Lacustrine Sequence Stratigraphy and Computer Modeling
of
the Erlian Fault Basin, North China
Changsong Lin, Li Sitian, Ren Jianye, and Zhang Yanmei
Erlian fault basin, a major oil prospecting and producing area in North China,
comprises about 40 grabens and half- grabens. The basin was formed by extension
from Jurassic to Early Cretaceous and filled with more than 3000m thick of
clastic lacustrine deposits. Based on the integrated analysis of seismic
profiles, logging and cores, 5 sequence sets and 12 sequences, bounded by
discontinuous, have been identified. Three types of lacustrine sequences have
been identified: (1) deep lacustrine basin sequences, mainly consisting of
sublacustrine fan and fan delta systems; (2) shallow lacustrine basin sequences,
predominately composed of fan delta and braided delta systems and (3) shallow
lacustrine and fluvial basin sequences. The sequence architecture and the basin
filling e olution were controlled by the basin structural framework and
lacustrine level changes. The computer
modeling
study by using the backstripping
and forward
modeling
technique has shown that the major unconformities confining
the sequences may be generated by the variation in tectonic subsidence rate
caused by episodic lithospheric stretching. The model have also be used to
predict the sequence architecture and the facies distribution in the basin.
AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California