地质科技通报2025，Vol.44Issue(4)：256-272,17.DOI:10.19509/j.cnki.dzkq.tb20240430
滇西保山地区奥陶系至志留系仁和桥组笔石生物地层
Graptolite Biostratigraphy of the Ordovician to Silurian Renheqiao Formation in the Baoshan region,southern Yunnan,China
摘要
Abstract
The Ordovician to Silurian Renheqiao Formation,characterized by a sequence of well-preserved black shales,is extensively developed in the Baoshan region,southwestern Yunnan Province,China.[Objective]The primary goal of this study is to establish a graptolite biostratigraphic framework for the Renheqiao Formation.To achieve this,the research focuses on the Banpo and Chadi sections in Shidian County,Baoshan City,Yunnan Province,which are critical outcrops for biostratigraphic analysis in the area.[Methods]A combination of high-resolution biostratigraphic and lithologic records was conducted to precisely define the stratigraphy and identify key biozones within the formation.[Results]The Renheqiao Formation in the study area is approximately 71.6 meters thick,with a about 25 cm of paleo-weathering crust at the base.It unconformably overlies the Pupiao Formation,indicating that the study area was subaerially exposed during the Late Ordovician.Based on detailed fieldwork and high-resolution surveys,a total of nine graptolite zones were identified,spanning from the upper Hirnantian in the Ordovician to the Silurian Llandovery Telychian stage.These identified graptolite zones are in ascending order as follows:the Metabolograptus persculptus zone(R1),Akidograptus ascensus zone(R2),Parakidograptus acuminatus zone(R3),Cystograptus vesiculosus zone(R4),Coronograptus cyphus zone(R5),Demirastrites triangulatus zone(R6),Lituigraptus convolutus zone(R7),Stimulograptus sedgwickii zone(R8),and Spirograptus guerichi zone(R9).[Conclusion]The nine graptolite zones of the Renheqiao Formation in the Baoshan region correlate well with those of the Longmaxi Formation(LM1-LM9)in the Yangtze region.This correlation not only strengthens the regional stratigraphic framework but also provides a solid basis for future shale gas exploration and assessment in the Baoshan region.关键词
奥陶系-志留系/仁和桥组/笔石生物地层/龙马溪组/滇西保山地区Key words
Ordovician-Silurian/Renheqiao Formation/graptolite biostratigraphy/Longmaxi Formation/Baoshan region,southern Yunnan分类
天文与地球科学引用本文复制引用
郑书粲,冯庆来,龙精杰,陶振鹏..滇西保山地区奥陶系至志留系仁和桥组笔石生物地层[J].地质科技通报,2025,44(4):256-272,17.基金项目
湖北省自然科学基金计划项目"滇西下志留统仁和桥组黑色岩系成烃生物类型对有机质富集的影响机理研究"(2024AFB337) （2024AFB337）
黄冈师范学院高级别培育项目"保山地块仁和桥组黑色泥页岩成烃生物演化规律研究"(202525404) （202525404）
湖北省教育厅哲学社会科学研究项目"鄂东古生物化石的调查、发掘与开发利用研究"(23Q072) （23Q072）
中石化勘探分公司项目"保山地块页岩气资源调查与评价"(合同编号"35450003-22-ZC0607-0003") （合同编号"35450003-22-ZC0607-0003"）
