论文部分内容阅读
本文作者对河北唐山赵各庄剖面的北庵庄组(原称下马家沟组)和马家沟组(原称上马家沟组)较系统地采集了牙形刺样品,通过对所获之牙形刺标本和安太库等(1983)在同一剖面所描述的牙形刺动物群仔细研究,得到一些新的认识、分带及对比意见。唐山赵各庄剖面不仅具有丰富各异的地方型分子,如Aurilobodus leptosomatus,Loxodus dissectus,Tangshanodus tangshanensis,Rhipidognathus maggolensis,R.laiwuensis,Triangulodus changshanensis和Erraticodon tangshanensis外,尚有一些分布广泛和具地层意义的重要分子,如Histiodella holodentata,Eoplacognathus pseudoplanus和Eoplacognathus suecicus等。根据这些重要分子和牙形刺分带原则,本文对安太庠等(1983)的牙形刺分带重新修订,即将北庵庄组的Aurilobodus leptosomatus-Loxodus dissectus带和Tangshanodus tangshanensis带修正为Histiodella holodentata-Tangshanodus tangshanensis带,并由下而上可划分为Rhipidognathus maggolensis和R.laiwuensis两地方型亚带;将马家沟组的Eoplacognathus suecicus-Acontiodus?linxiensis带和Plectodina onychodonta带修正为Eoplacognathus suecicus带,并由下而上又可划分为Acontiodus?linxiensis和Plectodina onychodonta两个地方型牙形刺亚带。因此,唐山地区的北庵庄组产牙形刺的部分和马家沟组可与华南的牯牛潭组和新疆塔里木盆地的大湾沟组对比,归入奥陶纪达瑞威尔阶(Darriwilian),从而改变了过去将北庵庄组产牙形刺的层位,即所谓的Aurilobodus leptosomatus-Loxodus dissectus带和Tangshanodus tangshanensis带与华南区大坪阶(Dapingian)的大湾组相对比的认识。
The authors collected conodont samples systematically from the North Anzhuang Formation (formerly Majiagou Formation) and the Majiagou Formation (formerly Majiagou Formation) of the Zhaogezhuang section of Tangshan, Hebei Province, Conodont specimens and amphibious fauna groups described by Antarctica (1983) in the same section have been carefully studied and some new insights, zonation and contrastive observations have been obtained. There are some widely distributed and stratigraphic significance outside the Zhaogezhuang section of Tangshan, including not only Aurilobodus leptosomatus, Loxodus dissectus, Tangshanodus tangshanensis, Rhipidognathus maggolensis, R. laiwuensis, Triangulodus changshanensis and Erraticodon tangshanensis Molecules such as Histiodella holodentata, Eoplacognathus pseudoplanus, and Eoplacognathus suecicus. According to these important molecular and conodont zoning principles, this paper redesigned the conodonts of Ann Taizi et al. (1983), that is, the Aurilobodus leptosomatus-Loxodus dissectus and Tangshanodus tangshanensis belts in Bei’anzhuang Formation were revised to Histiodella holodentata -Tangshanodus tangshanensis belt, and can be divided into two subfamilies of Rhipidognathus maggolensis and R.laiwuensis from bottom to top; the Eoplacognathus suecicus-Acontiodus linxiensis belt and Plectodina onychodonta belt in the Majiagou group were revised to Eoplacognathus suecicus belt, Bottom up and can be divided into Acontiodus linxiensis and Plectodina onychodonta two local toothache sub-band. Therefore, the part of the North Anzhuang Formation and the Majiagou Formation in the Tangshan area can be compared with the Darwanwur Formation in the Huanniutan Formation in South China and the Dawanggou Formation in the Tarim Basin in Xinjiang, and are classified as Darriwilian Ordovician, This changed the understanding of the past comparison of the formation of the conodonts in the North An Zhuang Formation with the so-called Aurilobodus leptosomatus-Loxodus dissectus and Tangshanodus tangshanensis and the Dapingian Dawan Formation in South China.