青藏高原东南缘四姑娘山地区末次冰期砾石沉积和冰楔特征  

The last glacial stage gravel sediments and ice wedge features of Siguniang Mountains on the southeast margin of Qinghai-Tibet plateau,China

作　　者：彭东[1] 谢云喜[2] 吴树通 杨晗 

机构地区：[1]成都理工大学沉积地质研究院,成都610059 [2]四川地矿局区调队,成都610213 [3]四姑娘山管理局,四川小金624200

出　　处：《成都理工大学学报（自然科学版）》2006年第5期491-496,共6页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：国土资源大调查项目(200113000001)

摘　　要：四姑娘山位于青藏高原东南缘，第四纪冰川可分为3期。末次冰期时长坪沟口属于冰缘地带，在前次冰期冰碛物上发育了冰楔构造，冰缘地带冰川融水形成黑色细砾堆积。根据新的证据，末次冰期时四姑娘山长坪沟口附近年平均气温比现在低14～20℃。末次冰川作用发生时恰好也是四姑娘山地区强烈抬升的时期，因此，这套粗碎屑堆积可能是推覆构造的沉积响应，表明末次冰期时可能存在气候与构造联动作用。四姑娘山地区末次冰川规模较倒数第二次冰期明显偏小。Siguniang Mountains is located on the southeast margin of Qinhai-Tibet plateau, and it developed 3 Quaternary ice ages. During the last glacial stage, the periglacial zone covered the river mouth area of Changping Valley. The ice-wedge developed in the prior moraines and the black fine gravels by glacial ablation accumulated on the periglacial zone. Based on the new evidences the authors suggest that the annual average temperature at the Changping Valley mouth of Siguniang Mountains in the last glacial stage was lower 14～20℃ than the present. It is just the time the of tectonic up-lifted on this areas when the last glacial stage occurred, therefore, the black fine gravels may be the sedimentary response of orogeny and the associating-action of climate and tectonic at the last glacial stage can be assumed. The scale of the last glacial stage was smaller than that of the last glacil stage but one on the Siguniang Mountains.

关 键 词：四姑娘山 末次冰期 砾石沉积 冰楔 

分 类 号：P512.4[天文地球—地质学] P534.63