Geologia Croatica, Vol. 65 No. 3, 2012.
Izvorni znanstveni članak
https://doi.org/10.4154/GC.2012.31
The evolution of the Čanište epidote-bearing pegmatite, Republic of Macedonia: evidence from mineralogical and geochemical features
Sabina Strmić Palinkaš
; University of Zagreb, Faculty of Science, Geological department
Vladimir Bermanec
; University of Zagreb, Faculty of Science, Geological department
Ladislav A. Palinkaš
; University of Zagreb, Faculty of Science, Geological department
Blažo Boev
; Goce Delčev University, Faculty of Mining, Geology and Polytechnic
Robert A. Gault
; Research Division, Canadian Museum of Nature
Walter Prochaska
; University of Leoben, Department of Applied Geosciences and Geophysics, Mineralogy and Petrology Group
Ronald J. Bakker
; University of Leoben, Department of Applied Geosciences and Geophysics, Mineralogy and Petrology Group
Sažetak
The epidote-bearing Čanište pegmatite and adjacent Upper Carboniferous granodiorites cut Precambrian gneises, at the western slopes of the Selečka Mts., the Eastern Pelagonian zone, FYRO Macedonia. The pegmatite exhibits zonal internal structure with the following sub-units: the wall zone (amazonite microcline ± biotite, quartz), the first intermediate zone (epidote + hematite + grossular + muscovite + quartz + almandine ± zircon, beryl, microcline, quartz), the second intermediate zone (albite + quartz ± microcline) and the core (massive quartz). According to the microprobe data epidote belongs to clinozoisite subgroup with formula (Ca1.96-1.99Mn0.02-0.03Fe2+0.00-0.02)(Al2.17-2.46Fe3+0.51-0.82Ti0.00-0.01)(Si2O7)(Si0.99-1.00Al0.00-0.01O4)O(OH). The occurrences of almandine and zircon with low U, Th and REE content, are indicative to weakly evolved granitic/granodioritic rocks. The absence of aplites suggests steady pressure condition during the course of pegmatite crystallization. Microthermometric data combined by the two-feldspar geothermometer gained pressure from 4.8 to 5.6 kbar for the second intermediate zone. The wall zone, composed of amazonite microcline, crystallized at temperature between 650 and 760. Dropping of melt temperature below 550°C, under the oxygen fugacity between 10-22 and 10-19.5 bar, was the principal trigger for deposition of minerals in the first intermediate zone. The residual fluid, depleted in Ca, Fe and K, and enriched in water, Na and Si, caused deposition of the second intermediate zone (albite + quartz) at temperature between 445 and 465°C. The massive quartz core crystallized in the very last stage of the pegmatite evolution (T ≈ 400-480°C) from melt residue enriched in silica, water and CO2 content.
Ključne riječi
magmatic-hydrothermal transition; granodiorite; pegmatite; epidote; fluid inclusions; Pelagonian zone; Republic of Macedonia
Hrčak ID:
124239
URI
Datum izdavanja:
30.10.2012.
Posjeta: 1.470 *