he Tsumeb ore-body is one of a number of steep pipe-like structures that pierce the Otavi Series of the Damara System in South West Africa. These structures lie on a well-defined ENE belt of ring-complexes; included in the latter are carbonatites. Strontium isotope and La and Ce analyses were carried out on 13 carbonate rocks taken from within the pipe and country-rocks. The mean⁸⁷Sr/⁸⁶Sr value of ≈0.712 combined with the low La and Ce contents of all the samples does not support a carbonatitic origin for the pipe. The problem of the age of the Tsumeb pipe remains unresolved. The most likely events that could be responsible for the development of the pipe are the post-kinematic Damara granites of Cambrian age or alternatively they could be associated with the magmatic activity responsible for the emplacement of the post-Triassic ring complexes.