Proterozoic anorogenic magmatic rocks and their constraints on mineralizations in the Bayan Obo deposit region, Inner Mongolia

【摘要】 <正> The Proterozoic anorogenic magmatic rocks are well developed in the Bayan Obo de-posit 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 lower eM (t) (4.52-5.88) with TDMNd =1.54-1.92 Ga. Their Nd isotopic compositions and TDMNd are consistentwith 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.更多还原

【Abstract】 The Proterozoic anorogenic magmatic rocks are well developed in the Bayan Obo de-posit 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 lower eM (t) (4.52-5.88) with TDMNd =1.54-1.92 Ga. Their Nd isotopic compositions and TDMNd are consistentwith 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.更多还原