THE INTERNAL ARCHITECTURE OF DEEPWATER CHANNELS IN BAIYUN SAG,PEARL RIVER MOUTH BASIN

Complex deepwater channels are well developed in the Baiyun Sag,Pearl River Mouth Basin. There are erosional base, basal lags, slump and inner levees in an individual channel. The channel complees, however, are rather complicated and may be divided into the superposition type and the incision type. The former reflects the aggradation of multi-phase channels and the latter the mutual incision of several channels. The internal channel fill are mainly in forms of lateral accretion, aggradation and the combination of lateral accretion and aggradation. The channel evolution is usually started from incision followed by a three-phase fill history. Different internal architecture of a channel corresponds to different fill phases. Basal lags and slumps are the product of the fill phase 1, whereas the inner levees are formed in the fill phase 2. In the fill phase 3, channel complexes are developed, the internal channel fill is mainly the product of aggradation, and the lateral accretion is also common. The precise analysis of the internal architecture is helpful not only to the research of the channel itself, but also to the study of reservoir architectures.