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长期以来,人们一直把四川盆地的侏罗—白垩系界线划在重庆群之顶,或城墙岩群之底,或天马山组之底。但经笔者深入研究有关介形类化石并与国际典型地区仔细对比之后认为,该界线应上提至城墙岩群中上部的七曲寺组上下段之间。典型的界线剖面位于中江石泉金鸡寺和永太老马山,以及德阳中德尖山寺。笔者对四川的侏罗—白亚系过渡层进行了生物地层单位的划分,命名了生物共存延限带Concurrent-range-zone(以下简称共延带)和生物组合 Assgmblage-zone.将整个过渡
For a long time, the Jurassic-Cretaceous boundary of Sichuan Basin has always been at the top of the group of Chongqing, or at the bottom of the wall-rock group or the bottom of the Tianmanshan Formation. However, after the author conducted an in-depth study of the related types of fossils and carefully compared them with other typical areas in the world, he believes the boundary should be raised between the upper and lower parts of the Qaishi Temple Formation in the upper part of the wall rock group. Typical boundary profiles are located in Zhongquan Shiquan Jinjue Temple and Yongtai Laoshan, and Deyang Sino-German Jianshan Temple. The author classifies the biostratigraphic units of the transitional layer of the Jurassic-Baiya System in Sichuan, and names the Concurrent-range-zone and Assgmblage-zone as the biological transitional zone.