Annals of the Former World

by John McPhee

  We walked back down to the mine, below which the stream—in flash flood once or twice a century over several million years—had cut the deep sharp V of its remarkably plunging valley. A number of acres of one side had been used as a dump, and Deffeyes began to sample this unused ore. “They must have depended on what they could see in the rock,” he said. “If it was easy to see, they got it all. If it was complicated and gradational, they couldn’t differentiate as well, and I think they threw it here.” The material was crumbly, loose, weathered, unstable underfoot, a pyramid side of decomposing shards. Filling small canvas bags at intervals of six feet, he worked his way across it. With each step, he sank in above his ankles. He was about two hundred feet above the stream. Given the steepness of the ground and the proximity of all the loose material to the critical angle of repose, I had no trouble imagining that he was about to avalanche, and that he would end up in an algal pool of the trickling stream below us, buried under megatons of unextracted silver. The little stream was a jumble of boulders, testimony of the floods, with phreatophytes around the boulders like implanted spears. Deffeyes obviously was happy and without a fear in the world. When a swift-rising wind blew dust in his face, he mooed. Working in cold sunshine with his orange-and-black conical cap on his head, he appeared to be the Gnome of Princeton, with evident ambition to escalate to Zurich.

  To make a recovery operation worthwhile, he said, he would have to get five ounces of silver per ton. The figures would turn out to be better than that. Before long, he would have a little plastic-lined pond of weak cyanide, looked after by a couple of technicians, down where the ore from this mine had been milled. A blue streak in the tailings there would come in at fifty-eight ounces a ton—richer than any tailings he had ever found in Nevada. “You put cyanide on that ore, the silver leaps out of it,” he would say. “I have enough cyanide there to kill Cincinnati. People have a love-hate relationship with cyanide. Abelson showed that lightning acts on carbon dioxide and other atmospheric components to make hydrogen cyanide, and hydrogen cyanide polymerizes and later reacts with water to form amino acids, which are the components of proteins—and that may be how life began. Phil Abelson is an editor at Science. He’s a geochemist, and he worked on the Manhattan Project. To get the silver out of here at an acceptable price, you need small-scale technology. You need miniaturized equipment, simple techniques. In the nineteenth century, they made sagebrush fires to heat the brine to dissolve the silver chloride. When mercury picked up the silver, they knew they had ‘the real stuff’ from the squeak. A mercury-and-silver mixture is what the dentist uses, and when he mashes it into your tooth it makes the same squeak.”

  Deffeyes’ methodology would depend on more than sagebrush and sound. In time, he would have a portable laboratory there, size of a two-hole privy, and in it would be, among other things, a silver single-ion electrode and an atomic-absorption spectrophotometer. He could turn on a flame, close two switches, and see at once the amount of silver in a sample. For a short while, he would have a five-pound ingot of raw silver on the floor, propping open the door. When he was finished with his pond, he would withdraw the cyanide and turn it into a marketable compound known as Prussian blue. He would cover his pond with dirt and sow it with crested wheat.

  And now, finishing up his sampling at the mine in the mountains, he filled a large burlap bag with ore he would take home to improve his technique of extraction. The smaller samples he had taken were for assays of silver in various parts of the slope. “I’m nothing but a ragpicker,” he said. “A scavenger armed with a forty-thousand-dollar X-ray machine.” The wind picked up another cloud of dust off the dump and blew it into his face. He mooed. “That may feel like dirt to you, but it feels like money to me,” he said.

  “How much money would you say that felt like?” I asked him.

  He took out a Magic Marker and began to do metric conversions, geometry, and arithmetic on the side of a new canvas bag. “Well, this section of the dump is at least fifteen thousand cubic metres,” he said. “That is the most conservative figure. At two hundred dollars a ton, that works out to about three million dollars, left here in the side of the hill.”

  “What are those red stakes up there?”

  “Somebody seems to think they’re finding new ore. I’m interested in the old stuff, down here.”

  “If you’ve got good silver in those bags, what about Eocene? What if they decide they still own you? What if they go to the sheriff?”

  “Eocene doesn’t own me, and Eocene doesn’t own the contents of my head. The law has long since decided that. But if anybody comes after me I want you to go to jail cheerfully rather than surrender your notes.”

  As we wound down the mountain at the end of the day, we stopped to regard the silent valley—the seventy miles of basin under a rouge sky, the circumvallate mountains, and, the better part of a hundred miles away, Sonoma Peak, of the Sonoma Range. Deffeyes said, “If you reduced the earth to the size of a baseball, you couldn’t feel that mountain. With a telephoto lens, you could convince someone it was Everest.” Even at this altitude, the air was scented powerfully with sage. There was coyote scat at our feet. In the dark, we drove back the way we had come, over the painted cattle guards and past jackrabbits dancing in the road, pitch-dark, and suddenly a Black Angus was there, standing broadside, middle of the road. With a scream of brakes, we stopped. The animal stood still, thinking, its eyes unmoving—a wall of beef. We moved slowly after that, and even more slowly when a white sphere materialized on our right in the moonless sky. It expanded some, like a cloud. Its light became so bright that we stopped finally and got out and looked up in awe. A smaller object, also spherical, moved out from within the large one, possibly from behind it. There was a Saturn-like ring around the smaller sphere. It moved here and there beside the large one for a few minutes and then went back inside. The story would be all over the papers the following day. The Nevada State journal would describe a “Mysterious Ball of Light” that had been reported by various people at least a hundred miles in every direction from the place where we had been. “By this time we decided to get the hell out of there,” a couple of hunters reported, “and hopped in our pickup and took off. As we looked back at it, we saw a smaller craft come out of the right lower corner. This smaller craft had a dome in the middle of it and two wings on either side, but the whole thing was oval-shaped.” Someone else had said, “I thought it was an optical illusion at first, but it just kept coming closer and closer so that I could see it wasn’t an illusion. Then something started coming out of the side of it. It looked like a star, and then a ring formed around it. A kind of ring like you’d see around Saturn. It didn’t make any noises, and then it vanished.”

  “Now we’re both believers,” said one of the hunters. “And I don’t ever want to see another one. We’re pretty good-sized men and ain’t scared of nothing except for snakes and now flying saucers.”

  After the small sphere disappeared, the large one rapidly faded and also disappeared. Deffeyes and I were left on the roadside among the starlighted eyes of dark and motionless cattle. “Copernicus took the world out of the center of the universe,” he said. “Hutton took us out of a special place somewhere near the beginning of things and left us awash in the middle of the immensity of time. An extraterrestrial civilization could show us where we are with regard to the creation of life.”

  We also went to Jersey Valley, between the Fish Creek Mountains and the Tobin Range, where Deffeyes had once spent a couple of field seasons collecting data for his doctoral thesis. He had lived in a tent in the oven weather, and had chugalugged water in quart draughts while examining the rising mountains and the sediments the mountains had shed. The thick welded tuff of the Oligocene catastrophe, having been the regional surface when the faulting started, was the first material to break into grains that washed and rolled downhill. When erosion wore through the tuff and into the older rock below, it sent the older rock also in fragments to the basins. Reading up thro
ugh a basin was like reading down through a range. Deffeyes had locally described this record, and now he wished to relate its timing to the development of the province as a whole. Forty miles off the interstate and with a lot of dust settling behind, he paused on the brow of a small hill at the head of Jersey Valley. It was intimate, compared with others in the Basin and Range. For perhaps twenty miles, it ran on south between snowcovered mountains and was filled with a delirium of sage. Deffeyes let out a cowboy yell. There were cinder cones standing in the valley, young and basaltic—enormous black anthills of the Pleistocene. Here and there was a minor butte, an erosional remnant, kept intact by sandstone at the top, but approaching complete disintegration, and, like a melting sugar lump, soon to be absorbed into the basin plain. “In a lot of valleys in Nevada all you will see is sagebrush, and not know that eight feet below you is a hell of an interesting story,” Deffeyes said. “I found late-Miocene horse teeth over there in the Tobin Range.”

  “How did you know they were late Miocene?”

  “I didn’t. I sent them to a horse-teeth expert. I also found beaver teeth, fish, a camel skeleton, and the jaw of a rhinoceros not so far from here. The jaw was late Miocene, too. Early- and middle-Miocene fossils are absent from the province. You’ll remember that wherever we have found fossils in the basin sediments the oldest have been late Miocene. So, if the vertebrate paleontologists have their heads screwed on right, the beginning of the faulting of the Basin and Range can be dated to the late Miocene. Vertebrate paleontology is an important old sport, like tossing the caber.”

  We left the dirt road and drove a mile or so up a pair of ruts, then continued on foot across a rough cobbly slope. We went down into a dry gulch, climbed out of it, and walked along the contour of another slope. These declivities were not discrete hills but fragments of great alluvial fans that were spilling off the mountains and were creased by streams that were as dry as cracks in leather. In their intermittent way, these streams had exposed successive layers of sediment, all of which happened to be dark in hue, with the pronounced exception of light-gray layers of ash. The ash was from elsewhere, from outside the province, punctuation brought in on the wind. It had come from volcanoes standing, probably, in what is now the Snake River Plain, two hundred miles away. Settling into the basin lakes—long-gone Miocene, Pliocene lakes—much of it had turned into zeolites. Among the zeolites, Deffeyes had found in Jersey Valley three million tons of a variety called erionite, which is named for wool, and is fibrous, and when it gets into the linings of human lungs causes mesothelioma. There are more millions of tons of erionite throughout the Basin and Range, passively causing nothing. But if twenty-five valleys of the province were to be filled up with forty-six hundred concrete shelters for MX missiles, as the Defense Department had proposed, wind would present extraordinary hazards during the process of construction. It would be difficult to overestimate the amount of fine material that can be borne long distances by the wind. The largest single layer of ash that Deffeyes found in Jersey Valley was ten feet thick. He once showed it to Howel Williams, of the University of California at Berkeley, whom he regarded as “the greatest of volcanologists.” Deffeyes asked Williams what might have been the size of a volcano that from two hundred miles away could send out such an explosion of ash. Williams just stood there impressed, shaking his head.

  On a shelf above us was a pile of sticks of a size that in moister country could well have been collected by a beaver. “Hawk,” Deffeyes said. “Note the southern exposure. The hawk went solar long ago. The sun incubates the eggs and the hawk is free to soar.” Running his eye over the sequence of sediments revealed in the slope before us, he decided to begin his work right there. He was carrying in his hand a device of his own invention with which he hoped to accomplish the delicate operation of removing paleomagnetic samples from unconsolidated lake sediments. Less delicately, he had equipped me with a military shovel. He asked me to go along the slope digging foxholes a couple of feet deep in order to get rid of the weathered surface and prepare the way for him. As the mountains had given up grains and the grains had come down into the basin, any that had magnetite in them would have settled in a uniform manner, pointing like compasses toward the earth’s magnetic pole. Since the late Miocene, the earth’s magnetic field had reversed itself twenty times—from north to south, from south back to north —and the dates of those reversals had by now become well established. If Deffeyes could somehow collect unconsolidated but firmly compacted sediment and keep it from falling apart and destroying its own evidence while he carried it to a paleomagnetic lab, he might be able to compare what he already knew from his vertebrate time scale—his expertized horse teeth, his rhinoceros jaw—with the paleomagnetic time scale as expressed by the magnetite in the successive basin sediments. He would thus improve his knowledge of what occurred when—in this basin, this range. Later, he could correlate the ash falls and other stratigraphy of Jersey Valley with other valleys in the region, and make clearer the story of how it all took shape, adding polish to chapters of the Basin and Range. And so he had invented and machined a corer that would tap clear-plastic tubing gingerly into the earth with a micropiledriver made of non-magnetic aluminum. As I began the crude initial digging, Deffeyes said, “There are ten thousand feet of sediment here, and all of it has been deposited in eight million years. I have high hopes for the success of these endeavors. For each sample, I would prefer to go twenty feet into the slope instead of two. I would like to have a bulldozer as a substitute for you. But one has to settle for what one can get.”

  The first time I put my foot to the ground, the shovel broke in half. It was decapitated. After that, I had to hold its head in my hands and scrape as with an awkward trowel.

  “There’s more to this paleomagnetism game than reversals,” Deffeyes said, “more than just determining when, and whether, the magnetic pole was in the north or south. The earth’s magnetic field is such that a compass needle at the equator will lie flat, while a compass needle at the poles will want to stand straight up on end —with all possible gradations of that in the latitudes between. So by looking at the paleomagnetic compasses in rock you can tell not only whether the magnetic pole was in the north or south when the rock formed but also—from the more subtle positions of the needles—the latitude of the rock at the time it formed.”

  On the striated pavement of Algeria lies the till of polar glaciers. There are tropical atolls in Canada, tropical limestones in Siberia, tropical limestones in Antarctica. From fossils, from climates preserved in stone, such facts were known long before paleomagnetism was discovered; but they were, to say the least, imperfectly understood. Paleomagnetism, first perceived in 1906, eventually confirmed what the paleoclimatologists and paleontologists had been saying about the latitudes of origins of rocks, but it did not resolve the mystery of the phenomenon, because there seemed to be two equally reasonable explanations. Either the rock had moved (and continents with it) or the whole earth had rolled, like a child’s top slowly turning on its side, and the poles and equator had wandered. Either the equator had gone to Minnesota or Minnesota had gone to the equator.

  As early as the sixteenth century, the specific movements of the earth’s surface that eventually became known as continental drift and plate tectonics had been hypothesized. The Flemish geographer Abraham Ortelius, in the third edition of his Thesaurus Geographicus (Antwerp, 1596), postulated that the American continents were “torn away from Europe and Africa” by earthquakes and other catastrophic events. “The vestiges of the rupture reveal themselves,” he continued, “if someone brings forward a map of the world and considers carefully the … projecting parts of Europe and Africa … along with the recesses of America.” In centuries that followed, various writers called attention to the suggestive shapes of landmasses, but almost no one else imagined that the landmasses had been driven apart, let alone by what mechanism. In 1838, the Scottish philosopher Thomas Dick, of County Angus, published his Celestial Scenery; or, the Wonde
rs of the Planetary System Displayed: Illustrating the Perfections of Deity and a Plurality of Worlds, in which he noted how neatly western Africa could lock itself tight around the horn of Brazil, “and Nova Scotia and Newfoundland would block up a portion of the Bay of Biscay and the English Channel, while Great Britain and Ireland would block up the entrance to Davis’s Straits.” Such an assembly would “form one compact continent.” And “a consideration of these circumstances renders it not altogether improbable that these continents were originally conjoined, and that, at some former physical revolution or catastrophe, they may have been rent asunder by some tremendous power, when the waters of the ocean rushed in between them, and left them separated as we now behold them.” I am indebted to Alan Goodacre, of the Geological Survey of Canada, for this high-assay nugget, and to James Romm, of Bard College, for the quotations from Ortelius, which they separately reported in the British journal Nature in 1991 and 1994, backdating by three centuries the continental-drift hypothesis attributed in textbooks to the meteorologist Alfred Wegener, of Graz in the Styrian Alps. Ortelius and Dick fared better than Wegener, for while their propositions achieved no significant attention, Wegener’s won a considerable fame that rapidly decayed into notoriety.

  In an address to the German Geological Association in 1912, and three years later in his essay Die Enstehung der Kontinente und Ozeane, Wegener based his concept not only on the jigsaw fit of Africa and the Americas but also on the likeness of certain rocks on the two sides of the ocean, and on comparisons of living and fossil creatures. He knew nothing of paleomagnetism, which was in its infancy and was many years away from yielding insight to the problem, but he was the promulgator of the hypothesis of continental drift. Unfortunately, he attempted to explain how the continents moved. He envisioned them plowing like icebreakers through solid basalt. Almost no one believed his hypothesis, any more than Benjamin Franklin had been believed when, in 1782, possibly after a visit to Edinburgh, he said he thought that the surface parts of the earth were floating about on a liquid interior. Wegener had received fame as a record-setting balloonist, an Arctic explorer, and now he was making an assertion for which his name would live in mockery for about fifty years. In life and in death, he was a target of scorn. His idea provoked gibes, jeers, sneers, derision, raillery, burlesque, mockery, irony, satire, and sarcasm, but it could not be ignored. In 1928, the American Association of Petroleum Geologists published a symposium on continental drift. It included a paper called “Some of the Objections to Wegener’s Theory,” by Rollin T. Chamberlin, of the University of Chicago, who expressed what was then the prevailing attitude among geologists and would continue to be until the nineteen-seventies, after which it would cease to prevail but not to survive: