新疆北塔山地区埃姆斯期腕足动物群

区内早泥盆世沉积为卓木巴斯套组, 产丰富的古生物化石, 以极为丰富的腕足为主要特征。通过地质路线调查与剖面测量, 采集到大量的腕足、珊瑚、三叶虫、苔藓虫、角石、菊石等动物化石, 其中, 腕足类占90%以上。本次工作鉴定出腕足化石24属48种。根据动物化石组成及面貌将其定为 “东准Spinatrypa khalfini动物群”。主要特征是腕足在动物群中的含量占绝对比例, 而且石燕类、无洞贝类占绝对优势。依据化石组合类型及产出层位将其划分为下部Leptocoelia sinica组合及上部Spinatrypa khalfini组合。将北塔山地区与我国北部其他地区同时代地层中的腕足动物群进行对比发现:北塔山地区的腕足化石的产出层位与内蒙古地区东乌珠穆沁旗敖包亭浑迪组、东北地区金水组、霍龙门组、黑台组、乌努尔组大致相当;并根据个别属种在世界范围的时代意义, 确定了卓木巴斯套组的时代为埃姆斯期。

Brachiopod Fauna of Emsian at Beita Mountain in Northern Junggar Basin,Xinjiang

Devonian is one of the most widely outcropping strata in Xinjiang. Lower Devonian at Beita Mountain in Qitai country is formed by Zhuomubasitao formation, which is rich in fossils like brachiopod, coral, trilobites, bryozoans, endoceratida, ammonites, and the brachiopod accounted for more than 90% of them. The brachiopod fauna includes 24 genera and 48 species. According to the composition of this brachiopod fauna, it could be named as the Eastern Junggar Spinatrypa khalfini Fauna, which is characterized by atypa and spirifer. The fauna can be divided into two brachiopod assemblages, such as the Leptocoelia sinica assemblage in the lower part and the Spinatrypa khalfini assemblage in the upper part. Based on the comparison of brachiopod faunas among lower Devonian Aobaotinghundi formation in Inner Mongolia, Jinshui formation, Huolongmen formation, Heitai formation and Wunuer formation in Northeast China, the age of Zhuomubasitao formation is confirmed to be the Emsian.