Compilation of almost 200 new maximum horizontal stress (SHmax) orientations in Texas reveals a complex intraplate stress field. A large extensional stress province is associated with extensive growth faulting from northeastern Mexico to Louisiana. SHmax is subparallel to the coastline, following the strikes of the growth faults. In contrast, we observe a strike‐slip/normal faulting regime with SHmax approximately E‐W in much of west Texas and the Texas Panhandle, similar to the stress fields observed in northeast New Mexico and north‐central Oklahoma. Within the Fort Worth Basin in northeast Texas, SHmax is NNE‐SSW. The faulting regime transitions from strike‐slip/normal faulting in the northern part of the basin to normal faulting with subequal horizontal principal stress magnitudes further south. Recent sites of apparently injection‐related seismicity near Snyder/Cogdell (west Texas), Karnes City/Fashing (south Texas), the Dallas‐Fort Worth metroplex, and Timpson (east Texas) involves fault slip compatible with local stress fields.

The Earth's crustal stress field controls active deformation and reflects the processes driving plate tectonics. Here we present the first quantitative synthesis of relative principal stress magnitudes throughout North America together with hundreds of new horizontal stress orientations, revealing coherent stress fields at various scales. A continent-scale transition from compression (strike-slip and/or reverse faulting) in eastern North America to strike-slip faulting in the mid-continent to predominantly extension in western intraplate North America is likely due (at least in part) to drag at the base of the lithosphere. Published geodynamic models, incorporating gravitational potential energy and tractions from plate motions or relative mantle flow, successfully predict most large-wavelength stress rotations but not the shorter-wavelength (<~200 km) rotations observed in the western USA. The stresses resulting from glacial isostatic adjustment appear to be much smaller than the magnitude of ambient tectonic stresses in the crust at depth.

The rate of seismicity in the hydrocarbon‐producing Fort Worth Basin of north‐central Texas, which underlies the Dallas–Fort Worth metropolitan area, increased markedly from 2008 through 2015, coinciding spatiotemporally with injection of 2 billion barrels of wastewater into deep aquifers. Although the rate of seismicity has declined with injection rates, some earthquake sequences remained active in 2018 and new clusters have developed. Most of this seismicity occurred away from regionally mapped faults, challenging efforts to constrain the continuing hazards of injection‐induced seismicity in the basin. Here, we present detailed new models of potentially seismogenic faults and the stress field, which we use to build a probabilistic assessment of fault‐slip potential. Our new fault map, based on reflection seismic data, tens of thousands of well logs, and outcrop characterization, includes 251 basement‐rooted normal faults that strike dominantly north‐northeast, several of which extend under populated areas. The updated stress map indicates a relatively consistent north‐northeast–south‐southwest azimuth of the maximum horizontal principal stress over seismically active parts of the basin, with a transition from strike‐slip faulting in the north to normal faulting in the southeast. Based on these new data, our probabilistic analysis shows that a majority of the total trace length of the mapped faults have slip potential that is equal to or higher than that of the faults that have already hosted injection‐induced earthquake sequences. We conclude that most faults in the system are highly sensitive to reactivation, and we postulate that many faults are still unidentified. Ongoing injection operations in the region should be conducted with these understandings in mind.

Since the 1960s, the Permian Basin of west Texas and southeast New Mexico has experienced earthquakes that were possibly triggered by oil and gas activities. In recent years, seismicity has been concentrated near Pecos, Texas; around the Dagger Draw Field, New Mexico; and near the Cogdell Field, Snyder, Texas. We have collected hundreds of measurements of stress orientation and relative magnitude to identify potentially active normal, normal/strike-slip, or strike-slip faults that might be susceptible to earthquake triggering in this region. In the Midland Basin and Central Basin Platform, the faulting regime is consistently normal/strike slip, and the direction of the maximum horizontal compressive stress (SHmax) is approximately east–west, although modest rotations of the SHmax direction are seen in some areas. Within the Delaware Basin, however, a large-magnitude clockwise rotation (∼150°) of SHmax occurs progressively from being nearly north–south in the north to east-southeast–west-northwest in the south, including the western Val Verde Basin. A normal faulting stress field is observed throughout the Delaware Basin. We use these stress data to estimate the potential for slip on mapped faults across the Permian Basin in response to injection-related pressure changes at depth that might be associated with future oil and gas development activities in the region.