Mineralogical evolution and REE mobility during crystallisation of ancylite-bearing ferrocarbonatite, Haast River, New Zealand

Cooper, Alan F.; Collins, Alice K.; Palin, J. Michael; Spratt, John

doi:10.1016/j.lithos.2015.01.005

Cited by 27 publications

(16 citation statements)

References 56 publications

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“…The association of bastnäsite and/or the related REE fluorocarbonates (synchysite, parisite, röntgenite) with quartz, baryte, and/or strontianite is common in other rare earth carbonatites (e.g., [13,18,62,108,109,[111][112][113]). This style of mineralization is one of the most important REE ore types, while ancylite rocks are less commonly ore grade [57,68], and the ancylite-quartz association is extremely rare. The dolomite fragments in the breccias were repeatedly overgrown by later dolomite generations (Figure 14e).…”

Section: Magnesiocarbonatite Breccias With Ree and Silicate Mineral Mmentioning

confidence: 99%

“…important REE ore types, while ancylite rocks are less commonly ore grade [57,68], and the ancylitequartz association is extremely rare. The dolomite fragments in the breccias were repeatedly overgrown by later dolomite generations (Figure 14e).…”

Section: Magnesiocarbonatite Breccias With Ree and Silicate Mineral Mmentioning

confidence: 99%

“…Importantly, the weight percentage levels of REEs required for an economic deposit commonly occur in magnesio-and iron-rich carbonatite dykes and veins (i.e., in the latest and most highly evolved parts of a carbonatite intrusion) [2,77]. In these rocks, REE accumulation is assumed to be controlled by fluid activity [2,45,57,62,68,[77][78][79][80][81][82].…”

Section: Introductionmentioning

confidence: 99%

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The Petyayan-Vara Carbonatite-Hosted Rare Earth Deposit (Vuoriyarvi, NW Russia): Mineralogy and Geochemistry

et al. 2020

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The Vuoriyarvi Devonian carbonatite–ijolite–pyroxenite–olivinite complex comprises several carbonatite fields: Neske Vara, Tukhta-Vara, and Petyayan-Vara. The most common carbonatites in the Tukhta-Vara and Neske-Vara fields are calciocarbonatites, which host several P, Fe, Nb, and Ta deposits. This paper focuses on the Petyayan-Vara field, in which the primary magmatic carbonatites are magnesian. The least altered magnesiocarbonatites are composed of dolomite with burbankite and are rich in REE (up to 2.0 wt. %), Sr (up to 1.2 wt. %), and Ba (up to 0.8 wt. %). These carbonatites underwent several stages of metasomatism. Each metasomatic event produced a new rock type with specific mineralization. The introduction of K, Si, Al, Fe, Ti, and Nb by a F-rich fluid (or fluid-saturated melt) resulted in the formation of high-Ti magnesiocarbonatites and silicocarbonatites, composed of dolomite, microcline, Ti-rich phlogopite, and Fe–Ti oxides. Alteration by a phosphate–fluoride fluid caused the crystallization of apatite in the carbonatites. A sulfate-rich Ba–Sr–rare-earth elements (REE) fluid (probably brine-melt) promoted the massive precipitation of ancylite and baryte and, to a lesser extent, strontianite, bastnäsite, and synchysite. Varieties of carbonatite that contain the highest concentrations of REE are ancylite-dominant. The influence of sulfate-rich Ba-Sr-REE fluid on the apatite-bearing rocks resulted in the dissolution and reprecipitation of apatite in situ. The newly formed apatite generation is rich in HREE, Sr, and S. During late-stage transformations, breccias of magnesiocarbonatites with quartz-bastnäsite matrixes were formed. Simultaneously, strontianite, quartz, calcite, monazite, HREE-rich thorite, and Fe-hydroxides were deposited. Breccias with quartz-bastnäsite matrix are poorer in REE (up to 4.5 wt. % total REE) than the ancylite-dominant rocks (up to 11 wt. % total REE).

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Section: Magnesiocarbonatite Breccias With Ree and Silicate Mineral Mmentioning

confidence: 99%

Section: Magnesiocarbonatite Breccias With Ree and Silicate Mineral Mmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The Petyayan-Vara Carbonatite-Hosted Rare Earth Deposit (Vuoriyarvi, NW Russia): Mineralogy and Geochemistry

et al. 2020

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“…REE enrichment is "most commonly found only in the latest and most highly evolved parts of a carbonatite intrusion" [6]. The accumulation of REE in late carbonatites is assumed to be controlled by fluid activity [7][8][9][10][11][12][13][14][15][16]. Such a surplus in articles reflects a keen interest in REE occurring in late carbonatites.…”

Section: Introductionmentioning

confidence: 99%

Ti-Nb Mineralization of Late Carbonatites and Role of Fluids in Its Formation: Petyayan-Vara Rare-Earth Carbonatites (Vuoriyarvi Massif, Russia)

et al. 2018

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This article is devoted to the geology of titanium-rich varieties of the Petyayan-Vara rare-earth dolomitic carbonatites in Vuoriyarvi, Northwest Russia. Analogues of these varieties are present in many carbonatite complexes. The aim of this study was to investigate the behavior of high field strength elements during the late stages of carbonatite formation. We conducted a multilateral study of titanium-and niobium-bearing minerals, including a petrographic study, Raman spectroscopy, microprobe determination of chemical composition, and electron backscatter diffraction. Three TiO 2 -polymorphs (anatase, brookite and rutile) and three pyrochlore group members (hydroxycalcio-, fluorcalcio-, and kenoplumbopyrochlore) were found to coexist in the studied rocks. The formation of these minerals occurred in several stages. First, Nb-poor Ti-oxides were formed in the fluid-permeable zones. The overprinting of this assemblage by residual fluids led to the generation of Nb-rich brookite (the main niobium concentrator in the Petyayan-Vara) and minerals of the pyrochlore group. This process also caused niobium enrichment with of early generations of Ti oxides. Our results indicate abrupt changes in the physicochemical parameters at the late hydro (carbo) thermal stage of the carbonatite formation and high migration capacity of Ti and Nb under these conditions. The metasomatism was accompanied by the separation of these elements.

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“…REE-rich carbonatites are commonly hydrothermally altered and overprinted, such that some degree of REE mobility is observed. REE can be redistributed in situ into different minerals (commonly LREE; Andrade et al 1999, Ruberti et al 2008, Doroshkevich et al 2009, Cooper et al 2015, Moore et al 2015, Trofanenko et al 2016, Andersen et al 2017, or transported externally from the carbonatite to a secondary distal deposit (commonly HREE;Bühn 2008, Andersen et al 2016, Bodeving et al 2017, Broom-Fendley et al 2017a. The REE are also considered hydrothermally mobile based on theoretical and experimental studies (e.g., Williams-Jones et al 2012, Migdisov & Williams-Jones 2014.…”

Section: Introductionmentioning

confidence: 99%

REE Redistribution Textures in Altered Fluorapatite: Symplectites, Veins, and Phosphate-Silicate-Carbonate Assemblages from the Nolans Bore P-REE-Th Deposit, Northern Territory, Australia

Anenburg

Burnham

Mavrogenes

2018

The Canadian Mineralogist

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The geochemical behavior and genesis of rare earth element (REE) ores remains poorly understood. In addition, the processes responsible for many features observed in REE ore deposits are not easily determined. Importantly, the distinction between igneous versus post-magmatic genesis, or the nature of the mineralizing and modifying fluids or melts, remains in dispute. Nolans Bore is a P-REE-Th deposit in the Northern Territory, Australia, hosting REE mineralization in fluorapatite and its alteration products. These mineralization textures are imaged in 3D by X-ray computed tomography and in 2D by electron microscopy, cathodoluminescence, and X-ray mapping. Primary igneous REE-rich fluorapatite was replaced in two stages. The first, at high temperature, was to endmember fluorapatite-britholite symplectite. The second, at lower temperatures, was to hydrothermal veins and patches comprised of REE-Th phosphate, silicate, and carbonate minerals. Quadrivalent Ce occurs together with Th, suggesting oxidized, low-temperature conditions. Strikingly similar textures are observed at Hoidas Lake, Saskatchewan, Canada, where igneous immiscibility or a pegmatitic boundary layer have been implicated in their formation. Our textural and chemical investigations establish that these symplectites and other similar textures are not primary igneous textures, but formed by subsequent cooling and alteration. Understanding the processes that formed these symplectic and vein textures is key to their theoretical and experimental modeling and should lead to a better understanding of ''hydrothermal'' REE deposits globally. The decoupling of Ce from the rest of the REE and the mineralogical preferences of the light REE versus the heavy REE should be considered when evaluating similar ore deposits for their economic value and mineral processing.

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Mineralogical evolution and REE mobility during crystallisation of ancylite-bearing ferrocarbonatite, Haast River, New Zealand

Cited by 27 publications

References 56 publications

The Petyayan-Vara Carbonatite-Hosted Rare Earth Deposit (Vuoriyarvi, NW Russia): Mineralogy and Geochemistry

The Petyayan-Vara Carbonatite-Hosted Rare Earth Deposit (Vuoriyarvi, NW Russia): Mineralogy and Geochemistry

Ti-Nb Mineralization of Late Carbonatites and Role of Fluids in Its Formation: Petyayan-Vara Rare-Earth Carbonatites (Vuoriyarvi Massif, Russia)

REE Redistribution Textures in Altered Fluorapatite: Symplectites, Veins, and Phosphate-Silicate-Carbonate Assemblages from the Nolans Bore P-REE-Th Deposit, Northern Territory, Australia

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