Crustal velocity structure beneath the eastern flank of the Ruby Mountains metamorphic core complex: Results from normal-incidence to wide-angle seismic data

P-wave velocity structure along the eastern side of the Ruby Mountains metamorphic core complex, determined using 2-D ray-inversion modeling, shows that: (1) the crust can be divided into three layers corresponding to the upper, middle, and lower crust; (2) from east of Ruby Dome to the northern end of the seismic profile, velocities of the upper crust range from 6.12 (±0.1) to 6.20 (±0.1) km/s and near-surface velocities range from 1.90 (±0.1) to 4.80 (±0.1) km/s. From this point to the southern end of the profile, upper crustal velocities range from 5.80 (±0.1) to 6.25 (±0.1) km/s and near-surface velocities range from 3.01 (±0.1) to 4.80 (±0.1) km/s; (3) middle crustal velocities range from 6.35 (±0.15) to 6.45 (±0.15) km/s; (4) lower crustal velocities range from 6.60 (±0.15) to 6.80 (±0.15) km/s; and (5) depths to the Moho vary irregularly between 30.5 and 33.5 km. From interpretation of these results, we conclude that: (1) the transition in metamorphic grade from deep upper crustal rocks south of Harrison Pass to middle crustal rocks north of Harrison Pass does not correlate with an increase in seismic velocity; near-surface basement seismic velocities increase in the central part of the range (near Ruby Dome) well north of the major metamorphic transition; (2) depths to the Moho do not reflect local surface relief; isostatic balance is achieved predominantly in the crust rather than by formation of a local crustal root; and (3) the crust has been modified during extension by intracrustal processes rather than by large-scale magmatic underplating.