广西荔浦晚泥盆世法门期竹节石

本文研究了广西荔浦上泥盆统榴江组上部扁豆状灰岩中所含的法门期竹节石2属3种,其产出层位分别为牙形刺化石带的 Palmatolepis crepida带和 Pa.marginifera带。

LATE DEVONIAN FAMENNIAN TENTACULITES FROM LIUJIANG FORMATION OF LIPU, GUANGXI, CHINA

The Lipu section(Fig.1)is located 2 km northwest of Lipu. The Liujiang Formation iswell-developed in Lipu County and is divided into two members. The lower member containsabundant radiolarians and tentaculitids. The upper member consists of crystalline limestone,a small amount of stratified limestone, containing numerous conodonts and some tentaculi-tids, the sequence of its upper part is as follows: Overlying bed:Lower Carboniferous Yanguanian silicalite --conformity--Liujiang Formation (upper member) 28. Grey crystalline limestone, Spathognathodus stabilis, S. crassidentatus, Falcodusangulus 0.20m 27. Grey crystalline limestone with a small amount of stratified limestone. Ozarkodi-na homoarcuata,Falcodus variabilis,Euprioniodina alternata 0.70m 26. Grey crystalline limestone. Ozarkodina sp. 0.30m 25. Grey and greyish green limestone. Styliolina sp. B,Palmatolepis glabra distorta,Pal. marginifera 0.60m 24. Grey crystalline limestone 0.25m 23. Greyish yellow crystalline limestone. Styliolina sp. A,Palmatolepis glabra pecti-nata,Pal. glabra lepta 0.25m 22. Grey crystalline limestone. Striatostyliolina striata,Scutula venusta 0.25m 21 -- 1. (omitted) The Lipu section shows that Striatostyliolina striata and Styliolina sp. A occur in Beds22 and 23 in association with Scutula venusta,Palmatolepis glabra pectinata,Pal. glabra leptawhich are the main components of the"crepida zone" and Bed 25 contains Styliolina sp. B inassociation with Palmatolepis glabra distorta,Pal. marginifera, the main elements of the"marginifera zone". This again proves that the extinction of tentaculitids is not in the Frasni-an Stage, but in the Famennian Stage.