Remnants of the Last Interglacial shoreline occur at Middle Lagoon on
the far south coast of New South Wales. Relict beach sediments can be
traced to a height of at least +4.8 m and are indicative of a former m
ean sea level of about +3 m. Thermoluminescence (TL) ages of 126 +/- 1
3 ka and 114 +/- 15 ka were determined for beach and aeolian facies re
spectively. Sands in the lower part of an exposure on the adjacent Gil
lards Beach gave TL ages of 108 +/- 13 ka, but sands in the upper part
of that exposure gave an age of 19.9 +/- 3.5 ka. This chronological e
vidence of a stratigraphic unconformity in what was initially taken as
pedogenic differentiation at Gillards Beach is supported by contrasti
ng electron traps and colour centres in crystal lattices of quartz gra
ins in these two samples. No tectonic displacement is apparent. This s
ite provides the first evidence of the Last Interglacial sea level for
1000 km along the coast between Gippsland and Newcastle.