Peter Bartok, 2003. "The Peripheral Bulge of the Interior Range of the Eastern Venezuela Basin and its Impact on Oil Accumulations", The Circum-Gulf of Mexico and the Caribbean: Hydrocarbon Habitats, Basin Formation and Plate Tectonics, Claudio Bartolini, Richard T. Buffler, Jon F. Blickwede
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The peripheral bulge of the Eastern Venezuela Basin is located along the Orinoco Heavy Oil Belt. The forebulge developed as a direct result of flexure of the continental lithosphere in Eastern Venezuela that resulted from the load of the overriding plate, the Interior Range. The Eastern Venezuela foreland basin lies mostly over crystalline basement that has been affected by three distinct phases of crustal evolution. The southernmost region, south of the Merey Fault, is Archean crystalline basement covered by thin late Paleogene to Neogene sediments. Archean crystalline basement and late Precambrian allochthonous terrains dominate the region between the Merey Fault and the Pirital Fault. This region underwent crustal attenuation during late Precambrian rifting. Jurassic rifting associated with the area north of the Pirital fault trend further attenuated the crust. Variations in thickness of lithosphere subjected to elastic deformation control the amount of flexure in the basin and the position of the peripheral bulge. The Pirital trend acted as a buttress to the southern migration of the principal thrusts. As a result, the peripheral bulge did not migrate significantly. Uplift on the bulge was episodic and slow. Fluvial systems from the shield had sufficient time to maintain their course and, as a result, continued to flow north across the slowly rising peripheral bulge but were focused in specific north-south-trending depressions. By latest Miocene/Pliocene an east-west-trending back-bulge depozone formed south of the Heavy Oil Belt and presently forms the Orinoco River valley. During most of the Miocene, the peripheral bulge acted as a major trap for the hydrocarbons generated along the northern portions of the Eastern Venezuela Basin.
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The Circum-Gulf of Mexico and the Caribbean: Hydrocarbon Habitats, Basin Formation and Plate Tectonics
The Circum-Gulf of Mexico and the Caribbean has long been one of the world's most important petroleum provinces, as well as one of the world's most geologically complex regions. These two characteristics have resulted in an extensive amount of ongoing research by both industry and academia. AAPG Memoir 79, The Circum-Gulf of Mexico and the Caribbean, is the first volume in more than a decade to document such a wide range of research on the geology of this vast area. Of the total 44 papers, roughly two-thirds pertain to the Gulf of Mexico, with an emphasis on the Mexican portion of the basin, and to the petroliferous areas of the southern Caribbean, including Colombia, Venezuela, Cuba, and Trinidad and Tobago. The remaining papers relate to the Antilles and Central America, as well as a series of papers that address region-wide topics such as plate tectonic evolution. A significant number of papers were contributed by authors from national oil companies and universities from within the region.