A preliminary study on rapid deposition bodies in the Zhujiang Delta since Holocene

Based on the typical bore holes of the Zhujiang Delta and the long-term morphodynamic model PRD-LTMM, rapid deposition body (RDB) is examined. The RDB is defined, and the formations of typical RDBs in the Zhujiang Delta are analyzed initially. The RDBs hold the specific sedimentary environment and particular sedimentary dynamics with the annual deposition rate of centimeters; so, the research on the RDBs can help disclose the mechanism of the basic sedimentary units in the Zhujiang Delta, providing a basis for the study of mechanism of the Zhujiang Delta evolution. The initially discovered RDBs include depositions at the paleo-tide convergent flow and the paleo-flood tidal jet, fringing deposition around the palco-terrance. A study result shows that the formation of RDBs, with being highly variable in time and space, is related to the small- to medium-scale dynamic structures under particular morphologic boundaries. Understanding the morphologic boundary,its evolution process and medium- to small-scale dynamic structures under corresponding morphologic boundaries in the Zhujiang Delta is key to the research of the RDBs.