“Upper Jurassic” sediments of South Africa

Abstract

MARINE sedimentary rocks exposed near Knysna in the Cape Province of South Africa were assigned to the Upper Jurassic on the basis of a fragment of an ammonoid and seven previously undescribed species of ostracod¹. A more thorough examination of the microfossils in these rocks indicates that this assignment was erroneous and that the beds are of Early Cretaceous, probably Hauterivian, age². This age determination was based on identification of fifty species of palynomorph, five species of calcareous nanno-fossil, and twelve species of foraminifera. Both the palynomorphs and the foraminifera indicate a correlation with the upper part of the Sundays River Formation, a unit reliably dated as Valanginian to Hauterivian. The nannofossils indicate a Valanginian or Hauterivian age.