本区熊耳群可划分为两个喷发旋回及五个地层组。自下而上,第一旋回包括磨石沟组、张合庙组、焦园组;第二旋回包括坡前街组、眼窑寨组。熊耳群古火山岩包括喷发相、火山管道相、次火山相及火山喷发沉积相。其喷发机构中央,发育一个熔岩穹丘带。伴随中央喷发,侧向火山活动环绕中央喷发带产生了一系列不同级别的古火山构造,包括熔岩穹丘、喷发盆地、溢流通道、爆发通道等形式,并形成一个环状卫星式的古火山构造群。 Bear ear group in this area can be divided into two eruption cycles and five stratigraphic groups. Bottom-up, the first cycle includes the Grindstone group, Zhanghemiao Formation and Jiaoyuan Formation. The second cycle includes the Poupizhan Formation and the Yaoyaozhai Formation. The Xiong’er Group ancient volcanic rocks include eruption phase, volcano pipeline phase, subvolcanic phase and volcanic eruption sedimentary facies. The center of its eruption, the development of a lava dome zone. Along with the central eruption, lateral volcanic activity surrounds the central eruption belt and produces a series of ancient volcanic structures of different levels, including lava dome, eruption basin, overflow channel, outbreak channel and other forms, and forms a ring satellite ancient volcano Constructs.