浙江常山黄泥塘水库剖面的生物地层学

BIOSTRATIGRAPHY OF THE HUANGNITANG RESERVOIR SECTION IN CHANGSHAN,ZHEJIANG PROVINCE

为有效保护我国第一个"金钉子"——浙江常山黄泥塘剖面的同时,又能较好地满足一般性补充研究的需求和普通大众对"金钉子"剖面化石的兴趣爱好,剖面保护单位在"金钉子"剖面附近水库边开辟了一条新剖面。该剖面地层序列完整,出露新鲜,自下而上包括印渚埠组上部、宁国组和胡乐组下部。剖面化石丰富,保存精美,除丰富的笔石外,还含有一些腕足动物、三叶虫、叶虾类和粪化石,自下而上可识别出Corymbograptus deflexus带、Azygograptus suecicus带、Exigraptus clavus带、Undulograptus austrodentatus带和Acrograptus ellesae带等笔石带。整个剖面的岩石和笔石序列与黄泥塘"金钉子"剖面一致,能进行良好对比,可作为"金钉子"剖面的一般性替代剖面,从而为进一步开展达瑞威尔阶的后层型研究提供了新的证据来源。

In order to protect effectively the Huangnitang GSSP section of the Darriwilian Stage （Ordoviclan）, a new section（the Reservoir section） near the GSSP section was excavated, to meet the demands of further research and public fossil collecting. The Reservoir section is well-exposed and has a stratigraphic sequence well comparable to that of the GSSP section, including in ascending order the Yinchufu, Ningkuo and Hulo Formations. The section contains abundant exquisitely preserved fossils, including pyritized graptolites, brachiopods, trilobites, phyllocarids and aecal pellets. Five graptolite biozones, in ascending order the Corymbograptus de flexus , Azygograptus suecicus , Exigraptus clavus , Undulograptus austrodentatus and Acrograptus ellesae Biozones are recognized in the section, showing a biostratigraphic sequence identical to that of the Huangnitang GSSP section. The reservoir section, with its complete sequence, abundant fossils and well exposure, may serve as a qualified supplementary section for the studies of the Darriwilian Stage.