习题6-9
一个地区沿着垂直于地层走向方向地层有对称重复出现,而且中间地层老,两侧地层新,地层分界线平行延伸,则该地区存在?There is a symmetrical repetition of strata along the direction perpendicular to the stratum stratum, and the middle stratum is old, the strata on both sides are new, and the stratum boundaries extend in parallel. This area exist( )?