New evidence on the accurate displacement along the Arava/Araba segment of the Dead Sea Transform

Abstract

The sinistral displacement along the Dead Sea Transform (DST), the plate boundary between the African and the Arabian plates, south of the Dead Sea basin, was previously attributed to two main fault zones: the Arava/Araba or Dead Sea fault and the Feinan or Al Quwayra fault zone. This was based on similarities of features on either side of the Araba Valley. In particular, the Timna and the Feinan copper mines, located north of the Themed and Dana faults, and the onlap of the Cambrian formations southward onto the Amram rhyolite and Ahyamir volcanics. To these we add a more accurate offset indicator in the form of an offset Early Cambrian (532 Ma) dolerite dyke previously mapped in Mount Amram (Israel) on the African plate and recently discovered across the Araba Valley in Jabal Sumr al Tayyiba (southwest Jordan) on the Arabian plate. This dolerite dyke is ~ 20 m thick, strikes N50°E and is the only dyke intruding the Jabal Sumr al Tayyiba pink rhyolite flows of the Ahyamir Volcanics. Geochemical and geochronological correlations between the Jabal Sumr al Tayyiba dolerite dyke and the Mount Amram dolerite dyke demonstrate 85 km of sinistral offset across the Arava/Araba fault. Our results also suggest approximately 109 km of combined sinistral displacement across the Arava/Araba and Feinan faults based on petrological correlations between the Timna and Jabal Hanna igneous complexes on the African and Arabian plates, respectively. This constrains the total sinistral displacement of the Feinan fault and its accessory faults to be 24 km.