By Jon Krupnick, Field Geologist
Armendaris Ranch
January 24, 2025
The Quaternary geology of the Jornada del Muerto basin on the east side of the Fra Cristobal Range is characterized by lava flows, sand dunes, alluvial fans, and low-gradient drainages feeding into a succession of playa lake deposits. Generous permission from the Armendaris Ranch has allowed the mapping program to assess the geologic history of this area. The field geologist mapping this quadrangle is especially interested in how these deposits relate to differences in erosion on the east and west side of the mountain range and how that erosion is controlled by tectonic faults and tributaries of the Rio Grande.