A Study of Detachment Faults of the Upper Crust in Manzhouli-Suifenhe GGT by the Method of Vertical Seismic Reflection

摘要

Manzhouli-Suifenhe geoscience transect(MS) is one of the eleven transects in China territory determined by global geoscience transect project. Data acquisition, data processing and interpretation of 130 km long vertical seismic reflection were accomplished. The main factor in data acquisition is source energy, and the major steps in data processing are migration and wide-band filtering, The principal purpose in data interpretation is to find out crust structure and its geological meanings. A number of groups of low angle faults, i.e., detachment faults from the upper crust have been found on this profile. These faults have different features but the same formational background, i.e., the compression and torsion stress field in the upper crust in continental margin near the west of Pacific produced by the oblique subduction of Pacific plate in the direction of west. The leading edge of fimction of the stress field at least reaches near the east of Taikang. Later, the pull-apart activities of these detachment faults arose and formed a series of faulted basins. The detachment faults play an important role in controlling the formation, range, deposit faces, and target estimation on oil and gas of the basin.