【摘要】 <正> 前言阿谢尔期介于石炭纪与二叠纪之间,是一段继往开来的重要地史时期。因而对这一时期的生物,特别是对这两个纪地层划分和对比起重要作用的菊石群的研究具特别大的意义。我国二叠纪海域广泛,环境多样,而又长期保持不咸化;有利于菊石群发育,并且反映出良好的生态分异。既有地方性很强的局限海生态类型,又有全球性很强的开阔海生态类型。它们代表着两个生态意义不同的系列(周祖仁,更多还原

【Abstract】 The Asselian ammonoid fauna in China was recently discovered from the upper“Maping For- mation”at a quarry near Liuzhai of Nandan County in Guangxi. The fossil locality is situated tectonically wi- thin a semi-active area between the faults of the Nanpanjiang River and Nandan-Hechi Region, and paleogeographically on the slope in front of the beach of“the South China Restricted Sea(plat- form)”, which borders on“the Dian-Qian-Gui Open-sea(basin)”(Zhou,1986).There the fossil- bearing strata are petrologically composed of car- bonate congromerates with debris flow texture,in which the fossil fauna consists of a mixed complex of different ecological patterns of many groups, such as ammonoids,brachiopods,bivalves,gastro- pods,corals,fusulinids,crinoids,ostracods,con- odonts and trilobites.All the amminisd dered as aucchthonous with pelagic or nek tonic habits and of the same age.更多还原