新疆青河玉勒肯哈腊苏铜矿区酸性岩锆石U-Pb法定年及其地质意义

新疆青河县哈腊苏地处南蒙古铜矿带的西延部分,是铜矿勘查与研究的重点和热点地区.文章以近年发现的玉勒肯哈腊苏铜矿床为主要研究对象,对矿区内铜矿化的斑状花岗岩和石英二长斑岩进行了锆石U-Pb法精确定年.研究表明,这2个主要矿化岩体先后形成于中泥盆世和早二叠世,两期岩浆活动形成了重要的斑岩型铜矿化.玉勒肯哈腊苏地区主期斑岩型矿化发生在中泥盆世,早二叠世有斑岩型矿化复合,中晚三叠纪有明显的构造-岩浆-热液引起的矿化-蚀变叠加,复合叠加铜矿化过程有确切的年代学纪录.该研究为认识铜矿成因和明确勘查方向提供了新的事实依据.

U-Pb dating of zircons from acid intrusions in Yulekenhalasu copper deposit of Qinghe, Xinjiang, and its geological significance

Located in the western part of the southern Mongolia copper belt, Halasu area in Qinghe County of Xinjiang is an important and interesting area for copper ore survey and research. Yulekenhalasu is a newly found copper deposit in this area. The authors dated the zircons from the mineralized porphyritic granite and quartz_monzonite porphyry in this deposit by using the LA-ICP-MS U-Pb dating method. The results show that the two ore_bearing intrusions were emplaced in Middle Devonian and Early Permian, respectively. Both of these two stages of magmatism produced porphyry_type copper mineralization, with the former intrusion in Middle Devonian being the main ore_forming stage, whereas the latter one in Early Permian resulting in complex mineralization. There also occurred the superimposition of mineralization-alteration caused by tectonic-magmatic-hydrothermal activities in Middle_Late Triassic. Complex and superimposed copper mineralizations have been well dated. This paper provides some new facts for understanding the genesis and exploration direction of copper ore deposits in this area.