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奥陶系宝塔组在扬子地层区内分布极广,以紫红色、灰白色龟裂纹(或马蹄石、网眼状)灰岩、泥灰岩著称。其岩性独特,野外易辨,可谓奥陶系上部的一个稳定标志层。但多年来,地质学界对宝塔组的确切时代及其归属于上奥陶统还是中奥陶统等存在争议。笔者据近年来在四川广元三磊坝和陕西宁强一带野外观察和所分析的牙形石化石,认为扬子地层区内该两地与其它产地的宝塔组牙形石群并非全部属于同一时期。扬子区的宝塔组应该被看成是一个穿时的跨越不同地质时期的地质体。
The Ordovician Pagoda Group is widely distributed in the Yangtze stratigraphic zone and is known for its purplish-red, gray-white tortoises (or crinoids, meshes) limestone and marl. Its unique lithology, easy to distinguish in the wild, can be described as the upper part of the Ordovician symbol of a stable layer. But over the years, geologists have argued over the exact age of pagodas and whether they belonged to the Upper Ordovician or Middle Ordovician. In recent years, the author has observed and analyzed the conodont fossils in Sanleiba, Guangyuan, Sichuan and Ningqiang areas in Shaanxi Province that not all of the pagodas in the palaeo-geoproterozoic in the Yangtze strata and other areas belong to the same period. The pagoda group in the Yangtze area should be considered as a geological body that traverses different geological periods.