Chromium in minerals as tracer of the polycyclic evolution of eclogite and related metabasite from the Pohorje Mountains, Slovenian Eastern Alps

dc.contributor.authorLi, Botao
dc.contributor.authorMassonne, Hans‐Joachim
dc.date.accessioned2024-07-24T12:48:38Z
dc.date.available2024-07-24T12:48:38Z
dc.date.issued2023de
dc.date.updated2024-04-25T13:23:50Z
dc.description.abstractSignificantly different peak pressure-temperature (P-T) conditions (18-26 kbar and 630-760°C versus 29-37 kbar and 750-940°C) have previously been published for eclogite and related metabasites from the south‐eastern flank of the Pohorje Mountains in Slovenia. These rocks can show a bimodal distribution of chromium in the rock‐forming minerals, particularly garnet, the role of which in their metamorphic evolution is unclear. Therefore, we studied an eclogite and a related rock with clinopyroxene containing only 17 mol% jadeite + acmite (sample 18Ca35a). KαCr intensity maps of garnet particularly in sample 18Ca35a show a sharp irregular boundary between the core (Gt1) and the mantle (Gt2). Gt1 of millimetre‐sized garnet in this rock is nearly Cr‐free and unzoned, whereas Gt2 is of different composition (0.22 wt.% Cr2O3) and slightly zoned. Nearly Cr‐free amphibole, (clino)zoisite, kyanite and staurolite inclusions are present in Gt1. The matrix consists of garnet and Cr‐bearing clinopyroxene, (clino)zoisite and amphibole. Thermodynamic modelling suggests peak P-T conditions of 22.5 ± 2 kbar at 710 ± 25°C (Gt1) and 23 ± 2 kbar at 700 ± 25°C (Gt2) in both samples. We interpret these findings to suggest that olivine‐ and hornblende‐bearing gabbros with some chromite experienced early metamorphism in the eclogite facies, when Gt1 formed. The rock was subsequently exhumed and cooled leading to significant garnet corrosion. A second stage of metamorphism, recognized by mappable Cr contents in garnet, led to the growth of Gt2 and other Cr‐bearing minerals at the expense of chromite relics, which survived stage I. The peak P-T conditions of stage II are compatible with those previously derived by same authors and support the view that probably no ultrahigh‐pressure eclogite exists in the Pohorje Mountains. We relate the two metamorphic events to the Cretaceous and Palaeogene high‐pressure events recently reported from micaschists of the Pohorje Mountains.en
dc.description.sponsorshipNational Natural Science Foundation of Chinade
dc.description.sponsorshipthe Most Special Fund from the State Key Laboratory of GPMR China University of Geosciences (Wuhan)de
dc.description.sponsorship111 Projectde
dc.identifier.issn1525-1314
dc.identifier.issn0263-4929
dc.identifier.other1896680801
dc.identifier.urihttp://nbn-resolving.de/urn:nbn:de:bsz:93-opus-ds-147205de
dc.identifier.urihttp://elib.uni-stuttgart.de/handle/11682/14720
dc.identifier.urihttp://dx.doi.org/10.18419/opus-14701
dc.language.isoende
dc.relation.uridoi:10.1111/jmg.12746de
dc.rightsinfo:eu-repo/semantics/openAccessde
dc.rights.urihttps://creativecommons.org/licenses/by-nc-nd/4.0/de
dc.subject.ddc540de
dc.titleChromium in minerals as tracer of the polycyclic evolution of eclogite and related metabasite from the Pohorje Mountains, Slovenian Eastern Alpsen
dc.typearticlede
ubs.fakultaetChemiede
ubs.fakultaetFakultätsübergreifend / Sonstige Einrichtungde
ubs.institutFakultät Chemie (Institutsübergreifend)de
ubs.institutFakultätsübergreifend / Sonstige Einrichtungde
ubs.publikation.seiten63-88de
ubs.publikation.sourceJournal of metamorphic geology 42 (2024), S. 63-88de
ubs.publikation.typZeitschriftenartikelde

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