白云鄂博群渣尔泰群和化德群的时代隶属

THE AGES OF THE BAYAN OBO GROUP,ZHARTAI GROUP AND HUADE GROUP

白云鄂博群的时代隶属一直存在着争论,因为缺乏可靠的古生物化石依据。笔者等在华北地台北缘“内蒙地轴”范围内原太古宙、元古宙地层中发现大量早寒武世小壳化石。本文根据小壳化石的出现和对叠层石、同位素年龄的认识和讨论,阐明笔者的观点和论据,认为白云鄂博群、渣尔泰群和化德群均形成于早古生代早期,是可以对比的同时代产物。

The age assignment of the Bayan Obo Group has long been disputed mainly for lack of reliable paleontological evidence. The author and his colleagues found large amounts of Early Cambrian small shelly fossils in the original Archean and Proterozoic strata within the realm of the 'Inner Mongolian axis'on the northern margin of the North China platform. On the basis of the appearance of small shelly fossils and recognition and discussion of strotomalites and isotopic ages, the author expounds his view and augurnents. He holds that the Bayan Obo Group, Zhartai Group and Huade Group were all formed in the early Early Paleozoic and are the contemporaneous products. They can be correlated.