摘要
本文采用4 0 Ar_3 9Ar真空击碎技术和阶段加热技术 ,测定了采自落雪矿的“东川式”层状铜矿之两个石英样品的年龄 ,获得了 810~ 770Ma的4 0 Ar_3 9Ar等时线年龄 ,这是首次获得的“东川式”铜矿的成矿年龄。这些年龄与作者以前获得的脉状铜矿石英的年龄范围一致 ,远远小于赋矿围岩落雪组的年龄。研究结果表明“东川式”层状铜矿并非沉积成因 ,与脉状铜矿一样 ,也是热液成因 。
Two quartz samples from the Dongchuan_type layered copper deposits in the Luoxue Mine were dated by 40 Ar_ 39 Ar crushing and heating techniques. Two age groups of ~1?470 Ma and 810~770 Ma are recognized from the 40 Ar_ 39 Ar isochron plots. The age of ~1?470 Ma, obtained from the isochron of the quartz 98_4aQ by vacuo crushing technique, is interpreted as the crystallization age of 98_4aQ from the hydrothermal fluid. The ages of 810~770 Ma, obtained from the 40 Ar_ 39 Ar isochrons of 98_4aQ by stepped heating and of 98_4fQ by crushing and stepped heating, seem quite in agreement with the 40 Ar_ 39 Ar isochron ages of the quartz samples DC_50_3Q and DC_51_1Q by crushing and siliceous breccia DC_5_2 by heating selected from the quartz_vein ores, and are interpreted as the copper mineralization ages. These ore_forming ages further indicate that the major ore_forming process in the Dongchuan copper deposits took place in the Jinning_Chengjiang period.
出处
《矿床地质》
CAS
CSCD
北大核心
2002年第2期129-136,共8页
Mineral Deposits
基金
国家自然科学基金 (编号 :49972 0 33)
国家 973项目 (编号 :G19990 432 0 1)
国家攀登预选项目 (编号 :95_YU_2 5 )
中国科学院大型仪器功能开发项目 (编号 :980 4A_0 77)