GEOCHEMICAL CHARACTERISTICS OF THE COMPOSITE KAçKAR BATHOLITH GENERATED IN A NEO-TETHYAN CONVERGENCE SYSTEM, EASTERN PONTIDES, TURKEY

Abstract

The composite Kaçkar batholith, of Cretaceous to Late Eocene age, consists of various intrusions derived from different geodynamic settings ranging from early to mature arc, through collision, to post-collisional extension in the Neo-Tethyan convergence system of the eastern Pontides of NE Turkey. The intrusions were emplaced into Cretaceous and Middle Eocene volcano-sedimentary units, and are unconformably overlain by Late Cretaceous, Early to Middle Eocene and Miocene units. The 10 lithological units are grouped into five geodynamic associations on the basis of geological setting and geochemical characteristics: (1) early arc origin as represented by the medium-K calc-alkaline (CALK) Çamli{dotless}kaya granitoid of Early Cretaceous age, (2) mature arc origin as represented by the medium- to high-K calc-alkaline Si{dotless}rtyayla and Marselevat granitoids of Late Cretaceous to Early Palaeocene age, (3) syn-collisional plutonism as represented by the peraluminous Asniyor leucogranite of Palaeocene age, (4) post-collisional plutonism as represented by the high-K calc-alkaline Ayder K-feldspar megacrystic granitoid and the Sasmistal microgranite of Middle to Late Eocene age, (5) the extension-related, mildly alkaline Güllübaǧ monzonite, the medium-K calc-alkaline to slightly tholeiitic (THOL) Halkali{dotless}taş quartz diorite, and the low-K tholeiitic Ardeşen gabbro and İsina diabase of Late Eocene age that are mainly exposed as small, shallow stocks and N-S, NE-SW, NW-SE and E-W trending veins. © 2005 Elsevier Ltd. All rights reserved.