Paints radiocarbon dating

Valladas, H. (2003), Direct radiocarbon dating of prehistoric cave paintings by accelerator mass spectrometry, Meas. Sci. Technol. 14, 1487-1492. 

Knowing k and the decay rates for the fresh sample and the old sample, we can calculate t, which is the age of the old sample. This ingenious technique is based on a remarkably simple idea. Its success depends on how accurately we can measure the rate of decay. In fresh samples, the ratio is about I/IO, so the equipment used to monitor the radioactive decay must be very sensitive. Precision is more difficult with older samples because they contain even fewer " C nuclei. Nevertheless, radiocarbon dating has become an extremely valuable tool for estimating the age of archaeological artifacts, paintings, and other objects dating back 1000 to 50,000 years. 

Armitage, R. A. Radiocarbon Dating of Charcoal-pigmented Rock Paintings Ph.D. Dissertation, Texas A M University UMI Dissertation Services Ann Arbor, MI, 1998. 

Valladas H et al (2001) Radiocarbon AMS dates for Paleolithic cave paintings. Radiocarbon 43(2B) 977-986... 

In exploring the question of the earliest date for human presence in Brazil, Steelman and coworkers apply the plasma chemical procedure to extract carbon from both the pigments of a rock painting from Toca do Serrote de Bastiana and the accretions covering its surface. The accretions were found to contain both monohydrate of calcium oxalate and calcium carbonate. The radiocarbon age of the oxalate carbon was determined to be 2540 60 B.P. while the radiocarbon age of carbon extracted from the pigment was determined to be 3730 90 B.P. These ages are much more recent than the 30,000-40,000 B.P. age determined by electron spin resonance and thermoluminescence of the accretions, but are consistent with dates of other pictographs in the same shelter. 

Third International Radiocarbon Intercomparison (TIRI) standard wood samples (5,6,8) and four different archaeological charcoal samples (2,3J8) for comparison with dates previously determined at other laboratories using standard combustion methods. These measurements were utilized to demonstrate the viability of the plasma extraction technique for dating rock paintings from around the world with charcoal and inorganic pigments. 

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