caa a22 4500 606149031 CHVBK 20210128100532.0 cr unu---uuuuu 210128e20150101xx s 000 0 eng 10.1007/s00531-014-1064-z doi (NATIONALLICENCE)springer-10.1007/s00531-014-1064-z Zircon U-Pb, O, and Hf isotopic constraints on Mesozoic magmatism in the Cyclades, Aegean Sea, Greece [Elektronische Daten] [Bin Fu, Michael Bröcker, Trevor Ireland, Peter Holden, Leslie Kinsley] Compared to the well-documented Cenozoic magmatic and metamorphic rocks of the Cyclades, Aegean Sea, Greece, the geodynamic context of older meta-igneous rocks occurring in the marble-schist sequences and mélanges of the Cycladic Blueschist Unit is as yet not fully understood. Here, we report O-Hf isotopic compositions of zircons ranging in age from ca. 320Ma to ca. 80Ma from metamorphic rocks exposed on the islands of Andros, Ios, Sifnos, and Syros with special emphasis on Triassic source rocks. Ion microprobe (SHRIMP II) single spot oxygen isotope analysis of pre-Cretaceous zircons from various felsic gneisses and meta-gabbros representing both the marble-schist sequences and the mélanges of the study area yielded a large range in δ18O values, varying from 2.7‰ to 10.1‰ VSMOW, with one outlier at −0.4%. Initial εHf values (−12.5 to +15.7) suggest diverse sources for melts formed between Late Carboniferous to Late Cretaceous time that record derivation from mantle and reworked older continental crust. In particular, variable δ18O and εHf(t) values for Triassic igneous zircons suggest that magmatism of this age is more likely rift- than subduction-related. The significant crustal component in 160Ma meta-gabbros from Andros implies that some Jurassic gabbroic rocks of the Hellenides are not part of SSZ-type (supra-subduction zone) ophiolites that are common elsewhere along the margin of the Pelagonian zone. Springer-Verlag Berlin Heidelberg, 2014 Ion microprobe nationallicence Oxygen isotopes nationallicence Hafnium isotopes nationallicence Zircon nationallicence Attic-Cycladic Crystalline Belt nationallicence Fu Bin Research School of Earth Sciences, The Australian National University, 0200, Canberra, ACT, Australia aut Bröcker Michael Institut für Mineralogie, Westfälische-Wilhelms Universität Münster, Corrensstraße 24, 48149, Münster, Germany aut Ireland Trevor Research School of Earth Sciences, The Australian National University, 0200, Canberra, ACT, Australia aut Holden Peter Research School of Earth Sciences, The Australian National University, 0200, Canberra, ACT, Australia aut Kinsley Leslie Research School of Earth Sciences, The Australian National University, 0200, Canberra, ACT, Australia aut International Journal of Earth Sciences Springer Berlin Heidelberg 104/1(2015-01-01), 75-87 1437-3254 104:1<75 2015 104 531 https://doi.org/10.1007/s00531-014-1064-z text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00531-014-1064-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Fu Bin Research School of Earth Sciences, The Australian National University, 0200, Canberra, ACT, Australia aut NATIONALLICENCE 700 1- Bröcker Michael Institut für Mineralogie, Westfälische-Wilhelms Universität Münster, Corrensstraße 24, 48149, Münster, Germany aut NATIONALLICENCE 700 1- Ireland Trevor Research School of Earth Sciences, The Australian National University, 0200, Canberra, ACT, Australia aut NATIONALLICENCE 700 1- Holden Peter Research School of Earth Sciences, The Australian National University, 0200, Canberra, ACT, Australia aut NATIONALLICENCE 700 1- Kinsley Leslie Research School of Earth Sciences, The Australian National University, 0200, Canberra, ACT, Australia aut NATIONALLICENCE 773 0- International Journal of Earth Sciences Springer Berlin Heidelberg 104/1(2015-01-01), 75-87 1437-3254 104:1<75 2015 104 531