钦-杭成矿带主要金属矿床成矿系列

Metallogenetic series of major metallic deposits in the Qinzhou-Hangzhou metallogenic belt

钦-杭成矿带是华南地区最重要的Cu-Pb-Zn-Au、W-Sn-Bi-Mo和Fe-Mn-S多金属成矿带。在前人工作基础上,根据矿床的成因组合、形成构造环境及其随地质历史演化的特点,将钦-杭成矿带主要金属矿床归纳为中新元古代海底喷流沉积型铜多金属矿床、新元古代海相沉积-变质型铁锰矿床、古生代海相沉积-叠生改造型铜铅锌铁锰矿床、加里东期与花岗岩类有关的钨钼金银多金属矿床、印支期与花岗岩类有关的钨锡铌钽铀多金属矿床、燕山期与花岗岩类有关的铜铅锌金钨锡多金属矿床、与区域动力变质热液作用有关的金银矿床等7个矿床成矿系列。进而讨论了各成矿系列的主要矿床类型、矿床地质特征和时空分布规律,初步认为,中新元古代海底喷流沉积型块状硫化物铜多金属矿床与大陆边缘岛弧火山作用有关,主要分布于扬子陆块东南缘和华夏陆块西北缘古岛弧褶皱区;新元古代受变质铁锰矿床与大陆裂谷火山作用有关,并经受了后期区域变质、热变质作用的改造,主要分布于加里东期隆起区;古生代层控型铜铅锌铁锰矿床与海底热水沉积成矿作用有关,且不同程度地受到后期岩浆-热液活动的叠加改造,主要分布于海西—印支期坳陷区与隆起区的过渡部位;加里东期斑岩-夕卡岩-热液脉型钨钼金银多金属矿床与奥陶纪末—志留纪陆内造山作用有关,主要分布于加里东期隆起区;印支期斑岩-夕卡岩-热液脉型钨锡铌钽铀多金属矿床与印支板块向华南板块的俯冲碰撞有关,成矿作用发生在后碰撞伸展阶段,主要分布于海西—印支期隆起区边缘;燕山期斑岩-夕卡岩-热液脉型铜铅锌金钨锡多金属矿床与岩石圈伸展引起的玄武岩底侵作用有关,广泛分布于海西—印支期拗陷区或中生代盆地边缘;与区域动力变质热液作用有关的金银矿床成矿系列,与印支—燕山期大规模的逆冲推覆作用有关,主要发育于钦-杭结合带两侧古陆边缘。

The Qinzhou-Hangzhou（Qin-hang） joint belt is the most important Cu-Pb-Zn-Au, W-Sn-Bi-Mo and Fe-Mn-S polymetallic metallogenic belt. In this study, on the basis of the previous study and the characteristics of the ore-forming genesis, tectonic setting and geological evolution history, we attempt to divide the main polymetallic deposits into seven metallogenic series, i.e. Meso-Neoproterozoic marine exhalative Cu polymetallic deposits, Neoproterozoic marine depositional metamorphic type of Fe-Mn deposits, Paleozoic marine depositional and superimposed reworked type of Cu-Pb-Zn-Fe-Mn deposits, Caledonian granitoids related W-Mo-Au-Ag polymetallic deposits, Indosinian granitoids related W-Sn-Nb-Ta-U polymetallic deposits, Yanshanian granitoids related Cu-Pb-Zn-W-Sn polymetallic deposits, and regional dynamic metamorphism and hydrothermal related Au-Ag deposits. Furthermore, we discussed the main deposit types, the geological characteristics of ore deposits, as well as the temporal and spatial distribution of the above metallogenic series and proposed the following conclusions. Meso-Neopmterozoic marine exhalative massive Cu polymetallic deposits, related to the continental margin island-arc volcanism, mostly occurred in the old arc-island folded area of the southeast edge of the Yangtze Plate and the northwest edge of the Cathaysian Block; Neoproterozoic metamorphosed type of Fe-Mn deposits, related to the continental rift volcanism and overprinted by the later regional and hydrothermal metamorphism, mostly occurred in the Caledonian uplift; Paleozoic stratabound type of Cu-Pb-Zn-Fe-Mn deposits, related to the seafloor hydrothermal sedimentary mineralization and overprinted by the later magmatism and hydrothermal in different degree, mainly occurred in the transition zone of the Hercynian- Indosinian depression and uplift; Caledonian porphyry-skarn-vein Mo-W-Au-Ag polymetallic deposits, related to the intracontinental orogeny during the latest Ordovician to the Silurian, mostly occurred in the Caledonian uplift; Indosinian porphyry-skarn-vein W-Sn-Nb-Ta-U polymetallic deposits, related to the Indochina Plate subduction/collision to the south China Plate, of which metallogenesis happened during the post-collisional extensional stage, mostly occurred in the margin of the Hercynian-Indosinian uplift area; Yanshanian porphyry-skarn-vein Cu-Pb-Zn-Au-W-Sn polymetallic deposits, related to the basaltic underplating caused by the lithospheric extension, widely occurred in the Hercynian-Indosinian depression or the Mesozoic basin margin; The Au-Ag metallogenic series linked to the regional dynamic metamorphism and hydrothermal,related to the large scale thrusting during the Indosinian to Yanshanian, mainly occurred in both sides of the ancient continental margin of the Qin-Hang joint belt.