The Eastern Makran Ophiolite (SE Iran): evidence for a Late Cretaceous fore-arc oceanic crust

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

“…The Makran Accretionary Prism (Figure 1a,b) extends between the Minab-Sabzevaran-Nayband dextral fault system and the Chaman-Ornach-Nal sinistral fault system [12,14,39], separating the still active Makran subduction zone from the Zagros fold-and-thrust belt and the Himalayan continent-continent collision zones, respectively (Figure 1a). The Makran Accretionary Prism formed in response to the Cretaceous-Present day northward subduction of the Neo-Tethys oceanic lithosphere beneath the Lut and Afghan continental blocks, which are parts of the southern Eurasia margin [16,18,22,40,41]. The subduction is related to the convergence between the Arabia and Eurasia plates [40,42,43], which is still active beneath the Makran, as outlined by the geophysical and earthquake focal mechanisms data [12,44,45].…”

“…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].…”

“…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].…”