U–Pb zircon ages of Late Cretaceous Nain–Dehshir ophiolites, central Iran

<p>Late Cretaceous Zagros ophiolites are part of the <em>c</em>. 3000 km long Late Cretaceous Ophiolite Belt of SW Asia including the Troodos (Cyprus), eastern Mediterranean (Turkey, Syria), Zagros (Iran) and Semail ophiolites (Oman). This ophiolite belt represents a magmatic forearc that formed when subduction of the Neotethys began along the SW margin of Eurasia. Geochronological data for Zagros ophiolites are limited to a few K–Ar and ⁴⁰Ar–³⁹Ar ages. New thermal ionization mass spectrometry U–Pb zircon ages indicate that the Nain and Dehshir ophiolites of central Iran formed <em>c</em>. 101–103 Ma, with Nain (102.9 ± 0.3 Ma) being <em>c</em>. 1 Ma older than Dehshir (100.9 ± 0.2 Ma; 100.4 ± 0.1 Ma), and that these ophiolites were emplaced almost immediately after formation (Nain emplacement 101.2 ± 0.2 Ma; Dehshir emplacement 99.0 ± 1.1 Ma). These formation ages are significantly older than the 98–90 Ma U–Pb zircon ages of other Late Cretaceous ophiolites in this belt such as the Kizildag (Turkey), Semail (Oman) and Troodos ophiolites (Cyprus). If the subduction initiation model applies to this ophiolite belt, it suggests that subduction initiation began near the Zagros margin and propagated at <em>c</em>. 7 cm a⁻¹ to the east (Semail) and <em>c</em>. 15 cm a⁻¹ to the west (Troodos). </p

Figure S1: Mineral chemistry and melt evolution of the mantle wedge peridotites in the Late Cretaceous Zagros Belt ophiolites (Iran): clues for the subduction initiation-induced forearc magmatism

Figure S1. Back-scattered images of Zagros mantle rocks reveal the following features: A. Orthopyroxene, clinopyroxene, and olivine porphyroclasts with small spinel crystals within Kermanshah lherzolites. B. Olivine and dark brown spinel crystals embedded in large clinopyroxene crystals within Kermanshah lherzolite cumulates. C. Large olivine crystals, clinopyroxene, and plagioclase present in coarse-grained olivine gabbros from Kermanshah. D. Olivine, clinopyroxene, and plagioclase in Kermanshah isotropic gabbros. E. Olivine, anhedral orthopyroxene and tiny clinopyroxene in Neyriz harzburgites. F. Olivine, clinopyroxene and plagioclase in Neyriz olivine gabbros. G- Serpentinized olivine and anhedral orthopyroxene in Haji-Abad harzburgites. H- Serpentinized olivine and medium to coarse-grained Cr-spinels in Haji-Abad dunites

Table S1 Mineral chemistry and melt evolution of the mantle wedge peridotites in the Late Cretaceous Zagros Belt ophiolites (Iran): clues for the subduction initiation-induced forearc magmatism

Table S1

Table S2 Mineral chemistry and melt evolution of the mantle wedge peridotites in the Late Cretaceous Zagros Belt ophiolites (Iran): clues for the subduction initiation-induced forearc magmatism

Table S2

Figure S2: Mineral chemistry and melt evolution of the mantle wedge peridotites in the Late Cretaceous Zagros Belt ophiolites (Iran): clues for the subduction initiation-induced forearc magmatism

Figure S2. Back-scattered images of Zagros ophiolite mantle rocks reveal the following characteristics: A. Rounded olivine crystals, clinopyroxene, and plagioclase crystals within Nain olivine gabbros. B. Serpentinized olivines, anhedral clinopyroxene, large grains of orthopyroxene, and brownish spinel (along with fine-grained clinopyroxene) at the embayment of orthopyroxene in Nain lherzolites. C. Serpentinized olivines, clinopyroxene, and altered plagioclase within Nain plagioclase lherzolites. D. Large crystals of clinopyroxene, olivine, orthopyroxene, and small brown spinel crystals (with occasional tiny clinopyroxene inclusions) in Nain lherzolites. E. Clinopyroxene and plagioclase crystals in Baft gabbros. Notably, plagioclases exhibit thin rims of sodic plagioclases surrounding the calcium-rich plagioclase crystals. F. Serpentinized olivines, orthopyroxene, and dark brown spinel in Dehshir-Shahr-e-Babak harzburgite. G and H. Plagioclase, clinopyroxene, and orthopyroxene crystals within Baft gabbronorites. Clinopyroxene displays slight alteration into actinolite (G), while plagioclase shows slight alteration into clay minerals (H)

Table S3 Mineral chemistry and melt evolution of the mantle wedge peridotites in the Late Cretaceous Zagros Belt ophiolites (Iran): clues for the subduction initiation-induced forearc magmatism

Table S3