9508023 Kay One of the big stumbling blocks in understanding Central Andean magmatic source regions has been the lack of chemical constraints from primitive, mantle-derived basalt. Analyses from basalts of this type have been touted as the required ingredient in making progress. Within this framework, the recent discovery of two Pleistocene primitive basaltic lavas is extremely significant. The major objective of this project is to collect and "completely" analyses a suite of the mafic lavas outcropping in the southern Central Volcanic Zone. Mapping and sampling is being supported by Chilean and Argentine agencies in collaboration with South American colleagues Mpodozis and Coira. A "complete" analyses means determining a full range of major and trace element by INAA, ICP-MS, XRF and microprobe techniques, as well as Pb, Nd and Sr isotopes. These analyses will fill an important gap in compilations of primitive mafic lavas in arcs and provide a basis for beginning to unravel the complex mantle processes occurring beneath the thickened Andean Crust.
