Tertiary Volcanics and Sediments

The Tertiary volcanics can be divided into three units:

(1) the plateau-forming Tertiary basalts that are predominantly olivine basalts with intercalations of intermediate lavas and tuffs;
(2) the lower Afar stratified basalts composed of
basaltic lava flows and tuffs that are usually found
intercalated with sediments of the Danakil Formation; and
(3) the Afar Basalts composed of recent lava flows and volcanic cones, with minor acid to intermediate volcanics, mainly trachytes, rhyolites and ignimbrites. The Tertiary basalts are currently actively exploited for aggregates.