黔东北志留系香树园组的生物-沉积相变  

BIOTIC AND LITHOLOGICAL TRANSITIONS OF THE SILURIAN XIANGSHUYUAN FORMATION IN THE NORTHEASTERN GUIZHOU

作　　者：郭伟[1] 邓小杰 梁萍萍[1] 于深洋 赵萌 李越[5] GUO Wei;DENG Xiaojie;LIANG Pingping;YU Shenyang;ZHAO Meng;LI Yue(PetroChina Research Institute of Exploration&Development,Beijing 100083,P.R.China;Guizhou Geological Survey,Guiyang 550081,P.R.China;School of Geography and Tourism,Qufu Normal University,Rizhao 276826,P.R.China;Southwest Oil&Gasfield Company of PetroChina,Chengdu 610000,P.R.China;State Key Laboratory of Palaeobiology and Stratigraphy,Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment,Chinese Academy of Sciences,Nanjing 210008,P.R.China)

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]贵州省地质调查院,贵阳550081 [3]曲阜师范大学地理与旅游学院,日照276826 [4]中国石油西南油气田分公司,成都610000 [5]中国科学院南京地质古生物研究所现代古生物学和地层学国家重点实验室,中国科学院生物和古环境卓越创新中心,南京210008

出　　处：《微体古生物学报》2023年第3期227-234,共8页Acta Micropalaeontologica Sinica

基　　金：贵州省科技计划项目(黔科合支撑[2020]4Y033号以及黔科合支撑[2021]一般463号);西南油气田分公司项目(编号:XNS25JS2020)的支持。

摘　　要：华南板块上扬子区志留系兰多维列统鲁丹阶中部–埃隆阶中部香树园组的沉积环境背景有差异性。滇黔桂古陆以北的陆表海区,即黔东北铜仁地区分别出现近岸浅海的白沙型礁滩相和远岸偏深水的印江型灰岩-碎屑岩相。印江型沉积区的缠溪剖面香树园组露头实测厚度约27 m,中-薄层灰岩中常含石英细砂颗粒,选择12个岩石薄片作微相鉴定和图示。灰岩中的生物多样性和丰度偏低,均为常见的正常浅海壳相化石类型,破碎程度偏高的细颗粒生屑与钙质砂屑共同形成浅海滩相单元。缠溪很接近白沙型分布区,白沙型-印江型的生物-岩相转换是在浪基面附近的缓坡带发生的,白沙型后生动物造礁群落短期生长且限于石阡-思南的近岸海域,未能向北面的缠溪外海区拓展。During the middle Rhuddanian to middle Aeronian(Llandovery,Silurian),sedimentary parameters on the marine-floor were differentiation in the upper Yangtze region of South China Block.The Xiangshuyuan Formation was deposited in Tongren of the northeastern Guizhou,an epicontinental sea northward of the Dian-Qian-Gui land palaeogeographically.The reef-bank facies of the Baisha-type in the near-shoal and equivalent mixed limestoneterrigenous clast of the Yinjiang-type in the off-shoal were respectively occurred.The Xiangshuyuan Formation with outcropped thickness of 27 m at the Chanxi section,Yinjiang County was situated in the Yinjiang-type region,but spatially closed to the Baisha-type region.Fine quartz grains exist commonly in the thin-medium bedded limestones.Altogether 12 thin sections are illustrated for microfacies dating.Biotic elements are common taxa of shallow-marine,but low in biodiversity and abundance.Fine-grained and higher fragmented shells and sandy-sized intraclasts are of the main components in bank formation.Biotic and lithological transitions between the Baisha and Yinjiang types were occurred in a shallow ramp with depth around the wave-base.Metazoan reef-building communities were short-term existence and limited ecological realm in the Shiqian-Sinan near-shoal without spatial extension toward off-shoal of Chanxi.

关 键 词：生物相-岩相 印江型香树园组 志留系 印江缠溪 上扬子区 

分 类 号：P618.13[天文地球—矿床学]