Geomorphic Evolution of Soft-cliffs since the Quaternary on the North Coast of Haitan Island, Fujian Province
In this paper,on the basis of field observation of profile texture and structure of soft-cliff and granulometric and magnetic analysis,and referring to the achievements of Quaternary chronostratigraphy in southern China,we focused on judging the geomorphic evolution process of soft-cliffs in Jingsha (JS) and Liushui (LS) on the north coast of Haitan Island of Fujian Province.The results showed in the early geomorphic evolution of soft-cliffs in JS,development of the aeolian "Old Red Sand" deposits under the background of the hot dry climate in the Last interglacial.Jun Mountain subjected to intense physical weathering and produced a large number of clastic rock under Last Glacial Maximum (LGM) of the cold dry climate,developed piedmont diluvial layer and covered the base level of denudation of "Old Red Sand" during the climate transition phase of postglacial period.Longterm erosion of wave,tidal power causing shoreline erosion back to the south under the background of rising sea level fluctuations since postglacial,developed into present soft-cliff landscape.The soft-cliff in LS recorded the rise and fall of sea-level alternately during early Pleistocene of Quaternary,LS deposited alternately by shallow sea and continental sediment and composed geomorphic basis of the tiebar.Converted continental sedinentary environment since the late mid-pleistocene and development of multi layers of "Old Red Sand" deposits under the background of the hot dry climate.LS also developed into soft-cliff landscape under the background of rising sea level fluctuations since late glacial epoch.The geomorphic evolution process of modern times in LS was mainly wave and sand erosion effect and the shoreline erosion back to the south under strong wave erosion.Although the difference of early sedimentary formation process was obvious between JS and LS soft-cliff,the geomorphic evolution process of soft-cliff was similar under the background of rising sea level fluctuations since postglacial.In general,the evolution process of soft-cliff on the north coast of Haitan Island was driven by internal and external force of crustal movement,climatic change,sea-level change and wave action.
soft-cliffgranulometric characteristicsmagnetic characteristicscoastal dynamicsgeomorphic evolutionHaitan Island
NETL
NSTL
万方数据
维普
