Sunday, December 17, 2017

The Desert Can Do That To You

Marsha and I have always been most comfortable either in dry, barren areas of land, or on sandy beaches.  And when I read this line of poetry –

“The desert holds the memory of ocean tides”

– it immediately brought back memories of our first visit to the Chihuahuan Desert in Big Bend National Park as part of an Elderhostel educational vacation in 1998

One of our instructors was a self-trained paleontologist named Ken. He was a surveyor by vocation who had come to the area a decade earlier on a job assignment. It was his maiden voyage to that part of the world and he just never left. He had been, I believe, married at the time.  But Ken simply became obsessed with the paleontological possibilities of, what he would say is, “one of the most complete pictures of a prehistoric ecosystem known anywhere on earth.” – and with the solitariness to pursue that fixation. The desert can do that to you.

We went out on a dig for fossils with Ken who, like the avaricious gold seekers in the movie Treasure of Sierra Madre, was unwilling to let us rank amateurs actually lay hands on any of the prehistoric leftovers that we came across. (The desert can do that to you also.)   Later on we visited the retired yellow school bus jam-packed with osteo-relics that was his museum for a hands-off tour.

The fossil record at Big Bend includes relics from the Age of Reptiles to the Age of Mammals, beginning about 100 million years ago when a huge sea covered most of what is today the Midwestern part of the United States.  Many of these marine fossils can be found in the remaining sea layers of limestone known as the Boquillas Formation, including a 30-foot long sea-dwelling reptile known as Mosasaurus.

The incongruity of standing on totally dry, almost barren land in unremitting 100 degree heat – and looking at the petrified remains of underwater creatures in the sun-blinding limestone at my feet muddled my ability to understand what I was actually seeing right in front of me.

This all might have made more sense to me if I had been standing in an ocean.  For the past twenty years Marsha and I spent part of September/October at the beach on Emerald Isle, North Carolina – definitely not as desolate as the Chihuahuan Desert, but at that time of year down to about two percent of its summer population.  Standing at the edge of the water with our backs to the empty, brightly-colored mega-cottages and high rise condos we could look out on an endless stretch of water with no signs of life other than an occasional fleet of pelicans gliding close to the waves, or a pod of dolphins arcing one at a time above the surface.

Somehow it is easier for me to picture future desert-like seascapes under this undulating water, than to grasp the actual after-effects while standing in the midst of them.

So now I wondered if the same geological saga was true of Santa Fe, New Mexico, the high desert land in which Marsha and I now live.

Some quick Googling revealed that during what is called the Pennsylvanian Period (323 to 299 million years ago) almost sixty percent of New Mexico was covered with shallow seas – including Santa Fe.

The ocean left behind the deepest basin, and the thickest rock strata in in a trough that subsequent mountain-building activity pushed up to form what we now call the Sangre de Cristo Mountains ­ – about fifteen miles to the northeast as the raven flies, and clearly visible from the walking trail at the end of our street.  On the Santa Fe side of the “Sangres” you can discern at least one cycle of sea level change, starting with beds of marine limestone deposited in a clear, well-aerated, sub-tidal environment, as well as interbedded limestone, and mudstone – plus ripple marks on sandstone that document the shifting tides of the sea.  Small numbers of Pennsylvanian Trilobites (a fossil group of extinct marine arthropods) have been found in the Santa Fe area.

Even before we moved to the Southwest Marsha and I knew we would deeply miss the sights and sounds of the white sands and crashing waves of what Carolinians like to call the Crystal Coast – and the sense of calm and belonging that we got from wading in the waters of the Atlantic, and feeling the sea salt drying on our tan sunbaked skin.

So it is comforting now to know that we don’t really have to fly 1,800 miles east to recapture that feeling.  Instead, all that we have to do is dig down about 300 million geological years beneath our feet.

The desert can do that to you.

(The opening line of poetry is from “Once There Was an Ocean Here” by Liz Paterson. Marsha and we came upon it the at the exhibit "Santa Fe Book Arts"
in the New Mexico State Capitol in Santa Fe.)

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