Eastern Venezuela Basin: Sequence stratigraphy and structural evolution

[摘要] A regional study has been carried out within the Eastern Venezuela Basin and its offshore continuation to the Orinoco Delta and the Barbados Accretionary Complex. The Eastern Venezuela Basin and its offshore continuation is a Neogene foredeep superimposed on a Mesozoic passive margin.The Cretaceous to Paleocene of Eastern Venezuela is best subdivided into five second order transgressive-regressive cycles bounded by a 131 Ma (basal Cretaceous) sequence boundary, four maximum flooding surfaces with the inferred age of lower Aptian (111 Ma), upper Albian (98 Ma), middle Cenomanian (95 Ma), middle Turonian (91.5 Ma) and an upper Paleocene sequence boundary (58.5 Ma).An upper Paleocene to Eocene second-order cycle (58.5 Ma-36 Ma) is followed by the Oligocene which is subdivided into two third-order cycles bounded respectively by 36 Ma, 30 Ma and 25.5 Ma sequence boundaries.An uppermost Oligocene to lower Miocene (25.5 Ma) basal foredeep unconformity is associated with the sudden deepening of the passive margin in response to the emplacement of the Serrania del Interior.The Neogene of the Eastern Venezuela foredeep consists of three second-order sequences defined by 25.5 Ma, 16.5 Ma and 10.5 Ma boundaries. In the offshore an upper Miocene (5.5 Ma) unconformity is associated with deeply incised submarine canyons. Sixteen third-order sequence boundaries are recognized and correlated over the region.

[发布机构] Rice University

[效力级别] Geophysics