The chemical composition of REE-Y-Th-U-rich accessory minerals in peraluminous granites of the Erzgebirge-Fichtelgebirge region, Germany; Part I, The monazite-(Ce)-brabantite solid solution series

Foerster, Hans-Juergen

doi:10.2138/am-1998-3-409

Cited by 252 publications

(141 citation statements)

References 28 publications

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“…In peraluminous granitoids, monazite is an abundant accessory phase (Förster 1998), and, together with Thorthosilicates, is a Th 'scavenger' (Montel 1993). It is thought that both zircon and monazite, which are found throughout the MC pluton, were in equilibrium with the peraluminous silicic melt at an early stage of magmatic differentiation.…”

Section: Magma Mixing and Relationships With Other Accessory Phasesmentioning

confidence: 99%

Zircon texture and chemical composition as a guide to magmatic processes and mixing in a granitic environment and coeval volcanic system

Gagnevin

Daly

Kronz

2009

Contrib Mineral Petrol

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This study documents the chemical and textural responses of zircon in the Elba igneous complex, with particular reference to the 7-to 7.8-Ma-old Monte Capanne pluton in relation to its coeval volcanic counterpart (Capraia), using BSE imaging and quantitative electron microprobe analyses. The Monte Capanne pluton displays multiple field and geochemical evidence for magma mixing. The samples we have investigated (including monzogranitic, mafic enclave and dyke samples) display similar zircon textures and are associated with an extremely large range of trace and minor element (Hf, Y, HREE, Th, U) compositions, which contrast with relatively simple textures and zoning patterns in zircons from a Capraia dacite. We have used a relatively simple textural classification (patchy zoning, homogenous cores, oscillatory zoning and unzoned zircon) as the basis for discussing the chemical composition and chemical variation within zircons from the Monte Capanne pluton. Based on these data and other works in Lithos 78:101-118, 2004 , it is inferred that mixing between metaluminous and peraluminous melts occurred early in the evolution of the Monte Capanne magma chamber. In particular, mixing was responsible for the development of the patchy-zoning texture in the zircon cores, which was associated with reactions between other accessory phases (including monazite, apatite, allanite), which we infer to have significantly affected the Th distribution in zircon. Zircons from the MC pluton displaying ''homogeneous cores'' have chemical affinities with zircons in the coeval Capraia volcanic system, consistent with the participation of a Capraia-like mantle end-member during mixing. Further zircon growth in the MC pluton produced the oscillatory zoning texture, which records both long-term (crystal fractionation) and transient (recharge with both silicic and mafic magmas) events in a hybrid magma chamber. It is inferred that Hf and the Th/U ratio cannot be used alone to infer magmatic processes due to their dependency on temperature, nor are they a diagnostic feature of xenocrystic grains. This study shows that zircon chemistry coupled with detailed textural analysis can provide a powerful tool to elucidate the complex evolution of a magma system.

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Section: Magma Mixing and Relationships With Other Accessory Phasesmentioning

confidence: 99%

Zircon texture and chemical composition as a guide to magmatic processes and mixing in a granitic environment and coeval volcanic system

Gagnevin

Daly

Kronz

2009

Contrib Mineral Petrol

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“…Compositions of monazite-(Ce) are characterized by 0.65-2.06 wt% SiO 2 , 4.06-10.73% ThO 2 , 0.2-0.43% UO 2 , 0.69-1.74% Y 2 O 3 and 0.12-0.83% CaO (Table 7). Monazite from S-type granites generally contains 6-12 wt% ThO 2 (Cuney & Friedrich 1987) or 4-12 wt% ThO 2 (Förster 1998a). In fact, concentrations of Th in monazite-(Ce) from the G-a granite fall near or within this range.…”

Section: Monazite-(ce)mentioning

confidence: 99%

Accessory Minerals in the Xihuashan Y-Enriched Granitic Complex, Southern China: A Record of Magmatic and Hydrothermal Stages of Evolution

Wang¹,

Fontan²,

Chen³

et al. 2003

The Canadian Mineralogist

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The Xihuashan granitic complex (southern China) is mainly composed of coarse-grained porphyritic biotite granite (G-a), medium-grained porphyritic biotite granite (G-b), and medium-to fine-grained porphyritic biotite granite (G-c). The G-a granite is characterized by monazite-(Ce) and xenotime-(Y), in addition to commonly observed zircon and uranoan thorite. In the G-b and G-c intrusive units, monazite-(Ce) becomes very scarce, whereas Y-bearing minerals, including Y-bearing spessartine, xenotime-(Y), gadolinite-(Y), fergusonite-(Y), and yttrian fluorite (up to 15 wt% Y 2 O 3 ), are concentrated to various extents. Spessartine exhibits chemical zoning, which is displayed, in the core, by elevated contents of Y and heavy REE (HREE) (up to 2.32 wt% Y 2 O 3 and 1.51% HREE 2 O 3 ) and micrometric inclusions of Y-bearing minerals. Similarly, zircon from the G-b and Gc granites contains polymineralic micro-inclusions in the core. Overall, the accessory minerals point to a magmatic environment of crystallization for the G-a granite. In contrast, the crystallization of the G-b and G-c granites involved magmatic and hydrothermal stages. The late-to postmagmatic fluid is enriched in F and CO 2 , and appeared as a result of the final oversaturation of the granitic melt in a fluid phase.Keywords: yttrian fluorite, yttrium-bearing spessartine-almandine, xenotime-(Y), zircon, electron-microprobe data, granite, Xihuashan, China. in the endo-and exocontact zones of the Xihuashan granitic complex (Hsu 1943). Mining of quartz-ferberitetype ores started in 1935. The metallogeny of the deposits and the petrology of associated granites were described by Hsu

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“…Monazite strongly favors LREE entrapment with the sum of LREE (La + Ce + Pr + Nd + Sm) ranging between 0.21 and 0.94 apfu (atoms per formula unit) ( Two main coupled substitution mechanisms have been proposed for monazite [2,27,28], namely the cheralite and huttonite substitutions. The analyzed monazite grains from all of the KGB magmatic suites plot between the cheralite and huttonite substitution vectors in the (Th + U + Si) vs. the (P + Y + REE) diagram.…”

Section: Monazite Compositionmentioning

confidence: 99%

REE and Y Mineralogy of the Krudum Granite Body (Saxothuringian Zone)

René

2018

Minerals

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Abstract:The Krudum granite body comprises highly fractionated granitic rocks ranging from medium-F biotite granites to high-F, high-P 2 O 5 Li-mica granites. This unique assemblage is an ideal site to continue recent efforts in petrology to characterize the role of zircon, monazite, and xenotime as hosts to rare earth elements (REEs). The granitic rocks of the Krudum body analyzed in this study were found to contain variable concentrations of monazite and zircon, while xenotime was only found in the high-F, high-P 2 O 5 Li-mica granites and in the alkali-feldspar syenites of the Vysoký Kámen stock. Intermediate trends between cheralite and huttonite substitutions are characteristic for analyzed monazite grains from all magmatic suites. The highest concentration of cheralite was found in monazite from the alkali-feldspar syenites (up to 69.3 mol %). The proportion of YPO 4 in analyzed xenotime grains ranges from 71 to 84 mol %. Xenotime grains are commonly enriched in heavy rare earth elements (HREEs; 9.3-19.5 wt % HREE 2 O 3 ) and thorite-coffinite and cheralite exchange was observed. Some xenotime analyses return low totals, suggesting their hydration during post-magmatic alterations. Analyzed zircon from granite suites of the Krudum granite body contains moderate Hf concentrations (1.0-4.7 wt % HfO 2 ; 0.010-0.047 apfu Hf). The highest concentrations of HfO 2 were found in zircon from the high-F, high-P 2 O 5 Li-mica granites (1.2-4.7 wt % HfO 2 ). Analyzed zircon grains from the high-F, high-P 2 O 5 Li-mica granites and alkali-feldspar syenites are enriched in P (up to 8.29 wt % P 2 O 5 ; 0.24 apfu P), Al (0.02-2.0 wt % Al 2 O 3 ; 0.00-0.08 apfu Al), Ca (up to 3.9 wt % CaO; 0.14 apfu Ca), Y (up to 5.5 wt % Y 2 O 3 ; 0.10 apfu Y), and Sc (up to 1.17 wt % Sc 2 O 3 ; 0.03 apfu Sc). Zircon grains from the high-F, high-P 2 O 5 Li-mica granites were sometimes hydrated and fluorized. The concentrations of F in zircon from partly greisenised high-F, high-P 2 O 5 Li-mica granites reached up to 1.2 wt % (0.26 apfu F).

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The chemical composition of REE-Y-Th-U-rich accessory minerals in peraluminous granites of the Erzgebirge-Fichtelgebirge region, Germany; Part I, The monazite-(Ce)-brabantite solid solution series

Cited by 252 publications

References 28 publications

Zircon texture and chemical composition as a guide to magmatic processes and mixing in a granitic environment and coeval volcanic system

Zircon texture and chemical composition as a guide to magmatic processes and mixing in a granitic environment and coeval volcanic system

Accessory Minerals in the Xihuashan Y-Enriched Granitic Complex, Southern China: A Record of Magmatic and Hydrothermal Stages of Evolution

REE and Y Mineralogy of the Krudum Granite Body (Saxothuringian Zone)

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