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Annals of the Former World

Page 31

by John McPhee


  Back on I-8o—and running now on a pitted outwash plain, now on a moraine—we crossed the St. Joseph River. Anita’s thoughts were still in Brooklyn. “My father died twenty years ago,” she said. “When he was a little boy, his mother told him that if he ever ate food with his yarmulke off he would be struck dead. When she wasn’t looking, he lifted his yarmulke and ate a spoonful of cereal. He didn’t die. He quit believing. His faith was shaken.”

  There was a gold dome on our left—like an egg resting in a bed of new green canopy leaves. It was the supreme roof of the University of Notre Dame. “They’re on outwash,” Anita said in passing, and returned to her reminiscences. “Religious prejudice in any form is despicable,” she went on. “In Brooklyn, when the Jehovah’s Witnesses tried to sell me The Watchtower I’d say, ‘I’m illiterate.’ If they persisted, I’d say, ‘Let me tell you about my God.’”

  Again the St. Joseph River intersected the highway, and we ran on through grass-covered roadcuts of a kame complex, and soon through others in a recessional moraine, locally called the Valparaiso Moraine. A road sign suggested the proximity of Valparaiso. “Where do they get a name like that in a lacklustre place like Indiana?” Anita said, and we swung out an exit for the Indiana Dunes.

  They are higher than the highest dunes of Cape Cod, and they are lined up in rows four deep along the shore of Lake Michigan—longitudinal dunes, transverse dunes, parabolic dunes. Glacial effects. On our map of Indiana, three of them were called mountains. They were covered with sand cherries, marram grass, cottonwoods, jack pines, junipers, and bluebells, except where the wind that made them had returned to them later to tear great blowouts in their sides. On foot, we approached the base of Mt. Tom. Staring upward, Anita said, “Look at the size of that son of a bitch.” We climbed to the summit—to a view that might have pleased Balboa, had he been fond of power plants. There was a power plant to our left, a power plant to our right—Gary, Michigan City. Chicago was a shimmer of structures up the lake. Chicago was underwater until two thousand years ago. The southern rim of Glacial Lake Chicago was the Valparaiso Moraine. As the lake level dropped, it left the makings of the Indiana Dunes. They are wind-built sands picked up from glacial till, so fresh that under a glass they are seen to be jagged. “It’s been ground up so recently it’s like the sand of Coney Island,” said Anita, looking at it through her hand lens. She held the lens to her eye and a palmful of sand close to the lens. “I see angular grains of red chert,” she said. “I see little fragments of igneous rock. I see amphibolite and red jasper—like the stuff that cut the grooves on Kelleys Island. I see red iron-oxide-coated quartz grains. You can see right through it to the quartz. I see little pieces of carbon. I see green chert. I see a bug crawling through the sand.”

  We sat in the lee of the top of Mt. Tom and watched whitecaps running on the lake. “As everybody knows, there are sand dunes in the Sahara,” Anita said. “As everybody does not know, there are also grooves in the Sahara like the ones on Kelleys Island. They were cut in the bedrock in the Ordovician, when the Sahara was in a polar position and the equator was in Montreal.”

  I asked how the Sahara had accomplished such a journey.

  “It is possible that the entire crust and some of the mantle can move around the interior earth—a sphere within a sphere,” she said. “You’ve got to change the position of the continental landmasses with respect to latitude through time. That I can’t deny.”

  “Do you believe that India smacked Asia?”

  “I don’t know. I know very little about the geology there, so how could I believe it? To many problems, plate tectonics is not the only solution. Often, it’s a lazy man’s out. It’s a way of saying, ‘I don’t have to think any further.’ It’s a way of getting out of a problem. The geology has refuted plate-tectonic interpretations time and again in the Appalachians. Geology often refutes plate tectonics. So the plate-tectonics boys tend to ignore data. The horror is the ignoring of basic facts, not bothering to be constrained by data. It’s like some modern art—done by people who throw paint at canvas and have never learned the fundamentals. Amateurs. Jumping into professionalism. Thinking they can get away with it. There are a lot of people out there in the profession like me who don’t believe much of it. But we can’t altogether complain. Plate tectonics has turned people on. It has brought a lot of new people into geology. You’ve always got to have devil’s advocates, and with respect to plate tectonics I am a devil’s advocate.”

  Book 3

  Rising from the Plains

  This is about high-country geology and a Rocky Mountain regional geologist. I raise that semaphore here at the start so no one will feel misled by an opening passage in which a slim young woman who is not in any sense a geologist steps down from a train in Rawlins, Wyoming, in order to go north by stagecoach into country that was still very much the Old West. She arrived in the autumn of 1905, when she was twenty-three. Her hair was so blond it looked white. In Massachusetts, a few months before, she had graduated from Wellesley College and had been awarded a Phi Beta Kappa key, which now hung from a chain around her neck. Her field was classical studies. In addition to her skills in Latin and Greek, she could handle a horse expertly, but never had she made a journey into a region as remote as the one that lay before her.

  Meanwhile, Rawlins surprised her: Rawlins, where shootings had once been so frequent that there seemed to be—as citizens put it—“a man for breakfast every morning”; Rawlins, halfway across a state that was spending per annum far more to kill wolves and coyotes than to support its nineteen-year-old university. She had expected a “backward” town, a “frontier” town, a street full of badmen like Big Nose George, the road agent, the plunderer of stagecoaches, who signed his hidden-treasure maps “B. N. George.” Instead, this October evening, she was met at the station by a lackey with a handcart, who wheeled her luggage to the Ferris Hotel. A bellboy took over, his chest a constellation of buttons. The place was three stories high, and cozy with steam heat. The lights were electric. There were lace curtains. What does it matter, she reflected, if the pitchers lack spouts?

  One spring day about three-quarters of a century later, a four-wheel-drive Bronco approached Rawlins from the east on Interstate 80. At the wheel was David Love, of the United States Geological Survey, supervisor of the Survey’s environmental branch in Laramie, and—to an extent unusual at the highest levels of the science—an autochthonous geologist. The term refers to rock that has not moved. Love was born in the center of Wyoming in 1913, and grew up on an isolated ranch, where he was educated mainly by his mother. To be sure, experience had come to him beyond the borders—a Yale Ph.D., explorations for oil in the southern Appalachians and the midcontinent—but his career had been accomplished almost wholly in his home terrain. For several decades now, he had been regarded by colleagues as one of the two or three most influential field geologists in the Survey, and, in recent time, inevitably, as “the grand old man of Rocky Mountain geology.” The grand old man had a full thatch of white hair, and crow’s feet around pale-blue eyes. He wore old gray boots with broken laces, brown canvas trousers, and a jacket made of horsehide. Between his hips was a brass belt buckle of the sort that suggests a conveyor. Ambiguously, it was scrolled with the word “LOVE.” On his head was a two-gallon Stetson, with a braided-horsehair band. He wore trifocals. There was stratigraphy even in his glasses.

  A remarkably broad geologist, he had worked on everything from geochemistry to structural geology, environmental geology to Pleistocene geology, stratigraphy to areal geology and mapping—and he had published extensively in all these fields. In the Bronco, he seemed confined—a restlessness that derived from a lifetime of travel on foot or horseback. He was taking me across Wyoming, at my request, looking at the rock in roadcuts of the interstate, which in seasons that followed would serve as portals for long digressions elsewhere in Wyoming in pursuit of the geologies the roadcuts represented. Once, in the Bighorn Basin, as we were rolling out our sleeping b
ags, I asked him what portion of the nights of his life he had spent out under the stars, and he answered, “One-third.” A few minutes later, half asleep, he added a correction: “Let’s say onequarter. I want to be careful not to exaggerate.” He rolled over and was gone for the night. I passed out more slowly, while my brain tumbled heavily with calculation. Love was about seventy, and this, I figured, was something like his six-thousandth night on the ground. Well, not precisely on the ground. One must be careful not to exaggerate. He’d had the same old U.S.G.S. air mattress for forty years. When it was quite new, it sprang a leak. He poured evaporated milk in through the valve and stopped the leak.

  Now, as we crossed the North Platte River and ran on toward Rawlins in May, over the road were veils of blowing snow. This was Wyoming, not some nice mild place like Baffin Island—Wyoming, a landlocked Spitsbergen—and gently, almost imperceptibly, we were climbing. The snow did not obscure the structure. We were running above—and, in the roadcuts, among—strata that were leaning toward us, strata that were influenced by the Rawlins Uplift, which could be regarded as a failed mountain range. The Medicine Bow Mountains and the Sierra Madre stood off to the south, and while they and other ranges were rising this one had tried, too, but had succeeded merely in warping the flat land. The tilt of the strata was steeper than the road. Therefore, as we moved from cut to cut we were descending in time, downsection, each successive layer stratigraphically lower and older than the one before. Had this been a May morning a hundred million years ago, in Cretaceous time, we would have been many fathoms underwater, in a broad arm of the sea, which covered the continental platform—reached across the North American craton, the Stable Interior Craton—from the Gulf of Mexico to the Arctic Ocean. The North Platte, scratching out the present landscape, had worked itself down into some dark shales that had been black muds in the organic richness of that epicratonic sea. The salt water rose and fell, spread and receded through time —in Love’s words, “advanced westward and then retreated, then advanced and retreated over and over again, leaving thick sequences of intertonguing sandstone and shale”—repeatedly exposing fresh coastal plains, and as surely flooding them once more. In what has become dry mountain country, vegetation flourished in coastal swamps. They would have been like the Florida Everglades, the peat fens of East Anglia, or borders of the Java Sea, which stand just as temporarily, and after they are flooded by a rising ocean may be buried under sand and mud, and reported to the future as coal. There were seams of coal in the roadcuts, under the layers of sandstone and shale. The Cretaceous swamps were particularly abundant in this part of Wyoming. A hundred million years later, the Union Pacific Railroad would choose this right-of-way so it could fuel itself with the coal.

  In cyclic rhythm with the other rock was limestone. Here and again, the highway was running on this soft impure limestone. It was sea-bottom lime, from dissolved or fragmented shells, which had lithified at least ten thousand feet lower than it is now. Woody asters were in bloom in the median, and blooming, too, by the side of the road, prospering on the lime. Love pointed them out with an edge in his voice. He said they were not Wyoming plants. They had come into Wyoming with trail herds of cattle and sheep, and later in trucks and railroad cars bringing hay from hundreds of miles to the south; and disastrously they had the ability—actually, a need—to draw selenium from the rock below. Selenium, which in concentration is toxic to people and animals, is given to the wind in some volcanic ash. A hundred million years ago, stratovolcanoes stood in Idaho, and they sent up ash that fell out eastward in the sea. The selenium went into the lime muds, and now these alien asters were drawing it out of the limestone and spreading the poison across the surface world, as few other plants can do. Most plants ignore selenium. Woody asters and a few others require selenium in order to germinate. After they take it up from the rock, they convert it into a form that nearly all plants will, in turn, take up, too. Selenium-contaminated plants are eaten by sheep and cattle, which are served to people as chops and burgers. Concentrated selenium destroys an enzyme that transmits messages from brain to muscles. “Cattle and sheep get the blind staggers,” Love went on. “People are also affected. They get dishrag heart. The liver is damaged, and the kidneys. Selenium causes sterility. Worse, it causes birth defects. It’s a cumulative poison, like lead or arsenic. It’s one of the ingredients of nerve gas.”

  He gestured left and right. “These were prize salt-sage flats for sheep-grazing once. They’re now poisoned and dangerous. A bad selenium area stinks like rotten garlic. On a warmer day, you could smell it. Fifty years ago, one of my first jobs was to look for selenium-converting plants up the Gros Ventre River. We camped there for a week, hunted for them day after day, and found a handful. Now, in the same place, they’re thicker than fleas on a dog. They can’t cross non-seleniferous barriers, except with the help of human beings. In the Rocky Mountains generally, millions of acres have been converted. People sometimes think neighbors have poisoned their pastures.”

  Ten miles beyond the North Platte, a flat-topped ridge formed the horizon before us—a tough sandstone, disintegrating at a lower rate than surrounding shale. The interstate, encountering this obstacle, had dealt with it with dynamite, opening up what highway engineers called a benched throughcut and geologists finding such a thing in nature call a wind gap. When we reached it, we stopped, got out, and put our noses on the outcrop, for this high multitiered exposure was Frontier sandstone, and Love referred to it as “a published roadcut,” studied to the last grain by paleontologists and stratigraphers. The reason for so much attention was not readily apparent in the gray and somewhat gloomy, sooty-looking rock, antiqued with fossil burrows. Nonetheless, it seemed to excite Love—as he picked at it with his hammer—at least as much as the woody asters had repelled him. The rock had been submarine sand, not far offshore. “Frontier is one of the great oil sands in the Rocky Mountain region,” he said. At five, ten, twenty thousand feet, wildcat after wildcat had found handsome pay in this celebrated host formation, and here it was at the surface, fresh, unweathered, presenting clues to its wealth. Because oil is vulnerable to destruction by increased heat—in the earth as in the engine of a car—the oldest oil that has been recovered in large quantity is probably Cretaceous in age (loosely speaking, about a hundred million years). For about one human life span, geologists have had the ability to discern where, in the subsurface, oil should be. A large percentage of all the oil on earth has been burned up in fifty years. Around 1975, the quantity being discovered had diminished to the level of the quantity being burned. Love remarked that half a billion barrels of oil had been found in the Frontier sandstone in one field alone. With reverence, I collected a wormy chunk.

  Less than a mile up the road, we stopped again—at a low, flaky roadcut of Mowry shale. Progressing thus across Wyoming with David Love struck me as being analogous to walking up and down outside a theatre in the company of David Garrick. The classic plays—Teton, Beartooth, Wind River—were not out here on the street, but meanwhile these roadcuts were like posters, advertising the dramatic events, suggesting their narratives, fabrics, and structures. This Mowry shale had been organic mud of the Cretaceous seafloor, wherein the oil of the Frontier could have formed. It was a shale so black it all but smelled of low tide. In it, like mica, were millions of fish scales. It was interlayered with bentonite, which is a rock so soft it is actually plastic—pliable and porous, color of cream, sometimes the color of chocolate. Bentonite is volcanic tuff—decomposed, devitrified. So much volcanic debris has settled on Wyoming that bentonite is widespread and, in many places, more than ten feet thick. To some extent, it covers every basin. Also known as mineral soap, it has a magical ability to adsorb water up to fifteen times its own volume, and when this happens it offers to a tire about as much resistance as soft butter. Wet, swollen bentonite soil is known as gumbo. We were crossing badlands of the Bighorn Basin one time when a light shower fell, and the surface of the road changed in moments from dust to colloidal
suspension. The wheels began to skid as if they were climbing ice. Four-wheel drive was no help. Many a geologist has walked out forty miles from a vehicle shipwrecked in gumbo. Bentonite is mined in Wyoming and sold to the rest of the world. Blessed is the land that can sell its mud. Bentonite is used in adhesives, automobile polish, detergent, and paint. It is in the drilling “mud” of oil rigs, sent down the pipe and through apertures in the bit to carry rock chips to the surface. It sticks to the walls of the drill hole and keeps out unwanted water. It is used to line irrigation ditches and reservoirs, and in facial makeup. Indians drove buffalo into swamps full of bentonite. It is an ingredient of insecticides, insect repellents, and toothpaste. It is used to clarify beer.

  If Love had ever tried bentonite to repair his air mattress, he did not mention it. He did remark that when there was rain in the Wind River Basin on the ranch where he grew up—an event that happened about as often as a birthday—wagons were stopped in their tracks. Much of Wyoming’s bentonite is Cretaceous in age and consistent in composition. Since it lies on every side of the mountain ranges, it seems not so much to imply as to certify that when it was so broadly deposited the mountains were not there. The Cretaceous is not far back in the history of the world. It’s in the last three per cent of time.

  Love walked back to the Bronco with a look on his face that suggested a man who had long since had his last beer. He said he was hungry. He said, “My belly thinks my throat’s been cut.” Over the next rise was Rawlins, spread across the Union Pacific.

 

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