南明水组和蛇绿岩之间不整合关系的确认及其意义

CONFIRMATION OF THE UNCONFORMABLE RELATIONSHIPS BETWEEN THE NANMINGSHUI FORMATION AND OPHIOLITES AND THEIR SIGNIFICANCE

依据菊石、腕足化石资料,将南明水组的时代置于 C_1~2—C_2~1。南明水组和蛇绿岩之间的不整合表明卡拉麦里缝合带中蛇绿岩的构造侵位发生于南明水组沉积之前,这一侵位是哈萨克斯坦古板块和西伯利亚古板块碰撞的结果。笔者认为在南明水组露头下面有可能赋存 Cr、Ni、Cu 等隐伏矿床。

The gabbroic pebble-bearing greywacke and bownish-black serpentine conglomerate of the Nanmingshui Formation overlie unconformably serpentinized harzburgite and metagabbro in the Karameri paleoplate suture zone in East Junggar,Xinjiang.On the basis of ammonoid fossils newly discovered and previous data of brachiopod fossils,the age of the Nanmingshui Formation is placed between C^2_1—C_2~1.The unconformity between the Nanmingshui Formation and ophiolites indicate that the tectonic emplacement of ophiolites in the Karameri suture zone took place before the deposition of the Manmingshui Formation.This emplacement resulted from collision of the Kazakhstan pale- oplate and the Siberia paleoplate.The author considers that there might occur hidden deposits of Cr,Ni and Cu below the outcrops of the Nanmingshui Formation.