苏南皖东五通组观山段中的痕迹化石及其环境意义

Environmental Significance of the Trace Fossils from Guanshan Member, Wutong Formation,Southern Jiangsu and Eastern Anhui,South China

在苏南孔山剖面和皖东太湖山剖面上泥盆统五通组观山段采集到痕迹化石１１属１３种，依据其组成和分布特征，将这些痕迹化石划分为两个组合，即Ａｒｅｎｉｃｏｌｉｔｅｓ组合和Ｐａｌａｅｏｐｈｙｃｕｓ组合．前者可归入Ｓｅｉｌａｃｈｅｒ（１９６７）的Ｓｋｏｌｉｔｈｏｓ痕迹相，代表高能滨岸环境；后者可归入Ｃｒｕｚｉａｎａ痕迹相，代表正常浅海环境．对Ｐａｌａｅｏｐｈｙｃｕｓ组合进一步划分，区别出Ａ、Ｂ两个亚组合．分析表明，亚组合Ｂ形成于比亚组合Ａ稍远稍深的滨外环境，这一结论，与前人认为五通组为陆相沉积不同．

Thirteen species of eleven ichnogenera have been found in Upper Devonian Guanshan Member of Wutong formation from Kongshan section of Southern Jiangsu and Taihushan section of Eastern Anhui province.In terms of the composition and distribution features of the trace fossils,they can be divided into two associations:(1)Arenicdites association;(2)Palaeophycus association.The former falls in Seilacher′s Skolithos ichnofacies,occurring in high energy shoreline environment,and the latter is a part of Cruziana ichnofacies,representing normal shallow marine environment.Two sub associations,A and B are recognized from palaeophycus association,analyses of which indicate that sub association B occurs in deeper and more distal shoreface zone.The conclusion is different from the previous view that Wutong Formation is terrestrial deposit.