New Mexico Geological Society Annual Spring Meeting — Abstracts

The Holt Mountain 7 ½ minute quadrangle is located east of Glenwood, New Mexico in the southwestern part of the mid-Tertiary Mogollon -Datil volcanic field, and at the west end of the Mogollon Mountains. The quadrangle includes the western and southern margins of the huge, 40 km (25 mile) diameter, Oligocene (28 Ma) Bursum caldera, as well as evidence indicating a pre-existing Mogollon caldera of Eocene (~ 34 Ma) age, within which the Bursum caldera is nested. Other evidence for the Mogollon caldera seems to have been largely destroyed during the development of the younger caldera cluster, including the Bursum caldera, in the Mogollon Mountains region.

The Holt Mountain quadrangle also is noteworthy for its base and precious metals mineral resource potential, including molybdenum, copper, lead, zinc, gold and silver, as well as past fluorite mining. The area’s mineral resource potential is enhanced by its location immediately south of the Mogollon mining district, but exploration is somewhat impeded by the location of most of the mineralized rocks within the boundaries of the Gila Wilderness.

The Holt Mountain quadrangle includes the trailhead, and large stretches of the Catwalk National Recreation Trail, in Whitewater Canyon, a major western gateway to the Gila Wilderness, and a popular tourist attraction in the Glenwood area. The Catwalk Trail is a beautiful hike for people of all ages and interests, and it traverses some of the rock exposures that are most critical to the interpretation of the geology in the Holt Mountain quadrangle and the Mogollon Range.