Geochemical constraints on petrogenesis of Late Cretaceous alkaline magmatism in east-central Anatolia (Hasancelebi–Basören, Malatya), Turkey

Abstract

Late Cretaceous alkali magmatic rocks occur widely in the Hasancelebi and Basoren regions (Malatya). The Hasancelebi and Basoren intrusive rocks are mainly peralkaline and alkaline-oversaturated. The Hasancelebi intrusive rocks are made up of syenite to quartz monzonite. On the other hand the Basoren intrusive rocks mainly contain feldspathoidal syenites that are cut by feldspathoid-bearing dykes. The Hasancelebi intrusive rocks show comparable field, petrographic and geochemical characteristics with A-type rocks. All intrusive rocks show enrichment in LILE and LREE relative to HFSE. The Th/Yb versus Ta/Yb diagram indicates that all magmatic rocks formed from an enriched mantle source region(s). The parental magma for the Basoren rocks has a higher intraplate component than that from the Hasancelebi rocks which could be attributed to mantle source heterogeneity before collision in east-central Anatolia. Either delamination of the thermal boundary layer or slab-breakoff are likely mechanisms for the initiation of post-collisional magmatism in the Hasancelebi–Basoren areas.