Složení stébelnatého vesuvianu ze skarnoidu od Moravských Bránic (Moravosilezikum)Článek v PDF
Composition of vesuvianite from skarnoid from Moravské Bránice (Moravosilesian Zone)
Study of long-prismatic vesuvianite-group minerals from skarnoid at the locality Moravské Bránice using the electron microprobe and LA-ICP-MS (laser ablation mass spectrometry with inductively coupled plasma) provided new results on its chemical and trace-element composition. Four texturally-paragenetic types of vesuvianite were distinguished. Primary vesuvianite VES 1 occurs in the mineral assemblage Ves + Di + Ep whereas the primary vesuvianites VES 2 and VES 3 were found in the mineral assemblage Ves + Di + Grs; both assemblages contain accessory apatite, titanite, zircon and rare malayaite. Alteration of VES 2 results in Ca, Al, F-depleted hydrated mineral (VES 4) with composition that still resembles vesuvianite stoichiometry. The primary vesuvianite from Moravské Bránice is remarkable by its high Ti contents (up to 0.97 apfu; 2.62 wt.% TiO2), and elevated Li (up to 157 ppm), Be (up to 90 ppm) and REE, Th, U amounts (up to 3100 ppm Ce, 1300 ppm Th, and 240 ppm U). Secondary alteration that removed part of Ca, Al, and F from VES 2 and increased B, Sr, REE, Th, and U contents in resulting VES 4 was most likely low-volume hydrothermal process. Vesuvianite stability during postmagmatic processes (recrystallization, alteration) makes it plausible tool for monitoring of postmagmatic processes.
Jakub Malý, Department of Geological Sciences, Masaryk University, Brno, Kotlářská 2, 611 37 Brno, Czech Republic, e-mail: email@example.com
Jan Cempírek, Department of Geological Sciences, Masaryk University, Brno, Kotlářská 2, 611 37 Brno, Czech Republic
Milan Novák, Department of Geological Sciences, Masaryk University, Brno, Kotlářská 2, 611 37 Brno, Czech Republic