DESERT TIME -- A JOURNEY THROUGH THE AMERICAN SOUTHWEST
Chapter 9: reef
We're coming to the reef down the Pecos River valley and two hundred and fifty million years and the rim of the sky is the dusty blue of bleached jeans. The valley is a flat bowl of a place so wide one can't see edge; land and sky meet in sulfurous air. It's really sulfurous, with the dead-egg stink of gas wells. There are oil wells here, too, and artesian water wells. This is country where people drill down.
I orient myself via maps rustling over the other seat -- geological maps, highway maps, ecologic zone maps, maps of Texas, maps of New Mexico. Over there, where the land rises at the other side of the Pecos, is the edge of the high plains and the end of the desert. The reef is up ahead.
We're east of the Rio Grande rift here and the soil is white. Caliche is what it is: calcium carbonate dissolved in groundwater, moved to the surface as water soaks upward, then left as the water dries away. If you turn a rock over here its underside will be layered with caliche like whitewash painted on again and again. In some places the caliche is thick enough to be mined for road pavings. Wherever you see it you know it came from below. You know that underneath is limestone, oceanic deposit, the bone minerals of vanished sea.
Plants have problems with caliche. The crust is in the way of roots and water -- it's a physical barrier -- and the chemistry is generally unfriendly, basic, bitter with salts and gypsum. This side of the valley is thinly furred by a slope of dun grass -- gyp-grama mostly, so named because it tolerates gypsum and is an indicator of its presence. In this thin grass are bony shapes of cholla and low domes of mesquite. The mesquites are as transparent as greenish ghosts. Here and there are the hedgehog profiles of soaptree yuccas, typical of the Chihuahuan desert, which this is; I'd know them anywhere by their fireplace-poker fruiting branches and slim bristling anatomy. They lurk in the dried grama grass like imps, prickly and durable, as if they were made of spikes and tire rubber. This uncomfortable landscape is the legacy of what was wet long ago and is now too thoroughly dried away.
Midday: to the east the tops of floodplain cottonwoods shiver in the heat, taproots sucking Pecos water. The road is dissolved in watery mirage. There could be anything ahead, even time crinkles here like cellophane.
Two hundred and fifty million years ago we would be in a shallow sea. Just back there we'd have entered the lapping wavelets of lagoon. It's the end of the great Age of the Fishes, reptiles haven't hoisted themselves yet into dinosaurean ferocity, and between the lagoon and the warm seas that stretch between the continents of North and South America lies a massive reef. Someday in the future it will be called the Capitan Reef. It lies in a bulging U-shaped curve, nearly four hundred and fifty miles long and up to ten miles broad, through most of what will be West Texas. It's been growing there since the sinking of the Delaware Basin -- the shallow seafloor -- thirty million years past. It will grow for twenty million years more. Shaley organic limestones and fine-grained sandstones build in deep layers in the sea itself, out where the Rio Grande will one day cut through them to carve the canyons of West Texas and define the borders of nations. From time to time, chunks break off the reef and roll seaward or lagoonward to pile up as a chunky breccia. This gets embedded in layers of sandstone, limestone, and dolomite. Corals and calcareous algae -- algae that deposit limestone-forming skeletons, much as corals do -- all colonize their own debris pile, and the reef swells below the surface of the sea. The life of the reef will come to an end only when the whole region tilts and is lifted, high and dry, into the air.
That happened two hundred and thirty million years ago. Since then the reef has been high and bare, or dropped and buried in overlayments, and submerged for short periods and tilted and lifted several times, the latest time being between one and three million years ago. With every shrug and dip of things the massive reef limestone cracked and the sediment layers around it cracked. Rock layers in a moving earth are like crockery in a mattress trampled by elephants. Everything cracks.
Uplift was followed by erosion. So, nowadays, erosion having exposed them, pieces of the reef lie high and bare again. There's Glass Mountain near Alpine, and the Apache Peaks north of Van Horn, and the Guadalupe Mountains that span the Texan border of New Mexico. The Guadalupes are a fifty-mile-long range of pure Capitan Reef limestone. They're the highest mountains anywhere around. They're riddled with caves: Carlsbad Caverns, New Cave, Lechuguilla Cave, and Black, Hell Below, Dry, Sand, Endless, Little Sand, Virgin, Pink Panther, Three Finger, Spider, and McKittrick caves, and more, some still undiscovered, some already broken away.
The caves are there because of the cracks. Whenever the reef rose above the water table, beginning back with that first emergence, water seeped downward through the cracks. This water was mildly acidic, having dissolved a little carbon dioxide from the atmosphere, just as acid rain does. The limestone dissolved into spongework, then into hollows and loops and domes and chambers and Swiss-cheesy "boneyard" corridors. It wasn't running water that did the work, it was acids dissolved in it; the carbonic acids, at first. Later -- after the most recent uplift caused natural gas to migrate from the oil and gas fields of the Delaware Basin up into the reef -- sulfuric acid formed in the water and dissolved the limestone, massively, like sun heat melting ice.
Water moves. Tubes widened where it punched upward from deep springs, scallops were eaten into walls by eddying flows, rooms more than two hundred feet across ballooned inside the body of the reef. The raw shapes of these solution caves are like the shapes of melting icebergs, inside out.
The caves formed as the Guadalupes rose. As the mountains pushed higher the water table dropped away, leaving damp caves full of air. Groundwater seeped through these, and, dripping or spurting, flowing, evaporating, leaving deposits behind, this solute-filled seepage made -- still makes -- what are known as "decorations."
This is only the first of many cave words that express an odd exuberance, though the people who discover caves and name their contents brave darkness and danger and get filthy, and may be excused for feeling awe. Perhaps a cave becomes an extension of one's own interior. As the deserts above stretch one skyward, the caves are a penetration to the core. Decorations may not be the wrong word. Most of them are old now, dry, finished, stained dun or reddish by dust and iron oxides. For all their fluid shape they have the look and feel of desert-varnished bone. They are what is known as "dead" -- and look it. Here and there a few are still "alive." Water drops hang from and over them like jewels, and the live decorations are cloaked in a calcite that sparkles like cold snow.
There are calcified siltstone cave rafts, and calcite stalagmites and stalactites that join in places to make columns. There are gypsum blocks, rinds, flowers, popcorn, hair, coral pipes; there are silklike travertine flowstones and delicate draperies of calcite and aragonite. Sometimes one finds aragonite moonmilk and frostlike anthodites, epsomite cotton and soda straws. Most caves hold spar crystals and sulfur crystals, lenses of chert, breccia, cobble gravel, red clay, graygreen clay, and pools (not many) of water. Helictites sprout from cave walls, twisted and knotted like stone string. On the ceilings are war shields formed by a spurting fissure, perfectly round, fringed with stalactite ermine tails and eagle feathers.
The shapes of these are wonderful, but not beautiful. They are an interior desert, a landscape of viscera. One has the sense down there of creeping through the gut of a large and sleeping animal.
Carlsbad Caverns has miles and miles of rooms, columns the size of houses, draperies like the contents of a hundred fabric emporiums unrolled and dipped in fluid marble. It's all too large, too deep, formed in too much silence and darkness, with the passage of too much time. I come out of the caves to the surface again like a diver gasping for air, for some familiar dimension.
Even the Carlsbad Cavern bats are out of scale. They are small lives multiplied into a mass composite phenomenon, like the reef itself. In the evening they coil out of the mountain like smoke and defy all description except in terms of numbers: there are more than 250,000 of them here. At a maximum rate of 5,000 bpm (bats per minute) it takes two hours for them to emerge for their nightly hunt. Bracken Cave, also in Texas, is summer home to twenty million bats; Carlsbad (in comparison) is village, suburb, a moderate dot on the bat map. Each bat weighs a half ounce, as much as three nickels, and lives ten years on the average -- though ages of fifteen to eighteen are not uncommon, and one has been known to survive to twenty-seven. They will feed for twelve hours -- from six P.M. to six A.M. -- logging 360 air miles in a single night. In that time they will fill their bellies with insects and empty them via guano a total of three times. They cruise at 25 to 35 mph, ranging up to 45 miles from their roost. They're known as Mexican free-tailed bats in part because their tails are longer than the flight membrane that stretches between their hind legs, and in part because they migrate six to eight hundred miles south, to Mexico, in the fall. They'll get to their winter homes in Mexico in two or three nights of flying time. They'll spend their summers as far north as South Dakota, Colorado, southern Oregon. In the East they'll summer as far north as Ohio, but for the most part they do their insect eating and baby-raising (one a year) across the southern tier. They've summered in this cave for seventeen thousand years. Their guano heaps are as much as fifty feet high, though one hundred thousand tons of the stuff was mined for fertilizer in the first two decades of the century. Guano composts to the color of warm sand, is as crumbly as stale cake, and odorless, except for the newest layer. Embedded in it are countless brown sticks like toothpicks or pine needles. These are bat bones.
Their cave entrance is in a hollow of the Guadalupe Mountains, and at dusk the bats swirl counterclockwise as they come, gaining airspeed and height, then they trail off across the orange face of the moon with a noise like leaves in a wind.
At dusk I build a campfire on a ridge. Dusk is long in the mountains, the moon brightens in a deepening sky. West Texas desert rolls out like a storm sea, the texture of silk; here and there hollows gleam white with gypsum and salt. Here and there are hogback ridges and punches of bluffs. One can see for a hundred shadowed miles. I sleep uneasily, traveling, as if I dreamed on the back of a dreaming animal.
I am moving by dawn. I find a canyon that is shady and narrow and walk in to a flittering tremolo of bird song. A pyrrhuloxia (can't think why such a medical-sounding name) sings from a treetop in musical chips; it looks like a northern cardinal but is gray, with a heavy yellow beak and red patches on its face, under its wings, at the tip of its topknot. It's as ripe-colored and mouthy as a parrot. A family of cactus wrens are ratcheting ruh ruh ruh ruh from the flank of the canyon, big loud speckled birds cocking an eye at me and rummaging noisily. There is a canyon profusion of plants: cholla, sotol, little-leaf sumac, catclaw acacia, algerita, juniper, Texas walnut. Not far along there is a spring, and a pool of water where fox sparrows are bathing, flipping droplets into the air. Near the pool is a room-sized shelf with a dome of roof blackened by smoke. There are spiral petroglyphs on the stones, clear as last week's doodles or graffiti.
Having spent days now living and thinking in deep time -- the millions of years it took the reef to grow, the millions of years ago it grew, the thousands of years' worth of seepage it took to form a stalagmite -- I think that my species -- Native American or non -- has a toehold here the width of a pencil.
Now the pool is a magnet for deer and peccary, according to the tracks, but it's also a magnet for other things. A brown towhee comes, two painted-lady butterflies, a monarch, and lots of wasps and bees that hunker on damp mud to suck their fill. I watch them gladly, happier than I've been in days. In the end this is where life is -- in single lives lived -- quirky and tenacious and individual; though this whole reef was like that, once. Corals, coralline algae, fish, shellfish; each one held territory, mated, ate, built, died, all that. Even in the bellies of the caves this was good to keep in mind, but it was difficult.
The canyon floor is a rumpus of white stones rounded by flash-floodwater, each one wearing the marks of its makers. Most look as if they were made of packed chalk marbles: the deposits of calcareous algae. Others show round starry shapes, like sections of bone: the remains of corals.
A coyote has left his dung on a stone, several times, as a marker. The dung is packed with green glittering insect wings, walnut hulls, bird feathers, seed hulls, rabbit hair. Sometimes his diet ran entirely to juniper berries.
A canyon wren hunts among the stones. A low pointed bird, very small, with a needly working end, a gray head, white bib and belly, a rusty tail streaked with pen lines of black, very elegant. She flirts her tail, bows, peers under stones, goes under stones and out the other side, goes on peering into every crevice and shadow, flitting, hopping, vanishing and appearing again, making little rusty squeaks. She is flirty, but calm.
The canyon keeps its cool through midday, though bulges of heat press in from the whitening land with the desert smell of hot stone, a smell spiked with juniper and herb. I stand frozen in the stones watching the canyon wren with wholly attentive delight. She comes toward me and cocks her head; she thinks this is an odd species of tree; she pokes her bill busily under the treads of my boots.
Sunset and Moonrise in the Guadalupe Mountains
Perhaps in the end what we call knowledge is only a kind of ritual, and naming and numbering have the values of a chant. Certainly my notebook has filled with this; details of geology, maps of time, intricate charts and lists. Perhaps these are ways to know the reef-that-is-now-mountain, perhaps they are only the preparation for knowing. There are other ways of knowing, too. Maybe I am learning to trust them.
After all, being is only the present instant, and I have learned to know harmony when it is here.