Recently the Geochemistry Division at Lamont-Doherty purchased a new Isomass 110 mass spectrometer. This machine, designed to their specifications, is the first of a new generation of solid-source mass spectrometers to be built by V.G. Isotopes. It will incorporate a number of features which will make possible techniques not possible by conventional thermal ionization mass spectrometry and thereby open the door to several exciting new research areas. One of the most important justifications for this machine is its potential for analysis of 187Os/186Os ratios in very small samples. Consequently it is the plan of the PI and his team to: 1) learn and develop the scientific potential of this machine working on a variety of different samples, and 2) establish the chemical techniques nessery to exploit the Re/Os isotope system as a tool for identifying and tracing the Earth's dynamic components. The majority of grant funds will go for the support of personnel who will be responsible for the development and implementation of these new techniques. Several scientific problems will eventually be studied, but the primary purpose of this award is to develop and establish the efficacy of the new mass spectrometer and the Re/Os system.