9305384 Lovera This research project will continue theoretical investigations of the multi-diffusion domain (MDD) behavior of the K-feldspar 40Ar/39Ar system. The results will ultimately find application in research that elucidates the tectonothermal evolution of the lithosphere. The goals of the proposal are to investigate all fundamental assumptions of the MDD model, to generalize the model to account for episodic loss and heating/cooling, and to develop an automatic inversion of the thermal history content of K- feldspars. Techniques to be utilized include laboratory annealing experiments and numerical analysis.