Abstract:

Based on the analysis of 3D seismic and log data, and associated with the technology of the sequence stratigraphy and paleogeomorphology recovery, the sequence boundaries of Hainan Xianhe zone of the western beach area of Liaohe depression are divided into four types according to the strata erosion level, including the parallel unconformity in the sag, the angular unconformity in overlap zone of the depression edge, the angular unconformity on the top of rotating fault blocks, and the angular unconformity on the top of the buried hill of the heavily erosion area. Different erosion recovery methods had been chosen for different surface types to reconstruct the key tectonic period paleogeomorphology of the zone, which shows that the area develops the incised valley, the slop break, and paleouplift. The paleogeomorphology presents the trough and the bridge arranged in oblique, incised valley and fault break in steep slop well developed, and provenance widely distributed and its direction cross intersected with Hainan fault. The paleogeomorphology plays an obvious role in controlling the provenance distribution, sequence stratigraphy constitution and the sandstone distribution, showing “the great trough developing the great fan, and the small trough to the little fan”. The sandstone distribution is controlled by the fault breaks in plane and the system tracts in vertical.

Key words:  , beach area in Liaohe depression；paleogeomorphology；slop break；incised valley；system tracts