中国志留纪年代地层学述评

198 4年国际地层委员会志留系分会提出的分统建阶新方案使各国地质学家得以在相同的时间界面上探讨具有全球意义的地质和生物事件。数十年来我国志留纪地层研究进展不小 ,但与国际水平相比 ,研究现状还不能令人满意 ;特别是系内绝大部分的统、阶的界线尚未在全国范围内划定 ,成为当前我国志留系研究最迫切需要解决的问题。本文赞成我国志留纪年代地层框架宜采用“四分统”的方案 ,论述国内志留系顶底界、温洛克统顶底界、罗德洛统顶界的确定并讨论扬子区大部分地区是否发育比兰多维列统更高的志留纪地层的问题。

Comments on Silurian Chronostratigraphy of China

The chronostratigraphical classification for the Silurian System,as arrived at by the Subcommission on Silurian Stratigraphy,was ratified by the International Commission on Stratigraphy in 1984.It makes all Silurian stratigraphers possible to study international geological and biological events at various synchronous intervals.Much progress has been made from research on the Silurian chronostratigraphy of China,but there are many steps to go.In particular,many boundaries between series and stages in China have not been defined yet.The lower and upper boundaries of the Sylurian System,lower and upper boundaries of Wenlock Series,and upper boundary of Ludlow Series in China are discussed in this paper.The development of the later Silurian rocks in the great majority part of the Yangtze Region,South China is discussed as well.