Sekundární bastnäsit-(Ce), bastnäsit-(La) a parisit-(Ce) z ložiska Cínovec – produkty interakce primárních REE minerálů s pozdními nízkoteplotními fluidyČlánek v PDF
Secondary bastnäsite-(Ce), bastnäsite-(La) and parisite-(Ce) from the Cínovec deposit – products of interaction of primary REE minerals with late low-temperature fluids
The Cínovec/Zinnwald is a world-class greisen-type Li-Sn-W-Nb-Ta deposit. The REE minerals as common accessories are present there. Primary REE-bearing phases are represented by zircon, thorite, monazite, xenotime group minerals and fluorite. Secondary REE minerals include bastnäsite and synchysite group minerals, REE oxyfluorides, REE fluorides as well as dussertite group minerals. Magmatic monazite-(Ce) is a ubiquitous mineral with a distinct negative Eu anomaly. High contents of Th in monazite are characteristic for upper part of the granitic cupola (5.0–11.4 wt.% ThO2). Within the deposit, replacement of monazite-(Ce) by bastnäsite-(Ce) was observed. Bastnäsite structure type is stable in mineral associations with elevated LREE concentrations which were formed by the reaction of primary monazite with relatively low temperature fluids rich in carbonate and fluoride ions. Different type of bastnäsite was formed by alteration of REE rich fluorite. However, the fluids responsible for both bastnäsite types formation were the most probably identical.
Sebastián Hreus, Institute of Geosciences, Park Komenského 15, 040 01 Košice, Slovakia; Department of Geological Sciences, Faculty of Science, Masaryk University, Kotlářská 2, 602 00 Brno, Czech Republic, e-mail: email@example.com
Jan Cempírek, Department of Geological Sciences, Faculty of Science, Masaryk University, Kotlářská 2, 602 00 Brno, Czech Republic
Karel Breiter, Institute of Geology of the Czech Academy of Sciences, Rozvojová 269, 165 00 Praha 6, Czech Republic
Jakub Výravský, TESCAN Brno s.r.o, Libušina třída 1, 623 00 Brno, Czech Republic; Department of Geological Sciences, Faculty of Science, Masaryk University. Kotlářská 2, 602 00 Brno, Czech Republic