title: Crustal Structure of Yunnan Province, People's Republic of China, from Seismic Refraction Profiles.
abstract: Seismic refraction, profiles in Yunnan Province, southwestern China, define the crustal structure in an area of active tectonics on the southern end of the Himalaya-Burma arc. The crustal thickness ranges from 38 to 46 kilometers, and the relatively low mean crustal velocity indicates a crustal composition compatible with normal continental crust and consisting mainly of meta-sedimentary and silicic intrusive rocks, with little mafic or ultramafic component. This composition suggests a crustal evolution involving sedimentary processes on the flank of the Yangtze platform rather than the accretion of oceanic island arcs, as has been proposed. An anomalously low upper-mantle velocity observed on one profile but not on another at right angles to it may indicate active tectonic processes in the mantle or seismic anisotropy.
authors.forename: R J
authors.initials: RJ
authors.lastname: Kan
authors.forename: H X
authors.initials: HX
authors.lastname: Hu
authors.forename: R S
authors.initials: RS
authors.lastname: Zeng
authors.forename: W D
authors.initials: WD
authors.lastname: Mooney
authors.forename: T V
authors.initials: TV
authors.lastname: McEvilly