Fixed hot spots

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From very deep in the mantle (and perhaps all the way from the core) the heat is thought to rise in a concentrated column, and for this reason is alternatively called a plume. Its surface features are not proof in themselves that they are the product of some plantstem phenomenon that is (or was) standing in the mantle far below. The chemistry of hot-spot lavas suggests that the rock is coming from below the asthenosphere, but there is no direct evidence of fixed hot spots in the mantle. They exist on inference alone. There is no way to sample the mantle. It can only be sensed-with vibrational waves, with viscosity computations, with tl1ermodynamic calculations of what minerals do at different temperatures and pressures. Sound waves move slowly in soft rock, and some modes of the sound can be stopped completely where the rock is molten. The speed and patterns of seismic waves tell the story of the rock. Seismology is not quite sophisticated enough to look through the earth and count hot spots, but it approaches that capability, and when it gets there hot spots should appear on the zakelijke energie screen like downspouts in a summer storm. If they don’t, that may be the end of the second-greatest story in the youthful explorations of geological geophysics. Hot spots seem to be active for roughly a hundred million years. Some of their effects on overriding plates last, of course, longer than they do. If they begin under continents, their initial manifestations at the surface are likely to be flood basalts. Hot-spot tracks have gone forth not only from the flood basalts of the Columbia River and the Serra Geral but in India from the flood basalts of the Deccan Plateau, in South Africa from the flood basalts of the Great Karroo, in East Africa from the flood basalts of the Ethiopian Plateau, in Russia from the flood basalts of the Siberian platform. Flood basalts are what the term implies-geologically fast, and voluminous in their declaration of the presence of a hot zakelijke energie vergelijken spot. In Oregon and Washington, in the middle Miocene, two hundred and fifty thousand cubic kilometres flowed out within three million years. Having achieved the surface in this form, the plume begins to make its track as the plate above slides by, just as Yellowstone, starting off from the flood basalts of Oregon and Washington, stretched out the pathway that has become the Snake River Plain.

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Professional papers

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He wrote more than twenty professional papers on subjects researched in the vicinity, and, with his colleague John Reed, published a summary volume for the general public called Creation of the Teton Landscape. When the Department of the Interior honored him with a Citation for Meritorious Service, it said, in part, that he had “established the fundamental stratigraphic and structural framework for a region.” In sho1t, he had put the petals back on the flower. And it was some flower. The Teton landscape contained not only the most complete geologic history in North America but also the most complex. (“One reason I’ve put in a part of my life here is that we have so much coming together. I don’t want to waste my time. I can make more zakelijke energie vergelijken of a contribution by concentrating here than on any other place.”) After more than half a century with the story assembling in his mind, he can roll it like a Roman scroll. From the Precambrian beginnings, he can watch the landscape change, see it move, grow, collapse, and shuffle itself in an intricate, imbricate manner, not in spatial chaos but by cause and effect through time. He can see it in motion now, in several ways responsively moving in the present-its appearance indebted to the paradox that while the region generally appears to have been rising the valley has collapsed. Splitting the wall of the Tetons is a diabase dike a hundred and fifty feet wide, running like a dark streak of warpaint straight up the face of the mountains. Diabase: a brother of gabbro, a distant relative of granite. Four miles below the surface of the earth, the space occupied by this now solid dike was once a fissure through which the dark rock flowed upward as zakelijke energie magma. At the same point in the narrative-i.3 billion years before the present, in the age of the Precambrian called Helikian time-marine beaches are not far to the west, and beyond them is a modest continental shelf. There is no Oregon, no Washington, not much Idaho-instead, blue ocean over ocean crust.

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Jumping-Off Draw

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Allan and David called it Jumping-Off Draw, its name on the map today. Finding numerous large bones in a meadowy bog, they named the place Buffalo Wallows. Indians had apparently driven the bison into the swamp to kill them. One could infer that. One could also see that the swamp was there because water was bleeding from rock outcrops above the meadows. In a youth spent on horseback, there was not a lot to do but look at the landscape. The rock that was bleeding water was not just porous but permeable. It was also strong. It was the same red rock that the granary stood on, and the bunkhouse. Very evidently, it was made of naturally cemented sand. The water could not have come from the creek. The Buffalo Wallows were sixty feet higher than the creek. The sandstone layers tilted north. They therefore reached out to the east and west. There was high ground to the east. The water must be coming down from there. One did not need a Ph.D. from Yale to figure that out-especially if one zakelijke energie vergelijken was growing up in a place where so much rock was exposed. Pending further study, his interpretation of the Buffalo Wallows was just a horseback guess. All through his life, when he would make a shrewd surmise he would call it a horseback guess. The water in the sandstone produced not only the bogs but the adjacent meadows as well-in this otherwise desiccated terrain. From the meadows came hay. There was an obvious and close relationship between bedrock geology and ranching. David would not have articulated that in just those words, of course, but he thought about the subject much of the time, and he was drawn to be a geologist in much the way that someone growing up in Gloucester, Massachusetts, would be drawn to be a fisherman. “It was something to think about on long rides day after day when everything was so monotonous,” he once zakelijke energie remarked. “Monotony was what we fought out there. Day after day, you had nothing but the terrain around you-you had nothing to think about but why the shale had stripes on it, why the boggy places were boggy, why the vegetation grew where it did, why trees grew only on certain types of rock, why water was good in some places and bad in others, why the meadows were where they were, why some creek crossings were so sandy they were all but impassable.

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The approximate volume

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“We know, however, the approximate volume of sediment from the Powder River Basin, the Bighorn Basin, the Wind River Basin, the Laramie Basin, and so forth. We can say it all went downhill to the Mississippi Delta. But go to the delta. Look at the volumes. There’s an enormous discrepancy. You add up what’s down there in the Gulf and what was removed here, and they don’t square. A great deal zakelijke energie more has been removed from here than is down there. Streams only account for about half the material that was taken up and out of here. Since it is not all in the delta, where did it go? So much has been taken away that it’s got to be explained in some other manner. I think the wind took it. My personal feeling is that a lot of it blew eastward to the Atlantic. Possibly some went to Hudson Bay. We don’t know. These are problems we are trying to grapple with at the present time. How much did the wind take? Again, we don’t know, but in one dust storm several years ago a great deal of debris from Kansas and Nebraska and Colorado went into the Atlantic-a storm that lasted only a couple of days.” Such storms are frequent, and this one was not unusual in size or duration. It is noteworthy because its effects were studied and published, in the Journal of Sedimentary Petrology. When the dust appeared above the coast of Georgia-as thick haze-it attracted the attention of researchers at the Skidaway Institute of Oceanography, near Savannah. The cloud of particles was two miles in height, and satellite photographs showed its other dimensions: four hundred thousand square miles. With air-sampling-and-measuring equipment, the Skidaway people collected particles. They reported in that one storm zakelijke energie vergelijken enough dust to account for twenty-five per cent of the annual rate of sedimentation-from all rivers as well as the air-in the proximate North Atlantic. Moreover, about eighty-five per cent of it was a clay mineral called illite. Silts coming out of east-coast rivers include very little illite, and yet illite is predominant among the sediments of the ocean floor. By Skidaway’s calculations, that one storm’s deposits in the ocean amounted to a million tons.

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A cruel country

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It is a cruel country as well as beautiful. Men seem here only on sufferance. After every severe storm we hear of people’s being lost. Yesterday it was a sheep camp mover who was lost in the Red Desert. People had hunted for him for a week, and found no trace. Mr. Love-Johnny Love-told of a man who had just been lost up in his country, around the Muskrat. “Stranger?” asked Mr. Mills. “No; born and brought up here.” “Old man?” “No; in the prime of life. Left Lost Cabin sober, too.” Mr. Love had been born near Portage, Wisconsin, on the farm of his uncle the environmentalist John Muir. The baby’s mother died that day. His father, a Scottish physician who was also a professional photographer and lecturer on world zakelijke energie vergelijken travel, ended his travels and took his family home. The infant had three older sisters to look after him in Scotland. The doctor died when John was twelve. The sisters emigrated to Broken Bow, Nebraska, where in the eighteen-seventies and eighties they all proved up on homesteads. When John was in his middle teens, he joined them there, in time to experience the Blizzard of ’88-a full week of blowing snow, with visibility so short that guide ropes led from house to barn. He was expelled from the University of Nebraska for erecting a sign in a dean’s flower bed, so he went to work as a cowboy, and soon began to think about moving farther west. When he had saved enough money, he bought matching black horses and a buggy, and set out for Wyoming. On his first night there, scarcely over the border, his horses drank from a poison spring and died. What he did next is probably the most encapsulating moment in his story. In Nebraska were three homes he could return to. He left the buggy beside the dead horses, abandoned almost every possession he had in the world, and zakelijke energie walked on into Wyoming. He walked about two hundred miles. At Split Rock, on the Oregon Trail-near Crooks Gap, near Independence Rock-he signed on as a cowboy with the 71 Ranch. The year was i891, and the State of Wyoming was ten months old.

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Cape Cod

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They are higher than the highest dunes of Cape Cod, and they are lined up in rows four deep along the shore of Lake Michiganlongitudinal 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 kantoor huren per uur breda 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 seeĀ kantoor huren per uur amersfoort 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 o.n 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.”

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The unsorted gravels

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By i871, 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 co-working space breda 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 natural 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 tills1 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 So meets the co-working space amersfoort 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 “s TAY AwA KE! 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.

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The encouragement

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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 co-working space breda 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 co-working space amersfoort 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 i864, 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 Commissfon.

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Moving cross-country

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They also reveal density, and hence the types of rock. Moving cross-country, the machines make subterranean profiles known as seismic lines. Seismic shots with explosives have been used for years in the search for oil. Alaska is crisscrossed with all but indelible “seismic” disruptions of tundra. The reserves of Prudhoe Bay were discovered in this manner. Dynamite in the populous East could irritate the public, so the universities and the U.S.G.S. use a behemoth called Vibroseis to shiver the timbers of the earth. One of the first discoveries the vibrations reported was that the Brevard Zone is relatively shallow and the crust below it is American rock that does not in any vague way reflect a continent-to-continent suture. Africa was co-working space groningen nowhere in the picture. The Brevard Zone proved to be the toboggan-like front end of a large and essentially horizontal thrust sheet. Plate-tectonic theorists accommodated this news by moving the suture fifty miles east. The new edge of Africa was under Kings Mountain. Seismic shots took the stitches out of Kings Mountain. ‘When we got the data for the Brevard” -as Leonard Harris liked to tell the story-“they pushed the suture to Kings Mountain, and when we got data for that they said the suture must be under the coastal plain, and now that we are getting data for the coastal plain they say it must. be in tl1e continental shelf. Well, we’ve got data out there, too.” Up and down the Appalachians, wherever such data were collected, thrust sheets were seen to have moved in a northwesterly direction, and much of the thrusting had never been suspected before. Conventional co-working space apeldoorn thought had been that the old rock of the Green Mountains, the Berkshires, the New Jersey Highlands, the Catoctin Mountains, and the northern Blue Ridge was in place, firmly rooted-autochthonous, as geologists are wont to say.

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Carbonaceous materia

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By weight, any rock that is half carbonaceous material is coal. Its density is roughly ten times the density of peat. In the United States, there is enough peat to keep Ireland warm for a thousand years. The United States uses almost none of it, because the United States also happens to have a great deal more coal than any other country in the world. Peat that remains near the surfa ce will never become coal. Buried three-quarters of a mile, it becomes bituminous. With a microscope, you can see wood and bark, leaves and roots, seed coats and spores in bituminous coal-and even identify the plants they came from. Buried deeper and folded severely co-working space breda under pressure, it becomes anthracite. Anthracite is roughly ninetyfive per cent carbon and is so hard that it fractures conchoidally, like an arrowhead. Anthracite is iridescent, and burns with a clear blue flame. Coal is a record of tectonics. In late Pennsylvanian time, when the third set of mountains came up in the east and shed still another wedge of debris, kneading it into what had gone before, the great pressure, deep burial, and severe folding produced the anthracites of eastern Pennsylvania, the pod-shaped coalfields of the folded-andfaulted mountains, which erosion and isostasy have lifted from the depths. Anthracite seams are often upside down or standing on end. Here in the Allegheny Plateau, burial was reasonably deep but tectonic pressures were co-working space amersfoort minor, and the result is a lesser grade of coal. 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.”

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