【摘要】 在鄂尔多斯盆地西北部,中奥陶统桌子山组和马五段到马三段斑状白云岩广泛分布。通过岩石、矿物学及地球化学特征研究,发现该白云岩具有岩溶、生物遗迹、深埋藏的证据,其原岩是早成岩阶段浅埋藏环境下形成的粉晶~细晶白云岩,在晚成岩阶段深埋藏环境下发生差异白云石化,形成细~粉晶白云石组成的斑块。因此,细晶~粗粉晶斑状白云岩受生物影响,是表生岩溶作用和深埋藏环境导致的差异白云石化作用的产物。更多还原

【Abstract】 The Middle Ordovician patchy dolomitite is widely exposed in the Northwest Ordos basin.Lithologic,mineralogical and geochemical studies indicate that the protolith was a crystal powder dolomite-aplite dolomite in the exogenetic stage with patchy aplite dolomite-crystal powder dolomite resulted from differential dolomitization in late diagenetic stage.更多还原