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湖北宜昌樟村坪位于峡东黄陵背斜北翼,区内埃迪卡拉系陡山沱组沉积序列与贵州瓮安地区相似.在其上部硅磷质结核中发现大量以具刺疑源类为主的微体化石,微体化石组合面貌显示出与瓮安磷酸盐化生物群和峡东硅化生物群具有明显的相似性,表明樟村坪地区陡山沱组可以作为贵州瓮安与峡东地区陡山沱组地层对比的桥梁.同时,还报道了在该区陡山沱组中部暴露间断面之下火山岩夹层中所获得的锆石SHRIMPⅡU-Pb年龄(614.0±7.6)Ma.这是首次在陡山沱组中部获得锆石年龄,这一结果不但丰富了扬子板块埃迪卡拉系陡山沱组的同位素测年数据,也为埃迪卡拉纪年代地层的精确划分提供了一个新的数据;该数据也将扬子板块陡山沱组中部普遍发育的暴露间断面的地质时代均限定在晚于(614.0±7.6)Ma,同时,这一数据将黔中地区陡山沱组中部暴露间断面之上出现的磷酸盐化生物群的地质时代也限定在晚于(614.0±7.6)Ma.
Zhangcunping, Yichang, Hubei Province, is located in the north wing of the Huangling anticline in the eastern part of the Gaxi. The sedimentary sequence of the Doushantuo Formation in the Edicala Formation in the area is similar to that of the Weng’an area in Guizhou Province. The assemblage of microfossils and microfossils showed obvious similarities with the Weng’an phosphate-salified biota and the Xiaodong silicified biota, indicating that the Doushantuo Formation in Zhangcunping can be used as the site of Weng’an and Gorge And a comparison of the Doushantuo Formation stratigraphy in the eastern region of China with the SHRIMPⅡU-Pb zircon (614.0 ± 7.6) Ma reported in volcanic intercalations beneath the exposed central section of the Doushantuo Formation in the area For the first time, the zircon age was obtained in the middle part of Doushantuo Formation. This result not only enriches the isotopic dating data of the Dachanntuo Formation of the Edicala Formation in the Yangtze Plate, but also provides a new definition for the precise division of the Edicala era strata This data also limits the geologic age of the exposed discontinuities commonly found in the middle of the Doushantuo Formation in the Yangtze block to be less than (614.0 ± 7.6) Ma. At the same time, this data disconnects the central part of the Doushantuo Formation in central Guizhou Phosphates appear above the surface Geological age group was also defines the Ma later than (614.0 ± 7.6).