摘要
四川桂溪地区志田纪地层，于１９７０年由四川省地质局第二区调队发现，并根据其中所含腕足类Ｅｏｓｐｉｒｉｆｅｒｔｉｎｇｉ笼统划归中志留统。１９９４年，笔者等在这段地层中发现了以牙形石Ｓｐａｔｈｏｇｎａｔｈｏｄｕｓｃｒｉｓｐｕｓ，腕足类Ｒｅｔｚｉｅｌｌａｕｎｉｐｌｉｃａｔａ，床板珊瑚Ｓｑｕａｍｅｏｆａｖｏｓｉｔｅｓ，Ｏａｃｈｙｆａｖｏｓｉｔｅｓ，Ｐａｃｈｙｃａｎａｌｉｃｕｌａ为代表的晚志留亚纪动物属种，说明该套地层的沉积时限为晚志留亚纪，并可与云南曲靖，四川广元、二郎山、盐边，甘肃迭部等地区相当地层对比。这一发现，对于完善该地区地层系统、研究扬子地台西北缘志日纪古地理演化、海进方向、地质发展史等都具有重要意义。
he Silurian strata in Guixi area, were discovered originally by the Second Party of Regional Heological Survey,Geologital Bureau of Sichuan in 1970. The strain were referred to the Middle-Upper Silurian Sweepingly based on brachiopod Eospirifer tingi. Authors of this poper found faunas with the hate Silurian characters in the strain through a detailed callection in 1994. The f3unas are represented by conodont Spathognthodus crispus,brachiopod Retziella uniplicata and tabulates:Squameofavosites,Pachyfavosites and Pachycanalicula. These faunas indicate that the strata belong to the ante Silurian and could be correlated with equivalents in Guangyan,Erlangshan and Yanbian,Sichuan,Quging,Yunnan,and Diebu, Gansu. This new discovery is very imPOrtant for study on the paleogeographical evolution, the direction of transgression and regression and geological history in the northwestern margin of the Yangtze Platform.
