新疆阿合奇地区石炭纪古岩溶的发现及其地质意义

The Carboniferous paleokarst in Akqi area of Xinjiang and its geological significance

位于塔里木西北缘的阿合奇地区石炭纪地层发育齐全,自下而上为:巴什索贡组、别根他乌组和康克林组。其中巴什索贡组和别根他乌组发育较多的古岩溶角砾岩及古岩溶构造,垂向上明显分为5次规模较大的古岩溶旋回。对巴什索贡组和别根他乌组古岩溶构造及古岩溶旋回进行了详细描述,讨论了古岩溶与区域海平面变化及当时冰期事件的关系,并指出早石炭世晚期和晚石炭世早期古岩溶与区域性的铝土矿成矿事件有密切的联系。

Carboniferous strata are perfectly developed in Akqi area on the northwest margin of Tarim basin and can be divided into Bashisuogong Formation, Biegengtawu Formation and Kangkelin Formation in upward succession. Abundant paleokarst breccias and paleokarst structures were discovered in Bashisuogong Formation and Biegengtawu Formation, in which five distinct large-scale pa- leokarst cycles are well developed vertically. This paper gives a detailed description of the above-mentioned paleokarst structures and paleokarst cycles, discusses the relationship of the paleokarst to regional sea-level changes and the contemporaneous glacial events, and points out the close relationship of the early Late Carboniferous paleokarst with regional bauxite ore-forming events, which could shed light on the exploration of bauxite deposits in the study area.