浙江省上石炭统-中二叠统生物地层划分进展

本文划分论述了浙江省上石炭统—中二叠统16条化石带（其中11条为新建化石带）,对比研究结果表明它们分布于老虎洞组、黄龙组、船山组、梁山组、栖霞组、孤峰组、龙潭组下部的地层,可分别与滑石板阶、达拉阶、逍遥阶、紫松阶、隆林阶、栖霞阶、祥播阶、茅口阶、冷坞阶等9个阶对比。探讨研究了上石炭统底界、下二叠统底界和中二叠统底界;指出上石炭统未见底,缺失罗苏期的沉积;下二叠统底界位于Sphaeroschwagerina subrotunda带之底,以Sphaeroschwagerina属的始现作为底界的标准;石炭—二叠系界线位于Triticites subcrassulu筵带与Sphaeroschwagerina subrotund筵带之间;中二叠统的底界位于Orthotichia chekiangensis腕足组合带之底,以Orthotichia chekiangensis的始现作为中二叠统底界的标准。进一步论证了船山组是一个跨越石炭—二叠系界线的岩石地层单位,下部归属上石炭统逍遥阶,中部归属下二叠统紫松阶和上部归属下二叠统隆林阶。

Biostratigraphic division of the Upper Carboniferous to Middle Permian in Zhejiang

This paper introduced sixteen fossil zones (eleven new established fossil zones) of the Upper Carboniferous to Middle Permian in Zhejiang province.The study results showed the fossil zones were distributed in the Laohudong formation, the Huanglong formation,the Chuanshan formation, the Liangshan formation,the Qixia formation, the Gufeng formation and the lower part of Longtan formation,which can be compared with nine stages of the Huashiban Stage,the Dala Stage,the Xiaoyao Stage,the Zisong Stage,the Longlin Stage,the Qixia Stage, the Xiangbo Stage,the Maokuo Stage and the Lengwu Stage.The boundaries of the Upper Carboniferous, the Lower Permian and the Middle Permian were discussed.The authors proposed that the basal boundary of Upper Carboniferous was inexistence and the sediment was lacking in Luosu Age.The basal boundary of Lower Permian was lying at the bottom of the Sphaeroschwagerina subrotunda fusulinid zone based on the standard of the first appearance of the Sphaeroschwagerina genus. Carboniferous-Permian boundary was located between Triticites subcrassulus fusulinid zone and Sphaeroschwagerina subrotunda fusulinid zone.The basal boundary of Middle Permian was lying at the bottom of the Orthotichia chekiangensis brachiopod assemblage zone based on the boundary standard of the first appearance of the Orthotichia chekiangensis.Further research indicated that the Chuanshan formation is a boundary, lithostratigraphic unit which spanned the Carboniferous-Permian.The lower part of it belonged to the Upper Carboniferous Xiaoyao Stage,the middle part belonged to the Lower Permian Zisong Stage and the upper part belonged to the Lower Permian Longlin Stage .