兰坪金顶地区推覆－滑动构造及其平衡剖面

本文选择横切哀牢山隆起，经金沙江－红河大断裂，金顶铅锌矿区至澜苍江大断裂的剖面进行平衡．确认该剖面的构造样式为一喜马拉雅期的背负式对冲模式，即较老的Ｊ－Ｔ３地层分别从东西方向向兰坪盆地内部逆冲，可以分为东西两个推覆带．东推覆带发育较全，由根带、中带和前缘带组成．在推覆事件之后雪邦山隆起带迅速抬升，其西坡下有同生断裂活动，雪邦山隆起之上的推覆体转换成重力滑覆，由此形成了金顶矿区和莱龙、金－一带颇具特色的滑覆构造带．经平衡复位该剖面在以喜马拉雅构造期为主的阶段压缩了４３ｋｍ．本文为金顶起大型铅锌矿床形成的区域构造背景提供了新的认识．

NAPPE-SLIDING STRUCTURE AND BALANCED CROSS-SECTION OF THE LANPING-JINDING REGION,YUNNAN, CHINA

A balanced cross-section in Lanping-Jinding area of the Western Yunnan,begins fromthe uplift of Jinshajiang-Honghe fault,through Jinding Pb-Zn deposit,to Lancangjiang fault at Yingpanjie.The study shows that the tectonic style during Himalayan orogeny in this area is characterized by ramp thrust pattern of piggyback propagation,by which the older strata thrusted toward the center of the Nanping basin simutaneously from the west of Lancangjiang in the west of the basin as well as the Ailao mountain in the east of tb basin.The section can be divided into two nappe belts:the eastern belt and the western belt.In the former,which is of a'width of 34 km,root zone,middle zone and sliding nappe zone can be recognized.The early nappes have changed into sliding mass due to the uplifting of Xuebang mountain and intensive growth fault activites in the western Xuebang mountain after the thrust events.The sliding nappe zone characterizes the Jinding.The section has been compressed over 43 km during the Himalayan thrust events.