Pb-207-(206) Pb single-zircon evaporation ages of some granitoid rocks reveal continent-oceanic island arc collision during the Cretaceous geodynamic evolution of the central Anatolian crust, Turkey

Abstract

(207) Pb-Pb-206 single-zircon evaporation age determinations carried out on nine different granitoid units of central Anatolia, Turkey have yielded three distinct granitoid groups with different emplacement ages. These are (1) Cenomanian Turonian granitoids, with a weighted mean age (wma) of 94.9 +/- 3.4 Nla; (2) Turonian-Santonian granitoids, with a wma of 85.5 +/- 5.5 Nla; and (3) Campanian granitoids, with a wma of 74.9 +/- 3.8 Ma. The spatial and temporal relationships between the formation of the metamorphic sole of the supra-subduction zone-type Central Anatolian Ophiolite (SSZ-type CAO), crustal metamorphism of the Central Anatolian Crystalline Complex (CACC), and the emplacement of Cenomanian-Turonian to Turonian-Santonian granitoids indicate a geodynamic setting in which all these geological events occurred quasi- simultaneously in central Anatolia. Such a geodynamic setting is thought to be related to the Cenomanian-Turonian collision of the Tauride-Anatolide Platform (TAP) and an oceanic island arc, including the SSZtype CAO. The Campanian granitoids appear to be the continuation of this collision-related protracted magmatism in central Anatolia. (C) 2007 Elsevier Ltd. All rights reserved.