Abstract:

Several unconformities are found within Tertiary fault basins in East China,forming various kinds of litho-stratigraphic traps in combination with various sand bodies developed along the unconformities. These traps are both obviously related to unconformities and controlled by various kinds of sand bodies. The utilization of seismic survey is well known for determining overlap and denudation surface. Therefore,after describing the geological setting of the formation of these litho-stratigraphic traps,emphasis is placed in this article on the geological properties of some main kinds of sand bodies,such as alluvial cones and subaqueous fans,lacustrine turbidites,deltic and subaqueous channel sands. Besides,large amount of seismic exploration examples are used to show their relative properties of seismic reflection. It is suggested that these sand bodies can be identified by recognizing the seismic reflection features so as to discover various kinds of subtle pools.