With National Science Foundation support the Berkeley Geochronology Center (BGC) will continue to develop the technique of 40Ar/39Ar dating and apply this technique to a series of significant paleoanthropological sites. The facilities include two fully automated laser-mass spectrometer systems with single- crystal 40Ar/39Ar dating capability which enables the analytically precise and geologically accurate dating of sub- milligram single volcanic crystals from multi-age component samples such as tuffaceous sediments. The laboratory has also added a system which can be tailored to date young or altered volcanic materials. Under the current NSF award the facility will add a second carbon dioxide laser low-bland extraction line. Argon dating is extremely important to paleoanthropologists because it can be used over almost the entire last 6 million years; this is the period when hominids emerged and developed. Many significant archaeological and paleontological sites are located in volcanic regions such as Eastern Africa and contain sediments which can be dated by this technique. The BGC has collaborated with researchers at a number of sites in Africa, Europe and Asia, and with NSF support such projects will be continued and expanded.
