An academic geologist

Afbeeldingsresultaat voor site:ilocate.nl

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.