Geologic Tour of New Mexico — Physiographic Provinces

A spectacular, eroded anticline and syncline pair lies between the Ojito Wilderness and the village of San Ysidro in north-central New Mexico. The San Ysidro area lies near the intersection of four significant geologic features, including the mildly deformed Colorado Plateau to the west, the Laramide-age (75 to 55 million years old) Sierra Nacimiento uplift to the north, and the late Oligocene to Miocene Rio Grande rift to east. The northeast-trending Jemez lineament, characterized by young volcanism, cuts across all three geologic provinces. The <15 million year old Jemez volcanic field is visible to the northeast, the 2 to 3 million year old Puerco Necks, including Cabezon Peak, are located just to the west, and the 1.5 to 3.3 million year old Mount Taylor volcano can be seen on the skyline to the west.

El Morro, which means "bluff" or "headland" in Spanish, is an imposing cliff made of Middle to Late Jurassic (155 to 165 million years old) Zuni Sandstone capped by Late Cretaceous Dakota (~95 to 96 million years old) sandstone and shale. Travelers, including Native Americans, Spaniards, and citizens of the United States, have carved their symbols, names, messages, and dates of their passage into the soft cross-bedded Zuni Sandstone for centuries.

Bandelier National Monument, best known for its cultural significance and well-preserved cliff dwellings, also offers visitors a chance to observe the volcanic geology that made the area so well-suited for prehistoric Puebloan civilization. The rock in most of the monument is Bandelier Tuff, a light-colored, soft volcanic rock that formed during two very large, explosive volcanic events that occurred 1.6 and 1.2 million years ago. These two large eruptions, which together produced hundreds of cubic miles of rock, created the thick sheets of white-to-pink volcanic ash and ignimbrite seen in cliffs in many parts of the Jemez Mountains. This rock, composed of pumice, ash, and volcanic crystals, is not very strongly cemented, and, in many places, has a chalky texture. The soft and easily eroded nature of this rock allowed the deep Frijoles Canyon to be incised by Frijoles Creek, and then provided the perfect setting for the prehistoric Puebloan civilization. These people carved cliff dwellings and building blocks for structures from the volcanic rocks. They occupied this idyllic setting until around A.D. 1,100, when climate change or a combination of factors forced them to abandon the dwellings, the remains of which we see today.

Monument Rock is located west of Socorro and north of U.S. Highway 60 in the eastern Sawtooth Mountains of Catron County, New Mexico. The area can be reached from Datil by traveling west along Highway 60, 12.3 miles to Forest Road 6A. Turn right on Forest Road 6A and drive north 3.7 miles to the prominent spire of Monument Rock.

The area can also be accessed from Pie Town by driving east along U.S. Highway 60 to Forest Road 316. Turn left onto Forest Road 316 and drive northeast 3.5 miles to Forest Road 6A. Turn left and drive 1.1 miles to Monument Rock.

Kasha-Katuwe Tent Rocks National Monument is on the southeast side of the Valles and Toledo calderas, large collapse features that formed during voluminous eruptions in the Jemez Mountain volcanic field 1.61 and 1.25 million years ago. Tent Rocks encompasses a fascinating landscape in the southeastern Jemez Mountains. Kasha-Katuwe means 'white cliffs' in Keresan, the traditional language of the nearby Pueblo de Cochiti. Delicately layered sand, gravel, volcanic ash, and tuff of the Peralta Tuff Member of the Bearhead Rhyolite and sand and gravel of the Cochiti Formation, which are older units (2 to 6 Ma) in the Jemez Mountain volcanic field, have been erodedinto fragile to robust spires with balanced rocks perched on top. The hoodoos, erosional cones, and pedestal rocks that characterize Tent Rocks form as the result of differential erosion.

America's newest national park (as of December 2019), White Sands is famous for its extensive sea of white gypsum dunes—indeed, it is the largest gypsum dune field in the world. Located in the southern Tularosa Basin, the park was established as a national monument in 1933 and encompasses nearly 176,000 acres (275 square miles, including 115 square miles of gypsum sand dunes). The park not only contains the large dune field but also a saline mudflat called Alkali Flat, a smaller ephemeral salt lake (or playa) named Lake Lucero, parts of the gypsum-dust plains east of the dune field, and alluvial fans from the surrounding mountains. The dune field and Alkali Flat extend more than 12 miles to the north of the park onto the White Sands Missile Range.

Also see the White Sands National Park sample chapter from our popular field guide: The Geology of Southern New Mexico's Parks Monuments and Public Lands.

Sugarite Canyon State Park, once the site of a thriving coal-mining camp, was established as a state park in 1985, but the canyon has been a recreational attraction in northeastern New Mexico for decades. Sugarite Canyon State Park is located about 5 miles northeast of Raton via NM-72 and NM-526 (paved). The elevation in the park ranges from about 6,900 ft to 8,400 ft. This heavily wooded mountain park has something for everyone year round. Trails are maintained through the ruins of the settlement and past coal dumps and mines.

The Chino mine, an open-pit porphyry copper mine, is 15 miles east of Silver City near the village of Hanover in southwestern New Mexico). An overlook of the pit, complete with educational displays, is located on the south side of New Mexico Highway 152 east of Hanover. The excavation is also known as the Santa Rita Mine or Santa Rita del Cobre, named for the former village of Santa Rita, which was removed in the 1950s as mining operations in the area expanded. Concern has been expressed about the stability of the famed landmark on the southeast side of the mine, the spire known as the Kneeling Nun, as the modern-day mining operation moves to the southeast. The Chino mine is the largest porphyry copper deposit in New Mexico. The pit is currently ~1.75 miles across and 1,350 feet deep. The Apaches were the first to notice native copper lying on the ground in a valley northwest of Santa Rita Mountain. The open-pit mining operation began in 1910. The mine became part of Freeport-McMoRan in 2007.

This recreation area in the Lincoln National Forest has spectacular cliffs and features a year-round spring-fed stream, waterfalls (the largest of which has a 150-foot drop), and many refreshing clear-water wading pools. There are picnic areas and several hiking trails, including T–68 and T–68A that lead to the spring source of the waterfalls. The Apache name for the area was “gostahanagunti,” which means hidden gulch, and the presence of flakes of worked chert, grinding holes (bedrock mortars), and nearby pictographs testify to long-standing Native American use of this wildlife-rich oasis in the desert.

Pancho Villa State Park in Columbus, New Mexico, was established in 1959 “in interest of preservation of the memory of the unique, historical occasion of the last hostile action by foreign troops within the continental United States”. It became the only park in the United States to be named after a foreign invader. The creation of the 60-acre park was a gesture of good will between the United States and Mexico. The town of Columbus has been designated a National Historic Site. Across the street from the park is the privately owned Pancho Villa Museum.