The Popotosa Formation is a geologic formation in New Mexico. It preserves fossils dating back to the Neogene period. These include the Socorro flora, notable for its fine preservation of plant reproductive structures.

The Mogollon-Datil volcanic field is a large silicic volcanic field in western New Mexico. It is a part of an extensive Eocene to Oligocene volcanic event which includes the San Juan volcanic field in southwestern Colorado, the Trans-Pecos volcanic field in west Texas and north central Mexico, the Boot Heel volcanic field in the bootheel of southwestern New Mexico and adjacent areas of Arizona and Mexico; and the vast volcanic field of the Sierra Madre Occidental of western Mexico. The Mogollon-Datil volcanic field was formed in "four discrete pulses representing synchronized activity of two separate cauldron complexes".