Evidence of tertiary forest in the Falkland Islands (Islas Malvinas)

Recent examination of the sediments and microfossils of a wood-bearing deposit in West Falklands (Lat. 51° 21′S, Long. 60° 42′W) indicates that it represents an in-situ forest environment and not driftwood, as originally assumed following its description in 1912. Palynomorphs in the organic matrix are consistent with wood identifications, and record a local palaeoenvironment of podocarp-type forest with some Nothofagus and tree ferns. Physical characteristics of the sediment matrix also indicate a terrestrial rather than coastal origin. The immense contrast of this forest with the treeless oceanic heath of the Falklands at the present time makes a Quaternary date extremely unlikely, despite the excellent preservation of micro- and macrofossils. In the context of present knowledge of the Southern Hemisphere palaeoclimate, a date of deposition prior to Antarctic cooling and the initiation of the circumpolar current is suggested. Palaeobotanical characteristics of the palynomorph assemblage also suggest pre-Late Tertiary date.