Deep seismic sounding in Namibia (South West Africa) were carried out in July / August 1975 by a German-Southafrican team. Three profiles were observed to study the crustal structure and the nature of the crust-mantle boundary of the Damara Orogen with regard to its evolution, supplementing extensive geological and petrological investigations. Profile I (350 km length — 6 shotpoints) in the Central Zone of the Damara Orogen. In the upper crust two velocity inversions are found. The crust-mantle boundary is a transition zone of variable width rising slightly from a depth of 47 km towards the Atlantic coast. Profile II (225 Ion length — 2 shotpoints) in the Southern Zone of the Damara Orogen. It shows relatively high velocities in the upper and middle crust. Because of the limited length only poor information is obtained on the crust-mantle boundary. Profile III (300 km length — 3 shotpoints) was placed, for reference, on the Kalahari Craton which is adjoining the Damara Orogen in the south. In contrast to Profile I no velocity inversions are found in the upper crust. On this profile the Moho appears as a more distinct discontinuity split into an upper level at 47 km and a lower level at 60 km approximately. There is also no indication of a “mountain root”. The interpretation is based on composite plane layer models with variable velocities. Keywords: Middle Crust, Southern Zone, Deep Seismic Sounding, Velocity Inversion, Quarry Blast .

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