Aeromagnetic Mapping in the Northern Tihamah region, Western Yemen

The basement geology of Yemen is related to the evolution of the late Archean to late Neoproterozoic Arabian-Nubian Shield and contains key records of microplate and island arc accretion during Gondwana assembly. Furthermore, Yemen also preserves important igneous and structural records related to the multi-stage extension and opening of the Gulf of Aden-Red Sea Rift System.

Here we focus on the interpretation of aeromagnetic anomaly data in western Yemen by analysing part of a magnetic anomaly compilation for the whole of Yemen that includes data collected from 26 different airborne surveys flown between 1976 and 1985.

Our reduced to the pole map reveals magnetic anomalies of varying amplitudes and wavelengths, reflecting differences in lithology, structure, and source depth. We applied edge-detection techniques, including tilt angle derivative, total horizontal derivative of the tilt angle, and 3D Euler deconvolution to aid depth to source estimation.

An intriguing result is the newly defined extent of largely buried Cenozoic igneous intrusions that we image from the scant exposures along the southern uplifted rift-related great escarpment to the downthrown block in the northern Tihamah plain. The trend of these anomalies lies at relatively high angle to the rift flank escarpment but is co-linear with some of the trends imaged in the Precambrian basement, suggesting an important role of the inherited structures on much later magma emplacement. To further contextualise our regional results we combine the data from western Yemen with lower resolution publically available data from adjacent sectors of the Arabian shield and the Red Sea Rift and discuss some of the potential tectonic implications.