The Geology of North-Eastern British Somaliland

Abstract

This paper deals with a strip of country lying along the 49th meridian east of Greenwich from the coast to about 80 miles inland, and with a belt 50 miles long running westwards of that meridian between latitudes 11° 00′ and 11° 08′. The political boundary between British and Italian Somaliland coincides with this meridian. I was fortunate in being provided with the topographical map, contoured at 250-foot intervals, which had recently been made by the officers of the Anglo-Italian Boundary Commission. Part of this was enlarged to the scale of 1 inch to a mile, and with it I mapped geologically a considerable area. North-eastern Somaliland has been visited previously by geologists on two occasions. R. A. Farquharson (1924), the Government Geologist of the Protectorate, made a reconnaissance from Las Khorai along the foot of the Al Hills for some 25 miles, and thence to Bunda Ziada, from whence he returned by a more northerly route. Prof. G. Stefanini (1925) journeyed southwards in 1924 from Bosaso on the coast, in Italian territory, and crossed into British Somaliland at Hegligab: thence he passed through Buran to the Nogal Valley. The greater part of the district I mapped had, therefore, been unvisited hitherto. II. Topography. The political boundary crosses four types of surface:― (1) The Nogal Valley and Sorl Haud: drainage east-ward. (2) The Hormo Plain: drainage eastward. (3) The A1 hills: drainage south to south-eastward on one flank, and northward on the other. (4) The coastal region: drainage northward. (1)