Jk. Feathers, LUMINESCENCE DATING OF SEDIMENT SAMPLES FROM WHITE PAINTINGS ROCKSHELTER, BOTSWANA, Quaternary science reviews, 16(3-5), 1997, pp. 321-331
Luminescence dating of sediments from rockshelters is complicated by t
he possibility of incomplete sunlight bleaching in antiquity and uncer
tainties in the distribution of radioactivity. Yet such dating is impo
rtant for the Middle Stone Age in southern Africa when rockshelters pr
ovide a large fraction of the known record. Sufficient bleaching is de
monstrated for sediments at White Paintings Rockshelter in northwest B
otswana by comparing results from slowly bleaching thermoluminescence
signals and rapidly bleaching optically stimulated luminescence. Radio
active disequilibrium is also shown to be present in these sediments a
nd believed to result from U-238 and U-234, requiring a small correcti
on to the dose rare. Derived ages are fractionation between in broad a
greement with independent dating evidence and archaeological expectati
ons. (C) 1997 Elsevier Science Ltd.