Geodynamic Significance of the Early Triassic Karaburun Granitoid (Western Turkey) for the Opening History of Neo-Tethys

AKAL C., KORALAY O. E., CANDAN O., Oberhansli R., Chen F.

TURKISH JOURNAL OF EARTH SCIENCES, cilt.20, sa.3, ss.255-271, 2011 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 20 Sayı: 3
  • Basım Tarihi: 2011
  • Doi Numarası: 10.3906/yer-1008-1
  • Dergi Adı: TURKISH JOURNAL OF EARTH SCIENCES
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, TR DİZİN (ULAKBİM)
  • Sayfa Sayıları: ss.255-271
  • Anahtar Kelimeler: Karaburun, Neo-Tethys, Palaeo-Tethys, diorite, Triassic, magmatism, S-TYPE GRANITES, ARC MAGMATISM, I-TYPE, SOUTHERN TURKEY, CHIOS ISLAND, SUBDUCTION, EVOLUTION, MANTLE, DISCRIMINATION, PENINSULA
  • Dokuz Eylül Üniversitesi Adresli: Evet

Özet

The Karaburun Peninsula, which is considered part of the Anatolide-Tauride Block of Turkey, contains clastic and carbonate sequences deposited on the northern margin of Gondwana. The Palaeozoic clastic sequence, which is intruded by the Early Triassic granitoid and tectonically overlies a Mesozoic melange sequence, can be divided into three subunits: a lower clastic subunit consisting of a sandstone-shale alternation, an upper clastic subunit consisting of black chert-bearing shales, sandstone and conglomerate, and a Permo-Carboniferous carbonate subunit. The lower Triassic Karaburun I-type granitoid has a high initial Sr-87/Sr-86 ratio (0.709021-0.709168), and low Nd-143/Nd-144 ratio (0.512004-0.512023) and epsilon Nd (-5.34 to -5.70) isotopic values. Geochronological data indicate a crystallization (intrusion) age of 247.1 +/- 2.0 Ma (Scythian). Geochemically, the acidic magmatism reflects a subduction-related continental-arc basin tectonic setting, which can be linked to the opening of the northern branch of Neo-Tethys as a continental back-arc rifting basin on the northern margin of Gondwana. This can be related to the closure through southward subduction of the Palaeotethys Ocean beneath Gondwana.