9508139 Halliday This group is involved in research using radiogenic isotope and trace element geochemistry to study igneous and hydrothermal processes. They propose to apply new geochronological techniques including In-Sn and Rb-Sr direct dating of sulfides, 40Ar/39Ar dating , <0.1mg sized clay separates and dating of high U/Pb hydrothermal and diagenetic minerals using laser ablation and an ICP magnetic sector multiple collector mass spectrometer (Plasma 54) to date the products of crustal fluid flow and test current hydrologic and other models for the genesis of mineral deposits. this grant, for a short period of time, is to keep this work going at a minimal level while longer term and more substantial funding is sought.