Revision of the Qimantage Group in West Part of East Kunlun

Through regional geological survey and research,the authors consider that the Qimantage Group or Tanjianshan Group,established by predecessors,include epimetamorphic clastic rock,intermediate acidity volcanic rock and basic-ultrabasic rock in different epoch.Based on the graptolite fossil assemblage of Silurian collected in the first subgroup of formerly named Ordovician Qimantage Group at east Kunlun (it is the first time to prove that there exists Silurian strata) and isotope dating information (Yazidaban volcanics age),it is suggested that its age includes Ordovician,Silurian and Triassic etc.According to stratum guidelines and stratum cleaning,authors dismember the Qimantage Group and redefined it as Tanjianshan Group of Ordovician system (OT),Baiganhu formation of Silurian system (Sb) back-arc basin flysch deposit and Yaziquan formation (Sy) island arc volcanics,Yazidaban silica rocks (Si) of carboniferous system,Elashan formation of triassic system (T₃e),Langyashan formation of the Jixianian system (Jxi>l) and Ayakekumu lake ophiolitic melange of Nanhua-Ordovician system [(Nh—OaΣ].The result provides some new important evidences for the stratigraphic division and correlation,structural evolution of early-palaeozoic at Qimantage area.