四川龙门山区晚泥盆世的轮藻化石层及其地质意义

本文描述了四川龙门山区晚泥盆世轮藻藏卵器的两个种,一是Sycidium melo F.Sandberger,(甜瓜形直立轮藻),另一是Sycidium melo var.pskowensis Karpinsky(甜瓜形直立轮藻卜斯科变种)。这两个Sycidium种的数量非常丰富,组成一Sycidium粘土层,这对理解法拉与法门期之间的生物灭绝,晚泥盆世的海退及地层中的似整合等问题是十分重要的。

THE Sycidium BED FROM UPPER DEVONIAN OF SICHUAN AND ITS GEOLOGIC SIGNIFICANCE

Two species of oogonium from the Upper Devonian Xiaolinpo Formation in Ganxi-Shawozhi section. Sichuan. are described. One isSycidutm Melo F. Sandberger which was reported by prof. Lu from Lower Devonian Lunghuashan Formation of Poxi. Yunnan. in 1948;the other is Sycidutm melo var. pskowensis Karpinsky which was reported by Wang Shui and Chang Shanjean from Middle Devonian of Ma-jiaoba, Jiangyou County. Sichuan. in 1956. Individual numbers of the two Sycidyum species are very abundant and consist of a Sycidium clay bed which is extremely important toexplain some of the current problems in argument. including mass extinction in the Fr/Fm. the Upper Devonian regression and strati-graphic paraconformities.