Ethiopian-Yemen flood basalts in the Djibouti area
(photos courtesy of Murray Surtees, Managing Director of Green River Geology Co. Pty. Ltd.)
The area is about 90 to 100 km west of the town of Djibouti in Djibouti (former French Somaliland). Here are spectacular NW-trending outcrops of the Ethiopian-Yemen flood volcanism (see January 2005 LIP of the month; Geological Society of America Special paper 352, Menzie et al., 2001, pp. 23-36; and event No. 2 of Ernst and Buchan, 2001, p. 486). This area is geologically poorly known, but its economic potential can be considerable for epithermal style Au-Ag deposits. Here the Green River Geology Company is actively prospecting for gold. Volcanic-rock hosted epithermal gold is usually associated with subduction-related volcanic arc systems (eg Chile, SW Pacific, Indonesia, New Zealand); the presence of epithermal gold in a LIP environment opens new frontiers in mineral exploration.
Afar region; arrow shows approximate location of area;
image taken from http://volcano.und.nodak.edu/vwdocs/volc_images/img_afar_region.html
Figure 1a, b and c: Basalt lavas flows (traps)
Figure 1d: panoramic of traps country
Figure 2: Lac Asal eruptive centre
Figure 3: Dome of trachytoid basalt
Figure 4: Rhyolite dyke intruding basalt
Figure 5: Epithermal sheeted quartz vein system
Figure 6: Vein of bladed calcite; the bladed texture is due to CO2-rich boiling fluids, commonly associated with Au mineralisation