Continued development and application of 40Ar/39Ar dating for archaeometric research

点击翻译按钮获取中文摘要

With National Science Foundation support, Drs. Alan Deino and Paul Renne will embark on a three-year effort to upgrade the 40Ar/39Ar dating facilities at the Berkeley Geochronology Center in Berkeley, California, in order to attain the highest possible levels of precision, accuracy and throughput, and the broadest range of capability in determining the age of geological samples related to archaeometry. The 40Ar/39Ar dating method has the broadest temporal range of applicability in archeological and paleoanthropological contexts, and is well established as a highly accurate and precise dating tool that has contributed widely to the study of hominid and hominoid evolution. Though routine in some regards, evolving technology permits continued improvements in the method's capabilities, particularly in dating younger, smaller, or less potassic materials. Such improvements pay large scientific dividends by expanding the scope of problems that can be solved.This grant will be vital both to maintaining routine availability of 40Ar/39Ar dating for the archeological and paleoanthropological communities, as well as to advance the capabilities of 40Ar/39Ar dating methods at BGC. It will help sustain routine access to high-quality 40Ar/39Ar data for archeological and paleoanthropological research worldwide and to continue refinement of 40Ar/39Ar methods to improve precision and accuracy, particularly at the younger end of applicability. Finally, this grant will provide the opportunity to replace or augment old equipment to maintain high levels of productivity and scientific excellence.In order to address these goals over the next three years, the grant will be focused primarily in three areas: 1) Development of an ultra clean, high-throughput extraction system that will be a suitable match to a separately funded, new multi-collector noble-gas mass spectrometer; 2) Continued development of the computer control systems and data reduction techniques necessary to utilize the new multi-collector machine; and 3) Modifications to sample processing facilities to improve efficiency of sample preparation. A new generation extraction line characterized by rapid throughput will be essential to take full advantage of the highly accelerated speed of data collection anticipated with the new multi-collector mass spectrometer. Further development of in-house computer control systems is necessitated by the requirements of a new generation of multi-collector machines that is now breaking on the 40Ar/39Ar dating community. Improvements in sample preparation will enable the supply of high-quality samples to keep pace with the increased analytical throughput.