青海南部曲麻莱—治多地区三叠纪遗迹化石的地层学意义

青海南部曲麻莱—治多地区广泛出露厚度巨大、岩性单一、实体化石稀少的三叠系巴颜喀拉山群,其地层划分与对比因缺乏明显标志而相对困难。最近,在该地区的研究中采获大量遗迹化石,建立了8个遗迹化石组合。古遗迹学的研究表明,遗迹化石丰度、分异度及遗迹化石组合在研究区内的地层序列中存在明显差异。提出将古遗迹学特征作为一定区域内岩石地层划分对比的标志之一,为解决巴颜喀拉山群中富含遗迹化石的上部板岩组和顶部砂岩夹板岩组的划分对比提出新思路。

THE STRATIGRAPHIC SIGNIFICANCE OF THE TRIASSIC TRACE FOSSILS IN THE QUMARLEB-ZHIDOI AREA, SOUTHERN QINGHAI

The Bayanharshan Group with a great thickness, unvarying lithology, and few body fossils outcrops widely in the Qumarleb-Zhidoi area, southern Qinghai. The stratigraphic subdivision and correlation of the Bayanharshan Group are relatively difficult because of the lack of distinct fossil assemblages. Recently, abundant trace fossils have been collected by the authors, and eight ichno-assemblages have been established. According to the ichnological study, the abundance, diversity and ichno-assemblages can be used in the stratigraphic subdivision and correlation of the Bayanharshan Group. This provides a new means for the stratigraphic investigation of the Bayanharshan Group which contains abundant trace fossils.