Structural Analysis of northern Oman using Receiver functions

The Oman ophiolite is one of the best preserved and studied ophiolites in the world, however, its 3D geometry and the properties of the underlying Arabian continental margin are largely undetermined. The obduction process occurred around 94-97 million years ago and remnants of the obducted oceanic lithosphere cover today an area of about 700 x 140 km. Due to Major uplift processes around 30 to 40 million years ago the ophiolite is today largely exposed and surrounded by Eocene to Quaternary sediments. We use P- and S- Receiver functions (RFs) to map seismic discontinuities in the continental lithosphere. In addition, we seek for information in the R F s on the thickness of the ophiolite and potentially other upper crustal structures, e.g. the Hawasina sedimentary units. We use data from 58 seismic stations, 40 of which we operated temporarily with continuous passive registration from October 2013 to February 2016 across the Oman mountains and 286 events with magnitude larger than 6 from the dataset for RF analysis.

We apply a semblance based migration to convert RF conversion times to estimates of conversion depth. The results show clear variations in Moho depth with a decrease from (north-)west to east. This is consistent for both P- and S- Receiver Functions. In addition we see clear indications for variations in LAB depth across the area from S- Receiver Functions and a shallowing towards the continental margin. At higher frequencies we see indications for upper crustal sequences like the Hawasina sediments.