东昆仑西段祁漫塔格群早志留世笔石化石的发现

Discovery of Early Silurian graptolite fossils in the Qimantag Group in the western sector of the East Kunlun

首次在东昆仑西段祁漫塔格山白干湖地区原划奥陶系祁漫塔格群浊积岩下部层位中发现Monoclimacisgriestoniensis(Nicol),Monograptuspriodon(Bronn),Monograptussp.,Streptograptuscf.becki(Barrande),Torngni-graptuscf.arcuatus(Barrade)早志留世笔石化石组合,表明祁漫塔格群除有奥陶纪地层外,还包含有早志留世地层。

The authors discovered an Early Silurian graptolite assemblage of Monoclimacis griestoniensis(Nicol ),Monograptus priodon(Brow),Monograptus sp.,Streeptograptus cf.becki (Barrande)and Torngn-igraptus cf.arcuatus(Borrade)within the lower horizon of turbidites in the original Ordovician Qimantag Group in the Baiganhu area,Qimantag Mountain,western sector of the East Kunlun Mountains.This sug-gests that Early Silurian strata also occur in the Qimantag Group in addition to Ordovician strata.This is the first time that reliable megafossils were discovered in the western East Kunlun,which has great signifi-cance for the study of the stratigraphic division and correlation and tectonic evolution in the area.