Illuminating Southeast Asian Prehistory: New Archaeological and Paleoanthropological Frontiers for Luminescence Dating

Since the explorations of Alfred Russel Wallace and Eugène Dubois in the nineteenth century, Southeast Asia has been one of the world's focal points for studies of biogeography and biodiversity, human evolution and dispersal, environmental change, and the spread of culture, farming, and language. Yet despite its prominence, reliable chronologies are not available for many of the critical archaeological, evolutionary, and environmental turning points that have taken place in the region during the last 1.5 million years. In this paper, we discuss some of these chronological problems and describe how luminescence dating may help overcome them. "Luminescence dating" is a term that embraces the techniques of thermoluminescence (TL) and optical dating, which can be used to estimate the time elapsed since ubiquitous mineral grains, such as quartz and potassium feldspar, were last heated to a high temperature or were last exposed to sunlight. Luminescence methods have been successfully deployed at late Quaternary archaeological, paleoanthropological, and geological sites around the world, but not to any great extent in Southeast Asia. Here we describe the principles of TL and optical dating and some of the difficulties that are likely to arise in dating the volcanic minerals found throughout the region. We also outline several long-standing archaeological and paleoanthropological questions that are the subject of a current program of luminescence dating in Southeast Asia, and present recent dating results from Liang Bua in Indonesia and Bukit Bunuh in Malaysia.