This project is to model the evolution of lithospheric and asthenospheric magma source regions during the tectonic transition of the Rio Grande Rift by examining the chemical, mineralogical, textural, and volcanological characteristics of volcanic suites produced episodically from 50 to 3 Ma in southern New Mexico. Major element, trace element, and isotopic (Sr, Nd, and Pb) compositions will provide constraints on the nature of magma-producing regions (asthenosphere, lithospheric mantle, lower crust, upper crust) as well as the processes involved in magma evolution. 40Ar/39Ar age determinations on key units will place temporal constraints on thermal evolution of the lithosphere.
