Petrogenesis and Geochemical Evolution of Mafic Dikes in the Kıratlı Region (Yüksekova Complex, SE Türkiye): Evidence for Tholeiitic-Alkaline Transition During Neo-Tethyan Evolution

Abstract

This study presents new petrographic and geochemical data on mafic dikes intruding the K & imath;ratl & imath; ophiolite (& Idot;pekyolu-Van, Eastern Anatolia), a segment of the southeastern branch of the Neo-Tethys. The dikes are mainly represented by microgabbros and diabases, composed of plagioclase and pyroxene, and display alteration features such as chloritization and sericitization. Major and trace element analyses indicate basaltic compositions that can be divided into tholeiitic and alkaline groups. Tholeiitic samples show depleted rare earth element (REE) patterns, Nb depletion, and Th enrichment, consistent with a supra-subduction zone origin, whereas alkaline samples exhibit light rare earth element (LREE)-enriched signatures and within-plate affinities, reflecting low-degree partial melting and/or crustal contamination during extensional phases. Comparisons with other ophiolitic dike suites in T & uuml;rkiye suggest that the K & imath;ratl & imath; dikes record polyphase magmatism related to both subduction and extension. These findings provide new insights into the tectono-magmatic evolution of the southeastern Anatolian Ophiolite Belt and highlight the complex interplay of mantle heterogeneity, fractional crystallization, and tectonic processes during the closure of the Neo-Tethys.