The status of the Kaigas glaciation or `` cooling event '' is unclear . Some do not recognize it as glacial , and others believe it may indeed be a third ice age . The status of the Kaigas `` glaciation '' or `` cooling event '' is currently unclear ; some workers do not recognize it as a glacial , others suspect that it may reflect poorly dated strata of Sturtian association , and others believe it may indeed be a third ice age .