四川天全、芦山、宝兴地区须家河组双壳类动物群

THE BIVALVE FAUNA OF XUJIAHE FORMATION IN TIANQUAN,LUSHAN,AND LINGGUAN-BAOXING REGIONS OF SICHUAN

文章报道四川天全沙坪、芦山双石、宝兴灵关等地的上三叠统须家河组中丰富的双壳类动物群，建立了一个以ＹｕｎｎａｎｏｐｈｏｒｕｓＰｅｒｍｏｐｈｏｒｕｓ－Ｗｅｉｙｕａｎｅｌｌａ为特征分子的组合带，分析了双壳类化石组合特征，描述双壳类化石５新种（Ｐａｃｈｙｃａｒｄｉａｓｉｃｈｕａｎｅｎｓｉｓ，Ｙｕｎｎａｎｏｐｈｏｒｕｓｂａｏｘｉｎｇｅｎｓｉｓ，Ｐｅｒｍｏｐｈｏｒｕｓｔｉａｎｑｕａｎｅｎｓｉｓ，Ｗａａｇｅｎｏｐｅｒｎａｔｕｍｉｄａ，Ｍｙｏｐｈｏｒｉｏｐｉｓｌｉｎｇｇｕａｎｅｎｓｉｓ）。它的研究对四川盆地西部和西北部须家河组地度的划分和邻区对比以及古地理概况和煤系地层的认识，提供了新的素材。

The paper reports the bivalve fauna of the Upper Triassic Xujiahe Formation inShaping-Tianquan,Shuangshi-Lushan,Lingguan-Baoxing regions of Sichuan for the first time. Abivalve 'Yunnanophorus-Permophorus -Weiyuanella' assemblage zone is established,and its characteristics are analysed. Five new species of bivalve (Pachycardia sichuanensis, Yunnanophorusbaoxingensis,Permophorus tianquanensis, Waagenoperna tumida, Myophoriopis lingguanensis) arealso described in detail and most of them are plated. This study is of practical and theoretical sigificance to the stratigraphic division and correlation of the Upper Triassic Xujiahe Formation in thewestern and north-western Sichuan Basin and adjacent regions. It also gives much new information on knowing palaeogeography and coal measures strata of these regions.