Proposed research involves a collaborative effort between two geochronology laboratories to study crustal evolution in the Trans- Hudson orogenic belt, Saskatchewan. Specifically, this region is interpreted to be an ancient (ca 1.8-1.9 Ga) collision zone in which remnants of island arc terranes were compressed against an Archean continental margin. The PIs plan to document time-space patterns for development of this orogenic belt and to investigate associated magmatic processes to determine the proportion mantle-derived juvenile igneous material relative to the extent of remelting of preexisting crust. Because this belt is well-exposed by modern glaciation, it offers an opportunity to study in detail the exumed roots of an ancient mountain belt that is analogous to the modern himalayas, for example. Well-established U-Pb zircon and whole-rock Sr-Nd, Rb-Sr, and U-Pb systematics will be employed to determine ages of key geologic units and as petrogenetic indicators to deduce magma sources.