Sinsedimentry volcanic activities in the cracking process of the Mesoproterozoic aulacogen of passive continental margin in Langshan-Zhaertai area, Inner Mongolia, and its indicating significance

• 内蒙古狼山-渣尔泰山中元古代被动陆缘裂陷槽裂解过程中的火山活动及其示踪意义