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001-es BibID:	BIBFORM116329
035-os BibID:	(Scopus)85175031969 (WoS)001092105000001 (cikkazonosító)83
Első szerző:	Molnár Kata
Cím:	Unravelling the pre-eruptive conditions of the rhyolitic Šumovit Greben lava dome from clinopyroxene-dominant glomeroporphyritic clots / Kata Molnár, Pierre Lahitte, Boglárka Döncző, Róbert Arató, János Szepesi, Zsolt Benkó, Sebastien Nomade, Jochen Gätjen, Stéphane Dibacto, Marjan Temovski
Dátum:	2023
ISSN:	0010-7999
Megjegyzések:	Detailed analyses of mineral composition and whole-rock geochemical data helped to unravel the volcanic plumbing system beneath the rhyolitic Sumovit Greben lava dome, the westernmost member of the Kozuf-Voras volcanic system (N. Macedonia). It is characterized by high SiO2 content (> 70 wt%) coupled with low MgO (< 1 wt%) and Sr (< 500 ppm) suggesting fractionation of clinopyroxene and plagioclase at depth forming a crystal mush and a crystal-poor rhyolitic lens by fractional crystallization and melt extraction on top of it. The crystal mush is composed of mainly clinopyroxene, biotite and plagioclase, whereas sanidine and plagioclase are the most abundant phenocrysts of the rhyolitic lens. The main dome forming event occurred at ca. 2.9 Ma, which sampled the crystal-poor rhyolitic lens. After a short quiescence time, an explosive eruption occurred depositing a massive lapilli tuff layer northwest of the lava dome, and an extrusion of a small-volume lava flow on the northern side of the lava dome at ca. 2.8 Ma. This latter sampled also the crystal mush, as it contains abundant glomeroporphyritic clots of clinopyroxene +/- plagioclase +/- biotite. The clinopyroxene phenocrysts are chemically homogeneous, their crystallization temperature is ca. 900(degrees)C representing the crystal mush, whereas the plagioclase and the sanidine crystallized at a lower temperature (ca. 790(degrees)C) representing the rhyolitic lens. Noble gas isotopic composition of the clinopyroxene indicate no mantle-derived fluids (< 0.5%) having an R/R-a of ca. 0.04 R-a. The rejuvenation of the system probably occurred due to implementation of mafic magma at depth leading to a heat transfer and partial melting of the cumulate. This led to crystallization of Ba-rich rims of the sanidine and An- and Sr-rich rims of the plagioclase. The crystal mush zone beneath Sumovit Greben might be connected to the nearby, more mafic volcanic centers, and the eruption of Sumovit Greben could have been the start of the last cycle in the lifetime of the Kozuf-Voras volcanic system.
Tárgyszavak:	Természettudományok Földtudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk Rhyolite Clinopyroxene Noble gases Volcanic plumbing system Sanidine Ar/Ar dating
Megjelenés:	Contributions To Mineralogy And Petrology. - 178 : 11 (2023), p. 1-17. -
További szerzők:	Lahitte, Pierre Döncző Boglárka (1987-) (biológiatanár-földrajztanár) Arató Róbert Szepesi János Benkó Zsolt (1980-) (geológus) Nomade, Sebastien Gätjen, Jochen Dibacto, Stéphane Temovski, Marjan
Pályázati támogatás:	GINOP-2.3.2-15-2016-00009 GINOP GINOP-2.3.3-15-2016-00029 GINOP
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