2018
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
ONDREJKA, Martin; Peter BACIK; Tomáš SOBOCKY; Pavel UHER; Radek ŠKODA et al.Základní údaje
Originální název
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
Autoři
ONDREJKA, Martin; Peter BACIK; Tomáš SOBOCKY; Pavel UHER; Radek ŠKODA; Tomáš MIKUS; Jarmila LUPTAKOVA a Pavel KONECNY
Vydání
Mineralogical Magazine, Middlesex, Mineralogical Society, 2018, 0026-461X
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
10504 Mineralogy
Stát vydavatele
Velká Británie a Severní Irsko
Utajení
není předmětem státního či obchodního tajemství
Odkazy
Impakt faktor
Impact factor: 2.210
Označené pro přenos do RIV
Ano
Kód RIV
RIV/00216224:14310/18:00106688
Organizační jednotka
Přírodovědecká fakulta
UT WoS
EID Scopus
Klíčová slova anglicky
rhabdophane group; alunite supergroup; jarosite; alunite; corkite; hinsdalite; supergene alteration; microgranite; Velence; Hungary
Příznaky
Mezinárodní význam, Recenzováno
Změněno: 23. 4. 2024 14:40, Mgr. Michal Petr
Anotace
V originále
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.
Návaznosti
| MUNI/A/1653/2016, interní kód MU |
|