Regional petroleum geology
Section editor – PhD in geology and mineralogy Makarevich V.N.
Article # 8_2008 displayed on website on 02/19/2008
28 p.
pdf  Tectonic position and major structures of the Laptev Sea
An analysis of geological-geophysical information shows that an opinion as to the presence of an ancient platform block on the larger part of the Laptev Sea is not justified. The available data, primarily the results of CDP profile shooting, testify about Late Kimmerian basement and a Cenozoic cover over it in the reef troughs. The Laptev Sea shelf, occurring on the continental margin to which the axis of Eurasian subbasin spreding comes orthogonally, has structure typical for butt margins. Like margins-analogues, it contains a major axial rift located transversely to a continental slope. It is the Laptev megarift containing internal grabens and horsts and terrace slopes. The morphology of a sedimentary cover of axial rifts is determined by a wide development of listric faults. The major structural form is the tilted monocline blocks associated with faults. They form lengthy steps on the slopes of the rifts and in their deep parts. On the margins-analogues, the majority of hydrocarbon fields are confined to the monocline traps on such steps. The anticlines associated with diapirism occur widely in the basins containing plastic strata; the presence of clay diapirs is possible in the Laptev megarift. Up to now the estimation of Laptev Sea shelf petroleum potential is performed on the basis of a platform postulate. The change of these concepts demands the revision of forecasting bases with taking into consideration the regularities in distributing the fields in the OGB of the butt margins-analogues.
Key words: butt continental margin, margins-analogues, Laptev megarift, regional unconformities, listric faults, monocline traps, diapirism.
article citation Andieva T.A. Tectonic position and major structures of the Laptev Sea // Neftegazovaya Geologiya. Teoriya I Praktika. – 2008. - V.3. - #1.- http://www.ngtp.ru/rub/4/8_2008.pdf