With National Science Foundation support the Berkeley Geochronology Center will purchase a state-of-the-art high abundance sensitivity thermal ionization mass spectormeter(TIMS) with multiple collectors, to be used for Uranium series and U-Th-Pb geochronology. The precision and small sample size required will permit the system to analyze samples and address questions which are not possible using more standard instrumentation. The techniques are particularly accurate in the 20,000 to 500,000 age range and it was during this period that many important events, including the emergence of anatomically and behaviorally modern humans occurred. Many sites which fall in this time period are undatable by the most reliable methods - radiocarbon and argon-argon - and provision of this TIMS will provide information of value not only to paleoanthropologists but to geologists, geophysists and ecologists. These techniques can be applied to a range of pedogenic material, speleothem or travertine carbonate, teeth/bones and volcanic zircons. Many of these are present in paleoanthropological situations and the ability to analyze teeth means that the techniques can be applied directly to specimens of interest and are not limited to associated geological materials. The Berkeley Geochronology Center will provide matching funds to construct a new high-quality clean laboratory and a new TIMS laboratory. The resultant servicves which these provide will have a direct and major benefit in a wide range of sciences.
