Lake George revisited: New evidence for the origin and evolution of a large closed lake, Southern Tablelands, NSW, Australia

Revisiting the abandoned shorelines of Lake George, Australia: a refined optical dating framework

“…1a), and drained into the upland tributaries of the Murrumbidgee River (Singh et al, 1981b;Macphail et al, 2015). The subsurface palaeochannel drainage network inferred by Macphail et al (2015) at least points to this location acting as the most likely spillway throughout the Neogene/early Quaternary. The Lake George Scarp and Range, and other areas of high relief, have produced the extensive alluvial fan deposits of (usually angular) cobbles and Fig.…”

“…At this depth, Coventry (1976) speculated that Lake George may have periodically overtopped the sill in the Lake George Range located at Geary's Gap (roughly half way along the western margin of the lake) which occurs at this same elevation (Fig. 1a), and drained into the upland tributaries of the Murrumbidgee River (Singh et al ., 1981b; Macphail et al ., 2015). The subsurface palaeochannel drainage network inferred by Macphail et al .…”

“…In this context, the palaeoenvironmental records preserved at Lake George, NSW, have long provided benchmark information on the long‐term climatic, vegetation and landscape history of south‐eastern Australia throughout the Quaternary. This benchmark status comes in part from the significant ~4 million year long record of lake bed facies, salinity, vegetation change and fire frequency records coming from lake cores collected in the 1970s (Singh et al ., 1981a,b; De Deckker, 1982; Singh and Geissler, 1985; Macphail et al ., 2015); a rare occurrence in Australian lakes that are prone to unconformities due to frequent drying and deflation. Given the endorheic nature of this basin, the past water inputs (precipitation) and outputs (evaporation), ameliorated by palaeotemperatures, have produced a record of fluctuating lake levels that effectively charts the complex interplay between these palaeoclimatic factors (Galloway, 1965; Jennings, 1981).…”

[RECTRACTED: A 120,000 Year Record of Paleoenvironmental Variability in Lake George, Australia]

“…GG-1 was subdivided into 52 sections according to chronological order by the RSES, each 1.52m in length, Based on correlation with an earlier core (C354) drilled by the Bureau of Mineral Resources in 1982 at Geary's Gap, the base of GG-1, section #52, is estimated to be approximately 2.3 Ma. old (Macphail et al, 2015). Although high resolution dating has not been conducted, preliminary paleomagnetic dating conducted by the RSES confirms that All 3 core sections contained regions of contamination, consisting of sediments of unknown composition and origin, or sediments introduced into the core as a contaminant during the drilling process, and/or during the processing of the core for storage.…”

“…Wales at an elevation of about 673m (Barrow, 2013). The basin contains the longest continuous sedimentary record of any Australian lake basin (Macphail et al, 2015).…”