by John McPhee
We stopped and tried to collect some but had difficulty finding a sample that would not break up in the hand. “This is very flaky, high-ash coal,” Anita said. “People take it anyway. They come out to these roadcuts with buckets and take it home to burn.”
We moved on through miles of coal-streaked roadcuts, and topographically to somewhat higher ground, where the coal seams were thicker. “As you go westward and upsection, you get more coal, because the rivers, growing older, became more sluggish,” Anita said. “The floodplains became broader. There was more ponded water. There was more area for vegetation to grow and accumulate—like the lower Mississippi Valley today.” About five miles east of Clearfield, we stopped at a long, high throughcut full of coal. Draglines were working on both sides of the road. We chipped out some samples with rock hammers. The samples had integrity. “This is a hell of a coal,” Anita remarked. “Good commercial coal. To make it, there would have been about three thousand feet of Pennsylvanian stuff on top of it, which has been removed by erosion. Three thousand feet is the amount of overburden that will produce coal of this rank.”
Stirred within by all these free B.t.u.s (twelve thousand per pound), I flailed at the cut with my rock hammer and filled a bag with good commercial coal, to take home and burn in my stove. Anita commented that coal dust was blacking my face.
I wiped at it with a bandanna, and asked her, “Did I get it all?”
She said, “Good enough for government work.” And we headed up the road.
When the final great pulse of mountain building folded eastern Pennsylvania, the deep burial and tectonic crush may have done wonders for the coal seams there, but all the oil in the country rock was burned black and destroyed. Conodonts were blackened, too. As Anita’s many samplings would prove, conodonts become lighter in color and hue in a westward trend across the state—from black to cordovan to dusky orange to brightening levels of yellow. Running west of Du Bois and Clarion now, and less than fifty miles from Ohio, we were out of the browns and well into the gold. If the quality of coal improves eastward, the theoretical quality of petroleum goes the other way. We took a right off the interstate. Soon we were cruising on Petroleum Street, in downtown Oil City.
We continued north. In the fifteen miles between Oil City and Titusville lay the Napa Valley of early American oil. It was a V-shaped, intimate valley, five hundred feet from rim to river, and along its floor were oil refineries so small they were almost cute. They did not suggest the starry lighted skeletal cities of Exxon’s Baton Rouge Refinery or Sunoco’s Marcus Hook. They suggested Christian Brothers, the Beringer Winery, the Beaulieu Vineyard. One refinery followed another. Wolfs Head, Pennzoil. They stood beside Oil Creek, which was so named in the eighteenth century because petroleum dripped out of its banks and into the water. Indians had found it, three centuries before, to judge by the age of trees that were growing in pits they had dug to collect the oil in pools. The Senecas rubbed their skins with it. They may have used it for light and heat. The use of petroleum is old in the world. Workmen laid asphalt three thousand years before Jesus Christ. The first energy crisis involving petroleum was in 1875 B.C. The first oil spills were natural, and were not so large that they could not be cleaned up by bacteria that feed on oil. In 1853, in California, a lieutenant in the Corps of Engineers reported that “the channel between Santa Barbara and the islands is sometimes covered with a film of mineral oil, giving to the surface the beautiful prismatic hues that are produced when oil is poured on water.” Always, it was found in seeps. Even until a few years after the Second World War, all Iranian oil fields were associated with surface seeps. The first well in Texas—1865—was drilled near a seep. A well in Ontario had been drilled six years earlier, and in the same summer the first commercial oil well in the United States was drilled in Pennsylvania by Colonel Edwin Drake—less than a hundred steps from Oil Creek.
Colonel Drake had no record of military service. He was a sick railroad conductor—forty years old but debilitated, too fragile to remain upright in the lurching aisles of the New York & New Haven. To the Pennsylvania Rock Oil Company of Connecticut, which had bought farmland and timberland along Oil Creek, he had committed his life savings. Drake was not a geologist. He did not know that petroleum is primarily the remains of marine algae that pile up dead on the floors of shallow seas in situations that prevent oxidation. He did not know that the algal corpses slowly stew for millions of years at temperatures just high enough to crack them into crude. He did not know that oil forms in one kind of rock and moves into another—forms in, say, the lagoonal muds of epicontinental seas, and moves later into the sandstones that were once the barrier beaches between the lagoons and the open sea. He did not know that Oil Creek had cut down through Pennsylvanian and Mississippian formations and on into a Devonian coast. Drake knew none of this in 1859, and neither did the science of geology. What Drake did know was that there was negotiability in the stuff that was dripping into Oil Creek. It was even used as medicine. Fleets of red wagons had been all over eastern America selling seepage as a health-enhancing drink. “Kier’s Genuine Petroleum! Or Rock Oil! A natural remedy … possessing wonderful curative powers in diseases of the Chest, Windpipe and Lungs, also for the care of Diarrhea, Cholera, Piles, Rheumatism, Gout, Asthma, Bronchitis, Scrofula, or King’s Evil; Burns and Scalds, Neuralgia, Tetter, Ringworm, obstinate eruptions of the skin, Blotches and Pimples on the face, biles, deafness, chronic sore eyes, erysipelas …” Drake had, in addition, the encouragement of a Yale professor of chemistry who ran a bottle of the seepage through his lab and said, “It appears to me … that your company have in their possession a raw material from which, by simple and not expensive process, they may manufacture very valuable products. It is worthy of note that my experiments prove that nearly the whole of the raw product may be manufactured without waste.” And what Drake had, above all, was the inspiration to go after the substance in its reservoir rock, not to be content to blot it up from the streambanks but to drill for it, never mind that he was making a fool of himself in the eyes of the local rubes. He would punch their tickets later. At sixty-nine and a half feet, he completed his discovery well.
There was an oil rush to Oil Creek, and frontier conditions in shantytowns, and forests of derricks on denuded hills. There was a town called Red Hot, Pennsylvania. There was Petroleum Centre. Pithole City. Babylon. In three months, the population of Pithole City went from nobody to fifteen thousand. River flatboats carried the oil to market. Their holds were divided into compartments, much as the holds of supertankers are divided now. Millers in the valley were paid royalties to release water on cue from millponds, raising the level of the creek to float the flatboats downstream. They sometimes broke and spilled.
The Dramatic Oil Company was established in the valley by John Wilkes Booth, who ruined his well trying to make it more productive. With failure, he departed, in the fall of 1864, to look for other things to do.
I am indebted for many of these facts to Ernest C. Miller, of the West Penn Oil Company, who collected them for the Pennsylvania Historical and Museum Commission.
By 1871, oil was being pumped from the ground in nine countries, but ninety-one per cent of world production still came from Pennsylvania. When it was distilled into its components—paraffin, kerosene, and so forth—the gasoline, which in those days had no commercial value, was poured off into the ground.
Petroleum is rare because it represents an extremely low percentage of the life that has lived on earth. In rock, the ratio of all organic carbon to petroleum carbon is eleven thousand to one. For petroleum carbon to turn into oil and be preserved, many conditions have to align, the most important of which is the thermal history of the source rock—the temperature through time as recorded by, among other things, the colors of conodonts. “The petroleum in this valley makes some of the best lubricating oil in the world,” Anita said. “It is a very low-specific-gravity oil and needs little refining, because it has been refined to near-perfection by natur
al earth processes. It has been at low temperatures—around a hundred degrees Celsius—for maybe two hundred million years. You can practically take it out of the ground and put it in your car.”
For a hundred and fifty miles, we had been traversing country that was free of glacial drift. Nowhere to be seen were the tills and erratics, the drumlins and kames left behind by Wisconsinan ice. Like a lifted hem, the line of maximum advance had been up in New York State somewhere, but now, in westernmost Pennsylvania, the glacial front had billowed south, and where Interstate 80 meets the eightieth meridian we again crossed the terminal moraine. Sign of the ice was everywhere—the alien boulders in the woods, the directional scratches on the country rock, the unsorted gravels, cobbles, and sands. The signature of glaciation is as bold as John Hancock’s and as consistently recognizable wherever ice has moved across the solid earth. In the presence of the evidence, one has no difficulty imagining the arctic ambience, the high blue-white ice lobes thickening to the north, the white surface wide as the continent and swept by uninterrupted gales, the view in sunlight blinding, relieved only by isolated mountain summits, ice moving around them in the way that water slides past boulders in a stream.
Welcome to Ohio. A sign in the median said “STAY AWAKE! STAY ALIVE!” Ohio is not rich in roadcuts. It is a little less poor, however, than Indiana, Illinois, Iowa, and Nebraska, and before long we were running through burrowed marine shales and walls of lithified river sand. It was rippled Carboniferous sandstone. We were still in rock of that age, but gradually and imperceptibly we had been losing altitude since we climbed the Allegheny front. The eastern rim of the plateau had been more than two thousand feet above sea level, and by now we were down to half that, as we moved farther away from the ancestral mountains and their wedge of sediment thinned.
We had come into the continent’s province of supreme tectonic calm, the Stable Interior Craton, where a thin veneer of sediment lies flat upon the stolid fundament, where the geology—even by geological standards—is exceptionally slow. “This is the most conservative part of the U.S.,” Anita said. “I’ve often thought about it. The wildest, craziest people are in the most tectonically active places.”
And yet the craton stirs. There is no part of the face of the earth that vertically and laterally does not move. The bedding planes in Midwestern rock, which appear to be absolutely level, do in fact dip. They will descend across a great many miles and then rise, arching over the far rim of a vast and shallow bowl, and then subtly dip again to form a similar bowl: the Findlay Arch, the Michigan Basin, the Kankakee Arch, the Illinois Basin. Anita called the arches “basement highs.” She said Hudson Bay is a continental basin, slowly filling up. The basins of the Midwest are filled to the brim with level ground. They are products of the creaking motions of the craton, in response perhaps to plays of force from deep within the mantle—a process that, in the general phrase, is “not well understood.” They represent a degree of tectonic activity about as lively as the setting in of rigor mortis. This has not always been the regional story. There are roots of long-gone mountains deep in the rock of the stable craton, but it has not had an orogeny in a thousand million years. “What has the Midwest been doing since then? It’s been sitting around doing nothing,” Anita said. “It has just sat here hohumming.” Shallow seas may have quietly arrived and departed, and coal beds formed in the ground, but in all that time there has been no occurrence that can begin to rival in scope or total change the advent from the north of walls of marching ice.
The ice was Antarctic in breadth. The traceable episodes of recent continental glaciation have each placed about as much ice over North America as is upon Antarctica now. In Wisconsinan time, which lasted about seventy-five thousand years and ended ten thousand years ago, three-fifths of all the ice in the world was on North America, another fifth covered much of Europe, and the rest was scattered. Of all special fields within the science, glacial geology is the most evident, the least inferred. It is, for one thing, contemporary. The ice is in recess but has not gone away. In addition to the ice of Antarctica, there is ice more than two miles thick over Greenland. There are twenty-seven thousand square miles of ice on Alaska (four per cent of Alaska). In Alaska, as in Switzerland and elsewhere in the world, you can see cirque glaciers feeding into the master glaciers of alpine valleys. You can see that the cirque glaciers have dug scallops into the high ridges, and where three or four cirque glaciers have been arranged like petals they have torn away the rock until all that remains is a slender horn—the Kitzsteinhorn, the Finsteraarhorn, the Matterhorn. Not only are ice sheets, ice fields, and individual glaciers operating today with effects observable as motions occur, but wherever they once flowed their products remain in abundance and intact. They have come and gone so recently.
The evidence may seem obvious now, but not until the eighteen-thirties did anyone comprehend its significance. There had been insights, hints, and clues. James Hutton, the figure from the Scottish Enlightenment who by himself developed the novel view of the world on which modern geology rests, mentioned in his Theory of the Earth (1795) that the gravels and boulders of Switzerland’s great valley appeared to have been put there by ancient extensions of alpine ice. But Hutton, who formed his theory among the scratched granites and drifted gravels of Scotland, never suspected that Scotland itself had been a hundred per cent covered—actually dunked into the mantle—by ten thousand feet of ice.
In 1815, in the Swiss Val de Bagnes, below the Pennine Alps, a mountaineer remarked to a geologist that all those big boulders standing around in odd places had been carried there by a glacier long since gone. The mountaineer’s name was Perraudin. He was a hunter of chamois. The geologist was Jean de Charpentier. He did not believe the hunter and ignored the information. In Europe, Noah’s Flood had for so long been regarded as the principal sculptor of the earth that almost no one was inclined to hazard an alternative interpretation. If boulders were out of touch with bedrock of their type, diluvian torrents had moved them, or flows of diluvian mud. In 1821, a Swiss bridge-and-highway engineer named Ignace Venetz told the Helvetic Society of Natural Sciences that he believed what the mountaineer had told Charpentier. He believed, in addition, that boulders had been scattered all over Switzerland by glaciers of “hauteur gigantesque” from “une époque qui se perd dans les nuits des temps.” Venetz was ignored, too—until Charpentier decided, twelve years later, that his suppositions were probably correct. Charpentier caused Venetz’s paper to be published and meanwhile went out to gather, name, and classify evidence of moving ice: erratic boulders, striations and polish on bedrock, lateral and terminal moraines. In 1834, he submitted to the Helvetic Society his “Notice sur la Cause Probable du Transport des Blocs Erratiques de la Suisse,” which was also ignored, not to say ridiculed.
Charpentier was political in the scientific world. Great “savants” like Leopold von Buch and Alexander von Humboldt had been classmates of his at the Freiberg Mining Academy. He lived above Lake Geneva in the alpine valley of the Rhone. Savants collected in numbers at his table. In the summer of 1836, Jean Louis Rodolphe Agassiz, a professor of natural history at the College of Neuchatel, took a house up the road. Agassiz was only twenty-nine years old, but he had done work in paleontology for which he had earned a considerable reputation. He had travelled, too. He had become a protégé of von Humboldt. He had worked in Paris for Georges Cuvier. And like von Humboldt, von Buch—like everybody else who had heard about the theory of the ice—he thought it absurd.
When von Humboldt went on field trips to look at rocks, he wore a top hat, a white cravat, and a black double-breasted frock coat that reached to his knees. He was imitated by, among others, Cuvier and von Buch. Agassiz was less formal, but in no particular did he resemble a scuffed-booted, blue-jeaned, twentieth-century field geologist when he set out with Charpentier to stroll through the valley of the upper Rhone. What Agassiz saw forever altered his life, as ice had altered the valley. When he left, he had no remaining doubt of the
truth of what Perraudin, Venetz, and Charpentier believed. Wandering the Swiss countryside low and high, he found further evidence everywhere he went—grooved rock, polished rock, moraines where ice had long been gone, boulders rounded off and set where water never could have shoved them. He visited similar landscapes in enough places to spread far in his imagination the contiguity they implied, and in one spark of intuition he saw the ice covering more than the valley, the canton, the nation. The idea of continental glaciation fell into place—a stunning moment of realization that ice many thousands of feet thick had been contiguous from Ireland to Russia. When the Helvetic Society met in Neuchatel in the summer of 1837, Louis Agassiz—as its president-elect—addressed the savants. Instead of reading an expected discourse in paleontology, he outlined at great length the evidence and chronology of glacial history as he had come to see it, announcing to the Society and to the world at large what would before long be known as the Ice Age.
He called it the Epoque Glaciaire. By any name, at home or abroad, it did not overwhelm his colleagues. He was attacked far more than defended. Von Buch literally threw up his hands, and not without the perspectives of the future partly on his side, for Agassiz—like the “plate-tectonics boys,” as seen by Anita Harris—had not known where to stop. His remarks had gone beyond his reconstruction from observable phenomena of a cover of ice across the whole of northern Europe: he had concluded that the newborn Alps, rising under the ice, had caused it to break up.
Agassiz’s friend and mentor Alexander von Humboldt, whose name reposes in the western Americas in the Humboldt Current, the Humboldt River, and the Humboldt Range, strongly urged Agassiz to go back to cataloguing fossil fishes, the work for which Agassiz was internationally known and for which the Geological Society of London had awarded him the Wollaston Medal. “You spread your intellect over too many subjects at once,” he wrote to Agassiz. “I think that you should concentrate … on fossil fishes. In so doing, you will render a greater service to positive geology than by these general considerations (a little icy withal) on the revolutions of the primitive world … . You will say that this is making you the slave of others; perfectly true, but such is the pleasing position of affairs here below. Have I not been driven for thirty-three years to busy myself with that tiresome America … ? Your ice frightens me.”