东川式层状铜矿^(40)Ar-^(39)Ar成矿年龄研究:华南地区晋宁-澄江期成矿作用新证据  

New ^(40)Ar-^(39)Ar Evidence for Ore-forming Process During Jinning-Chengjiang Period in Dongchuan Type Copper Deposits, Yunnan

作　　者：邱华宁[1] J.R.Wijbrans 李献华[1] 朱炳泉[1] 朱崇林 曾保成 

机构地区：[1]中国科学院广州地球化学研究所,广东广州510640 [2]荷兰阿姆斯特丹自由大学 [3]东川矿务局,云南东川654101

出　　处：《矿床地质》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)

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.

关 键 词：华南地区 成矿作用 ^40Ar-^39Ar法 流体包裹体 铜矿床 澄江期 氩同位素 

分 类 号：P618.41[天文地球—矿床学] P597.1[天文地球—地质学]