Title: Paleozoic paleogeographic and depositional developments on the central proto-Pacific margin of Gondwana: Their importance to hydrocarbon accumulation
Abstract: During the Paleozoic Era, the western portion of the Gondwana continent between the equator and latitude 27°S of present-day South America bordered the proto-Pacific Ocean as a predominantly convergent margin. Following the Middle Cambrian accretion of the Arequipa-Belen-Antofalla Terrane, an epicontinental sea with communication to the proto-Pacific Ocean established itself along the length of the western margin of Gondwana during Late Cambrian and Early Ordovician time. The emergence of a proto-Cordillera led to significant separation of the epicontinental sea from the proto-Pacific Ocean during Silurian and Devonian times. Gradual erosion of that proto-Cordillera during Carboniferous and Early Permian time once again facilitated widespread transgression of the proto-Pacific Ocean into the epicontinental domain. At the end of the Early Permian, the sea retreated from Gondwana and a proto-Cordillera was re-established. The proto-Cordillera and the craton of Gondwana controlled sediment type and distribution in the epicontinental sea. Deposition occurred in five tectono-sedimentary cycles, which were separated by orogenic pulses that resulted in regional erosion of the previously deposited section. Oil and gas have been produced from the Paleozoic epicontinental sediments of Argentina, Bolivia, Peru, and Brazil, in an area in which exploration efforts are ongoing. Sandstone reservoirs and argillaceous source rocks of commercial importance formed during the episodes of sedimentation, but carbonates do not contribute to commercial hydrocarbon generation and accumulation. Cap rocks are provided by shales or evaporites. Durante la era Paleozoica, la porción oeste de el continente de Gondwana entre el ecuador y latitud 27°S de Sur América limitó el Oceano proto-Pacífico como un margen predominantemente convergente. Siguiendo la acreción de el terreno Arequipa-Belén-Antofalla, durante el Cámbrico medio, un mar epicontinental con comunicación al Oceano proto-Pacífico se estableció a lo largo del margen oeste de Gondwana durante el Cámbrico tardío y Ordovicico temprano. La emergencia de la proto-Cordillera durante el Silúrico y Devónico causó una separación significante entre el mar epicontinental y el Oceano proto-Pacífico. La gradual erosión de la proto-Cordillera durante el Carbonífero y Pérmico temprano facilitó una vez más una amplia transgressión del Oceano proto-Pacífico dentro del dominio epicontinental. Al final del Pérmico temprano el mar se retiró de Gondwana y la proto-Cordillera fue retablecida. La proto-Cordillera y el craton de Gondwana controlaron el tipo de sedimentos y distribución en el mar epicontinental. La depositación ocurrió en cinco ciclos tectono-sedimentarios los cuales fueron separados por pulsos orogénicos que resultaron en erosión regional de los secciones depositadas previamente. Aceite y gas han sido producidos de los sedimentos epicontinentales Paleozoicos de Argentina, Boliva, Peru y Brazil. Areniscas reservorio y rocas generadoras de comercial importancia fueron formados durante episodios de sedimentación, pero carbonatos no contribuyeron a la generación y acumulación comercial de hidrocarburos. Shale y evaporitas forman la roca sello.
Publication Year: 1992
Publication Date: 1992-11-01
Language: es
Type: article
Indexed In: ['crossref']
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Cited By Count: 41
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