滇中鱼坝村组的建立及陆相侏罗系底界

Establishment of the Yubacun Formation and the Lower Boundary of the Continental Jurassic in Central Yunnan

滇中及相邻地区上三叠统舍资组含煤层与下侏罗统冯家河组红层之间,连续沉积了一套杂色细碎屑岩过渡层。其分布稳定,该层所含化石及磁性地层特征表明其时代属早侏罗世。因此建立下侏罗统鱼坝村组,并确定该组底界为陆相侏罗系的底界。

A set of variegated transition beds of fine-clastic rocks was continuously between coal-bearing beds of the Upper Triassic Shezi Formation and red beds of the Lower Jurassic Lufeng Formation (formerly Lower Lufeng Formation) in central Yunnan and its adjacent areas. It is persistent and was recognized as a part of the Shezi Formation and assigned to the Upper Triassic. In this paper, a new formation, the Yubacun Formation, is erected for the transition beds according to the lithological, biological and magnetostratigraphic characteristics. The new unit is identified to be Jurassic in age and its lower boundary is the lower boundary of the Jurassic System.