Studies of kimberlites and associated rocks and minerals provide significant and often unique information pertinent to petrologic models, and magmatic and isotopic processes in the mantle beneath ancient cratonic regions. However, probably 90% of the available data are based on southern African kimberlites. In order to geographically expand the existing database, this project will investigate the geology, mineralogy and petrology of Brazilian kimberlites, xenoliths and diamonds. The results will be used to aid in modelling the magmatic evolution of kimberlite and the nature of the lithosphere and upper mantle beneath the Brazilian shield. The data obtained will also be used to compare and contrast the Brazilian kimberlites, about which little is known, with those from southern Africa and elsewhere, notably the U. S. and Siberia.