2015
Two paragenetic types of cookeite from Dolní Bory-Hatě pegmatites, Moldanubian Zone, Czech Republic: proximal and distal alteration products of Li-bearing sekaninaite
NOVÁK, Milan, Renata ČOPJAKOVÁ, Marek DOSBABA, Michaela VAŠINOVÁ GALIOVÁ, Dalibor VŠIANSKÝ et. al.Základní údaje
Originální název
Two paragenetic types of cookeite from Dolní Bory-Hatě pegmatites, Moldanubian Zone, Czech Republic: proximal and distal alteration products of Li-bearing sekaninaite
Autoři
NOVÁK, Milan (203 Česká republika, garant, domácí), Renata ČOPJAKOVÁ (203 Česká republika, domácí), Marek DOSBABA (203 Česká republika, domácí), Michaela VAŠINOVÁ GALIOVÁ (203 Česká republika, domácí), Dalibor VŠIANSKÝ (203 Česká republika, domácí) a Josef STANĚK (203 Česká republika, domácí)
Vydání
Canadian Mineralogist, 2015, 0008-4476
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
10500 1.5. Earth and related environmental sciences
Stát vydavatele
Kanada
Utajení
není předmětem státního či obchodního tajemství
Impakt faktor
Impact factor: 0.862
Kód RIV
RIV/00216224:14310/15:00088763
Organizační jednotka
Přírodovědecká fakulta
UT WoS
000390630300004
Klíčová slova anglicky
cookeite; Li-bearing sekaninaite; electron microprobe; LA-ICP-MS; alteration processes
Změněno: 17. 4. 2017 13:42, Ing. Andrea Mikešková
Anotace
V originále
Cookeite occurs in pseudomorphs after sekaninaite associated with muscovite, quartz, tourmaline, albite, nontronite, and chlorite in pegmatite No. 1 (proximal cookeite type), and in pockets lined with albite and quartz in the Oldrˇich pegmatite (distal cookeite type), Dolní Bory-Hateˇ, Bory pegmatite district, Moldanubian Zone, Czech Republic. The mineral assemblages of the Bory pegmatites with common Al,Fe-rich minerals (annite, schorl, sekaninaite, andalusite, diaspore, ilmenite, and almandine) suggest their primitive, peraluminous, LCT geochemical signature. Proximal cookeite forms aggregates of sheets, up to B500 mm in diameter, intergrown with prevailing muscovite and quartz. Beige to grayish, porous aggregates of distal cookeite, up to 15 cm in size, consist of thin sheets, up to B70 mm in diameter, locally associated with small grains of pyrite and pale brown siderite as a matrix. Electron microprobe data of cookeite from the No. 1 and Oldrˇich pegmatites yielded very similar results: Si (3.23–3.27, 3.21–3.32 apfu) and Al (4.59–4.65, 4.48–4.65 apfu), respectively, and low concentrations of Fe (Fetot p 0.08 apfu), Mg (p 0.07 apfu), and K (p 0.15 apfu). Concentrations of Li, B, and Be obtained by LA-ICP-MS (and wet chemical analysis— Li, Oldrˇich) of cookeite from both pegmatite dikes yielded an average of 2.22 wt.% Li2O (0.78 apfu) and 2.38 wt.% Li2O (0.84 apfu), low contents of B = 370–780 ppm and 250–430 ppm, and very low Be p16 ppm and p1.2 ppm for pegmatite No. 1 and the Oldrˇich pegmatite, respectively. Strong hydrothermal alteration of common Li-bearing sekaninaite (0.11–0.55 wt.% Li2O) is evident and a potential source of Li for both the proximal and distal cookeites. Cookeite precipitated from hydrothermal fluids at T B350–270 °C and P o B2 kbar. These data are consistent with the cookeite formation in granitic pegmatites and the distal cookeite demonstrates the high mobility of Li in hydrothermal conditions.
Návaznosti
GA14-13347S, projekt VaV |
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