9526954 Willett The objective of this research is to construct an improved orogenesis model and conduct numerical experiments that will reveal the nature and strengths of feedback between tectonic deformation and surface processes in evolving mountain belts. The experiments will be guided by a dataset of geologic and topographic observations of active mountain belts, collected both from the literature and digital elevation models. To accomplish this objective, two extant surface-processes models (SPMs) will be synthesized, and a new model constructed that accounts for orographic climate, chemical weathering, and alpine glaciation. The macrogeomorphology and exhumation patterns of a few carefully selected mountain belts will be predicted using the coupled model and the results tested against observations. The ultimate outcome of this research should be an improved underqtanding of the nature and strengths of feedback between tectonic deformation and surface processes in evolving mountain belts.