摘要
东昆仑地区存在新元古界万宝沟群(Pt3W)紫红色硅质岩和下寒武统沙松乌拉组(Є1s)紫红色、灰白色硅质岩。MnO/TiO2、U/Th、V/Cr、V/(V+Ni)、Fe2O3 T/TiO2、LaN/CeN、Al2O3/(Al2O3+Fe2O3 T)比值特征均显示研究区万宝沟群紫红色硅质岩为热液成因,形成于大洋中脊附件强烈的缺氧环境;沙松乌拉组紫红色硅质岩为热液成因,可能形成于远洋盆地的贫氧环境,而灰白色硅质岩为非热液成因,可能形成于大陆边缘的氧化环境。因此推断新元古界万宝沟群硅质岩形成于原特提斯洋扩张阶段,下寒武统沙松乌拉组硅质岩形成于原特提斯洋俯冲阶段。
There are Wanbaogou group(Pt3W)claret-colored cherts,Shasongwula Formation(Є1s)purple red cherts and offwhite cherts in the East Kunlun Orogenic Belt(EKOB).The characteristics of MnO/TiO2,U/Th,V/Cr,V/(V+Ni),Fe2O3 T/TiO2,LaN/CeN,Al2O3/(Al2O3+Fe2O3 T)ratios showed that the Wanbaogou group purple red cherts are submarine hydrothermal genesis and developed in oxygen-deficient condition near mid-ocean ridge,the Shasongwula Formation purple red cherts are submarine hydrothermal genesis and developted in oxygen-poor condition in pelagic basin,and the offwhite cherts are not submarine hydrothermal genesis and developed in oxidation environment related to continental shelf setting.Therefore,the Wanbaogou group cherts may developed in Proto-Tethyan oceanic expansion stage,while the Shasongwula Formation cherts developed in the subduction of the Proto-Tethyan oceanic crust.
作者
武若晨
WU Ruo-chen(Beijing Key Laboratory of Metal Mineral Resources Test and Evaluation,BGRIMM Technology Group,Beijing 102628,China)
出处
《世界有色金属》
2020年第1期158-163,共6页
World Nonferrous Metals
关键词
东昆仑
硅质岩
地球化学
East Kunlun Orogenic Belt
cherts
geochemistry
