9418367 Bickford The Tans-Hudson orogen is the most extensively preserved Early Proterozoic Orogenic belt on earth extending from north-central US to Greenland. It is coeval with the 1.a-1.8Ga Penokean and Wopmay orogens and is unique in preserving a collage of mainly juvenile arc rocks and later plutons between the two juxtaposed terranes- the Archean Superior craton ont he southeast and the Archean Hearne and Rae provinces on the northwest. The Canadian Lithoprobe reflection seismic section across the orogen has revealed a complex history of the collision of the Superior and Rae/Hearne cratons, however the nature and kinematics of the collisional orogensis is largely unconstrained. This program will utilize distinctive differences in several isotopic system to differentiate an correlate these terranes and their fragments and to use the spatial distributions to infer tectonic style and kinematics of the collision. Results will not only improve understanding of this orogen, but help reconstruct early assembly of Laurentia.