The calcareous nannofossil Sollasites falklandensis (Coccolithophyceae) and its biostratigraphic and palaeoceanographic importance in the Albian of the Austral Basin, Argentina

Abstract

The presence of the calcareous nannofossil Sollasites falklandensis has been recorded in four exploration boreholes in the southeastern Austral Basin at levels assigned an Early to Middle Albian age. This study evaluates its biostratigraphic and paleoceanographic importance for the austral hemisphere and for the Austral Basin in particular. Illustrations and a description of S. falklandensis are provided, and all records are discussed to evaluate its origin and extinction bio-horizons. A Tethyan origin during the Late Aptian is proposed along with a subsequent migration to austral high-latitude regions during the Early Albian. It is believed that S. falklandensis has an affinity for cold surface waters in epicontinental shelf environments. Although it has a diachroneous geographic distribution, it serves as an important marker species in the Early Albian-Middle Albian austral high-latitudes.