Stable isotope record and its palaeoenvironmental interpretation for a late Middle Pleistocene speleothem from Victoria fossil Cave, Naracoorte, South Australia

Abstract

A speleothem from Victoria Fossil Cave, South Australia, provides a continuous stable isotope record from 185 to 157 ka. Oxygen isotope analysis indicates that, at commencement of deposition, mean annual temperatures were much lower than at present and that between 178 and 162 ka regional surface temperatures were similar to today. Such high temperatures during an interstadial are surprising but may be attributable to increased continentality due to low sealevels. Carbon isotope analysis indicates the presence of an active vegetation cover dominated by C3 plants during the interstadial while a sparse vegetation dominated by C4 grasses appears to have been dominant during full-glacial conditions. Variations in moisture availability and vegetation productivity are probably closely related to stages in pressesional cycle. (C) 2000 Elsevier Science Ltd.