珠江三角洲白坭组的沉积环境探讨

Approach to the Depositional Environment of Baini Formation in the Zhujiang Delta

通过野外观察和室内多项沉积学分析，认为珠江三角洲新近发现的白坭组砂砾层应归属河流冲积相沉积，并不能代表有过海侵期，它们的沉积年代、ＴＬ测年数据均为中更新统。

Baini formation,age of middle pleistocens,have been discovered recently in the northpart of the Zhujiang Delta. Its origin,age and paleoenvironmental signijicance lead to many con-troversies.However,on research on systematic sedimentological analysis had been done for thesedeposits.The authors,after a series of observations in the fields and analysis in laboratory,pte-liminarily affirm:①Baini Formation lays on the second-order rock-bed river terrace,and pos-sess a duality layer structure of fluvial sediments.②The granulometric,morphometric,andquartz surface features of the clasts show that the deposition took place in the fluvial environmentof which the hydrological ch a racters are different from the recent river system of the ZhujiangDeIta。③The pollen and clay mineral characteristics show that the deposit can not represent anevent of marine transRression,④Although the depositing age may be considered as Middle pleis-tocene,the accuracy of the TL dating data in some profiles needs further study.