A Field Trip to the Past

A Field Trip to the Past

Our fearless leader, Sylvia, took us on a field trip to Pilar, then across the Rio Grande to US 285 and Ojo Caliente and on to Ghost Ranch at Abiquiu. Quite the adventure. We stopped at the Visitor’s Center in Pilar to look at the topo map of the Rio Grande as it runs down through New Mexico from our northern border in Costilla to where it flows into El Paso and becomes the Texas-Mexico boundary in Big Bend country. The most interesting thing about the Rio Grande is that it flows through a continental rift, the second largest in the world. (The largest is in Africa.) One of my fellow students, Peggy, who is up on her geology, explained that the Rio Grande Rift is not the river itself, but the valley it runs through which, in Arroyo Hondo, spans thirty miles from the foothills of the Sangre de Cristos in the northeast to Tres Piedras in the southwest.

A rift is a tear in the crust of the earth where the continent is slowly being pulled apart by opposing forces. We have some small tremors around here from time to time, but Taos Pueblo--about a thousand years old--is still standing firm. (A major earthquake would tumble an adobe structure like the Pueblo.) Peggy pointed out that on the northeast side of the highway we were looking at tall, sandy cliffs that were once the beachfront of an inland sea. Behind us on the southwest side of the highway rose a steep hillside littered with volcanic basalt, dotted with piñon and juniper.

We drove along the Rio Grande upstream toward Taos Junction Bridge. This section the riverbank is crowded with salt cedar (tamarisk), an invasive non-native tree that sucks up salt and deep groundwater. When it rains, the salt is washed off the leaves and eventually into the river. The salt inhibits competition from the natural flora and can even alter the chemical composition of river. Entomologists are considering releasing swarms of hungry Asian beetles to eat the leaves, but scientists are not so sure this is a good idea.

Over a decade ago I helped an earnest group of environmentalists plant young cottonwoods along these banks where beavers had cut down many of the native trees. Our class examined the current cottonwood transplants that were protected by fencing. Sylvia noted that because the beavers couldn’t get to the fenced trees, they had cut down a natural cottonwood instead.

We stopped near the bridge to study the opposite hillside where—strangely enough—mature cottonwoods were growing out of the otherwise barren hillside. Sylvia said they grew along fault lines tapping seepage from the water table. I never would have noticed if she hadn’t pointed it out.

We ate lunch not far from Abiquiu on a cliff overlooking the ruins of an ancient pueblo, Poshuouinge. The Santa Fe National Forest guide says it was still inhabited around AD 1420. Perhaps several thousand people lived here and many others visited. They don’t know why the site was abandoned in the late 1400s. At my feet I noticed a small circle of dark, baseball-sized stones. “A marker,” Sylvia said. I thought it was a fine place for a lookout with a broad view over a dry riverbed that snaked through the cliffs, a place to make a signal fire.

Sylvia said, “How many stones are there?”

We counted twelve.

“What’s the significance of the number twelve in the Pueblo culture?”

Darned if I knew. In classic religious architecture, twelve symbolizes the twelve disciples.

The rich light of sunset washed over the layered cliffs of Abiquiu as we turned at the entrance to Ghost Ranch. It was here that Georgia O’Keeffe painted many landscapes of the dramatic red, white and yellow 1300-foot escarpment. She made Ghost Ranch her permanent home from 1949 until her death in 1986. She was ninety-nine years old. Her ashes are scattered here.

Ghost Ranch was the site of the University of California-Berkeley digs from 1928 to 1934--the Hayden Quarry excavation. In 1947 George Whitaker found one of the earliest dinosaurs in North America preserved among at least three hundreds of skeletons in what must have been a flash flood or sudden flow of mud-like silt. This was the Coelophysis bauri (SEE-Low-FY-sis bar), a six to eight-foot dinosaur that lived 220 million years ago that was assembled from three different skeletons. The mount is on display at the Cleveland Museum of Natural History. A large block of these fossils was carried to where the Ghost Ranch Museum now stands and other blocks have been distributed to museums all over the world.

We were treated to an animated lecture by a paleontologist who had been busy extracting dinosaur bones from a mass of rock and assembling the pieces. It was exciting to catch him in the act as he wielded a small paintbrush, plaster still on his hands. We examined and passed around huge curved incisors while he explained that some of the dinosaurs had feathers; the only surviving dinosaur relatives today are birds.

After dinner we climbed a steep hill above the ranch to look at the night sky through a digital telescope. Once you have the coordinates, you can punch in the number of the planet, star or galaxy you want to view, fine tune the focus and then let the telescope track it electronically while people take turns looking. Without electronics, you’d have to refocus the telescope every three or four minutes.

We peered at the new moon just as it was about to set. The reflecting edge glowed orange while on the border between light and shadow, we saw many pocked craters. Next we looked at a double star in the constellation of Lyra, named for the harp of the mythical musician Orpheus. A yellow star and a blue one circled each other in measured dance. We also viewed my favorite, the blue star Vega. I fell in love with that star the first time I saw it ten years ago. I thought it was a private love affair. I was surprised to discover that Vega is a popular star. Our guide, Willy, said it was the fifth brightest star in the sky and the farthest west in the summer triangle. Vega is twenty-five light years from Earth. In the cold night air it shone with the purity of a blue diamond.

We also took a peek at Jupiter, the fifth planet from the sun and eleven Earth diameters wide. This huge planet is actually a ball of dense gases, hydrogen, helium, water, nitrogen etc. that surround a small rocky core. Jupiter was perfectly round and crisp, shining bright so I couldn’t see the ring of dust around it, but four of its moons were in staggered orbits, all on the right. Willy explained that’s just where they happen to be right now. According to the NASA website, Jupiter has sixty-two known moons and they are still counting. One of them, Ganymede, is bigger than the planet Mercury.

The last and best thing we viewed was a vast rainbow-colored nebula at the bottom of Orion’s sword, a veil of gas that looked like angel wings which spread thirty light years across the constellation. It probably contains thousands of stars. In the lower corner glittered three “baby stars” that were born from those gases. Mysterious and beautiful.

I stepped back and saw a “falling star” from the famous Leonids meteor shower. The night wind was cold on my face. I felt humble and exhilarated.