内蒙古中部中--晚志留世西别河组的划分和时代

Division and age of the Mid-Upper Silurian Xibiehe Formation in central Inner Mongolia

摘要: 华北板块北缘早古生代造山带的稳定盖层——西别河组是顶底清晰,下界不整合覆于早—中奥陶世岛弧建造之上,其上被下泥盆统查干哈布组、上石炭统阿木山组不整合覆盖的一套稳定的滨浅海相沉积建造。本次工作根据岩石地层特征划分了砂砾岩段、灰岩段、砂板岩段和巴特敖包礁4个填图单元;在生物地层工作的基础上分别划分了2个珊瑚、腕足化石组合带,确立了该组为中—晚志留世地层,即Wenlockian-Pridolian期的沉积。

Abstract: The Xibiehe Formation is a stable littoral-neritic sequence in an Early Paleozoic orogenic belt on the northern margin of the North China plate. With a clear-cut top and base, it is unconformably underlain by an Early-Mid Ordovician island-arc sedimentary