Extremely rare

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Ice ages, such as the present one, are extremely rare. What seems likely is that ocean floors were higher in Cambra-Ordovician time, fluffed up by more than the usual amount of heat from the restless mantle-heat of the sort that has created the Hawaiian Islands in the middle of a lithospheric plate, and heat of the sort that lifts mid-ocean ridges, where plates diverge. Whatever the reason, the sea came up so far that it covered more than half of what is now the Nortl1 American craton. And after the white clean beaches and shelf sands had spread their broad veneer, lime muds began to accumulate in the epicratonic seas. The lime muds were the skeletons, the macerated shells, the calcareous hard parts of marine creatures. The material flexplek huren hilversum turned into limestone, and where conditions were appropriate the limestone, infiltrated by magnesium, became dolomite. As the deposit grew to a general thickness of two thousand feet, these Cambra-Ordovician carbonates buried ever deeper the sandstone below them and the Precambrian rock below that, pressing it all downward like tl1e hull of a loading ship, into the viscous mantle-but sedately, calmly, a few inches every thousand years. Absorbing the valley scene, the gapped and distant ridgeline, the newly plowed fields where arrowheads appear in the spring, I remarked that we had entered the dominion of tlrn Minsi, the northernmost band of the Lenape. They came into the region toward the dawn of Holocene time and lost claim to it in the beginnings of the Age of Washington. Like index fossils, they now represent this distinct historical stratum. Their home and prime hunting ground was the Minisink-over the mountain, beside the river, the country upstream from the gap. The name Delaware meant nothing to them. It flexplek huren rotterdam belonged to a family of English peers. The Lenape named the river for themselves. I knew some of this from my grade-school days, not many miles away. The Minisink is a world of corn shocks and islands and valley mists, of trout streams and bears, today. Especially in New Jersey, it has not been mistreated, and, with respect to the epoch of the Minsi, geologically it is the same. The Indians of the Minisink were good geologists. Their trails ran great distances, not only to other hunting parks and shell-mounded beach camps but also to their quarries. They set up camps at the quarries. They cooked in vessels made of soapstone, which they cut from the ground in what is now London Britain Township, Chester County, Pennsylvania.

In Suspect Terrain

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He would spend three years in traction, earning nothing. Gradually, Anita’s expeditions on foot into Manhattan increased in length until she was covering, round trip, as much as twelve miles. Her line of maximum advance was somewhere in Central Park. “That’s as far as I ever got. I was too scared.” Going up the Bowery and through the East Village, she had no more sense of the geology than did the men who were lying in the doorways. When she looked up at the Empire State Building, she was unaware that it owed its elevation to the formation that outcropped in Central Park; and when she saw the outcrops there, she did not wonder why, in the moist atmosphere of the American East, those flexplek huren dordrecht great bare shelves of sparkling rock were not covered with soil and vegetation. In Wyoming, wind might have stripped them bare, but Wyoming is miles high and drier than the oceans of the moon. Here in the East, a river could wash rock clean, but this rock was on the high ground of an island, far above flood and tide. She never thought to wonder why the rock was scratched and grooved, and elsewhere polished like the foyer of a bank She didn’t know from geology. In Brooklyn College, from age fifteen onward, she read physics, mineralogy, structural geology, igneous and metamorphic petrology. She took extra courses to the extent permitted. To attend the college she had to pay six dollars a semester, and she meant to get everything out of the investment she could. There were also lab fees and breakage fees. Breakage fees, in geology, were not a great problem. Among undergraduate colleges in the United States, this one was relatively small, about the size of Harvard, which it resembled, with its brick-and-white-trim flexplek huren amsterdam sedate Colonial buildings, its symmetrical courtyards and enclosed lawns; and like Harvard it stood on outwash. Brooklyn College is in south Flatbush, seaward of the terminal moraine. When Anita was there, in the middle nineteen-fifties, there were so many leftists present that the college was known as the Little Red Schoolhouse. She did not know from politics, either. She was in a world of roof pendants and discordant batholiths, elastic collisions and neutron scatteration, and she branched out into mineral deposits, field mapping, geophysics, and historical geology, adding such things to the skills she had established earlier in accounting, bookkeeping, typing, and shorthand. It had been assumed in her family that she would be a secretary, like her mother.

A suggestion

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Then in October, i965, J. Tuzo Wilson, of the University of Toronto, and Fred Vine, of Cambridge, published a paper in which they defined an oddly isolated piece of mid-ocean ridge off the coasts of Oregon and Washington. It was the spreading center of what would eventually become known as the Juan de Fuca Plate, one of the smallest of all the crustal plates in the world. The volcanoes of the Cascades-Mt. Hood, Mt. Rainier, Mt. St. Helens, Glacier Peak-were lined up behind its flexplek huren hilversum trench. “Continental drift is one hypothesis I’ll get seasick for,” Deffeyes decided, and he signed up for a week’s use of the ship. He had no program in mind. To ask for a suggestion, he picked up a telephone and called Harry Hess. Instantly, Hess said, “Go to the ridge and dredge some rock from the axial valley. It better not be old.” Hess’s hypothesis that new seaBoor forms at ocean rises had scarcely been tested. This was before the Eltanin profile, and before the voyages of the Glomar Challenger. Hess’s immediate response to Deffeyes was to suggest a test that could have shelved his hypothesis then and there. Deffeyes went out to dredge the rock, but first he had to find the ridge, so he made a long pass with his echo sounder tracing the  profile of the bottom. The ridge-axis rock, when he dredged it up, was extremely young. But what in the end interested Deffeyes at least as much was the benthic profile that had been  flexplek huren rotterdam traced by the stylus of the sounder. The profile of the spreading center in the ocean bottom off Oregon seemed remarkably familiar to someone who had done his thesis field work in Nevada. It appeared to be, in miniature, a cross section of the Basin and Range. The new crust, spreading out, had broken into fault blocks and had become a microcosm of the Basin and Range, because both were expressions of the same cause. It was a microcosm, too, of the Triassic lowlands of the East two hundred and ten million years ago-Triassic Connecticut, Triassic New Jersey-with their border faults and basalt flows, their basins and ranges, gradually extending, pulling apart, to open the Atlantic. The Red Sea of today was what the Atlantic and its two sides had looked like about twenty million years after the Atlantic began to open. The Red Sea today was what the Basin and Range would probably look like at some time in the future. In December, i972, the astronaut Harrison Schmitt, riding in Apollo i7, looked down at the Red Sea and the Gulf of Aden-at a simple geometry that seemed to have been made with a jigsaw barely separating Africa and the Arabian peninsula. He told the people at Mission Control,

The Pleistocene

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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 zakelijke energie 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 middleMiocene 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 zakelijke energie vergelijken 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.

Civilization

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In geologists’ own lives, the least effect of time is that they think in two languages, function on two different scales. “You care less about civilization. Half of me gets upset with civilization. The other half does not get upset. I shrug and think, So let the cockroaches take over.” “Mammalian species last, typically, two million years. We’ve about used up ours. Every time zakelijke energie Leakey finds something older, I say, ‘Oh! We’re overdue.’ We will be handing the dominant-species-onearth position to some other group. We’ll have to be clever not to.” “A sense of geologic time is the most important thing to suggest to the nongeologist: the slow rate of geologic processes, centimetres per year, with huge effects, if continued for enough years.” “A million years is a short time-the shortest worth messing with for most problems. You begin tuning your mind to a time scale that is the planet’s time scale. For me, it is almost unconscious now and is a kind of companionship with the earth.”
“It didn’t take very long for those mountains to come up, to be deroofed, and to be thrust eastward. Then the motion stopped. That happened in maybe ten million years, and to a geologist that’s really fast.” “If you free yourself from the conventional reaction to a quantity like a million years, you zakelijke energie vergelijken free yourself a bit from the boundaries of human time. And then in a way you do not live at all, but in another way you live forever.”
One is tempted to condense time, somewhat glibly-to say, for example, that the faulting which lifted up the mountains of the Basin and Range began “only” eight million years ago. The late Miocene was “a mere” eight million years ago. That the Rocky Mountains were building seventy million years ago and the Appalachians were folding four hundred million years ago does not impose brevity on eight million years. What is to be avoided is an abridgment of deep time in a manner that tends to veil its already obscure dimensions. The periods are so long-the eighty million years of the Cretaceous, the forty-six million years of the Devonian-that each has acquired its own internal time scale, intricately constructed and elaborately named. I will not attempt to reproduce this amazing list but only to suggest its profusion.

An academic geologist

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This all but leaves the false impression that an academic geologist chose the sites-and now, as we approached the tunnel at Carlin Canyon, Deffeyes became so evidently excited that one might have thought he had done so himself. “Yewee zink bogawa!” he said as the pickup rounded a curve and the tunnel appeared in view. I glanced at him, and then followed his gaze to the slope above the tunnel, and failed to see there in the junipers and the rubble what it was what could cause this professor to break out in such language. He did not slow up. He had been here before. He drove through the westbound tube, came out into zakelijke energie daylight, and, pointing to the right,[ said, “Shazam!” He stopped on the shoulder, and we admired the sfene.
boldt River, blue and full, was flowing toward us, with panes of white ice at its edges, sage and green meadow beside it, and dry russet uplands rising behind. I said I thought that was lovely. He said yes, it was lovely indeed, it was one of the loveliest angular unconformities I was ever likely to see. The river turned in our direction after bending by a wall of its canyon, and the wall had eroded so unevenly that a prominent remnant now stood on its own as a steep six-hundred-foot hill. It made a mammary silhouette against the sky. My mind worked its way through that image, but still I was not seeing what Deffeyes was seeing. Finally, I took it in. More junipers and rubble and minor creases of erosion had helped withhold the story from my eye. The hill, structurally, consisted of two distinct rock formations, awry to each other, awry to the gyroscope of the earth-just stuck together there like two artistic impulses in a pointedly haphazard collage. Both formations were of stratified rock, sedimentary rock, put down originally in and beside the sea, where they had lain, initially, flat. But now the strata of the upper pa1t of the hill were dipping more than sixty degrees, and the strata of the lower part of the hill were zakelijke energie vergelijken standing almost straight up on end. It was as if, through an error in demolition, one urban building had collapsed upon another. In order to account for that hillside, Deffeyes was saying, you had to build a mountain range, destroy it, and then build a second set of mountains in the same place, and then for the most part destroy them.

Mountains

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Mountains are not somehow created whole and subsequently worn away. They wear down as they  come up, and these mountains have been rising and eroding in fairly even ratio for millions of years-rising and shedding sediment steadily through time, always the same, never the same, like row upon row of fountains. In the southern part of the province, in the Mojave, the ranges have stopped rising and are gradually wearing away. The Shadow Mountains. The Dead Mountains, Old Dad Mountains, Cowhole Mountains, Bullion, Mule, and Chocolate mountains. They are inselberge now, buried ever deeper in their own waste. For the most part, though, the ranges zakelijke energie vergelijken are rising, and there can be no doubt of it here, hundreds of miles north of the Mojave, for we are looking at a new seismic scar that runs as far as we can see. It runs along the foot of the mountains, along the fault where the basin meets the range. From out in the valley, it looks like a long, buff-painted, essentially horizontal stripe. Up close, it is a gap in the vegetation, where plants growing side by side were suddenly separated by sev1 eral metres, where, one October evening, the basin and the range -Pleasant Valley, Tobin Range-moved, all in tln instant, apart. They jumped sixteen feet. The erosion rate at which the mountains were coming down was an inch a century. So in the mountains’ contest with erosion they gained in one moment about twenty thousand years. These mountains do not rise like bread.I They sit still for a long time and build up tension, and then suddenly; jump. Passively, they are zakelijke energie eroded for millennia, and then they jump again. They have I been doing this for about eight million years. This fault, which jumped in 1915, opened like a zipper far up the valley, and, exploding into the silence, tore along the mountain base for upward of twenty miles with a sound that suggested a runaway locomotive. ‘This is the sort of place where you really do not put a nuclear plant,” says Deffeyes. “There was other action in tHe neighborhood at the same time-in the Stillwater Range, the Sonoma Range, Pumpernickel Valley. Actually, this is not a particularly S_F>ectacular scarp. The lesson is that the whole thing-the whole Basin and Range, or most of it-is alive.

Two miles below the surface

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This particular sill came into the earth about two miles below the surface, Kleinspehn remarks, and she smacks it with the sledge. An air horn blasts. The passing tires, in their numbers, sound like heavy surf. She has to shout to be heard. She pounds again. The rock is competent. The wall of the cut is sheer. She hits it again and again-until a chunk of some poundage falls free. Its fresh surface is asparkle with crystals-free-form, asymmetrical, improvisational plagioclase crystals, bestrewn against a field of dark pyroxene. The rock as a whole is called diabase. It is salt-and-peppery charcoaltweed savings-bank rock. It came to be that way by cooling slowly, at depth, and forming these beautiful crystals. “It pays to put your nose on tl1e outcrop,” she says, turning the sample in her hand. With a smaller  zakelijke energie hammer, she tidies it up, like a butcher trimming a roast. With a felt-tip pen, she marks it “i.” Moving along the cut, she points out xenoliths-blobs of the country rock that fell into the magma and became encased there like raisins in bread. She points to flow patterns, to swirls in the diabase where solidifying segments were rolled over, to layers of coarse-grained crystals that settled, like sediments, in beds. The Palisades Sill-in its chemistry and its texture-is a standard example of homogeneous
magma resulting in multiple expressions of rock. It tilts westward. The sill came into a crustal block whose western extremity-known in New Jersey as the Border Fault-is thirty miles away. As the block’s western end went down, it formed the Newark Basin. The high eastern end gradually eroded, shedding sediments into the basin, and the sill was ultimately revealed-a process assisted by the creation and development of the Hudson, which eventually cut out the cliff side panorama of New Jersey as seen across the river from Manhattan: the broad sill, which had cracked, while cooling, into slender columns so upright and uniform that inevitably they would be likened to palisades. In the many fractures of these big roadcuts, there is some suggestion of columns, but actually the cracks running through the cuts are too various to be explained by columnar jointing, let alone by zakelijke energie vergelijken the impudence of dynamite. The sill may have been stressed pretty severely by the tilting of the fault block, Kleinspehn says, or it may have cracked in response to the release of weight as the load above it was eroded away. Solid-earth tides could break it up, too. The sea is not all that responds to the moon. Twice a day the solid earth bobs up and down, as much as a foot. That kind of force and that kind of distance are more than enough to break hard rock. Wells will flow faster during lunar high tides.