Apatite paragenesis in the Bayan Obo REE-Nb-Fe ore deposit, inner Mongolia, China

被引：58

作者：

Campbell, LS ^{[1
]}

Henderson, P ^{[1
]}

机构：

[1] Nat Hist Museum, Dept Mineral, London SW7 5BD, England

来源：

LITHOS | 1997年 / 42卷 / 1-2期

关键词：

carbonatites; cathodoluminescence; mineral-deposits; phosphates; Proterozoic; rare earth elements;

D O I：

10.1016/S0024-4937(97)00038-8

中图分类号：

P3 [地球物理学]; P59 [地球化学];

学科分类号：

0708 ; 070902 ;

摘要：

Many studies of the Bayan Obo REE-Nb-Fe ore deposit have suggested that the REE mineralization was episodic. To investigate this, mineralized rocks from the main and east orebodies at Bayan Obo were selected for a paragenetic study of apatite. Apatite is abundant at Bayan Obo, displaying a diversity of textures and occurrences, and it is a mineral that is geochemically sensitive to REE environments, and hence, ideal for the purpose. The apatites were examined for their cathodoluminescent (CL) properties, and quantitative electron probe microanalyses were undertaken to determine their compositions. Four distinctive fluorapatite occurrences are recognized: (1) Discrete grains, with minimal trace element substitution, and displaying yellow/green CL. (2) Anhedral, REE-enriched apatites, displaying pink/cream/grey CL. (3) REE-bearing, high-Sr vein apatites with yellow/cream CL. (4) Fluorite-vein associated, large, euhedral, pure apatites, displaying cream/grey CL. Interpretation of the paragenetic sequence indicates a sedimentary host (apatite 1) for the multiple stages of ore deposition (apatites 2 and 3). The source of the hydrothermal/metasomatic ore-fluids is interpreted as carbonatitic, partly from the high Sr-Mn ratios (in apatites 2 and 3). A late event is recorded by type 4 apatites, but its relationship to the main era of REE-ore formation is not clear. (C) 1997 Elsevier Science B.V.

引用

页码：89 / 103

页数：15

共 33 条

[1] SOLUBILITY OF APATITE, MONAZITE, ZIRCON, AND RUTILE IN SUPERCRITICAL AQUEOUS FLUIDS WITH IMPLICATIONS FOR SUBDUCTION ZONE GEOCHEMISTRY [J].

AYERS, JC ;

WATSON, EB .

PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY OF LONDON SERIES A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, 1991, 335 (1638) :365-375

[2] APATITE/FLUID PARTITIONING OF RARE-EARTH ELEMENTS AND STRONTIUM - EXPERIMENTAL RESULTS AT 1.0 GPA AND 1000-DEGREES-C AND APPLICATION TO MODELS OF FLUID-ROCK INTERACTION [J].

AYERS, JC ;

WATSON, EB .

CHEMICAL GEOLOGY, 1993, 110 (1-3) :299-314

[3] HOST-ROCK CONTROLLED EPIGENETIC, HYDROTHERMAL METASOMATIC ORIGIN OF THE BAYAN OBO REE-FE-NB ORE DEPOSIT, INNER-MONGOLIA, PRC [J].

CHAO, ECT ;

BACK, JM ;

MINKIN, JA ;

REN, YC .

APPLIED GEOCHEMISTRY, 1992, 7 (05) :443-458

[4]

CHAO ECT, 1989, INT GEOL C

[5]

CHAO ECT, 1988, US GEOL SURV CIRC, V1035, P8

[6]

CHAO ECT, 1990, 11 USGS OP FIL

[7] 40AR/39AR DATING OF VEIN AMPHIBOLE FROM THE BAYAN OBO IRON-RARE EARTH ELEMENT-NIOBIUM DEPOSIT, INNER-MONGOLIA, CHINA - CONSTRAINTS ON MINERALIZATION AND DEPOSITION OF THE BAYAN OBO GROUP [J].

CONRAD, JE ;

MCKEE, EH .

ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS, 1992, 87 (01) :185-188

[8] THE BAYAN OBO IRON RARE-EARTH NIOBIUM DEPOSITS, INNER-MONGOLIA, CHINA [J].

DREW, LJ ;

QINGRUN, M ;

WEIJUN, S .

LITHOS, 1990, 26 (1-2) :43-65

[9]

Giere R., 1996, MINERALOGICAL SOC SE, V7, P105

[10] RARE-EARTH ELEMENTS IN HYDROTHERMAL SYSTEMS - ESTIMATES OF STANDARD PARTIAL MOLAL THERMODYNAMIC PROPERTIES OF AQUEOUS COMPLEXES OF THE RARE-EARTH ELEMENTS AT HIGH-PRESSURES AND TEMPERATURES [J].

HAAS, JR ;

SHOCK, EL ;

SASSANI, DC .

GEOCHIMICA ET COSMOCHIMICA ACTA, 1995, 59 (21) :4329-4350

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