Minerals of the rhabdophane group and the alunite supergroup in microgranite: products of low-temperature alteration in a highly acidic environment from the Velence Hills, Hungary
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F18%3A00106688" target="_blank" >RIV/00216224:14310/18:00106688 - isvavai.cz</a>
Result on the web
<a href="http://dx.doi.org/10.1180/mgm.2018.137" target="_blank" >http://dx.doi.org/10.1180/mgm.2018.137</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1180/mgm.2018.137" target="_blank" >10.1180/mgm.2018.137</a>
Alternative languages
Result language
angličtina
Original language name
Minerals of the rhabdophane group and the alunite supergroup in microgranite: products of low-temperature alteration in a highly acidic environment from the Velence Hills, Hungary
Original language description
An assemblage of alunite-supergroup minerals (ASM), rhabdophane-group minerals (RGM), goethite and associated clay minerals occurs in Permian A-type porphyritic microgranite in the eastern part of the Velence Hills, Hungary. The secondary sulfates/phosphates include jarosite, Pb-rich jamsite and alunite, corkite, hinsdalite and rhabdophane-(Ce), -(La) and -(Nd). Detailed electron probe microanalysis and Raman spectroscopy reveal a wide miscibility among RGM end-members and show a rhabdophane- tristramite-brockite solid solution with extensive compositional variation. Moreover, ASM show heterogeneous composition and complex substitution mechanisms within the alunite, beudantite and plumbogummite groups. The formation of this rare mineral assemblage reveals extensive remobilization of rare-earth elements (REE), Th, U, P, S, Fe and Pb under supergene conditions. Compositional variations and substitution trends of the RGM investigated indicate that Th, U, Ca and Pb are incorporated into the rhabdophane structure by a (Ca, Pb)(2+) + (Th, U)(4+) <--> 2REE(3+) substitution mechanism. Consequently, we suggest the following end-member formulae for RGM containing divalent and tetravalent cations: (Ca0.5Th0.5)PO4 center dot H2O for brockite, (Pb0.5Th0.5)PO4 center dot H2O for grayite and (Ca0.5U0.5)PO4 center dot H2O for tristramite. The ASM and RGM originated from total leaching of the primary magmatic REE, Th, U and P minerals in the microgranite [most probably allanite-(Ce), fluorapatite and possibly also xenotime-(Y)]. together with input of Pb and S in low-temperature, acid sulfate solutions, connected with an adjacent Palaeogene andesite-diorite intrusion and the accompanying hydrothermal sulfide mineralization.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10504 - Mineralogy
Result continuities
Project
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Continuities
S - Specificky vyzkum na vysokych skolach<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2018
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Mineralogical Magazine
ISSN
0026-461X
e-ISSN
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Volume of the periodical
82
Issue of the periodical within the volume
6
Country of publishing house
GB - UNITED KINGDOM
Number of pages
24
Pages from-to
1277-1300
UT code for WoS article
000456950000005
EID of the result in the Scopus database
2-s2.0-85060793445