Geologic Tour of New Mexico — Physiographic Provinces

West of the flocks of birds and birdwatchers along the wetlands of the Rio Grande, a story of cataclysmic volcanic eruptions, ancient dune fields, and long-gone towering mountains lie quietly awaiting visitors to the Bosque del Apache National Wildlife Refuge. The Chupadera Wilderness Trail and the Canyon Trail traverse this geologic record in the contemplative solitude of a wilderness setting, affording “rockwatchers” a quick trip through millions of years of Earth history.

Pecos National Historical Park lies in the extreme western portion of San Miguel County, in the broad valley of the Pecos River where the river leaves its deep canyon in the Sangre de Cristo Mountains. The timeless cycles of geologic history are on display in the ancient and modern river deposits in the park. The spectacular cliffs of sedimentary rocks on Glorieta Mesa to the south and the rugged mountains to the north provide a beautiful geologic setting for the ruins and contain rocks that record shifting shorelines and the birth and erosion of mountains.

The site is of enormous cultural and historical significance. The pueblo here was occupied at least as early as 1450. The Coronado Expedition passed through here in 1541 en route to the Great Plains. Spanish missionaries followed soon thereafter. In 1621 the Franciscans built the adobe church whose ruins tower over the park today. In 1680 the Pueblo Revolt put an end to the efforts of the church throughout northern New Mexico; the priest at Pecos was killed and the church laid waste. The site was occupied by the Pecos Indians until 1838.

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.

Gila Cliff Dwellings National Monument is in the Mogollon Mountains approximately 44 miles north of Silver City, New Mexico. Gila Cliff Dwellings National Monument was established in 1907 and is one of the nation’s oldest monuments. The monument lies within the Mogollon-Datil volcanic field; volcanic eruptions from this field covered 40,000 km2 of southwestern New Mexico and southeastern Arizona with lava and ash flow tuffs 40 to 24 million years ago.

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.

This is a virtual field trip to the classic Permian reef complex and other geologic features of the Guadalupe Mountains, including those in Carlsbad Caverns National Park and Guadalupe National Park in Texas. It contains an introduction to the geology of the Permian reef complex plus several roadlogs with diagrams and photographs, as well as an extensive bibliography in order to provide a balanced presentation for a geology student audience.

Bottomless Lakes State Park is located 14 mi southeast of Roswell, on the east edge of the Pecos River valley. The park is 4 mi long, and the loop drive is 9 mi long. The park consists of approximately 1,611 acres and includes eight of nine lakes; the Fin and Feather Club owns Dimmitt Lake, the southernmost lake. Vaqueros (cowboys) who could not find the bottom of the lakes reportedly gave them their name (Young, 1984). They would tie two or three ropes together and drop them into the lakes to try to reach the bottom. The ropes were not long enough, so the vaqueros thought the lakes were bottomless! The greenish-blue color created by algae and other aquatic plants also added to the illusion of great depth.

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.

City of Rocks State Park is truly a geologic monument; it is formed by large sculptured rock columns (pinnacles) or boulders rising as high as 40 ft and separated by paths or lanes resembling city streets. About 34.9 million years ago a large volcano erupted, forming the rocks in an instant (geologically speaking); then erosion over millions of years slowly formed the sculptured columns that now provide a natural playground for children and adults alike. City of Rocks State Park was established in May 1952 to preserve this geologic wonder.

This small park, established in 1916 by presidential proclamation, offers a close-up view of one of the most perfectly preserved cinder cones in North America. The road to the summit provides access to the summit crater, and if you have ever wanted to walk into a volcano, Capulin Mountain is one of the few places you can do so. A 0.2-mile-long trail from the summit parking lot descends to the vent at the bottom of the crater. The view from the crater rim encompasses all of northeastern New Mexico as well as parts of Texas, Oklahoma, and Colorado.