The geochronologic unit is belonged to Early Age of Middle Devonian Epoch, and correspond to Eifelicus Stage-Jiweite Stage, and is belonged to Daminshan Formation of Devonian system.
时代属于中泥盆世早期，大体相当于艾菲尔阶-吉维特阶，应归属为大民山组。
2
From the geochronologic studies of sandstone-type uranium deposits, it is discovered that the ore-forming processes of sandstone-type uranium deposits are characterized by "episodes" and multi-stages.