Kinematic Analysis of the Sakhalin Fault Zones for Oil and Gas Prospecting

Abstract

Sakhalin Island is bounded by a framework of submeridional and northeast-trending deep-seated faults (sinistral and dextral slips). These faults mirror the fault pattern in the east Pacific. The Sakhalin lithospheric block is broken by a conjugate system of northeast-trending shear zones and northwest-trending extension zones. Local structures develop as a result of this system. Hydrocarbon resources are mainly concentrated in the Hokkaido-Sakhalin deep fault zone. In the sedimentary cover, this fault is expressed as a chain of complex linear uplifts, which are both folded and faulted on a variety of scales. Such deformation is described as displicate (an abbreviated form of the words [open quotes]disjunctive[close quotes] and [open quotes]plicative[close quotes]). The paper proposes a classification of strike-slip and thrust displicates. In the Miocene and Pliocene, there were two stages of displicate development. Strike-slip dislocations formed during the first stage were later transformed into thrust by lateral compression during the second stage. The upper parts of the strike-slip displicates are often sheared and displaced in a latitudinal (east-west) direction. Hydrocarbon accumulations are associated with the location of displicates in the mother fault zone (Wilcox, 1973). Most oil and gas reserves are located in autochthonous structures, and 13 types of oil poolmore » have been identified.« less