河南固始花园墙组时代的新认识

Reinterpretation of the age of the Huayuanqiang Formation in Gushi, Henan

北淮阳区原来一直划归于下石炭统最下部的花园墙组其实际时代属于晚泥盆世－早石炭世早期。古孢子分析显示，其下段具有以Ｃｙｃｌｏｇｒａｎｉｔｒｉｌｅｔｅｓ－Ａｎｅｕｒｏｓｐｏｒａ－Ｒｅｔｉｓｐｏｒａ为代表的组合特征，与江苏宝应、南京茨山、安徽巢湖等地的晚泥盆世五通组孢子组合面貌类似；上段具有早石炭世杜内期色彩。为大别山北麓地层层序的建立提供了确切的生物地层资料。

Detailed investigation of stratigraphic cross-sections shows that the Huayuanqiang Formation in the Northern Huaiyang region, which was considered as the Lower Carboniferous strata, is the Upper Devonian to Lower Carboniferous in fact.The analysis of palaeo-spores indicated that its lower member contained a sporal assemblage represented by Cyclogranitriletes-Aneurospora- Retispora. This sporal assemblage is similar to that in the Wutong Formation of Late Devonian in Cishan of Nanjing, Baoyin of Jiangsu Province and Chaohu of Anhui Province. The upper member has features of Tournaisian, Early Carboniferous. This provides precise and fundamental information on biostratigraphy for the establishment of stratigraphic sequence in northern Dabieshan.