辽宁太子河流域奥陶系新观察兼论寒武-奥陶系界线

<正> 辽宁太子河流域的奥陶系经王钰等(1954)研究并取得重要进展以后,已成为华北地区奥陶系的典型剖面和对比基础。1979年8—9月间,笔者在本溪、田师付和辽阳五顶山等剖面采集了化石并着重对区内凤山组的生物群序列、寒武系与奥陶系之分界、奥陶纪地层系统及动物群序列等问题作进一步补充研究和探讨。 野外工作期间得到赵祥麟、段吉业、梁仲发等支持和帮助;施从广鉴定介形虫,杨荣庆

New investigation of Ordovician strata, with remarks on the Cambrian-Ordovician boundary in the Taizihe Valley of Liaoning province

A predominantly carbonate succession of Ordovician strata in the area of Taizihe Valley has yielded diverse faunas of cephalopods, trilobites, graptolites and conodonts which are closely related to those in the other areas of North China. Based on data available, a subdivision of Ordovician strata into five formations and seven conodont, five trilobite, five cephalopod, and four graptolite zones (assemblages, or beds) has been suggested (Table 3). However traditional practice in China is to define the Cambrian-Ordovician boundary in terms of trilobite succession. It is worthy of note that the boundary as defined on the basis of the trilobite succession lies about 15 meters below the first appearance of the Dictyonema flabelliforme-Staurograptus dicho-tomus fauna in section at Doufanggou, as well as of the Cordylodus intermedius fauna and the Levisoceras-Cumberloceras fauna in the section near Tienshifu town.