黔东北思南大息场志留系香树园组的时代和岩相-生物相  

AGE,LITHO-AND BIOFACIES OF THE EARLY SILURIAN XIANGSHUYUAN FORMATION AT THE DAXICHANG SECTION IN SINAN COUNTY,NORTHEASTERN GUIZHOU PROVINCE

作　　者：于深洋 李启剑[2] 刘运泽 毛颖颜[2] 胡伟 邓小杰 YU Shenyang;LI Qijian;LIU Yunze;MAO Yingyan;HU Wei;DENG Xiaojie(School of Geography and Tourism,Qufu Normal University,Rizhao 276826,P.R.China;Nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences,Nanjing 210008,P.R.China;The Xinjiang Branch of Daqing Oilfield Limited Company,Korla 841009,P.R.China;Shaanxi Yanchang Petroleum,Yanan 716000,P.R.China;Guizhou Geological Survey,Guiyang 550081,P.R.China)

机构地区：[1]曲阜师范大学地理与旅游学院,日照276826 [2]中国科学院南京地质古生物研究所,南京210008 [3]大庆油田有限责任公司新疆分公司,库尔勒841009 [4]延长石油集团延长气田采气四厂,延安716000 [5]贵州省地质调查院,贵阳550081

出　　处：《微体古生物学报(中英文)》2024年第4期320-331,共12页Acta Micropalaeontologica Sinica

基　　金：山东省自然科学基金(ZR2021QD147,ZR2022QC257);国家自然科学基金(42202007);江苏省青年科学基金项目(BK20210993);现代古生物学和地层学国家重点实验室开放课题的资助(223135)。

摘　　要：黔东北志留纪兰多维列世鲁丹中期至埃隆中期的香树园组,具有显著的岩相-生物相分异。靠近滇黔桂古陆的“白沙型”香树园组,记录了奥陶纪末大灭绝后,志留纪早期后生动物礁在浅水区的复苏过程;离古陆稍远的思南鹦鹉溪镇大息场剖面的“印江型”香树园组,以正常浪基面之下、伴有少量陆源碎屑的碳酸盐岩沉积为主,后生动物化石的多样性和丰度较低,志留纪常见的造礁生物如珊瑚、层孔虫、苔藓虫等较少见。大息场剖面香树园组的无机碳同位素曲线,结合枝线贝类风暴层层位和大息场组产出的笔石,指示该剖面香树园组时代为埃隆早期。在埃隆早期,滇黔桂古陆从近岸浅水区到远岸广海区,依次呈现出造礁生物密集生长的生物层-缺少造礁生物的碳酸盐岩-黑色笔石页岩的岩相-生物相分异,凸显了志留纪早期黔东北地区海水深度对底栖生态组合多样性和后生动物礁分布的控制作用。The Xiangshuyuan Formation of Middle Rhuddanian to Middle Aeronian(Llandovery,Silurian)in the northeastern Guizhou Province is divided into the“Baisha-type”and“Yinjiang-type”based on lithofacies and biofacies.The“Baisha-type”Xiangshuyuan Formation,deposited near the shore of the Dianqiangui Oldland,records the recovery history of metazoan reefs in shallow waters in the aftermath of the end-Ordovician mass extinction.In contrast,the"Yinjiang-type"Xiangshuyuan Formation at the Daxichang section in Yingwuxi Town,Sinan County,located slightly farther from the Dianqiangui Oldland,consists mainly of limestones deposited below the fair-weather wave base with limited terrigenous clastic input.The limestones of the Xiangshuyuan Formation at the Daxichang section contain metazoan fossils with a lower diversity and abundance,and rare occurrences of Silurian reef-builders such as corals,stromatoporoids,and bryozoans.Theδ13Ccarb curve and the horizon of virgianid brachiopod tempestites of the Xiangshuyuan Formation,together with graptolites from the Daxichang Formation,suggests the Xiangshuyuan Formation at the Daxichang section dates to the Early Aeronian.During the Early Aeronian,high-abundance metazoan biostromes,carbonates lacking reef-builders,and black graptolitic shales occurred respectively from the nearshore zone of the Dianqiangui Oldland to the open sea.The litho-and biofacies differentiations indicate that the water depth played a crucial role in shaping the benthic diversity and distribution of metazoan reefs in the northeastern Guizhou during the Early Silurian.

关 键 词：无机碳同位素地层 岩相-生物相 香树园组 埃隆早期 华南 

分 类 号：Q911[天文地球—古生物学与地层学] P534.43[生物学—古生物学]