川西稻城古冰帽的地貌特征与冰期探讨

A Study on the Geomorphological Characteristics and Glaciations in Paleo－Daocheng Ice Cap，Western Sichuan

稻城古冰帽现保存有各种类型的冰川侵蚀和堆积地貌，依其规模大小、分布范围和组合特征可明显区分出四个地貌地带。数量众多的各种冰川作用遗迹表明，中更新世以来稻城古冰帽地区曾先后经历过三次冰川作用。

Various landforms of glacial erosion and glacial deposition，recognized in Daocheng IceCap，are divided into four distictive zones，according to their developing scales，distributionareas and composition characteristics．They are（A）Weak erosional and depositional zone lo- cated in the center of the paleo－ice cap，（B）Moderate erosional and depositional zone，（C）Intensive erosional and weak depositional zone and（D）Intensive depositional zone in themargin troughs．The large number of glacial relics indicated that three glaciations had occurred in this region since Middle Pleistocene and the glaciations of Daocheng can be comparaedwith the glaciations in Mt． Gongga region。However the model of glaciation evolution between the two regions is different．The glaciation maximum occurred during Early stage ofMiddle Pleistocene in Paleo－Daocheng lce Cap region，but the glaciation maximum occunredin penultimate glaciation on eastern slope of Mt．Gongga. The reason is the uplift ofmoun-tain in Late stage of M iddle Pleistocene. At that time，the precipitation decreased inDaocheng area，but on the east slope of Mt. Gongga a good precipitation conditionappeared.