摘要
本区炒米店组上部出现了厚达几十米的白云岩夹灰岩层段，按地层清理对“三山子组”的定义—以连续的大套白云岩出现为其底界［１］，这段地层不属三山子组，应归炒米店组。然而，不但这里的三山子组白云岩均含燧石结核，炒米店组顶部的灰岩也含大量的燧石结核和条带。于白云岩夹灰岩之层段发现大量的头足类化石，其时代属早奥陶世。该段地层可与区域上的三山子组ａ段下部和ｂ段相对比。这是鲁西地区寒武—奥陶系剖面的一种新类型。
There are a dolomite with limestone section which is with scores of meters thick in the upper part of Chaomidian formation.According to the definition of Sanshanzi formation given by“stratigraphic sortout”,that is,the bottom boundary of Sanshanzi formation is it when a large set of and continuous dolomite comes,so this section doesn't belong to Sanshanzi formation,and it should belong to Chaomidian formation.However,not only dolomite in Sanshanzi formation contains nodular chert,but also in large amount limestone in the upper part of Chaomidian formation.A lot cephalopoda fossils were found in the section of dolomite with limestone,which belong to early Ordovician.Its position regionally equivalent to the lower part of“asection”and to“bsection”of Sanshanzi formation.This is a new type of Cambrian-Ordovician profile in Luxi area(west of Shandong).
出处
《山东地质》
1998年第3期13-17,共5页
Geology of Shandong
