Pre-, transitional- and post-rift volcanism: the changing face of the Ethiopian Rift

The geology of the Afar Depression in Ethiopia presents a record of volcanism from pre-rift Oligocene to Miocene flood basalts, silicic complexes, Pliocene and Quaternary rift axis basalts to the most recent august 2007 basaltic fissure eruption. Recent mapping methods permit descriptions of the stratigraphy and regional significance of volcanism in this active rifting centre. We apply an integrated mapping approach involving remote sensing and three-dimensional image analysis of topography and surface rock chemistry based on mineral maps generated from false colour Landsat and ASTER imagery within an immersive visualisation suite. Subsequent fieldwork involves targeted spot mapping, transects and detailed mapping of poor resolution areas. This approach is proving to be particularly successful in producing a subdivision of basaltic lava flows based on surface features, morphology of flow lobes and emplacement styles, where chemostratigraphic applications fail to identify individual eruption units. The success of this technique is particularly significant when working in areas which are difficult to access, and may be applied in the future within environmentally or logistically challenging regions