北羌塘盆地侏罗系索瓦组生物地层学研究  

Biostratigraphy of Jurassic Suowa Formation in North Qiangtang Basin

作　　者：白培荣 陈启飞 张厚松 熊兴国 Bai Peirong;Chen Qifei;Zhang Housong;Xiong Xingguo(Guizhou Institute Geological Survey,Guiyang 550081)

机构地区：[1]贵州省地质调查院,贵阳550081

出　　处：《地质科学》2025年第2期446-457,共12页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：中国矿产地质志项目(编号:DD20221695,DD20190379,DD20160346);全国油气资源战略选区调查与评价项目资助。

摘　　要：近年来,北羌塘盆地内广泛发育的索瓦组相关的油气资源潜力已经受到石油地质工作者广泛关注,对其勘探已取得阶段性进展,但关于该组的形成时代和时空对比关系尚存较大争议,制约着油气勘探工作的进一步开展。本文基于半岛湖地区索瓦组众多露头剖面的古生物资料,系统梳理和综合分析古生物化石组合地质年代。其中,双壳类丰富且类型多样,以Anisocardia、Astarte、Chlamys(Radulopecten)、Corbula、Goniomya、Homomya、Pholadomya、Pleuromya、Pseudotrapezium、Tancredia、Gryphaea、Pronoella、Ceratomya、Entolium、Exogyra、Lima(Acesta)、Lopha、Mactromya、Gervillella、Pinna、Pseudolimea等23属和亚属为代表,其时代特征为中-晚侏罗世;腕足类以较为丰富的Burmirhynchia-Holcothyris化石组合为代表,其时代指示为中侏罗世;菊石类以Virgatosphinctes和Aulacosphinctoides等具有全球对比意义的晚侏罗世分子为代表,同时可见Marcrocephalites、Dolikephalites和Choffatia中侏罗世卡洛期化石分子;海胆类Conula subrotundus为中-晚侏罗世;腹足类Natica hulliana为晚侏罗世。综上所述,本文根据生物地层学研究成果,将北羌塘盆地索瓦组时代精确限定为中-晚侏罗世。生物地层学和岩相学相结合,反映了温暖正常的近岸浅水碳酸盐岩沉积环境的底栖生物面貌。这一研究将为该地区基础地质调查和油气勘探提供思路和参考。In recent years,the oil and gas resource potential related to the Suowa Formation,which is widely developed in the North Qiangtang Basin,has been widely concerned by petroleum geologists and has made exploration progress.However,there are still great controversies about the formation era and the correlation between time and space of the formation,which restricts the further development of oil and gas exploration work.Based on the paleontological data of many outcrop profiles of the Suowa Formation in the Peninsula Lake area,this paper systematically combs and comprehensively analyzes the geological age of paleontological fossil assemblages,among which bivalves are abundant and diverse,including Anisocardia,Astarte,Chlamys(Radulopecten),Corbula,Goniomya,Homomya,Pholadomya,Pleuromya,Pseudotrapezium,Tancredia,Gryphaea,Pronoella,Ceratomya,Entolium,Exogyra,Lima(Acesta),Lopha,Mactromya,Gervillella,Pinna,Pseudolimea and other 23 genera and subgenera are represented,and their epochal characteristics are Middle⁃Late Jurassic.The brachiopods are represented by the relatively rich Burmirhynchia‑Holcothyris fossil association,whose age indicates the Middle Jurassic.The ammonites are represented by the Late Jurassic molecules of global comparative significance,such as Virgatosphinctes and Aulacosphinctoides,and the Middle Jurassic Carlow fossils of Marcrocephalites,Dolikephalites and Choffatia.Conula subrotundus belongs to the Middle⁃Late Jurassic.The gastropod Natica hulliana is from Late Jurassic.In summary,based on the biostratigraphic research results,this paper has precisely defined the age of the Suowa Formation in the North Qiangtang Basin as the Middle⁃Late Jurassic.At the same time,the biological fauna and the rock strata combined reflect the bottom⁃dwelling fauna of a warm and normal nearshore carbonate rock sedimentary environment.This research will also provide ideas and references for the basic geological survey and oil and gas exploration in the area.

关 键 词：索瓦组 侏罗系 半岛湖地区 北羌塘盆地 生物地层学 

分 类 号：P52[天文地球—古生物学与地层学] P535[天文地球—地质学]