CRUSTAL ROOT BENEATH THE URALS - WIDE-ANGLE SEISMIC EVIDENCE

Wide-angle reflection and refraction data acquired as part of the URSE IS '95 geophysical experiment across the southern Uralide orogen provi de evidence for a 12- to 15-kilometer-thick crustal root, yielding a t otal crustal thickness of 55 to 58 kilometers, Strong reflections from the Mohorovicic discontinuity (Moho) at relatively small precritical distances suggest that the crust-mantle transition beneath the crustal root is a sharp feature, The derived P- and S-wave velocity models co nstrain key physical properties of the crust, including the depth oi t he mafic rocks of the Magnitogorsk volcanic are and the existence of a lower crustal zone of possible basic rock enrichment beneath the East Uralian zone.