Re-imbrication of the Hawasina allochthons in the Sufrat ad Dawh range, Oman Mountains

Abstract

The Hawasina complex consists of deformed slope to basinal sedimentary rocks of Mesozoic age, emplaced on the Arabian continental margin in the Late Cretaceous as a series of nappes. This complex is well exposed in the Sufrat ad Dawh range where it is represented by the Hamrat Duru Group and the Wahrah Formation. Two generations of imbricate faults are recognized in this area. The first is the imbrication of the Hamrat Duru and the Wahrah units into two separate nappes. These nappes were then folded and cross-cut by a second set of imbricate faults, resulting in the systematic tectonic repetition of the Wahrah-Hamrat Duru Nappe stratigraphy. The late-stage faulting event correlates with the origin of re-imbrication structures documented from other parts of the Oman orogen, interpreted to be of a post-emplacement, Early Tertiary age. This implies that Tertiary deformation of the Oman allochthons was expressed at least in part as a continuation of nappe development, initiated during the Late Cretaceous orogeny.