We report a hitherto unknown occurrence of ancient Neoproterozoic evaporite deposits from an allochthonous terrane in the Pan-African Gariep belt in Namibia. Low contents of Rb, Cs, Ba, Zr, Hf, Th, and U, flat chondrite-normalised rare earth element (REE) patterns, 8 7 Sr/ 8 6 Sr ratios as low as 0.7075, Na-Cl-Br systematics of fluid inclusion leachates, and high δ 1 1 B values for stratiform tourmalinites, together with geologic evidence, such as association with oceanic basalt, gabbro, and stromatolitic dolomite, point to a marine evaporitic origin. An atoll environment on an oceanic island is envisaged as a likely depositional setting. In the associated mafic sequence we found a diamictite with metre-sized ice rafted detritus, suggesting the presence of sea ice cover at relatively low latitude around the time of evaporite deposition. Based on chemostratigraphic ( 8 7 Sr/ 8 6 Sr, δ 1 3 C) comparison with passive continental margin sediments in the para-autochthonous external part of the Gariep belt, a correlation of the mafic diamicitite with the global Varangian (590-560 Ma) glaciation is proposed.