ABSTRACT: Geodynamic Oil-Gas-Bearing Peculiarities in the Sedimentary Basins of Circum Pacific Rim

L. E. Levin, O. V. Vasiljeva, Y. A. Viskovsky

The geodynamic processes are reflected in the formation of the genetic basins groups: A, recent active margin; B, transitional area to recent active margin; C, transitional area of passive margin that has undergone a collision with Mesozoic-Cenozoic island arcs; D, recent passive margin. Elsewhere rifting is due to mantle diapirs; this in its turn contributed to the volcanic activity, the growth of the temperature, and pressure in oil-gas strata. The interrelations of volcanism and oil-gas-bearing are particularly important for the basins of groups "A" and "B." They contain up to 7% of hydrocarbon fields in the mentioned basin groups. The positive estimate depends on the interrelation between the presence of rhyolite-dacite formations in the section characterized by bette reservoir rock properties, P-T conditions favorable for oil-gas-bearing, the occurrence of the volcanogenic reservoir rocks in the conditions contributing to oil-gas accumulation (individual parts of Aleutian, Kuril, Japan, and other island arcs). The more detailed basin differentiation of groups "B," "C," and "D" by perspectives for oil and gas potential depends on the interrelations between the type and the rate of the collision, controlling the potential of the underthrusted layers, the rate of the sedimentation, the enrichment degree of the sedimentary layers by organic material, the position of the oil-gas formation zones in the section, and the direction of geofluidal process with account of its change in time and space. The four regions with the most potential are the Okhotsk-Jap n seas, the South China-Andaman seas, the Mexico-Caribbean seas, and the Bering sea, including Aleutian basin.

AAPG Search and Discovery Article #90097©1990 Fifth Circum-Pacific Energy and Mineral Resources Conference, Honolulu, Hawaii, July 29-August 3, 1990