OROGENIC EVOLUTION OF THE URAL MOUNTAINS - RESULTS FROM AN INTEGRATEDSEISMIC EXPERIMENT

Results of the URSEIS '95 integrated seismic experiment document the l ithospheric structure of an intact Paleozoic collisional orogen in the Ural Mountains. Hybrid-source seismic reflection and refraction data provide images of a crustal-scale collisional fabric and a pronounced crustal root preserved since Paleozoic time. Mantle reflections are ob served at depths of more than 150 kilometers, possibly representing th e base of the lithosphere. The Urals do not conform to existing models of postorogenic evolution involving large-scale extension, which may be a consequence of an incomplete or arrested collisional process that has led to the preservation of the largest continental landmass.