New Mexico’s geologic past is exposed like few other places in the world.
Of course, tourist attractions like the underground limestone caves of Carlsbad Caverns National Park and White Sands National Monument, the largest gypsum dune field in the world, are world famous.
But rockhounds and dinosaur sleuths can find equally impressive geologic adventures all across the state from Sandia Mountains in Albuquerque’s backyard to dinosaur tracks in the northeast corner to the Valles Caldera, a volcano that blew its top in the north central part of the state, to 40-foot pinnacles in City of Rocks in the southwest corner.
Although scientist Spencer Lucas, paleontology curator at the New Mexico Museum of Natural History and Science, has traveled to exotic locations across the globe, it’s New Mexico’s abundant geology that’s kept him engaged throughout his long career.
“We have one of the greatest geologic landscapes in the world,” Lucas says. “We have a tremendous opportunity to learn about geology in New Mexico. Any kind of geology can be learned here.”
Lucas says paleontologists from all over the world know about the well-preserved fossil records and finds in the state.
When he was in China he says scientists were excited to have been to New Mexico or planned to come soon.
“Somewhere back East or a even a place like Missouri you can’t see so much because it’s covered with so much soil and vegetation,” he says.
Not a problem in arid New Mexico.
Where to explore
While any great geologic excursion for adults or those with grandchildren or other youngsters in tow could start at the Natural History Museum on Mountain Road NW (nmnaturalhistory.org), heading out in any direction can land explorers in vastly different geology, he says.
“It’s all a very incredible part of our natural history and it’s all right in front of us. How old is the Earth? It’s hundreds of billions of years old. So much has happened here. So much has changed and will continue to change. It really puts your place in history into perspective,” Lucas says.
Susie Welch, an editor at the New Mexico Bureau of Geology and Mineral Resources, a division of New Mexico Institute of Mining and Technology, says there are so many interesting places to explore in the state that her annual teacher training, “Rockin’ New Mexico,” meets in various locations, from volcanoes to copper mines to the Rio Grande rift.
Welch says earth science is something that anyone from kindergarten to retirement age can understand and appreciate: “It’s where geology and sociology overlap. You recognize that if your resources are mined out of the earth and you are dependent on fossil fuel, you have to respect the sources of these things. From a conservation point of view, more education makes better decision makers for the future,” she says.
For information on the geology of the state, the New Mexico Bureau of Geology and Mineral Resources publishes “New Mexico Geologic Highway Map” and a number of “Scenic Trip” guidebooks. They are available online and at the New Mexico Tech branch on Central SE. Welch is co-editor of semiannual Web publications, “Earth Matters” and “Lite Geology,” that highlight points of interest. Visit geoinfo.nmt.edu/publications for current and back issues.
Day and night
Here are suggestions for some day and overnight trips, from the experts.
EAST TO SANDIA MOUNTAINS: Geologists at New Mexico Tech say the mystery of disappeared time, the Great Unconformity, is one of the marvels of the Sandias, just east of Albuquerque. The rock record of more than 1 billion years is lost between the mountains’ granite, about 1.4 billion years old, and the limestone cap, about 300 million years old. The age of the limestone is measured by fossils embedded there, from animals without backbones who lived in a warm shallow sea that once covered the area. The mountains are much younger than their granite base. The Sandias rose with the Rio Grande Rift about 30 million years ago, a grand scale shift of the Earth’s plate tectonics. For a first glimpse at invertebrate fossils, Lucas suggests stopping at Doc Long picnic area and examining the limestone visible in the road cuts.
NORTHEAST TO CAPULIN VOLCANO NATIONAL MONUMENT AND DINOSAUR TRACKS AT CLAYTON LAKE STATE PARK: Capulin Volcano is 33 miles east of Interstate 25 at Raton, along U.S. 64/87. The volcano, a cinder cone, is part of an 8,000-square-mile volcanic field in New Mexico and Colorado. The volcano may have erupted about 55,000 years ago, but could be as recent as 22,000 years ago based on carbon dating. Farther east along U.S. 64/87 is Clayton Lake State Park. The park has about 500 dinosaur tracks that are preserved in sandstone. Lucas says they were mainly plant-eating dinosaurs like duckbills, but a few meat-eating dinosaurs were also present. The tracks at Clayton Lake are about 100 million years old.
NORTHWEST TO JEMEZ MOUNTAINS: New Mexico’s volcanic nature is exposed in and around Jemez, most spectacularly with Valles Caldera, a National Preserve: “It’s an enormous volcano that blew its top,” Lucas says of the activity more than a million years ago.
Soda Dam, about a quarter mile north of the Jemez Ranger Station on NM 4, is a rock structure formed by hot springs from geothermal activity. Groundwater is heated by hot volcanic rocks deep beneath the earth and travels along a fault and surfaces at Soda Dam, according to “Lite Geology.” The hot water carries dissolved minerals and deposits them at the surface in thin layers of finely crystalline calcium carbonate, called travertine. These formations began forming hundreds of thousands of years ago. Farther north, a volcanic rock, Battleship Rock, juts into the sky with a winding trail to waterfalls, just south of Spence Hot Springs.
SOUTHWEST TO THE CITY OF ROCKS: The aftermath of a volcano also formed City of Rocks, near Deming, at the junction of NM 61 and U.S. 180: A large volcano erupted about 34.9 million years ago forming the City of Rocks that tower 40 feet high. Erosion over time created the rounded columns that are separated by paths. The state park has 680 acres with camp sites, picnic areas and hiking trails. Rockhounds can collect rocks at designated areas.