A P-wave seismic velocity model derived from analysis of data from a seismic refraction/reflection survey provides the first regional-scale view of the subsurface structure of the upper crust of the southern Rio Grande rift. The seismic survey was conducted along a 205-km-long east-west transect that crosses a portion of the Basin and Range province and the Rio Grande rift in southernmost New Mexico and west Texas. In the upper few kilometers of the crust, the model shows a series of low- and high-velocity zones that correlate with the mid-Tertiary to Holocene Basin and Range structure at the surface. Typically, basins are 10–20 km wide and ~1–3 km deep. Beneath the mid-Tertiary to Holocene structures are velocity anomalies interpreted to be the result of tectonic activity of Paleozoic to early Tertiary age. The geometry of high-velocity zones at 3–10 km depth in the eastern half of the model correlates well with Laramide block uplifts mapped at the surface and suggests that the thrusts that bound these blocks may sole into a regional detachment at 10–15 km depth. In the western half of the model, a low-velocity zone that reaches depths as great as 11 km has geometry highly suggestive of a deep basin. This previously unrecognized feature may represent a combination of great thicknesses of the Upper Jurassic to Lower Cretaceous rocks of the Chihuahua Trough and Bisbee Basin stacked above rocks of the older Paleozoic Pedregosa Basin. Alternatively, portions of this region may have been thickened by thrust stacking during the Laramide orogeny.

The Trans-European Suture zone in eastern Europe is a complex region that marks the suture of Phanerozoic western European terranes with the Precambrian East European craton. Because of sedimentary cover and the Baltic Sea, the nature of this suture is known primarily from geophysical studies. Seismic velocity and gravity models from earlier experiments indicate changes of crustal thickness from 28–35 km to 42–47 km across the Teisseyre-Tornquist zone from the Paleozoic platform of western Europe to the East European craton. Tectonic models suggest the presence of a Precambrian–early Paleozoic passive margin beneath the Teisseyre-Tornquist zone. The Holy Cross Mountains in southeastern Poland represent an anomalous crustal block whose origin and interaction with the East European craton is unknown. We have employed a new approach to quantitatively integrate (i.e., data fusion) industry-acquired drilling and seismic reflection data, as well as refraction data from the CELEBRATION 2000, POLONAISE ‘97, and Teisseyre-Tornquist zone experiments in a tomographic inversion. We find that it is feasible to integrate data of different resolutions in a tomographic inversion. Secondly, we constrained upper-crustal velocities within our study area to create a more completely resolved velocity structure. Thirdly, we modeled a uniform gravity data set to validate all available data and construct models of crustal structure across the Holy Cross Mountains region.