Zircon U–Pb, O, and Hf isotopic constraints on Mesozoic magmatism in the Cyclades, Aegean Sea, Greece

Identifying Laurentian and SW Gondwana sources in the Neoproterozoic to Early Paleozoic metasedimentary rocks of the Sierras Pampeanas: Paleogeographic and tectonic implications

“…After selecting zircon populations of known age, and re-polishing the epoxy mounts, oxygen analyses were carried out using SHRIMP II, while Lu-Hf analyses were performed on a Neptune MC-ICPMS coupled with a HelEx 193 μm ArF Excimer laser ablation system, following procedures described in Fu et al (2014). Full analytical results are presented in Table 3 of the Supplementary Appendix of this paper.…”

Tectono‐magmatic and Stratigraphic Evolution of the Cycladic Basement, Ios Island, Greece

“…The ages of intercalated volcanic rocks and DZ studies in the western and northern Cyclades demonstrated that CBU deposition spanned from Triassic to Paleogene (Bröcker et al, ; Henjes‐Kunst & Kreuzer, ; Hinsken et al, ; Keay, ; Löwen et al, ; Seman et al, ) and was likely initially accumulated along a rifted continental margin (Seman et al, ). In the southern and central Cyclades, Fu et al () demonstrated that the CBU contains Middle Triassic zircon characterized by rift‐related δO 18 and εHf values.…”

“…These radiometric ages often yielded complex and difficult‐to‐interpret results indicative of partially reset and/or mixed ages related to post‐Carboniferous, Eocene HP‐LT blueschist facies metamorphism, and/or Oligo‐Miocene greenschist facies tectono‐metamorphic events. Fu et al () provide robust zircon U‐Pb, O, and Hf data that reveal distinct age populations of Late Carboniferous, Triassic, Late Jurassic, and Late Cretaceous zircon from Andros, Ios, Sifnos, and Syros islands. Variable εHf and δO 18 values within Triassic zircon have been interpreted as rift‐ rather than subduction‐related (Fu et al, ).…”

“…Fu et al () provide robust zircon U‐Pb, O, and Hf data that reveal distinct age populations of Late Carboniferous, Triassic, Late Jurassic, and Late Cretaceous zircon from Andros, Ios, Sifnos, and Syros islands. Variable εHf and δO 18 values within Triassic zircon have been interpreted as rift‐ rather than subduction‐related (Fu et al, ).…”

“…The Cycladic Blueschist Unit (CBU), which lies at the heart of the Attic‐Cycladic subduction complex, has been the focus of numerous studies constraining its prograde and retrograde HP‐LT metamorphic evolution and exhumation, especially on the islands of Syros and Sifnos where HP‐LT blueschist facies rocks are excellently preserved alongside younger greenschist to amphibolite facies (e.g., Avigad & Garfunkel, ; Behr et al, ; Dürr et al, ; Grasemann et al, ; Grasemann et al, ; Jolivet et al, ; Laurent et al, ; Philippon et al, ; Soukis & Stockli, ). However, limited detailed work exists about the chronostratigraphy, the depositional history, or the paleogeographic and tectonic evolution of the CBU or Cycladic Basement (CB) protoliths, consequently hampering insights into subduction processes, the juxtaposition of different HP‐LT units, and Aegean exhumation history (e.g., Bröcker et al, ; Bröcker & Pidgeon, ; Fu et al, ; Henjes‐Kunst & Kreuzer, ; Hinsken et al, ; Keay, ; Keay & Lister, ; Löwen et al, ; Poulaki et al, ; Seman et al, ). In particular, little is known about the structurally lowest unit, the CB, which represents a fragment of Adria/Pelagonia continental crust underlying the CBU in the southern Cyclades (Jolivet & Brun, ; Ring et al, ; Stampfli et al, ; Stampfli & Borel, ).…”