【摘要】 采用Sr ,C同位素地层学方法 ,对苏皖北部和辽南地区新元古代地层中碳酸盐岩进行了系统的采样和测试 ,并将其测试结果与新元古代海水Sr,C同位素组成演变曲线相比较 ,试图从中获得研究区有关地层自然层序、形成时限范围及其有关同位素年龄数据取舍等方面新的信息。研究结果表明 ,研究区的新元古代淮南群、徐淮群、宿县群和细河群、五行山群、金县群等 ,均形成于南沱冰期或Sturtian冰期之前 ,为 90 0～ 70 0Ma。并且进一步印证了淮南生物群应该属于前伊迪卡拉期的一次重要的生物大爆发。更多还原

【Abstract】 According to the methods of Sr and C isotopic stratigraphy,limestone samples were systematically collected from the Neoproterozoic successions in northern Jiangsu,northern Anhui and southern Liaoning Provinces. New findings,such as the physical sequences of the strata,the depositional ages,and the choice of the isotopic geochronologic data of the study area,were obtained by comparing the Sr and C isotope compositions with the evolution curves of the Sr and C isotopes for the Neoproterozoic and Cambrian seawater. The findings suggested that the Huainan Group,the Xihe Group and the Wuxingshan Group in the studied regions were all formed 900 Ma to 700 Ma ago,a period before the Nantuo ice period or the Sturtian ice period,and it is proved further that the Huainan Biota should be one important life explosion that belongs to the pre-Ediacaran period.更多还原