Paleo-exhumation histories of the Sakarya and the Istanbul Zones of the Western Pontides, the Almacık Block and its surroundings, NW Turkey

The Almacık Block is a tectonic sliver formed during the activity of North Anatolian Fault Zone (NAFZ). It includes two important zones Western Pontides (NW Anatolia): İstanbul and Sakarya Zones meet along suture zone called Intra-Pontide Suture (IPSZ). units within are exposed in eastern part Block, whereas rocks west. In presented study, some magmatic have been analysed using zircon U-Pb method: these previously either incorrectly or not dated. results shown that granitic Zone, which intruded into amphibolites crystallization age 559–556 Ma. A granitoid block Upper Cretaceous wild flysch over had an ~566 Two distinct bodies were dated at 404.5 ± 3.9 Ma (Early Devonian) 161.8 0.82 (Late Jurassic) ages. palaeo-exhumation evolutions obtained (U-Th)/He technique (ZrHe) to understand differences geological evolution individual zones. ZrHe ages samples from indicate pronounced Early period. Middle-Upper Jurassic Mudurnu Formation gave close its sedimentation age, indicates major unit was buried too deep open closure system. Unlike those main peaks ~202, 160, 98, 74, 52 Finally, sample metamorphic assigned IPSZ yielded peak ~63 Ma, final Ocean (IPO) took place Tertiary.