Terrestrial Heat Flow along the Rio Grande Rift, New Mexico and Southern Colorado
From heat-flow data obtained in New Mexico and southern Colorado, one finds: (1) a major geothermal anomaly with heat-flow values greater than 2.5 HFU (heat-flow unit, microcal/(sq cm) sec) coincident with the western part of the Rio Grande rift; (2) a complex heat-flow pattern in the eastern Colorado Plateau with values of 1.5 HFU and less, apparently associated with major structural basins, and values of 2.0 HFU and greater, apparently associated with some intrusions and perhaps major uplifts; and (3) a regional increase in heat-flow values from 1.5 to 2.0 HFU to values greater than 2.5 HFU in southwestern New Mexico, which may be coincident with the north-trending geothermal transition zone between the Colorado Plateau and the Basin and Range provinces.