Rare earth element fluorocarbonate minerals such as bastnaesite and parisite are firstly discovered in carbonatite dykes from Bayan Obo, Inner Mongolia, China. Bastnaesite rarely occurs as homogeneously single crystal...Rare earth element fluorocarbonate minerals such as bastnaesite and parisite are firstly discovered in carbonatite dykes from Bayan Obo, Inner Mongolia, China. Bastnaesite rarely occurs as homogeneously single crystal, but contains microfine phase of parisite. They form regular intergrowth along (0001) plane net, which is identified as epitaxy. This eptactic texture results from the variation of chemical composition of crystallizing agents of those minerals that crystallize directly from carbonatite magma.展开更多
THE origin of the giant Bayan Obo REE-Nb-Fe ore deposit has been under much debate since its discoveryas an iron deposit by Prof. Ding Daoheng in 1927. The main dispute is concentrated on the genesis of theore-hosted ...THE origin of the giant Bayan Obo REE-Nb-Fe ore deposit has been under much debate since its discoveryas an iron deposit by Prof. Ding Daoheng in 1927. The main dispute is concentrated on the genesis of theore-hosted dolomite marbles of the deposit, Some authors considered them to be sedimentary in origin,while others pointed out that they could be carbonatite. However, there are very few researches concerning the compositions of carbonate minerals which may provide a direct clue to their petrogenesis. Herewe show the variations of compositions in carbonate minerals from Bayan Obo. Carbonate rocks from Bayan Obo, Inner Mongolia, could be divided into sedimentary limestone anddolostone (H8_s), coarse-grained dolomite marble (H8_c), fine-grained dolomite marble (H8_f) and carbonatite dykes (D) based on their texture, structure, mineral progenesis and occurrences. H8_s thatshows weak metamorphism and deformation is distributed to the north of the Kuangou fault, occurring展开更多
文摘Rare earth element fluorocarbonate minerals such as bastnaesite and parisite are firstly discovered in carbonatite dykes from Bayan Obo, Inner Mongolia, China. Bastnaesite rarely occurs as homogeneously single crystal, but contains microfine phase of parisite. They form regular intergrowth along (0001) plane net, which is identified as epitaxy. This eptactic texture results from the variation of chemical composition of crystallizing agents of those minerals that crystallize directly from carbonatite magma.
文摘THE origin of the giant Bayan Obo REE-Nb-Fe ore deposit has been under much debate since its discoveryas an iron deposit by Prof. Ding Daoheng in 1927. The main dispute is concentrated on the genesis of theore-hosted dolomite marbles of the deposit, Some authors considered them to be sedimentary in origin,while others pointed out that they could be carbonatite. However, there are very few researches concerning the compositions of carbonate minerals which may provide a direct clue to their petrogenesis. Herewe show the variations of compositions in carbonate minerals from Bayan Obo. Carbonate rocks from Bayan Obo, Inner Mongolia, could be divided into sedimentary limestone anddolostone (H8_s), coarse-grained dolomite marble (H8_c), fine-grained dolomite marble (H8_f) and carbonatite dykes (D) based on their texture, structure, mineral progenesis and occurrences. H8_s thatshows weak metamorphism and deformation is distributed to the north of the Kuangou fault, occurring