The Proterozoic anorogenic magmatic rocks are well developed in the Bayan Obo deposit region. They are composed of trachyte, magnesioarfvedesonite-feldspatite, potash-rhyolite, dacite, rhyolite, quartz porphyry and tr...The Proterozoic anorogenic magmatic rocks are well developed in the Bayan Obo deposit region. They are composed of trachyte, magnesioarfvedesonite-feldspatite, potash-rhyolite, dacite, rhyolite, quartz porphyry and trachy basalt. A lot of high-K diabase veins (dykes) are also found. These anorogenic magmatic rocks are derived from the mantle. They have lowerεNd (t) (4.52-5.88) with T(Nd DM)=1.54-1.92 Ga. Their Nd isotopic compositions and T(Nd DM)are consistent with those of ores, implying that the ore-forming materials were derived from these anorogenic magmatic rocks. The zircon U-Pb ages of the rocks are 1.8 Ga. Research results indicate that the Bayan Obo Group was replaced by the hydrothermal solution related to the anorogenic magmatic rocks, resulting in the formation of the deposit.展开更多
文摘The Proterozoic anorogenic magmatic rocks are well developed in the Bayan Obo deposit region. They are composed of trachyte, magnesioarfvedesonite-feldspatite, potash-rhyolite, dacite, rhyolite, quartz porphyry and trachy basalt. A lot of high-K diabase veins (dykes) are also found. These anorogenic magmatic rocks are derived from the mantle. They have lowerεNd (t) (4.52-5.88) with T(Nd DM)=1.54-1.92 Ga. Their Nd isotopic compositions and T(Nd DM)are consistent with those of ores, implying that the ore-forming materials were derived from these anorogenic magmatic rocks. The zircon U-Pb ages of the rocks are 1.8 Ga. Research results indicate that the Bayan Obo Group was replaced by the hydrothermal solution related to the anorogenic magmatic rocks, resulting in the formation of the deposit.