Preliminary palynological investigation of the Byers Group (Late Jurassic-Early Cretaceous), Livingston Island, Antarctic Peninsula
Dinoflagellate cyst assemblages of the Byers Group have been correlated with palynostratigraphical zones established for the Mesozoic of Australia. The President Beaches Formation is believed to be latest Early Berriasian-Berriasian in age, based on its similarity to the Kalyptea wisemaniae and Cassiculosphaeridia delicata Interval Zones. The precise age assignment of the Chester Cone Formation is more problematic as the dinoflagellate cyst assemblages present are significantly different to those previously known from the Southern Hemisphere. However, it is suggested that the upper part of the formation is probably latest Berriasian to earliest Valangianian in age. Palynological and macrofossil evidence date an important unconformity between the President Beaches and Chester Cone formations as latest Berriasian-early Valangianian. The palynological content of the Byers Group implies that the palaeo-oceanographic setting varied from dominantly marginal marine to occasionally more fully marine conditions.