Surface waves and the structure of the Great Basin of Nevada and western Utah

摘要: Fundamental mode Rayleigh wave (4- to 120-s period) and Love 40-s phase velocities have been measured for several paths wholly within the Great Basin of Nevada western Utah. An average structural model this area was derived from dispersion data existing refraction data. This consists a three-layer, 35-km-thick crust 29-km-thick, higher-velocity (Vs = 4.5 km/s) cap at top mantle, below which lies broad (180-km-thick) low-velocity zone shear waves 4.05–4.12 km/s). Intermediate-period (15- 32-s) over shorter indicate existence significant local variations in shallow (20- 30-km-deep) structure may result varying crustal thickness or depths partial melting. Comparison our mantle with structures other areas (oceanic, shield, alpine, rise) shows greatest similarity East African Rift Pacific Rise. Like these be tensional region where deep material has intruded near surface created