TY - JOUR
T1 - Metamorphic evolution of iron-rich mafic cumulates from the Oetztal-Stubai crystalline complex, Eastern Alps, Austria
AU - Konzett, Jürgen
AU - Miller, Christine
AU - Armstrong, Richard A
AU - Thöni, Martin
N1 - DOI: 10.1093/petrology/egh095
Affiliations: Inst. für Mineral./Petrographie, Universität Innsbruck, Innrain 52, A-6020 Innsbruck, Austria; Research School of Earth Sciences, The Australian National University, Canberra, ACT 0200, Australia; Inst. für Geol. Wissenschaften, Universität Wien, Geozentrum, Althangasse 14, A-1090 Vienna, Austria
Adressen: Konzett, J.; Inst. fur Mineralogie/Petrographie; Universität Innsbruck; Innrain 52 A-6020 Innsbruck, Austria; email: [email protected]
Source-File: EarthScienceScopus_iso.csv
Import aus Scopus: 2-s2.0-16444367853
Importdatum: 27.11.2006 19:23:21
30.10.2007: Datenanforderung 1951 (Import Sachbearbeiter)
PY - 2005
Y1 - 2005
N2 - Olivine-rich rocks containing olivine + orthopyroxene + spinel + Ca-amphibole ‘ clinopyroxene ‘ garnet are present in the central Oštztal-Stubai crystalline basement associated with eclogites of tholeiitic affinity. These rocks contain centimetre-sized garnet layers and lenses with garnet + clinopyroxene ‘ corundum. Protoliths of the olivine-rich rocks are thought to be olivine + orthopyroxene + spinel dominated cumulates generated from an already differentiated Fe-rich (XMgmelt = 0ž 57-0ž65) tholeiitic magma that was emplaced into shallow continental crust. Protoliths of the garnet-rich rocks are interpreted as layers enriched in plagioclase and spinel intercalated in a cumulate rock sequence that is devoid of, or poor in, plagioclase. U-Pb sensitive high-resolution ion microprobe dating of zircons from a garnet layer indicates that emplacement of the cumulates took place no later than 517 ‘ 7 Myr ago. After their emplacement, the cumulates were subjected to progressive metamorphism, reaching eclogite-facies conditions around 800°C and > 2 GPa during a Variscan metamorphic event between 350 and 360 Ma. Progressive high-P metamorphism induced breakdown of spinel to form garnet in the olivine-rich rocks and of plagioclase + spinel to form garnet + clinopyroxene ‘ corundum in the garnet layers. Retrogressive metamorphism at T e0-680°C led to the formation of Ca-amphibole, chlorite and talc in the olivine-rich rocks. In the garnet layers, hošgbomite formed from corundum + spinel along with Al-rich spinel, Ca-amphibole, chlorite, aspidolite preiswerkite, magnetite, ilmenite and apatite at the interface between olivine-rich rocks and garnet layers at P
AB - Olivine-rich rocks containing olivine + orthopyroxene + spinel + Ca-amphibole ‘ clinopyroxene ‘ garnet are present in the central Oštztal-Stubai crystalline basement associated with eclogites of tholeiitic affinity. These rocks contain centimetre-sized garnet layers and lenses with garnet + clinopyroxene ‘ corundum. Protoliths of the olivine-rich rocks are thought to be olivine + orthopyroxene + spinel dominated cumulates generated from an already differentiated Fe-rich (XMgmelt = 0ž 57-0ž65) tholeiitic magma that was emplaced into shallow continental crust. Protoliths of the garnet-rich rocks are interpreted as layers enriched in plagioclase and spinel intercalated in a cumulate rock sequence that is devoid of, or poor in, plagioclase. U-Pb sensitive high-resolution ion microprobe dating of zircons from a garnet layer indicates that emplacement of the cumulates took place no later than 517 ‘ 7 Myr ago. After their emplacement, the cumulates were subjected to progressive metamorphism, reaching eclogite-facies conditions around 800°C and > 2 GPa during a Variscan metamorphic event between 350 and 360 Ma. Progressive high-P metamorphism induced breakdown of spinel to form garnet in the olivine-rich rocks and of plagioclase + spinel to form garnet + clinopyroxene ‘ corundum in the garnet layers. Retrogressive metamorphism at T e0-680°C led to the formation of Ca-amphibole, chlorite and talc in the olivine-rich rocks. In the garnet layers, hošgbomite formed from corundum + spinel along with Al-rich spinel, Ca-amphibole, chlorite, aspidolite preiswerkite, magnetite, ilmenite and apatite at the interface between olivine-rich rocks and garnet layers at P
M3 - Article
SN - 0022-3530
VL - 46
SP - 717
EP - 747
JO - Journal of Petrology
JF - Journal of Petrology
IS - 4
ER -