Cenozoic extension in coastal Dhofar (southern Oman): implications on the oblique rifting of the Gulf of Aden
Abstract
A detailed analysis of fault populations that affect the Paleocene to early Miocene sedimentary succession of southern Dhofar allows the definition of a time-sequence of paleostresses and the reconstruction of the rifting history of the eastern Gulf of Aden. Two distinct phases of N20°- and N160°-trending extensions took place during the deposition of the synrift Dhofar Group from late Priabonian (35 Ma) to middle Burdigalian (18 Ma). A period of tectonic instability preceded these events, marked by normal and strike–slip faulting as early as the mid-Eocene. The two main directions of extension, also recorded in southern Yemen, developed respectively oblique and normal to the N75E trend of the Gulf of Aden. An anticlockwise succession of the two episodes from N20 to N160, only established in Yemen, accounts for the observed synrift fault pattern, which is consistent with the type and geometry of faults predicted in analogue models of oblique rifting. A latest phase of NS compression, marked by strike–slip faulting, may represent a far echo of the Arabia–Eurasia collision.