| Abstract: | Roter Kamm, located in the Namib Desert of SW Africa, is an 8,000-foot-diameter crater developed essentially in Precambrian granitic rocks. Sand overburden is pervasive both inside ami outside the crater and the only significant rock exposures are high in the crater rim. In most cases these exposed rocks proved entirely normal when examined microscopically but two specimens were found which exhibited features compatible with, and suggestive of, shock pressures in the range of 50 to 100 kilobars. Both specimens are probably foreign to the rim environment and may represent remnants of ejecta from the crater formation. There is a strong negative residual gravity anomaly across the structure which reaches a maximum of ?9.3 milligals. The size and shape of the anomaly are fully compatible with a meteorite impact structure of “normal” dimensions. It is more difficult to interpret the gravity data in terms of an explosive volcanic origin and neither is there any evidence of such an origin in the rim rock exposures. An impact origin for the crater is strongly suggested by all the evidence to date. Definitive evidence of shock metamorphism could perhaps be found by a further search for “exotic” rocks in the rim. |
