TY - JOUR
T1 - Ion-probe (SIMS) U-Pb geochronology and geochemistry of the Upper Cretaceous Kızıldağ (Hatay) ophiolite: Implications for supra-subduction zone spreading in the Southern Neotethys
AU - Şimşek, Emrah
AU - Parlak, Osman
AU - Robertson, Alastair h.f.
N1 - Funding Information:
This work is based on a MSc study by the first author. Financial support from the Çukurova University Research Foundation (Project no: FYL-2015-3872) is gratefully acknowledged. We would like to thank Seher Kuru and Aynur Gürbüz for their help during the CL imaging of the zircons at Mersin University. Dr. Richard Hinton (University of Edinburgh) is thanked for carrying out the ion microprobe analysis of the zircons. Constructive reviews by Timur Ustaömer and an anonymous reviewer are acknowledged. Andrea Festa and Emilio Saccani are thanked for editorial handling.
Funding Information:
This work is based on a MSc study by the first author. Financial support from the Çukurova University Research Foundation (Project no: FYL-2015-3872) is gratefully acknowledged. We would like to thank Seher Kuru and Aynur Gürbüz for their help during the CL imaging of the zircons at Mersin University. Dr. Richard Hinton (University of Edinburgh) is thanked for carrying out the ion microprobe analysis of the zircons. Constructive reviews by Timur Ustaömer and an anonymous reviewer are acknowledged. Andrea Festa and Emilio Saccani are thanked for editorial handling.
Publisher Copyright:
© 2022 The Author(s)
PY - 2023/8/3
Y1 - 2023/8/3
N2 - The Kızıldağ (Hatay) ophiolite in southern Turkey represents a complete, although fault-dissected, remnant of oceanic lithosphere that formed within the South Tethyan ocean during the late Cretaceous. The Kızıldağ forms part of the Upper Cretaceous belt which includes the Troodos (Cyprus), Baer-Bassit (Syria), Amanos (S Tukey), S Iran and Semail (Oman) ophiolites. Ion-probe (SIMS) dating of seven samples of crustal rocks (cumulate gabbro, isotropic gabbro and isolated dykes in mantle tectonite), and a plagiogranite intrusion provides important clues concerning the temporal development of the emplaced oceanic crust. Single grain 206Pb/238U dates that overlap within analytical uncertainty for four samples, including the plagiogranite (93.83 ± 0.46 Ma), the isotropic gabbro (92.9 ± 0.52 Ma) and the isolated dykes (92.54 ± 0.44 Ma to 93.6 ± 0.75 Ma), are interpreted as magmatic crystallisation ages, and suggest that the Kızıldağ ophiolite formed within 1-2 Ma. Three other samples with single grain 206Pb/238U dates that are outside the range of analytical uncertainty yielded nearly identical lower intercept ages of 94.2 ± 2.5 Ma to 94.4 ± 0.97 Ma for two cumulate gabbros and 90.0 ± 6.4 Ma for an isotropic gabbro. Comparison of the new and published radiometric ages of the Kızıldağ suggest that this ophiolite is ∼1.5 Ma older than previously believed, and is similar to the crystallisation ages of plagiogranites from the Troodos (Cyprus) and the Semail (Oman) ophiolites. The new age data emphasise the value of dating a range of ophiolitic rocks. Geochemically, the crustal rocks of the Kızıldağ ophiolite formed from boninitic magmas (cumulate gabbros and isolated dykes) and from island arc tholeiitic magmas (isotropic gabbro). The new whole-rock chemical data support a subduction-initiation (fore-arc) setting for the Kızıldağ ophiolite, in common with the Troodos, Semail, Baër-Bassit and other Upper Cretaceous ophiolites of the South-Tethyan region.
AB - The Kızıldağ (Hatay) ophiolite in southern Turkey represents a complete, although fault-dissected, remnant of oceanic lithosphere that formed within the South Tethyan ocean during the late Cretaceous. The Kızıldağ forms part of the Upper Cretaceous belt which includes the Troodos (Cyprus), Baer-Bassit (Syria), Amanos (S Tukey), S Iran and Semail (Oman) ophiolites. Ion-probe (SIMS) dating of seven samples of crustal rocks (cumulate gabbro, isotropic gabbro and isolated dykes in mantle tectonite), and a plagiogranite intrusion provides important clues concerning the temporal development of the emplaced oceanic crust. Single grain 206Pb/238U dates that overlap within analytical uncertainty for four samples, including the plagiogranite (93.83 ± 0.46 Ma), the isotropic gabbro (92.9 ± 0.52 Ma) and the isolated dykes (92.54 ± 0.44 Ma to 93.6 ± 0.75 Ma), are interpreted as magmatic crystallisation ages, and suggest that the Kızıldağ ophiolite formed within 1-2 Ma. Three other samples with single grain 206Pb/238U dates that are outside the range of analytical uncertainty yielded nearly identical lower intercept ages of 94.2 ± 2.5 Ma to 94.4 ± 0.97 Ma for two cumulate gabbros and 90.0 ± 6.4 Ma for an isotropic gabbro. Comparison of the new and published radiometric ages of the Kızıldağ suggest that this ophiolite is ∼1.5 Ma older than previously believed, and is similar to the crystallisation ages of plagiogranites from the Troodos (Cyprus) and the Semail (Oman) ophiolites. The new age data emphasise the value of dating a range of ophiolitic rocks. Geochemically, the crustal rocks of the Kızıldağ ophiolite formed from boninitic magmas (cumulate gabbros and isolated dykes) and from island arc tholeiitic magmas (isotropic gabbro). The new whole-rock chemical data support a subduction-initiation (fore-arc) setting for the Kızıldağ ophiolite, in common with the Troodos, Semail, Baër-Bassit and other Upper Cretaceous ophiolites of the South-Tethyan region.
U2 - 10.1016/j.geogeo.2022.100165
DO - 10.1016/j.geogeo.2022.100165
M3 - Article
SN - 2772-8838
VL - 2
JO - Geosystems and Geoenvironment
JF - Geosystems and Geoenvironment
IS - 3
M1 - 100165
ER -