Tertiary lava (53 Ma) from Barrington Tops, New South Wales, Australia has been studied using conventional thermal and microwave techniques. Twenty-seven flows in two sections were sampled and their rock magnetic characteristics determined. On heating the majority of samples exhibited a single Curie temperature at around 200 o C, indicating a titanium rich titanomagnetite. Some samples exhibited two magnetic phases and a few a single low titanium titanomagnetite phase. Thermal demagnetisation yielded a mean direction of D=189.5, I=63.6, α 9 5 =4.3, which corroborates the previous findings of Wellman et al. [Geophys. J. R. Astron. Soc. 18 (1969) 371-395]. A pilot conventional Thellier palaeointensity analysis was unsuccessful mainly due to the samples being highly susceptible to thermo-chemical alteration. Far greater success was achieved (58%) using the microwave palaeointensity technique, where heating of the bulk sample and hence alteration is vastly reduced. Palaeointensity estimates range from 3 to 28 μT (mean 11+/-5 μT), which, assuming that the remanence is a primary thermal remanent magnetisation, indicates a low field intensity (a fifth of the present day value) in the early Tertiary. This study demonstrates the applicability of the microwave palaeointensity technique to ancient lava.