宜昌峡东地区埃迪卡拉系陡山沱组疑源类化石新材料及其生物地层学意义  

NEW MICROFOSSILS FROM THE EDIACARAN DOUSHANTUO FORMATION IN THE YANGTZE GORGES AREA,SOUTH CHINA,AND THEIR BIOSTRATIGRAPHIC IMPLICATIONS

作　　者：欧阳晴[1,2] 周传明[1] 关成国[1] 王伟[1] 

机构地区：[1]中国科学院资源地层学与古地理学重点实验室,中国科学院南京地质古生物研究所,南京210008 [2]中国科学院大学,北京100049

出　　处：《古生物学报》2015年第2期207-229,共23页Acta Palaeontologica Sinica

基　　金：国家科技部973项目(2013CB835005);中国科学院重点部署项目(KZZD-EW-02)的经费资助

摘　　要：在湖北宜昌秭归青林口剖面埃迪卡拉系陡山沱组二段燧石结核中发现大量微体化石,其中包括大型带刺疑源类8属9种(含1个未定种):Appendisphaera?hemisphaerica,A.magnifica,Dicrospinasphaera zhangii,Eotylotopalla dactylos,Mengeosphaera chadianensis,Taedigerasphaera lappacea,Tanariumsp.,Tianzhushania spinosa,以及Variomargosphaeridium lithoschum。同时在宜昌秭归金瓜墩剖面陡山沱组二段发现一些新的具刺疑源类化石材料,结合过去的报道,总结该剖面陡山沱组二段的疑源类化石组成:共7属9种(含3个未定种和1个相似种),及1个不定种,包括Appendisphaera magnifica,Appendisphaera sp.,Dicrospinasphaera zhangii,Knollisphaeridiumsp.,Mengeosphaera chadianensis,Mengeosphaera sp.indet.,Tianzhushania spinosa,Variomargosphaeridium lithoschum,Weissiella cf.brevis,以及Weissiella sp.。在宜昌三斗坪九龙湾剖面陡山沱组二段发现具刺疑源类Variomargosphaeridium lithoschum。这些化石材料丰富了对峡东地区陡山沱组二段具刺疑源类化石组成的认识,表明峡东地区陡山沱组具刺疑源类下组合与上组合在化石组成上的差别或许小于过去的认识。Diverse and abundant acanthomorphic acritarchs,which in recent years have emerged as a useful biostratigraphic tool for the subdivision and correlation of the lower Ediacaran,occur in the Ediacaran Doushantuo Formation in the Yangtze Gorges area, South China. Two acritarch assemblages have been established in the lower and upper Doushantuo Formation,respectively,in the Yangtze Gorges area.Their correlations with Ediacaran acritarch assemblages outside the Yangtze Gorges area,however,are open to debate.Here we report microfossils discovered from Member II chert nodules of the Doushantuo Formation in the Qinglinkou and Jinguadun section of the Yangtze Gorges area.The Qinglinkou microfossil assemblage contains cyanobacteria,acritarchs and multicellular algae,from which 8genera and 9species of large acanthomorphic acritarchs were identified：Appendisphaera？hemisphaerica,A.magnifica,Dicrospinasphaera zhangii,Eotylotopalla dactylos, Mengeosphaera chadianensis,Taedigerasphaera lappacea, Tanarium sp.,Tianzhushania spinosa,and Variomargosphaeridium lithoschum.The Jinguadun microfossil assemblage includes 7genera and 9species of large acanthomorphic acritarchs：Appendisphaera magnifica,Appendisphaera sp.,Dicrospinasphaera zhangii,Knollisphaeridium sp.,Mengeosphaera chadianensis, Mengeosphaera sp. indet.,Tianzhushania spinosa,Variomargosphaeridium lithoschum,Weissiella cf.brevis,and Weissiella sp..In addition,one specimen of Variomargosphaeridium lithoschum was discovered in the Jiulongwan section. Among these microfossils,Taedigerasphaera lappacea has been previously described only in Weng＇an,Guizhou Province,and Variomargosphaeridium and Weissiella are for the first time reported in Member II of Doushantuo Formation in the Yangtze Gorges area.The discovery of these microfossils indicates that the acritarch assemblage in the lower Doushantuo Formation may be more diverse than previously thought,and the radiation of large acanthomorphic acritarchs may take place soon after the termination of the Neoproterozoic global

关 键 词：疑源类 生物地层学 陡山沱组 埃迪卡拉系 峡东地区 

分 类 号：Q913.2[天文地球—古生物学与地层学]