Geology of the Caballo Mountains, New Mexico

Abstract

The Caballo Mountains, just south of Truth or Consequences, rise to an elevation of 7,065 feet. Today they are flanked on the west side by Caballo Reservoir and on the east side by the Jornada del Muerto. An extraordinary geologic section is preserved here. Precambrian igneous and metamorphic rocks (granites and schists) provide a view of the Precambrian history of this part of the country, and an extraordinary thickness of sedimentary rocks (whose collective thickness is more than 3.5 miles) gives us an unparalleled picture of the evolution of southern New Mexico. Development of these mountains began with compression and uplift associated with the Laramide orogeny, at the end of the Mesozoic. Since then the complex geologic history of this part of New Mexico has included uplift, erosion, faulting, volcanic activity, continental deposition, and, finally, the development of the Rio Grande rift. That complex geologic history is well documented in this volume. This memoir is the result of many years of study and field work on the part of the authors, who have drawn together in one place this comprehensive description of the region. The volume is heavily illustrated with photographs, maps, stratigraphic sections, and other graphics. It contains both an index and a glossary.

Landforms of the central Jornada del Muerto: Influencing the path of El Camino Real de Tierra Adentro

“…Finally, this project has benefited from the detailed geologic work of many dedicated researchers, including Seager and Mack (2003), Mack and Seager (1995), Seager (1995a, b, c), Seager (2002), Seager (2005), Lozinsky (1986), Lozinsky and Hawley (1986), Lozinsky (1987), Lozinsky et al (1995), Kelley and Silver (1952) and the early excellent work by Darton (1922). Many details of geologic history of the area are published in Lucas et al (2012).…”

“…Not all of the volcanoes in the region have been radiometrically dated. The two that have, Black Hill 0.6 miles SW of Cutter and an unnamed cinder cone 3.5 miles SW of Engle, have age determinations of about 2 to 2.4 million years old (Bachman and Mehnert, 1978;Seager and Mack, 2003). The landforms consist of cinder cones, a shield volcano, and eroded cliffy escarpments around the margins of the flows.…”

Assessment of the sustainability of geothermal development within the Truth or Consequences Hot-Springs district, New Mexico

“…The Percha Shale is an important lower Paleozoic confining unit (Fig. 3) that is present in the Mud Springs and southern Caballo mountains, but is absent in the northern Caballo Mountains (Seager and Mack, 2003). The Paleozoic strata are strongly folded upward at the southern terminus of the Engle basin where Truth or Consequences is located.…”

“…The location of the geothermal system at Truth or Consequences is controlled, in part, by geologic structures that formed during three major tectonic events that affected New Mexico and the southwestern United States. First, folds and thrust faults with a Nw-striking trend and strike-slip faults with a NNE-striking trend were created in the vicinity of Truth or Consequences during NE-Sw directed compressional laramide deformation between 75 to 45 million years ago (Seager and Mack, 2003;harrison and Cather, 2004). Some of the folds created by this deformation are visible from Truth or Consequences in the western escarpment of the Caballo Mountains to the east of town and in the Mud Springs Mountains to the west of town.…”

“…The third major tectonic event that shaped the landscape in the region around Truth or Consequences is Rio Grande rift extension that began about 36 million years ago and peaked at 16 to 5 million years ago (Kelley and Chapin, 1997;Seager and Mack, 2003). This event caused the uplift of the Caballo Mountains to the east of town and the Mud Springs Mountains, the Sierra Cuchillo, and the San Mateo Mountains to the west and northwest of Truth or Consequences.…”