Slow Senonian and fast Palaeocene-Early Eocene uplift of the granitoids in the Central Eastern Pontides, Turkey: apatite fission-track results

Abstract

Dating and forward modelling of the fission-track data of apatite samples from the Dereli-Sebinkarahisar region, south of Giresun in the Eastern Turkish Pontides, provides quantitative data on the regional tectonics resulting from the closure of neo-Thetys and the collision of Eurasia and Gondwana. The age vs. elevation profiles identified Senonian (80.7 +/- 3.2 to 62.4 +/- 2.5 Ma) slow uplift and denudation, interpreted as the result of the diapiric ascent of subduction-related plutons above the neo-Tethyan subduction zone beneath the Eurasian continent. This was followed by rapid differential uplift during the Palaeocene-Early Eocene (57.4 +/- 2.4 to 47.8 +/- 2.4 Ma), which juxtaposed granitoid units of different ages, compositions, and emplacement levels in the crust, and is thought to be related to the collision between the Pontide (Eurasian) and Anatolide (Gondwana) basements. The modelling results must be interpreted with caution, but appear to indicate a period of Mio-Pliocene (ca. 5 Ma) reheating related to volcanism associated with the westward escape of the Anatolian plate and uplift from the Pliocene (ca. 3.5 Ma) up to the present. (C) 2004 Elsevier B.V. All rights reserved.