Advances in Earth Science ›› 2001, Vol. 16 ›› Issue (4): 501-507. doi: 10.11867/j.issn.1001-8166.2001.04.0501

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RECENT PROGRESS IN CARBONATITIE RESEARCH

QIN Chaojian,QIU Yuzhuo   

  1. Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry,CAS, Guiyang 550002, China
  • Received:2000-08-17 Revised:2001-01-20 Online:2001-08-01 Published:2001-08-01

QIN Chaojian,QIU Yuzhuo. RECENT PROGRESS IN CARBONATITIE RESEARCH[J]. Advances in Earth Science, 2001, 16(4): 501-507.

On the basis of mineralogy, petrology, carbon, oxygen and strontium isotopes and the relationship between carbonatite and mineralizations, the originand features of carbonatite is summarized. The carbonatites mainly occurred in the rift zones of cratons and within plates. They are often associated with mafic, ultramafic and alkaline rocks as a ring complex. The carbonatites might be accompanied by various mineralizations of Nb, Ta, P, REE, F, Ba and etc.Carbon and oxygen isotopic studies show that most of carbonatites are derived from the mantle, and they are in agreement to the associated maficultramafic rocks in C and O isotopic features. The initial Sr ratios of carbonatites are similar to that of mantle, except for some due to the crustal contamination. In combination with experimental petrology, fluid inclusions and the property of CO2-H2O-NaCl fluid system, the carbonatitic magma is inferred being generated from the mantle except for those of remelting type. The CO2 and H2O play an important role in the generation and formation of carbonatitic magma during metasomatism and partial melting in the mantle. The investigation on melt/fluid inclusions of carbonatites revealed a whole evolutional order from magmatic to hydrothermal stages. Experimental studies confirmed the evolution series from early magmatic system typical with K, Na, Ca and Mg to the hydrothermal system with alkaline ions such as Na and K. The fenitization of wall rocks occurred in later hydrothermal stage. The formation of carbonatites includes at least three stages: the magmatic crystallization stage, the post-magmatic (gaseous carbonatitic) stage, and the
 metasomatic carbonatitic stage. And the mafic, ultramafic and alkaline rocks, closely related to carbonatite in space and origin, are suffered the immiscible phase segregation, the differentiation of magma, the crystallization and the fenitization. 

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