粤西第四纪洞穴化石的氨基酸年龄及混杂堆积现象

Study on the Amino Acid Ages of Fossils Teeth and Mixed-Deposition Phenomenon in Some Caves

分析了肇庆、云浮、封开、阳春等地第四纪洞穴堆积中几十个哺乳动物化石样品的氨基酸外消旋程度及氨基酸年龄，年代属全新世晚期至晚更新世晚期之间，发现某些化石地点的同一层堆积中既含有同一时期的化石。也含有不同时期的化石，这些洞穴堆积物经历了后期的改造、再搬运，最终使新老化石混杂堆积在同一层，即洞穴混杂堆积现象。

The degree of amino acid racemization and ages of dozens of fossils teeth in deposit ofsome caves distributing in Zhaoqing,Yunfu,Fengkai,Yangchun in west Guangdong provincewere analyzed in this paper.The ages of these fossils were dated to be 2000～20000a BP,whichsuggests that they deposited from late stage of late Holocene to late stage of late Pleistocene. Onthe basis of these data,it was found that not only the fossils of the same period,but also the fos-sils of different periods were deposited in the identical layer in some caves.Therefore,it was in-ferred that the cave deposit may have undergone reformation and transpOrtation once again beforedepositing in the cave,which made fossils of various periods mix up in the same layer.This paperprovides some new evidences and a new method for studying more details on the evolution ofQuaternary mammal and on the paleoenvironment and paleoclimate。