湖北利川二叠纪生物礁的埋藏学特征及其环境意义  

TAPHONOMIC CHARACTERISTICS OF A PERMIAN CALCISPONGE REEF IN LICHUAN,HUBEI PROVINCE AND ITS PALEOENVIRONMENTAL SIGNIFICANCE

作　　者：李阳[1,2,3] 吴亚生[1,2,3] 姜红霞 LI Yang;WU Ya-sheng;JIANG Hong-xia(Key Laboratory of Petroleum Research, CAS;Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China;2 Institutions of Earth Science, Chinese Academy of Sciences, Beijing 100029, Chin;3 University of Chinese Academy of Sciences, Beijing 100049, China;4 Hebei GEO University, Shijiazhuang 050031, China)

机构地区：[1]中国科学院油气资源研究重点实验室中国科学院地质与地球物理研究所,北京100029 [2]中国科学院地球科学研究院,北京100029 [3]中国科学院大学,北京100049 [4]河北地质大学,石家庄050031

出　　处：《古生物学报》2018年第2期212-227,共16页Acta Palaeontologica Sinica

基　　金：国家自然科学基金(41372121);国家重大专项(2016ZX05004006)联合资助

摘　　要：二叠纪钙质海绵礁的研究已逾百年,但缺乏埋藏学方面的研究。本文选取鄂西利川典型钙质海绵礁剖面,对造架生物的属种组成、保存状态(直立还是倒伏)、个体大小、古石孔藻包壳和泥晶含量进行统计研究。共鉴定出17个属种的钙质海绵和一个属种的水螅;通过统计研究发现,含钙质海绵的灰岩厚98m,其下部4/5厚度所含钙质海绵以倒伏的为主,上部1/5厚度以直立的为主;含倒伏钙质海绵的灰岩中藻包壳(古石孔藻)不发育,钙质海绵以直立为主的灰岩中,藻包壳发育;钙质海绵的个体大小由海绵灰岩下部而上增大不明显;泥晶基质的含量自海绵灰岩的下部而上明显减少。由此推断:下部的钙质海绵灰岩形成时由于没有藻包壳,大多被风浪打倒。上部具有藻包壳的钙质海绵灰岩,尽管形成时的水动力能量更强,但由于有藻包壳,其抗风浪能力得到加强,所以大多直立保存。The calcisponge reefs in Lichuan, western Hubei Province is analyzed for reef-building organism composition, preservation status calcisponges, size of calcisponges, contents Archaeolithoporella encrustations and micrites. A total of 17 genera of calcisponges and one genus of hydrozoan are found in the reef-core facies （Layers 8-10）. The 8th to 9th layers are mainly composed of toppled sponges and have little content of Archaeolithoporella encrustations, while the 10th layer has more contents of erect calcisponges and Archaeolithoporella encrustations. The average diameters of the calcisponges in the 8th to 10th layers increase a little, but the content of micrites gradually declines. Thus we infer that the reef-building organisms in the 8th to 9th layers formed under less strong hydrodynamic conditions, and were mostly toppled. For the 10th layer, the hydrodynamic conditions are stronger, but, the Archaeolithoporella encrustations enhanced the anti-wave organisms positions. capability of the reef-building and they were preserved in erect

关 键 词：生物礁 钙质海绵 埋藏学 古石孔藻包壳 泥晶含量 二叠纪 湖北利川 

分 类 号：Q911[天文地球—古生物学与地层学]