Arizona, New Mexico & the Grand Canyon Trips (Lonely Planet, 1st Edition) - Aaron Anderson [151]
Continue west on I-40, through the endless plains and valleys punctuated by sandstone- or basalt-topped mesas, just over 100 miles to the 26,300-acre El Malpais National Monument, one of many volcanic regions along the Jemez Lineament, a line of volcanic activity that stretches from El Capulin in Raton, NM, to Springerville, AZ. Named after the Spanish word for badlands, El Malpais’s raw landscape of jagged black lava flows and desert shrubs, searing under the summer sun, offers miles of hiking trails, primitive camping and scenic drives.
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DETOUR
The Sandia Mountains are a tale of two slopes. Formed by the Rio Grande Rift, the west slope exposes 1.4-billion-year-old granite roots under parched desert scrub. The east side is capped with 300-million-year-old, water-retaining limestone, and thus thriving alpine forests. The billion-year-long gap in time represented by the contact between granite and limestone is visible 300ft downhill from the Doc Long Picnic Area on the road to Cedar Crest (I-40 exit 175).
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Twenty-eight miles south of Grants on Hwy 53, fire and ice intertwine at Ice Cave and Bandera Crater. A short climb reveals a great view into the Bandera Crater, the largest cinder cone in the region. Another trail winds through the lava to an ice cave, an exposed portion of lava tube which maintains a below-freezing temperature year-round.
Back in the ’50s, when folks thought we were going to run the world on nuclear energy and the US was building nuclear bombs, uranium mining in the Grants area boomed. Before returning to Albuquerque, stop at the New Mexico Mining Museum in Grants, where a cage takes you down into a recreated uranium mine.
Return for a late dinner and another night in Corrales, before packing up and heading north on Hwy 4 to the Jemez Mountains, a gigantic, low-profile volcano that erupted huge amounts of volcanic ash two million years ago. Drive through the red-rock canyon of the Jemez River, past layers of volcanic tuff, pumice, lava and obsidian, stopping for a scramble over the travertine deposit of the sulphur-smelling Soda Dam.
A turnout on the west side of Hwy 4, 15 miles north of the Wallatowa Visitor Center, offers great fossil picking through ancient sea-floor sediment, and there are several stretches along Hwy 4 where you can pull over and pick up pumice, lava and obsidian. Pause to read the roadside marker on the geology of the ranchlands of Valles Grande, the Jemez’s collapsed volcanic crater. On weekdays, the caldera offers walk-in geology van tours that depart from the visitors center, visible from Hwy 4.
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RIO GRANDE RIFT
The Rio Grande Rift is a linked series of 10-million-year-old north–south trending valleys stretching from southern Colorado through New Mexico and into Texas. Rifting – the stretching and thinning of the earth’s crust – resulted in sunken valley floors with outer edges defined by volcanoes resting atop fractures in the crust (which served as magma conduits) or mountains formed by uplift and rotation of huge granite blocks. The Three Sisters cinder cones on the west side of Albuquerque are an example of the former, the Sandia Mountains the latter.
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From here, drive through Los Alamos and Espanola and follow Hwy 84 up onto the Colorado Plateau to Ghost Ranch. New Mexico’s state fossil, the dinosaur Coelophysis, was first discovered in the fossil-rich beds of the ranch in 1947. You can often see Ghost Ranch’s own paleontologist, Alex Downs, excavating dinosaur bones at the paleontology museum here. Several hikes lead through exposed large sections of rock from the Mesozoic, the age of dinosaurs (250 million to 66 million years ago).
After a swim in Abiquiu Reservoir, head through El Rito and on up to Taos. An unpaved road descends the Rio Grande Gorge through hundreds