江苏句容青山早三叠世鱼类化石埋藏学研究  

Taphonomy of Early Triassic fish fossils near Qingshan,Jurong City,Jiangsu Province,China

作　　者：章其华[1] 钱迈平[2] 马雪[2] 单以春 陈彦瑾[1] 续琰祺 Zhang Qihua;Qian Maiping;Ma Xue;Shan Yichun;Chen Yanjin;Xu Yanqi(Geological Survey of Jiangsu Province,Nanjing 210018,Jiangsu,China;Nanjing Center,China Geological Survey,Nanjing 210016,Jiangsu,China)

机构地区：[1]江苏省地质调查研究院,江苏南京210018 [2]中国地质调查局南京地质调查中心,江苏南京210016

出　　处：《地质学刊》2022年第1期9-16,共8页Journal of Geology

基　　金：江苏省自然资源科技项目“江苏省句容青山中生代地质遗址调查与评价”(KJXM2019029)。

摘　　要：江苏句容青山出露一套下三叠统青龙组和龙山段滨海-浅海相泥岩、碳酸盐岩沉积地层,含鱼类、节肢类、菊石、双壳类及牙形石等化石。有的鱼类化石保存在结核中,反映了一种特殊的埋藏环境。沉积学研究显示,早三叠世奥伦尼克阶斯密斯亚阶时期,该区主要为热带浅海大陆架,局部为潮坪。软质海底通常水动力条件较弱,海水富氧清澈,但大风暴或海啸会将海底淤泥掀起,海水因而缺氧浑浊。从化石埋藏保存的状态分析,不同生长阶段的、呈直挺或扭曲挣扎姿态的鱼类化石以及一些其他生物化石均保存在结核中,埋藏在一层灰黑色富含微小草莓状黄铁矿颗粒的泥岩里。显然,当时一场灾变突发,一股富含H_(2)S的黑色泥浆水团侵入了鱼类等生物生活的水域,毒杀并掩埋了这些生物,经厌氧微生物的作用,最终形成包裹鱼类等生物化石的泥灰岩结核。Fossil fishes,arthropods,ammonites,bivalves,conodonts and so on were preserved in a suite of littoral and shallow-marine facies mud and carbonate sedimentary rocks of the Lower Triassic Helongshan Member of the Qinglong Formation near Qingshan,Jurong City,Jiangsu Province.Some of the fish fossils preserved inside of the marl concretions of the mudstone indicated a kind of special burial environment.Sedimentologic researches indicated the fish fossils sites were mainly located in a tropical shallow continental shelf,partly in tidal beach,during the Smithian Substage of the Olenekian Stage of the Early Triassic.It was ooze seabed with weak hydrodynamic condition,oxygen-rich and clear seawater,while anoxic turbid seawater with mud would be raised from seabed when giant storm surges or seismic sea waves occurr.Taphonomic analysis found that these fishes and other creatures of different ages,straight and twisted postures died and were buried in the grey-black mud with abundant small pyrite framboids almost at the same time.It is suggested that a sudden catastrophic event occurred when a black mass of H_(2)S-rich muddy water invaded the waters where fish and other creatures lived,poisoned and buried them,and eventually formed marl concretions that wrapped fish and other creatures′fossils by anaerobic microbial action.

关 键 词：早三叠世 鱼类化石 埋藏学 江苏句容 

分 类 号：P534.51[天文地球—古生物学与地层学] Q915.23[天文地球—地质学]