俯冲、碰撞、深断裂和埃达克岩与斑岩铜矿  

SUBDUCTION,COLLISION,DEEP FRACTURE,ADAKITE AND PORPHYRY COPPER DEPOSITS

作　　者：芮宗瑶[1] 侯增谦[1] 李光明[2] 张立生[2] 王龙生[1] 唐索寒[3] 

机构地区：[1]中国地质科学院矿产资源研究所,北京100037 [2]中国地质调查局成都地质矿产研究所,成都610082 [3]中国地质科学院地质研究所,北京100037

出　　处：《地质与勘探》2006年第1期1-6,共6页Geology and Exploration

基　　金：国土资源部大地调项目(编号:199910200246);国家重点基础研究发展规划项目(编号:2002CB4126010)资助

摘　　要：无论是碰撞前的B型俯冲,还是碰撞后的A型俯冲,形成斑岩铜矿都必须要有洋壳或上地幔为主的物质参与。因此斑岩铜矿的初始锶值都小于0.708,超过0.708,则意味地壳物质的增多,将形成斑岩钼矿和斑岩钨锡矿。斑岩铜矿带常常与切穿地壳的深断裂带平行共生,并产于其上盘,在该地带往往发育壳幔混合以幔为主的深源花岗质浅成-超浅成小斑岩体。含铜斑岩和埃达克岩可能均为俯冲和交代产物,因而具有相似的特征,但到俯冲末期它们分道扬镳了。文章通过对冈底斯斑岩铜(钼、金和多金属)矿带的分析,来讨论俯冲、碰撞和深断裂带与斑岩铜矿的关系。同时也通过我国中央碰撞造山带仅发育斑岩钼矿,而缺乏斑岩铜矿,从而证明上地幔物质的加入对斑岩铜(金)矿的重要意义。Participation of oceanic crust - derived or upper mantle - derived material is essential for porphyry copper deposits which are formed by pre -collisional B -type subduction and post -collisional A -type subduction, Initial Sr isotopic （^87Sr/^86 Sr） ratio for a porphyry copper deposit must be less than 0.708, The initial Sr isotopic ratio of more than 0.708 is characteristic of porphyry Mo deposits or porphyry W - Sn deposits because of participa- tion of continental crust - derived material. Porphyry copper belts are often parallel to deep fracture zones which cut through crust, and are confined to the hanging wall of the deep fractures where small granitic porphyry masses are often developed. Granitic porphyry is crust - mantle mixture - derived and mainly mantle -derived in material origin. Copper -bearing porphyry and adakite probably result from subduction and metasomatism. These two rocks have the same features, but they become different in late subduction stage. The present paper deals with the relationship of subduction, collision and deep fracture zone with porphyry copper deposits exemplified by Gandese porphyry Cu （ Mo, Au and polymetallic ） ore belt. Meanwhile, the development of porphyry Mo deposits other than porphyry Cu deposit in the central collision orogens in China indicates that participation of upper mantle - derived material is of great importance for porphyry Cu （Au） deposits.

关 键 词：B型俯冲 A型俯冲 碰撞造山带 深断裂带 埃达克岩 斑岩铜矿 

分 类 号：P618.41[天文地球—矿床学]