冰川沉积物成因确定的一种新方法

A New Method for Identifying Moraine

冰川沉积物的成因鉴定一直存在争论 ,尤其是体现在讨论第四纪冰川沉积物的成因确定问题方面 ,传统地质学从冰川沉积物的沉积学和地貌学特征方面来讨论其成因受到了挑战。本文试图从沉积砾石中寻找与冰川成因直接相关的应力信息 ,进而提出用砾石的声发射应力测量法确定其冰川成因的新认识。首先对现代冰川砾石进行声发射应力测量 ,将此测量值再与砾石所受的实际铅直应力值比较 ,研究显示二者对应很好 ,说明冰川砾石是能够记忆上覆冰层所造成的应力 ;其次 ,无争议的第四纪冰川砾石亦具有对应的应力记录 ;最后讨论有争议的庐山地区第四纪冰川沉积 ,研究揭示了砾石中存在对应于古冰川成因的历史应力 ,证实该区第四纪泥砾层为古冰川沉积。因此 ,砾石的声发射应力测量法是冰川沉积物成因确定的一种新方法。

The identification of glacial sediment has long been a subject of controversy,especially about how to identify the Quaternary moraine.It is really a challenge for us to recognize moraine by means of characteristic analysis in sedimentology and geomorphology.These years we have tried our best to find the stress information of gravel in relation to glaciation,and have obtained some new understanding concerning the identification of moraine through the measurement of historical stress of acoustic emission.First,we determined the acoustic emission stress of the gravel beneath the existing glacier,then compared it with the actual stress by calculation,which showed that they were nearly equal.Then,the gravel of real Quaternary moraine was proved to have corresponding record of accoustic emission stress related to glaciation.At last,we probed into the Quaternary moraine in Lushan Mountain through the measurement of AE stress of gravel,and found the stress related to Quaternary glacier.It is undoubtedly believable that the Quaternary muddy gravel in Lushan Mountain is moraine instead of other sediments.The measurement of stress of accoustic emission of gravel is a new method for recognizing moraine.