摘要
系统分析兴山古洞口下奥陶统,包括南津关组、分乡组、红花园组及大湾组底部的几丁虫微体生物化石。鉴定几丁虫5属14种,含早奥陶世特征种Eremochitina baculata,早中奥陶世常见种Conochitina decipiens,以及华南上扬子区早奥陶世常见属种Euconochitina fenxiangensis和Lagenochitina chongqingensis。E.baculata是北冈瓦纳地区弗洛早中期的特征带化石,本文的材料为该种在华南的首次确切报道,且产出层位略低,为特马豆克期。在华南,常见于特马豆克晚期的带化石Euconochitina symmetrica在该剖面的同时段地层中暂未被发现,但形态上与之高度相似的Euconochitina fenxiangensis在该时段大量出现。比较以往发表的数据后发现,E.fenxiangensis在华南的分布广泛且产出层位较为稳定,较之E.symmetrica更易获得,或可将其作为特马豆克晚期至弗洛初期区域内地层对比的一个有效卡尺。
Chitinozoans have been systematically studied from the Lower Ordovician,including the Nantsinkuan,Fenghsiang,Hunghuayuan,and the lowermost Dawan formations,at the Gudongkou section,Xingshan Town of Hubei Province.Five genera and 14 species from this interval are identified,including the index species Eremochitina baculata,characterized species Conochitina decipiens,and regional species such as Euconochitina fenxiangensis and Lagenochitina chongqingensis.The Eremochitina baculata Biozone was used to specify the lower-middle Floian which was underlain by the Eremochitina brevis Biozone and overlies the Euconochitina symmetrica Biozone.However,the index species was discovered in the upper Tremadocian at Gudongkou,which is older than previously known.In South China,the index species Euconochitina symmetrica was missing at Gudongkou.Instead,Euconochitina fen-xiangensis,which resembles E.symmetrica in morphology and vesicle size,is abundant in the same interval.More-over,by summarizing the previous data,it is obvious that the E.fenxiangensis is widely distributed on the South China Palaeoplate with a relatively stable and limited lithostratigraphic range,and a significant abundance.It seems E.fenxiangensis has the potential to be an index fossil for the upper Tremadocian to lower Floian within South China.
作者
梁艳
栾晓聪
LIANG Yan;LUAN Xiaocong(State Key Laboratory of Palaeobiology and Stratigraphy,Nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences,Nanjing 210008;Center for Excellence in Life and Paleoenvironment,Chinese Academy of Sciences,Nanjing 210008)
出处
《微体古生物学报》
CSCD
北大核心
2019年第4期328-336,共9页
Acta Micropalaeontologica Sinica
基金
国家自然科学基金委(41602010,41972015)
中国科学院先导B专项(XDB26000000)的资助
国际地学项目IGCP653‘The Onset of the Great Ordovician Biodiversification Event’的阶段性成果.
关键词
分乡组
红花园组
特马豆克期
弗洛期
生物地层
扬子区
Fenghsiang Formation
Hunghuayuan Formation
Tremadocian
Floian
biostrati-graphy
Yangtze Platform
作者简介
通讯作者:梁艳,E-mail:liangyan@nigpas.ac.cn;通讯作者:栾晓聪,E-mail:xcluan@nigpas.ac.cn
