Contribution of an intercomparison of nuclear methods (230Th/234U, ESR and 40Ar/39Ar) to the dating of Pleistocene fossiliferous beds in the Sangiran dome (Java, Indonesia)

An application of radiometric dating intercomparison (uranium series disequilibrium (230Th/234U), electron resonance of spin (ESR) and 40Ar/39Ar) was realised on different samples from the Sangiran dome: bones, teeth (enamel and dentine), bipyramidal quartz and amphiboles (volcanic breccia, pumice and tuff). Concerning the supports we have used in this work, the amphiboles and the bipyramidal quartz have many advantages, like them the resistance alteration to the sediment. However, the ESR ages of quartz were affected by this alteration. The uranium- series and ESR dating of bones and teeth showed that this kind of samples behaved systematically at opened system. For the Sangiran dome, we propose the following chronology: the volcanic breccia was deposited between 2,05 ± 0,08 and 1,56 ± 0,05 Ma. The Pucangan unity followed immediately. The putting of the Grenzbank in its place happened during the upper limit of the Jaramillo period at 0,9 Ma. A rapid sedimentation at Grogolan area, and Ngebung site with the archaeological layer containing some bones which are supposed to have been burnt between 250 and 500 deg C about 0,8-0,9 Ma before the Brunhes/Matuyama magnetic reversal. The Notopuro unity was deposited at 150 ± ka in mud-flow form. (author)