Characteristics and significance of detrital zircons from podiform chromitites of the Lycian ophiolite, SW Türkiye: Evidence for crustal recycling in the İzmir-Ankara-Erzincan Ocean


Xu Y., PARLAK O., Robinson P. T., Dönmez C., Hong J.

Lithos, cilt.482-483, 2024 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 482-483
  • Basım Tarihi: 2024
  • Doi Numarası: 10.1016/j.lithos.2024.107712
  • Dergi Adı: Lithos
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aquatic Science & Fisheries Abstracts (ASFA), Chemical Abstracts Core, Geobase, INSPEC, Pollution Abstracts
  • Anahtar Kelimeler: Chromitites, Detrital zircon, Hf-isotopes, Lycian ophiolite, Trace elements, Türkiye, U-Pb geochronology
  • Çukurova Üniversitesi Adresli: Evet

Özet

The Lycian ophiolite in SW Türkiye includes both high-Al and high-Cr chromitites hosted in mantle peridotites. Detrital zircons have been recovered from both types of chromitite, and are typically much older than the crystallization age (91–92 Ma) of the ophiolite. The U–Pb ages range widely, but most cluster in one of four groups, namely Neoarchean to Paleoproterozoic (2515 ± 28 Ma to 1735 ± 44 Ma), Neoproterozoic (828 ± 10 Ma to 558 ± 9 Ma), Late Silurian-Early Devonian (416 ± 8 Ma) and Middle Triassic (242 ± 7 Ma). Rare earth element (REE) patterns and trace element contents of the zircon grains suggest that they were derived from continental sources. For example, εHf(t) values (−11.32 to 11.03) point to derivation from highly evolved crustal sources with very limited juvenile melt. Thus, the detrital zircons from the Lycian chromitites are very similar to those recovered from the underlying Menderes Metamorphic Massif (MMM) and Afyon Zone (Anatolides) that separated in the past from Western Gondwana. The presence of the unusually old zircons suggests that they were captured by the high-Al and high-Cr chromitites during rifting, slab roll-back and slab tear during subduction initiation in a forearc environment within the İzmir-Ankara-Erzincan Ocean during the Late Cretaceous.