鄂尔多斯西、南部中奥陶世环陆架沉积特征

PALEOGEOGRAPHIC FEATURES OF MIDDLE ORDOVICIAN SEDIMENTS ON ORDOS CONTINENTAL SHELF

张吉森 费安琦 王志辉

Zhang Jisen Fei Anqi Wang Zhihui

国内多数研究者均将华北峰峰组与本区中奥陶统对比。近年来笔者等发现,本区早中奥陶世牙形刺动物群面貌显著不同,峰峰组牙形刺组合,出现于本区南缘歧山、泾阳、富平一带下奥陶统顶部的石马坪组之中,且与整个下奥陶统牙形刺动物群同属太平洋型。

Middle Ordovician sediments locally occurred at the western and southern margins of Ordos platform and are represented by sand-shale facies and carbonates respectively.They are formed in Qilian-Qinling marine trough and Weibei carbonate platform is line with comprehensive analysts of simple-factor based diagrams, facies sequence and charaetus of paleobiota of individual atratigraphical column. Weibei carbonatc platform has correspondingly been subdivided into backbeach Iagoonal zone, shallow-water beach zone and forebeach seaward-sloping Zone.

10.11743/ogg19820417