Geochemistry and tectonic significance of the Fannuj-Maskutan SSZ-type ophiolite (Inner Makran, SE Iran)

Early Cretaceous Plume–Ridge Interaction Recorded in the Band-e-Zeyarat Ophiolite (North Makran, Iran): New Constraints from Petrological, Mineral Chemistry, and Geochronological Data

“…These ophiolites show Early to Late Cretaceous ages and magmatic rocks displaying different geochemical features. In detail, the Early Cretaceous ophiolites have enriched mid-ocean ridge basalt (E-MORB) geochemical affinity, whereas the Late Cretaceous units display supra-subduction zone geochemical affinity [16,18,19,24,53]. The Band-e-Zeyarat ophiolite consists of an incomplete ophiolitic sequence characterized by cumulate and isotropic intrusive rocks, a sheeted dykes complex, and pillow basalts interbedded with and capped by pelagic sedimentary rocks [20,24].…”

“…In addition, whole-rock and mineral separates (i.e., amphibole and plagioclase) 40 K- 40 Ar dating yielded ages of 128-112 Ma and 128-88 Ma for diorites and plagiogranites, respectively [25]. In contrast, the Fannuj-Maskutan and Remeshk-Mokhtarabad ophiolites show a complete ophiolitic sequence from mantle peridotites to pillow-lava basalts [16,19,52,53]. Pillow basalts are capped by an Early Cretaceous pelagic sedimentary cover [46].…”

“…Pillow basalts are capped by an Early Cretaceous pelagic sedimentary cover [46]. All these ophiolites are considered as the remnants of an Early Cretaceous oceanic basin, i.e., the North Makran Ocean, which was interpreted as either a marginal basin opened during the Late Jurassic-Early Cretaceous at the southern margin of the Lut Block [15,16] or a back-arc basin and/or supra-subduction zone basin related to the Neo-Tethys northward subduction [17][18][19]. Regardless of these different interpretations, the opening of the North Makran Ocean is thought to have led to the drift of the so-called Bajgan-Durkan microcontinent from the Lut Block [15][16][17][18][19][20].…”

“…In the North Makran (southeast Iran), several ophiolitic units crop out at the rear of the accretionary wedge developed within the convergent margin resulting from the subduction of the Neo-Tethyan oceanic lithosphere beneath the Lut and Afghan continental blocks (Figure 1a) [11][12][13][14]. All these ophiolitic units are interpreted as the remnants of the Early Cretaceous North Makran Ocean located south of Lut and Afghan continental blocks [15][16][17][18][19]. This oceanic basin was interpreted as either a marginal basin [15,16] or a back-arc basin related to the Neo-Tethys northward subduction [17][18][19].…”

“…All these ophiolitic units are interpreted as the remnants of the Early Cretaceous North Makran Ocean located south of Lut and Afghan continental blocks [15][16][17][18][19]. This oceanic basin was interpreted as either a marginal basin [15,16] or a back-arc basin related to the Neo-Tethys northward subduction [17][18][19]. This oceanic basin played an important role during the Late Cretaceous-Eocene convergent tectonics, when the North Makran acquired most of its present-day tectonic setting [15,16,[20][21][22][23].…”