西秦岭西汉水群中的牙形石及其地层价值

Conodonts and their Stratigraphic Value in Xihanshui Group,Western Qinling Mountains

首次发现并鉴定了西秦岭西汉水群的牙形石31属、98种,获2120个体。据其垂直分布情况划分为6个牙形石带,从而认为西汉水群至少应包括中、晚泥盆世的地层。

The abundant conodonts were first found in Xihanshui Group of Western Qinling Mountains.According to their erect distributions of total 31 genera,98 species and 2120 elements,six conodont zones(varcus zone,hermanni-cristatus zone,disparilis zone,asymmetricus zone,trangularis zone and gigas zone)are set up in the stratigraphy,and thereby the age of Xihanshui Group should be Middle to Late Devonian.