Radiocarbon determinations luminescence dating and australian archaeology
Reckitt’s Blue is the commercial name given to a laundry product used to whiten clothing (Chaloupka 19).The use of Reckitt’s Blue as a paint was first reported in the Alligator Rivers region in 1912 by Baldwin Spencer (191).Source: Photograph by Damien Finch with line drawing by Daryl Wesley. Motif 1 is a very large red motif, composed of distinct curved lines. Parts of the motif are solid infilled with protruding lines that are suggestive of spines. A combination of radiocarbon dating and optically stimulated luminescence (OSL) dating on mud wasp nests has proved fruitful in dating rock art in the Kimberley (see Roberts et al. A previous Australian study used radiocarbon determinations for a calcium oxalate crust encasing rockfall within excavated deposits.Those results were compared with radiocarbon ages for charcoal samples in the same stratigraphic units (Watchman et al. These studies show the potential of both calcium oxalate and mud wasp nests for radiocarbon dating of rock art.Pigment colours include red, orange, black, white and yellow, with many complex images bichromatic or polychromatic.Notable motifs include four painted in Reckitt’s Blue pigment in Area B, and a high number of hand, forearm and foot stencils in Area C.
As field time was limited, all art panels were mapped, but not all individual motifs recorded.
Absolute radiocarbon dates are made on two different substances that have been related with relative dates derived by assessing motif superimpositions, the stylistic analysis of motifs and degrees of preservation.
Combined, the absolute and relative methods provide reliable dates for the painted motifs on a rock art panel at Red Lily Lagoon Site 3 (see Figure 2.1).
Radiocarbon dates were obtained for mineral accretions suspected to contain the minerals whewellite and whedellite (both are hydrated forms of calcium oxalate Ca C, and called hereafter ‘calcium oxalate’), and from preserved non-reactive organics contained within ancient mud wasp nest stumps.
This is the first attempt to apply radiocarbon dating to these two different materials, calcium oxalate and mud wasp nests, directly associated with the same rock art.