Late Quaternary ostracods from Lake George, New South Wales

Abstract

Fossil ostracods from the uppermost 3m of core LG4 from Lake George all have modern living representatives. This part of the core is thought to represent deposition during the last 60,000 years (see Singh et al., 1981b) and the lake hisotry is traced from a knowledge of the ostracod ecology. The following distinct phases, and their respective timing, are postulated for Lake George (the timing of events should be considered with caution as few ¹⁴C dates are available): water fresh and lake full for the periods of 10,200 – 12,000 yBP and 19,100 – 20,700 yBP, water fresh, ephemeral at times, for the periods of 3,200–4,000 yBP, 7,000 yBP, 7,500 yBP, 8,500–10,200 yBP, 12,000–13,500 yBP, 20,700–23,500 yBP, 23,800–27,600 yBP and at some stage between 27,000 and 60,000 yBP; ephemeral saline water for a few short episodes between 3,200 and 4,000 yBP and for the periods of 15,600–17,400 yBP and 23,800–27,600 yBP; lake definitely dry between 17,400 and 19,100 yBP. Data obtained from the ostracods correlate reasonably well with those of lake level fluctuations based on the study of ancient shorelines by Coventry (1976) and others based on facies analyses and the record of plant microfossils by Singh et al. (1981b).