新疆库鲁克塔格地区新元古代末期汉格尔乔克冰期成因新证据  

New Evidences on Neoproterozoic Hankalchough Glaciation in Quruqtagh,Xinjiang,West China

作　　者：杨瑞东[1] 张传林[2] 罗新荣 魏怀瑞[1] 王伟 

机构地区：[1]贵州大学研究生院,贵阳550003 [2]中国地质调查局南京地质矿产研究所,南京210016 [3]新疆第三地质大队地质调查所,新疆库尔勒841000

出　　处：《地质论评》2007年第2期228-232,I0009,共6页Geological Review

基　　金：国家自然科学基金(批准号40462001);贵州省优秀科技人才基金;中国博士后科学基金;贵州省长基金资助项目的成果

摘　　要：新疆是世界上保存有完整的新元古代三大冰期的地区之一,有关新疆新元古代最末期冰期为大陆冰川早就提出,但由于证据不充分而一直受到质疑。汉格尔乔克冰碛砾岩具有典型的冰川“落石”,属于典型的冰川沉积,对其上覆的帽碳酸盐岩进行系统的碳、氧同位素研究证明,帽碳酸盐岩具有全球新元古代冰后碳酸盐岩沉积类似的碳同位素负异常特征,特别是在帽碳酸盐岩底部发现具有典型的大气淡水成因的白云岩,证明汉格尔乔克冰期为大陆冰川。Neoproterozoic g there are three d acial depositions in the Quruqtagh Mountain, Xinjiang, west China, have proven screte Neoproterozoic glaciations. Xinjiang is one of the regions occurring all three Neoproterozoic glaciations in the world. The latest Neoproterozoic glaciation （Hankalchough diamictite） was discovered in 1980 and considered as glacio-territorial in origin. Nevertheless, the origin of the latest Neoproterozoic glaciation is in debate forbecause of lack of ample evidences. Striated clasts and dropstones are common in all throughout the Hankalchough diamictite units. Therefore, writersauthors suggest that the Hankalchough diamictite is glaciation in origin. Additionally, the cap dolomite covering over the Hankalchough diamictite aisre characterized by subaerial exposure crust （vadose pisolite structure, calcareous crust structure）; , and the carbon isotopic values of the cap dolomite show has negative with negative abnormal δ^13CPDB values, ranging from -4. 56 %0 to -11.45 ‰, which it is similar to carbon isotopic composition of the cap carbonate post-glaciation in the world. WritersAuthors suggest that the Hankalchough glaciation belongs to terrestrial glaciation.

关 键 词：冰川 帽碳酸盐岩 新元古代 新疆 

分 类 号：P534.3[天文地球—古生物学与地层学]