Discussion on "Syn-metamorphic sulfidation of the Gamsberg zinc deposit, South Africa" by Stefan Höhn, Hartwig E. Frimmel, and Westley Price.

Höhn et al. (2021) proposed that the giant Gamsberg Zn deposit, South Africa, initially formed as a sedimentary exhalative (SEDEX) deposit during the Mesoproterozoic and was subsequently oxidized near surface. The oxidized ore was then supposedly sulfidized by sulfur-rich metamorphic fluids during and after upper amphibolite facies metamorphism. We view this model as untenable for various reasons and suggest that the Gamsberg deposit and others in the Aggeneys-Gamsberg district (Swartberg, Broken Hill-Deeps, Big Syncline) are metamorphosed clastic SEDEX deposits rather than having formed by synmetamorphic sulfidation processes. [ABSTRACT FROM AUTHOR]