Cosmogenic nuclide dating applied to human evolution

Cosmogenic nuclides have become a well-established tool in geomorphology for quantifying surface process rates and for dating landforms and sedimentary deposits such as terraces, alluvial fans, lakes, and cave infills.  In many cases, these sedimentary deposits can tell us not only about landscape evolution, but if they contain artifacts or fossils, they can also inform us about human evolution, migration, and the development of stone tool technology.   

Burial dating with ²⁶Al and ¹⁰Be is becoming increasingly important in archaeology and paleoanthropology, particularly in areas that lack volcanic rocks suitable for dating. The development of isochron methods has improved both the precision and reliability of dating results, lending confidence to the age interpretations.  However, because cosmogenic nuclides reflect the exposure and burial history of rocks near the ground surface, it is important to recognize that properly interpreting the depositional age requires understanding the surface processes responsible for sediment erosion and deposition. 

Cosmogenic nuclides have now been applied to archaeology and human evolution at a variety of sites across Africa, Asia, and Europe.  In most cases, the new dates conform to pre-existing models and provide a fuller picture of human occupation of the landscape.  However, a few sites have challenged current paradigms.  I will present recent studies from caves and terraces in South Africa and China that have produced surprising results, pushing the boundaries of where early humans were found.