CRUSTAL STRUCTURE OF DABIESHAN OROGENIC BELT

The crustal structures of P velocity and density on the deep seismic s ounding profile across the Dabieshan orogenic belt are presented. Ther e is a 5-km-thick crustal ''root'' between the Yuexi and Xiaotian wher e the elevation is highest on the profile. An apparent Moho offset of 4.5 km beneath the Xiaotian-Mozitan fault marks the paleo-suture oi th e Triassic collision. Pt high-velocity anomaly zone at the depth below ; 3 km beneath the ultra-high pressure (UHP) zone may be correlated to the higher content of UHP metamorphic rocks.