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

Late Cretaceous alkali magmatic rocks occur widely in the Hasancelebi and Basören regions (Malatya). The Hasancelebi and Basören 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 Basören 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 Basören 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–Basören areas.