黔南早石炭世牙形石及泥盆－石炭系界线

THE EVONIAN-CARBONIFEROUS BOUNDARY BASED ON LOWER CARBONIFEROUS CONODONTS IN GUIZHOU

本文根据早石炭世牙形石、珊瑚、腕足等化石的对比研究，认为贵州独山及睦化一带的泥盆－石炭系界线应划在革老河组底部，主要依据如下：（１）者王组的牙形石Ｂｉｓｐａｔｈｏｄｕｓａｃｕｌｅａｔｕｓ，Ｂ．ａｎｔｅｐｏｓｉｃｏｒｎｉｓ，最早出现在晚泥盆末期的Ｗｏｃｋｌｕｍｅｒｉａ带内；（２）者王组中Ａｃｔｉｎｏｓｔｒｏｍａ，Ｐｓｅｕｄｏｌｅｂｅｃｈｉａ，Ｓｔｒｏｍａｔｏｅｅｒｉｕｍ等层孔虫的一些属种，与西欧晚泥盆世艾特隆层的分子极为相近；（３）革老河组产腕足，珊瑚、牙形石等，与上覆汤耙组的一些属种，具有密切的演化关系，但与其下伏者王组的属种却存在很大差异。因此，作者提出将泥盆－石炭系的分界线，置于革老河组Ｃｙｓｔｏｐｈｒｅｎｔｉｓ－ｃｏｍｐｓｉｔｅ－Ｓｈｕｃｈｅｒｔｅｌｌａ组合带之底部。

On the basis of the correlation of conodont, brachiopod and coral fossils contained in EarlyCarboniferous strata of platform facies in Duoshan and basinal facies in Muhua, Guizhou, the au-thor holds that the Devonian-Carboniferous boundary should be placed at the base of the GedaoheFormation. The main grounds are as follows: (1) the conodonts Bispathodus aculeatus and B. an-teposicornis in the Zhewang Formation first appear in the terminal Late Devonian WocklumeiaZone; (2) the stromatoporoids Pseudolebechia cumpacta, Stromatocerium eximium and Actinostro-ma contortum occurring in the Zhewang Formation are very similar to those from the Etroeungti-am (Late Devonian) bed of Western Europe; (3) the brachiopods, corals and conodonts in theGelaohe Formation have a close phylogenetic relation with some taxa in the Tangbagou Formationbut are notably different from those in the underlying Zhewang Formation. Therefore, the authorsuggests that the Devonian-Carboniferous boundary should be placed at the base of theCystophrentis -Compsite-Shuchertella Zone.