly deformed foreland settings. |
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Growth history of Miocene isolated platforms in the Indonesian backarc basin. We have completed a study that examined the growth history of numerous isolated carbonate platforms in the North Madura area in the Indonesian backarc basin. We were given access to an extensive 2D seismic survey that allowed us to map seismic facies within these platforms and document five distinct growth phases across the study area (Figure 7). These platforms record an incredible history of progradation and coalescence that reflects regional paleowind patterns and differential subsidence across the North Madura area. I am trying to acquire recent 3D seismic coverage across the region, which will allow us to document the growth history of these platforms in an unprecedented fashion. These Miocene platforms are important analogs for the numerous age-equivalent platforms (many of which contain important petroleum reserves) that can be found across most of the Indonesian backarc region. |
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Structural inversion and its influence on siliciclastic sedimentation across the Neuquen foreland basin, Argentina. One of my students has gained access to extensive 2D and 3D seismic data and well information across the Neuquen foreland basin, Argentina. Major inversion structures can be found across the Neuquen Basin and probably are related to reactivation of normal faults during later contraction across the Andean foreland. Preliminary examination of the 3D data indicates that siliciclastic dispersal patterns were strongly influenced by uplift of these inversion structures. We are also interested in documenting the kinematic history of the inversion structures and want to understand the driving mechanisms for the inversion. |
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GEOL 104, Physical Geology Earth materials, structure, external and internal characteristics; physical processes at work upon or within the planet. |
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GEOP 628, Basin Architecture Tectonic classification of basins; tectonic mechanisms responsible for basin formation; mechanical behavior of the lithosphere; subsidence; geophysical signatures of sedimentary basins; tectonic controls on sedimentation and basin filling; petroleum systems and basin-scale hydrologic systems. |
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GEOL 622, Stratigraphy Principles for correlating and naming stratigraphic units; controls on stratigraphic development (sediment supply, base-level change, subsidence, climate, and compaction); principles and application of sequence stratigraphy; subsurface stratigraphy; facies analysis and stratigraphic architecture. |
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 (* indicates co-author) |
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| Dorobek, S.L., 1995, Synorogenic carbonate platforms and reefs in foreland basins: controls on stratigraphic evolution and platform/reef morphology, in, Dorobek, S.L., and Ross, G.M., eds., Stratigraphic Evolution of Foreland Basins: SEPM Special Publication 52, p. 127-147. *Bachtel, S.L., and Dorobek, S.L., 1998, Mississippian carbonate ramp-to-basin transitions in south-central New Mexico: Sequence stratigraphic response to progressively steepening outer-ramp profiles: Journal of Sedimentary Research, v. 68, p. 1189-1200. *Cung, T.C., Dorobek, S., Richter, C., Flower, M., Kikawa, E., Nguyen, Y.T., and McCabe, R., 1998, Paleomagnetism of Late Neogene basalts in Vietnam and Thailand: Implications for the post-Miocene tectonic history of Indochina in Flower, M.F.J., Chung, S.-L., Lo, C.-H., and Lee, T.-Y., eds., Mantle Dynamics and Plate Interactions in East Asia: American Geophysical Union Geodynamics Series 27, p. 289-299. Dorobek, S.L., and *Bachtel, S.L., 2001, Supply of allochthonous sediment and its effects on development of carbonate mud mounds, Mississippian Lake Valley Formation, Sacramento Mountains, south-central New Mexico: Journal of Sedimentary Research, v. 71, p. 1003-1016. *Cung, T.C., and Dorobek, S.L., in press, Late Jurassic-Cretaceous paleomagnetism of Indochina and surrounding regions and their Cenozoic tectonic implications: Journal of the Geological Society of London. *Murillo-Muñeton, G., and Dorobek, S.L., in press (2003), Carbonate mud mounds in the lower Cupido Formation (Lower Cretaceous), northeastern Mexico: Journal of Sedimentary Research. Dorobek, S.L., in review, Initiation and termination of Cenozoic carbonate platforms across the South China Sea region: submitted to Geology. *Iannello-Gonzales, C., and Dorobek, S.L., in review, Seismic characteristics, timing, and hydrogeochemical significance of dissolution-collapse zones in Lower Cretaceous carbonate strata, Desoto Canyon area, northeastern Gulf Of Mexico: Journal of Sedimentary Research. |
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Sedimentology, Stratigraphy, and Petroleum Geology. |
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