淮北地区新元古代燧石相三维保存微生物化石  

Three-dimensional preserved Neoproterozoic microorganism fossils in cherts in North Anhui region

作　　者：钱迈平[1] 袁训来[1] 汪迎平[2] 厉建华[3] 

机构地区：[1]中国科学院南京地质古生物研究所,江苏南京210018 [2]南京地质矿产研究所,江苏南京210016 [3]江苏省地质调查研究院徐州分院,江苏徐州221004

出　　处：《江苏地质》2005年第3期129-138,共10页Jiangsu Geology

基　　金：国家重点基础研究(G2000077701);基础工作专项基金(2001DEB20056);中国地质调查局综合研究项目(200113000053)共同资助

摘　　要：在淮北新元古代倪园组和九顶山组海相碳酸盐岩地层中,保存着许多燧石相微生物化石。通过对其形态结构、群落组合特征及埋藏保存状态研究,探讨其系统分类、生存环境及区域地层对比,确定这些微生物化石结构的原始性和群落的低分异性。结合相关地层中原始的光球状浮游微生物、Chuaria-Tawuia类型宏体碳质化石生物群及叠层石优势的特征考虑,这些微生物的生存时间是在南沱冰期之前。Well preserved three-dimensional microfossils, including hollow-tube-like filaments, coccoid cell-like units and spinose mierospheres, have been obtained from black-gray chert lenses in Neoproterozoie dolomites, having a Sr and C isotopoie age of about 700 Ma- 850 Ma（ Yang et al. , 2000） in Huaibei region, North China. They occur in three different levels, with grey-purple dolomite in upper part of Niyuan Formation, grey dolomite in lower part of Niyuan Formation, and grey dolomite in upper part of Jiudingshan Formation at Qingtongshan of Xuzhou and Longshan of Lingbi（Anhui） and Zhaowei-Shengdian of Tongshan（ Jiangsu ） , and are dominanted by filaments, lesser amounts of eoeeoid cells and rare spinose mierospheres. Some of eoeeid cells exhibit undivided single , spheroids, dyads, tetrads and grape-like clusters in various stages of life cycles. Morphologically, the Huaibei mierobiota, including 7 categories is largely prokaryotes or/and early eukaryotes, with filamentous forms dominating over eoceoid. Most of the Huaibei mierofossils, such as Siphonophycus sp., Eoentophysalis belcherensis, Eozygion grande, Tetraphycus conjionceum, Globophycus rugosum and Caryosphaeroides pristina, can be referred to be as cyanobacteria or other simple algae, and or perhaps bacteria, with a fair degree of certainty （Schopf, 1968; Schopf and Blacic, 1971; Hofmann, 1976; Oehler, 1978; Lo, 1980; Zhang and Yan, 1984）. The most abundant element in the Huaibei microfossils is Siphonophycus sp. （ Fig. 2 ）, characterized by hollow-tube-like filaments, nonseptate, unbranched, commonly quite long, smooth or finely rugose in surface texture. They are solitary, straight to bent, 〉200μm long （incomplete specimen） and 2μm - 12μm wide, occasionally folded and distorted. Apices apparenty capitate, more or less constricted adjacent to expanded, broadly conical, bluntly pointed terminus. Siphonophycus sp. apparently represents the preserved, originally mucilaginous, empty sheath of a Lyngbya-like or perhaps Phormidiu

关 键 词：微生物化石 新元古代 燧石岩 同位素年龄 浅海相碎屑沉积 淮北地区 

分 类 号：Q913.8[天文地球—古生物学与地层学]