Articles by Osman PARLAK

The Mersin ophiolite of southern Turkey is a well-exposed, Late Cretaceous, Neo-Tethyan suprasubduction zone ophiolite. It is underlain by metamorphic sole rocks inferred to have formed at the top of a down-going plate during subduction. These have a well-developed foliation and lineation observable in the field (defined by the preferred orientations of hornblende and plagioclase crystals). Here we present the first magnetic fabric data reported from the Mersin ophiolite with such settings. Anisotropy of low field magnetic susceptibility ellipsoids in sampled amphibolites have clustered, NW-plunging minimum principal axes representing poles to a SE-dipping magnetic foliation that aligns with the macroscopic metamorphic foliation plane seen in the field. Maximum AMS principal axes define a SE-plunging magnetic lineation that is parallel to the macroscopic metamorphic lineation. Oblate magnetic fabrics at specimen-level and an overall triaxial fabric at locality-level in these rocks are consistent with the development of the dominant metamorphic fabric by a combination of pure shear flattening and simple shearing during the formation and exhumation of the Mersin sole rocks. These observations are compatible with a recent tectonic model for the evolution of the ophiolite based on paleomagnetic data that invokes flattening and exhumation of the down-going slab in an incipient subduction zone during supra-subduction zone spreading.

Yarpuz-Kaypak (Osmaniye) region, located in Amanos Mountains, contains harzburgitic tectonites and mafic cumulates. The tectonites are represented by serpantinized harzburgites, whereas the cumulates are characterized by gabbronorite and gabbro compositions. The crystallization order within the cumulates is clinopyroxene, orthopyroxene plagioclase and amphibole. The major element compositions of the tectonites and cumulate rocks are consistent with formation in an arc-related tectonic setting. Trace element concentrations of these rocks exhibit large ion litophile element enrichments. Both geochemical and petrographic evidence suggest that the tectonite and cumulate rocks from the Yarpuz-Kaypak (Osmaniye) region represent the remnants of an oceanic lithosphere that formed in a supra-subduction zone tectonic setting during the closure of the Southern Neotethyan ocean and emplaced onto the northern margin of the Arabian platform in Late Cretaceous. https://doi.org/10.19111/bulletinofmre.501393