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 accumulatelike the lower Mississippi Valley today.” About five miles east of Clearfield, we co-working space amersfoort 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 bum in my stove. Anita commented that coal co-working space enschede 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.
“A number of these people took very interesting ideas that apply to ocean floors and tried to apply them to everything,” she remarked. “They tried to extrapolate plate tectonics through all geologic time. I don’t know that that holds. My husband has blown some of their ideas apart.” Leonard Harris, sometimes known as Appalachian Harris, was very much a protester, too. Tragically, he died in i982, a relatively early victim of cancer and related trouble. He was a genial and softspoken, almost laconic man with a lean figure that had walked long distances without the help of trails. He liked to build ideas on studied rock, and was not easily charmed by megapictures global in their sweep. He referred to the long deep time before the conference room amersfoort Appalachian orogenies as “the good old days.” With regard to plate tectonics, he looked upon himself as a missionary of contrary opinion-not flat and rigid but selective, where he had knowledge to contribute. His wife has compared him to Martin Luther, nailing theses to the door of the castle church. For some years he assisted oil companies in the training of geologists and geophysicists in southern-Appalachian geology, and in return the companies made available to him their proprietary data from seismic investigations of the Appalachian crust. Later on, these data were supplemented by the seismic co-working space enschede thumpings of the U.S.G.S. and several university consortiums, whose big trucks go out with devices that literally shake the earth while vibration sensors record wave patterns reflected off the rock deep below. The technique is like computed axial tomography-the medical CAT scan. The patterns reveal structure. They reveal folds, faults, laminations, magmatic bodies both active and cooled. They report the top of the mantle. They also reveal density, and hence the types of rock. Moving cross-country, the machines make subterranean profiles known as seismic lines.
And now, half a mile up the highway and twenty million years up the time scale, we were looking at the younger of the two formations of which Kittatinny Mountain is locally composed. Generally red, the rock is named for Bloomsburg, outer reach of the deltaic plain in late Silurian time, four hundred and ten million years before the present. Less than two hundred years before the present, when the United States was twenty-four years old, the first wagon road was co-working space amersfoort achieved through the Water Gap. The dark narrow passage in rattlesnake-clefe nded rock had seemed formidable to Colonial people, and the Water Gap had not served them as a transportational gateway but had been left aloof, mysterious, frightening, and natural. In the hundred feet or so of transition rocks between the gray Shawangunk and the red Bloomsburg, we had seen the Silurian picture change from sea and seashore to a low alluviated coastal plain; and if we had a microscope, Anita said, we would see a few fishscales in the Bloomsburg river sands-from fish that looked like pancake spatulas, with eyes in the front comers. In i820, the Water Gap was discovered by tourists. They were Philadelphians with names like Binney. Breaking away some red sandstone, Anita remarked that it was telling a story of cut-and-fill-the classic story of a meandering stream. The stream cuts on one side while it fills in on the other. Where bits and hunks of mudstone were included in the sandstone, the stream had cut into a bank so vigorously co-working space enschede that it undermined the muddy soil above and caused it to fall. Meanwhile, from the opposite bank-from the inside of the bend in the river-a point bar had been building outward, protruding into the channel, and the point bar was preserved in clean sandstones, where curvilinear layers, the crossbeds, seemed to have been woven of rushes.
About ten, she told him. The last thing she had wished to do was to keep it secret, but no one had shown much interest. She gave him slides of the New York State east-west series, and told him that a comparable set could be got together for Pennsylvania, too. Harris went south and traversed the state of Tennessee, collecting carbonate rocks that were close in age, and when Anita ran the conodonts she found the color alterations quite the same as in the northern states-dark in the east, pale in the west. Leonard and Anita reported all this to Peter Rose, leader flexplek huren amersfoort of the Oil & Gas Branch, pointing out that the variations in conodont color could lead to a cheap and rapid technique of finding rock in the petroleum window. Rose said he couldn’t understand why no one in the United States had ever thought of this if it was as obvious as all that. Anita told him that for years she had been puzzled by the same question, since the procedure would be one that “any idiot ought to be able to follow, because all you need is to be not color-blind.” At Rose’s request, Anita’s division of the Geological Survey allowed her to work two days a week on conodonts. Weekends, she worked on them at home. Actual temperature values had not been assigned to the varying colors. She did so in a year of experiments. She began with the palest of flexplek huren enschede conodonts from Kentucky and heated them at varying temperatures until they became canary and golden and amber and chocolate and cordovan, black, and gray. With enough added heat, they would turn white and then clear. At nine hundred degrees Celsius, they disintegrated. By cooking her samples in a great many variations of the ratio of time to temperature, she was able to develop a method of extrapolating laboratory findings onto the scale of geologic time. She concluded that pale-yellow conodonts could remain at about fifty degrees indefinitely without changing color. If they were to remain at sixty to ninety degrees for a million years or more, they would be amber. The earth’s thermal gradient varies locally, but generally speaking the temperature of rock increases about one degree Celsius for each hundred feet of depth. A conodont would have to be lodged in rock buried three thousand to six thousand feet in order to experience temperatures of the sort that would turn it amber.
“In Siberia, a few years ago, a couple of diamond pipes were located after diamonds were discovered in glacial drift,” Anita told me. I said, “Possibly some Russian geologists could be helpful here.” Looking out across the water of Lake James at a line of morainal hills, she chose to ignore the suggestion. The hills screened the outwash plain beyond. After some moments, she said, “Rocks remember. They may not be able to tell you exactly where in Canada to look for a diamond pipe, but when you have diamonds in this drift you’d better believe it is telling you that diamond pipes are there. Rocks are the record of events that took place at the time they formed. They are books. They have a different vocabulary, a different alphabet, but you learn how to flexplek huren apeldoorn read them. Igneous rocks tell you the temperature at which they changed from the molten to the solid state, and they tell you the date when that happened, and hence they give you a picture of the earth at that time, whether they formed three thousand million years ago or flowed out of the ground yesterday. In sedimentary rock, the colors, the grain sizes, the ripples, the crossbedding give you clues to the energy of the environment of deposition-for example, the force and direction and nature of the rivers that laid down the sediments. Tracks and trails left by organisms-and hard parts of their bodies, and flora in the rocktell whether the material came together in the ocean or on the continent, and possibly the depth and temperature of the water, and the temperature on the land. Metamorphic rocks have been heated, compressed, and recrystallized. Their mineral composition tells you if they were originally igneous or sedimentary. Then they tell you flexplek huren breda what happened later on. They tell you the temperatures when they changed. At one point, I wanted to major in history. My teachers steered me into science, but I really majored in history. I grew up in topography like this, believe it or not. Looking at these lakes and hills, you’d never think of Brooklyn. For that matter, you’d never think of Indiana. I didn’t know what bedrock meant. I remember how amazed I was to discover, in learning to read rocks, how much history there was. All the glacial stuff arrived just yesterday and is sitting on the surface. Most of Brooklyn is a pitted outwash plain. Brooklyn means broken land.”
These eventually came to be regarded as rift valleys, for they proved to be the boundaries between separating plates. As early as i956, oceanographers at Columbia had assembled seismological data suggesting that a remarkable percentage of all earthquakes were occurring in the mid-ocean rifts-a finding that was supported, and then some, after a worldwide system of more than a hundred seismological monitoring stations was established in anticipation of the flexplek huren amersfoort nuclear-test-ban treaty of i963. If there was to be underground testing, one had to be able to detect someone else’s tests, so a by-product of the Cold War was seismological data on a scale unapproached before. The whole of plate tectonics, a story of steady-state violence along boundaries, was being brought to light largely as a result of the development of instruments of war. Earthquakes “focus” where earth begins to move, and along transform faults like the San Andreas the focusses were shallow. At the ocean trenches they could be very deep. The facts accrued. Global maps of the new seismological data showed earthquakes not only clustered all along the ridges of the seafloor mountains but also in the trenches and transform faults, with the result that the seismology was flexplek huren enschede sketching the earth’s crustal plates. To Rear Admiral Hess, as he had become in the U.S. Naval Reserve, it now seemed apparent that seafloors were spreading away from mid-ocean ridges, where new seafloor was continuously being created in deep cracks, and, thinking through as many related phenomena as he was able to discern at the time, he marshalled his own research and the published work of others up to ig6o and wrote in that year his “History of Ocean Basins.” In the nineteen-forties, a professor at Delft had written a book called The Pulse of the Earth, in which he asserted with mild cynicism that where gaps exist among the facts of geology the space between is often filled with things “geopoetical,” and now Hess, with good-humored candor, adopted the term and announced in his first paragraph that while he meant “not to travel any further into the realm of fantasy than is absolutely necessary,” he nonetheless looked upon what he was about to present as “an essay in geopoetry.” He could not be sure which of his suppositions might be empty conjecture and which might in retrospect be regarded as precocious insights.
“The light of our candles disclosed great black sparkling masses of silver on every side. The walls were of silver, the roof over our heads was of silver, and the very dust that filled our lungs and covered our boots and zakelijke energie clothing with a gray coating was of fine silver. We were told that in this chamber a million dollars’ worth of silver lies exposed to the naked eye and our observations confirm the statement. How much lies back of it, Heaven only knows.” Heaven knew exactly. For while tlrn supergene enrichmentsin their prodigal dispersal through the Basin and Range-were some of the richest silver deposits ever discovered in the world, they were also the shallowest. There was just so much lying there, and it was truly bonanzan-to print money would take more time than to pick up this silver-but when it was gone it was gone, and it went quickly. Sometimes-as in the Comstock Lode in Virginia City-there were “true veins” in fissures below, containing silver of considerable value if more modest assay, but more often than not there was nothing below the enrichment. Mining and milling towns developed and died in less than a decade. We were on our way to a nineteenth-century mine, and were now turning switchbacks and climbing the high mountainside. Deffeyes, in zakelijke energie vergelijken order to consult maps, had turned over the wheel to me. He said his interest in the secondary recovery of silver had been one result of certain computer models that had been given wide circulation in the early nineteen-seventies, using differential equations to link such things as world population, pollution, resources, and food, and allow them to swim forward through time, with a resulting prediction that the world was more or less going to come to an end by the year 2000, because it would run out of resources. “We have found all obvious deposits, and, true enough, we’ve got to pay the price,” he said. “But they did not take into account reserves or future discoveries or picking over once again what the old-timers left behind.” Seeking commissions from, for example, the Department of Energy, he began doing studies of expectable discoveries of petroleum and uranium. He sort of slid inadvertently from uranium into silver after a syndicate of New York businessmen came to him to ask for his help in their quest for gold.
There had evidently been a wave of death, in which thousands of species had vanished from the world. No one has explained what happened-at least not to the general satisfaction. A drastic retreat of shallow seas may have destroyed innumerable environments. The cause may zakelijke energie have been extraterrestrial-lethal radiation from a supernova dying nearby. The wave of death occurred 250.1 million years before the present, and exactly that long ago flood basalts emerged in Siberia and quickly covered about a million and a half square kilometres with incandescent lava. The brief, intense greenhouse effect, the surge of carbondioxide emissions, would have stopped the upwelling of the oceans and the associated growth of nutrients. None of these hypotheses has attracted enough concurrence to be dressed out in full as a theory, but, whatever the cause, no one argues that at least half the fish and invertebrates and three-quarters of all amphibians-perhaps as much as ninety-six per cent of all marine faunal species-disappeared from the world in what has come to be known as the Permian Extinction. It was an extinction of a magnitude that would be approached only once in subsequent history, or-to express that more gravely -only once before the present day. The sharp line of creation at the outset of the Cambrian had an antiphonal parallel in the Permian Extinction, and the whole long stretch between the one and the other was set apart in histo1y as the Paleozoic era. It was zakelijke energie vergelijken a unit-well below the surface but far above the bottom-just hanging there suspended in the formless pelagics of time. The Paleozoic-544 to 250 million years before the present, a fifteenth of the history of the earth. Cambrian, Ordovician, Silurian, Devonian, Mississippian, Pennsylvanian, Permian. When I was seventeen, I used to accordion-pleat those words, mnemonically capturing the vanished worlds of “Cosdmpp,” the order of the periods, the sequence of the systems. It was either that or write them in the palm of one hand.
The wagon trail aims directly at Pilot Peak of the Pilot Range, which we could see clearly, upward of fifty miles away-a pyramidal summit with cloud coming off it in the wind like a banner unfurling. Across the dry lakebed, the emigrants homed on Pilot Peak, standing in what is now Nevada, above ten thousand feet. Along the fault scarp, at the base of Pilot Peak, are cold springs. When the emigrants arrived at the springs, their tongues were bloody and black. “Imagine those poor sons of bitches out here with their animals, getting thirsty,” Deffeyes said. “It’s a zakelijke energie wonder they didn’t string the guy that invented this route up by his thumbs.” The flats for the most part were alkaline, a leatl1er-colored mud
superficially dry. Dig down two inches and it was damp and greasy. Come a little rain and an ox could go in to its knees. The emigrants made no intended stops on the Great Salt Lake Desert. They drove day and night for the Pilot Range. In the day, they saw miragestowers and towns and shimmering lakes. Sometimes the lakes were real-playa lakes, temporary waters after a storm. Under a wind, playa lakes move like puddles of mercury in motion on a floor-two or three hundred square miles of water on the move, here today, there tomorrow, gone before long like a mirage) leaving wagons mired in unimagined mud. Very few emigrants chose to cross the Bonneville flats, although the route was promoted as a shortcut-“a nigher route”- rejoining the main migration four basins into Nevada. It was the invention of Lansford Hastings and was known as the Hastings Cutoff. Hastings wrote the helpful note in Skull Valley. His route was geologically unfavorable, but this escaped his zakelijke energie vergelijken knowledge and notice. His preoccupations were with politics. He wished to become President of California. He saw California-for the moment undefendably Mexican-as a new nation, under God, con1 ceived at liberty and dedicated to the proposition that anything can be accomplished through promotion: President Lansford Hastings, in residence in a western White House. His stratdgy for achieving high office was to create a new shortcut on the way west, to promote both the route and the destination through recruitiJg and pamphleteering, to attract emigrants by the thousands year after year, and as their counsellor and deliverer to use them as constituent soldiers in the promised heaven.
There were few hints of all that when I was seventeen, and now, a shake later, middle-aged and fading, I wanted to learn some geology again, to feel the difference between the Old and the New, to sense if possible how the science had settled down a decade after its great upheaval, but less in megapictures than in day-to-day contact with country rock, seeing what had not changed as well as what had changed. The thought occurred to me that if you were to walk a series of zakelijke energie vergelijken roadcuts with a geologist something illuminating would in all likelihood occur. This was long before I met Karen Kleinspehn, or, for that matter, David Love, of the United States Geological Survey, or Anita Harris, also of the Survey, or Eldridge Moores, of the University of California at Davis, all of whom would eventually take me with them through various stretches of the continent. What I did first off was what anyone would do. I called my local geologist. I live in Princeton, New Jersey, and the man I got in touch with was Kenneth Deffeyes, a senior professor who teaches introducto1y geology at Princeton University. It is an assignment that is angled wide. Students who have little aptitude for the sciences are required to take a course or two in the sciences en route to some cerebral Valhalla dangled high by the designers of curriculum. Deffeyes’ course is one that such students are drawn to select. He calls it Earth and Its Resources. They call it Rocks for Jocks. Deffeyes is a big man with a tenured waistline. His hair flies behind him like Ludwig van Beethoven’s. He lectures in sneakers. His voice is syllabic, elocutionary, operatic. He has been described by a colleague as “an intellectual roving shortstop, with zakelijke energie more ideas per square metre than anyone else in the department-they just tumble out.” His surname rhymes with “the maze.” He has been a geological engineer, a chemical oceanographer, a sedimentary petrologist. As he lectures, his eyes search the hall. He is careful to be clear but also to bring forth the full promise of his topic, for he knows that while the odd jock and the pale poet are the white of his target the bull’s-eye is the future geologist. Undergraduates do not come to Princeton intending to study geology. When freshmen fill out cards stating their three principal interests, no one includes rocks.