Geochronology of early human settlements in Java: What is at stake?

Despite the fact Java Island is a volcanic area, it has been challenging to build a chronological framework of its early human settlements, from the oldest Lower Pleistocene Homo erectus up to the dispersals that followed the Last Glacial Maximum (LGM). Various dating methods are implemented on volcanic effluents, sedimentary deposits, speleothems and also on fossils (including direct analyses on human remains), thanks to radiometric and palaeodosimetric grounded techniques as well as to magnetostratigraphy. However, a number of results must be considered with caution, in order to identify specific bias originating from reworking of volcanic effluents or post-depositional geochemical evolution. Such bias might well explain apparent contradictions between absolute dating results and other chronologically significant proxies (e.g. biostratigraphy). Converging age estimates resulting from the implementation of several dating methods, though being sometimes less precise, seem to have a higher reliability.