he temporal and tectonic evolution of the deepest portions of orogens has been the focus of considerable interest and debate. Regional exposures of granulite to eclogite transitional rocks in the Bergen Arcs of western Norway provide a unique opportunity to study the processes affecting lowermost continental crustal rocks in the roots of a continent-continent collisional orogen. Pseudotachylyte veins within the partially eclogitized granulites are interpreted to represent the products of fracturing, faulting and seismicity at depths of ;The U-Pb, Sm-Nd and... |