The mountain is encircled by the doughnut-shaped depression of the caldera. 山为环形的破火山口洼地环抱着。
Daqiaowu uranium deposit oaurs in the contact Zone of quartz porphyry massif and explosive breccia chimney in the Mesozoic Mengshan caldera, belonging to porphyry type. 大桥坞斑岩型铀矿床产于中生代蒙山破火山口中一石英斑岩体的内外接触带及其隐爆角砾岩筒中。
