内蒙古西乌珠穆沁旗地区下二叠统寿山沟组遗迹化石的发现及意义

The discovery of trace fossils of Early Permian Shoushangou Formation in Xi Ujimqin Banner of Inner Mongolia and its geological significance

内蒙古西乌旗地区寿山沟组化石稀少,沉积环境不明.在内蒙古西乌旗塔宾庙林场剖面识别出了一套海相碎屑岩沉积,发育有泥岩与砂岩韵律性互层,在该剖面的16～18层暗色粉砂岩、粉砂质板岩及泥灰岩透镜体中发育有大量的遗迹化石.这些主要遗迹属有Zoophycos,Sc olic ia,Planolites,Taenidium,Chondrites,Helminthoida,Helminthopsis.分析其形态、习性,将其划分为Zoophycos和Helminthopsis 2个遗迹化石组合,这2个组合均属Zoophycos遗迹相,反映了半深海环境的大陆斜坡沉积,为西乌旗地区沉积环境的研究提供了新的依据.

This paper systematically describes seven genera and seven species of trace fossils of flysch facies found for the first time in the early Permian Shoushangou Formation in Xi Ujimqin Banner,southeastern Inner Mongolia.The main genera of trace fossils are Zoophycos,Scolicia,Planolites,Taenidium,Chondrites,Helminthoida,and Helminthopsis.The forms,habits and water depth distribution of the trace fossils clearly prove that the trace fossils are typical representatives of the bathyal Zoophycos ichnofacies,reflecting the features of the flysch facies in the deep-water sedimentary environment.