摘要
特提斯喜马拉雅前陆断褶带由近东西向展布的藏南拆离系主拆离带和洛扎、绒布—哲古两条断裂带及一系列倒转复式褶皱组成,是始喜马拉雅期印度板块与欧亚大陆发生大规模陆-陆碰撞,导致特提斯喜马拉雅前陆盆地发生大规模缩短、沉积盖层以藏南拆离系为底界自北向南大规模逆冲推覆、褶皱,以及新喜马拉雅期高喜马拉雅结晶岩系自北向南挤出导致藏南拆离系主拆离带和洛扎、哲古两条次级构造带上盘地层自南向北伸展的产物。特提斯喜马拉雅前陆断褶带内的锑金多金属矿床在空间上具有明显的分带性,自北向南依次构成沙拉岗—查拉普锑金成矿带、错美—隆子锑铅锌多金属成矿带和拉康—错那银铅锌成矿带,其间分别以绒布—哲古和洛扎两个次级断裂带为界。矿体主要受褶皱翼部近东西向层间破碎带和近南北向构造带控制,成矿类型为浅成低温热液型,成矿时代为新喜马拉雅期。成矿作用与新生代构造演化和新喜马拉雅期岩浆活动关系密切。在新喜马拉雅期高喜马拉雅结晶岩系向南挤出过程中,特提斯喜马拉雅前陆断褶带沿着始喜马拉雅期形成的逆冲推覆构造带发生自南向北伸展,诱发地壳部分熔融,形成的岩浆沿构造带侵位,并促使沿构造带下渗地下水循环对流。当这些循环的地下水与沿构造带上升的岩浆期后含矿热液混合时,成矿流体的物理化学条件发生改变,成矿物质沉淀形成沿褶皱翼部近东西向层间破碎带和近南北向构造带分布的似层状、脉状和透镜状锑金多金属矿床。
The Tethyan Himalayan foreland fanlt-fold belt in southern Tibet is made up of the southern Tibet detachment system, Luoza and Rongbu--Zhegu faults, and a series of inverted complex folds. This fault-fold belt was formed by the continent-continent collsion between India and Eurasia plates which resulted in crust shorting, sedimentary cover thrusting from north to south and folding in the Tethyan Himalayan foreland basin during Eohimalayanian. The hanging walls of the southern Tibet detachment system, Luoza and Rongbu--Zhegu faults detached along the thrusting zones formed in Eohimalayanian from south to north, which resulted from the extrusion of the Great Himalayan Crystallines during Neohimalayanian. The antimony and gold polymetallic deposits in the Tethyan Himalayan foreland fanlt-fold belt in southern Tibet distributed in zoning. They are Shalagang--Chalapu antimony and gold metallogenic belt, Cuomei--Longzi antimony and lead-zinc metallogenic belt, and Lakang--Cuona metallogenic belt in order from north to south, which are divided by Rongbu--Zhegu fault and Luoza fault, respectively. The orebodies are mainly controlled by E-W direction interformational faults within limbs of folds and S-N direction faults. The metallogenic type is epithermal deposit. The metallization occurred in the Neohimalayanian, and is related with Cenozoic tectonic evolution and magmatism. During the extrusion of the Great Himalayan Crystallines in Eohimalayanian, the Tethyan Himalayan foreland fault-fold belt detached from south to north, and resulted in partial melting. The magma formed by partial melting intruded along faults, and provoked groundwater which penetrated along tectonic zone to circulate and converte. When this groundwater met postmagmatic ore-bearing fluid that moved up along fault, the physicochemical condition of the ore-beating fluid was changed, which resulted in the ore-forming elements precipitated from the ore-beating fluid, and formed layed, vain and lenticular orebodies in E-W direction interformational fault
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
2008年第7期1638-1648,共11页
Acta Petrologica Sinica
基金
中国地质调查局项目(1212010611811)
中国地质科学院实验室基金资助成果
关键词
特提斯喜马拉雅
锑金多金属矿床
藏南拆离系
构造演化
Tethyan Himalayas
Antimony-gold polymetallic deposit
Southern Tibet detachment system
Tectonic evolution
