Geology of the Caldiran Fault, Eastern Turkey: Age, slip rate and implications on the characteristic slip behaviour

Abstract

The Caldiran Fault is a strike slip fault with a dextral slip in East Anatolia. The activity on this fault was marked by the November, 241976 earthquake (Mw: 7.1) which produced an similar to 50 km long surface rupture and caused 3840 fatalities, which was close to half of the population living along the fault at that time. Together with the North Tabriz Fault in Iran, it is regarded as the southern boundary of the Caucasus Block. The fault has an average annual slip rate of 8.1 from 10.8 mm yr(-1), as derived from elastic block modelling. We present results from a detailed morphotectonic survey along the fault. The Caldiran Fault is comprised of three segments, each of which is eparated by bend structures that bend towards the SW with a total change in strike of 20 degrees from east to west. The offsets of lithological contact markers show that the long-term geological slip rate for the Caldiran fault is approximately 3.27 +/- 0.17 mm yr(-1) for a duration of approximately 290 ka. The cumulative offset of the fault was determined from an analysis of a dome-shaped rhyolitic volcano which constrained the age of the fault to the Middle-Late Pleistocene. An analysis of small-scale morphological offset markers indicates a characteristic slip behaviour of the Caldiran Fault for the last 3 events with an average offset of 2.6 m. (C) 2016 Elsevier B.V. All rights reserved.