Geomorphological significance of late quaternary deposits of the Lake George Area, N.S.W.

Summary

A dated stratigraphy of surficial deposits is described for the Lake George area in the Southern Highlands of New South Wales. It includes lacustrine‐littoral, alluvial and aeolian sediments. The oldest stratigraphic reference is the highest strandline of the much enlarged late Pleistocene Lake George, at 30–37 m above the present lake bottom and with a dated age range of 21 000–27 000 y B.P. Five subsequent periods of shoreline aggradation have already been established. Four stratigraphic units were identified in aeolian deposits on the eastern side of Lake George. They indicated periodic instability to wind of lake margin deposits during the interval 23 000 to 2000 y B.P. Dated stratigraphies of alluvial fans and valley fill deposits in the Lake George Basin, and in the adjacent Grove Creek Basin, also reflected periodic instability of hillslope terrain during the last 30 000 years. Evidence available in the area suggested that accelerated fan building and valley aggradation were contemporaneous with some high levels of Lake George. These depositional phases would by inference have been related to relatively cooler and effectively moister climatic phases of the past. Further critical evaluation of these climatic associations is required in order to establish the regional picture.