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Laval-way back

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You will remember also that Laval-way back, i965-came out with late Ordovician fossils in the Sherbrooke anomalies. Where else do you find a continuous sedimentation from the middle Ordovician up
to the Silurian-from Rangeley Lake up to New Brunswick in one belt? The Sherbrooke thing, restored, would come from where it ought to come from. So I’m suggesting either that two continents collided, and you have one basin there, receiving continuous sedimentation, or …” “You may have a double arc.” “You might have a double arc.” “There’s another solution.” “Sure, but I’m saying let’s take the simplest configuration.” “Why not just have one arc with basins on both sides of it?” “No. No. You have the Bronson Hill anticlinorium, and then you have the Ascot-Weedon.” “You have a volcanic arc on the stable side of the conference room rotterdam subduction zone, an expected arc above the downgoing slab.” “You have a short-lived slab going down below the AscotWeedon and the one of longer duration that’s on the other side. I would somehow think that there has to be something in these rocks, in the limestones, that you’d be able to hopefully connect to that platform.” “The only thing I can say is . . . ” “What about the blue quartz?” ‘What about the blue quartz? The stratigraphy of the Taconic rock matches unit for unit with Cambrian rocks of Avalon, and the fossils look alike. That’s all I can tell you. Nowhere else do we find this sort of thing except Wales.” A structural geologist with a foot on conference room utrecht each continent looks up and aside from this contentious scene. “While geologists argue, the rocks just sit there,” he remarks. “And sometimes they seem to smile.”

At high temperature

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“The sea lilies grew in clear, shallow water a little offshore,” Anita said. “It was a coast like Fiji’s, or the Philippines’, or Guatemala’s. The coral and the thick shells tell you the water was warm. The rock is dark because it is full of dead oil, which came in later-much later. Oil migrated into these rocks and was cooked at high temperature. The conodonts will tell me the temperature.” In the deformed, sedimentary Appalachians, the rock not only had been compressed like a carpet shoved across a floor but in places  had been squeezed and shoved until the folds tumbled forward into recumbent positions. Some folds had broken. Some entire regions had been picked up and thrust many miles northwest. Dozem of other complexing events had locally co-working space rotterdam affected the structures of the Ridge and Valley Province. One therefore could not know what to expect next. Whole sequences might suddenly be upside down, or repeat themselves, or stand on end reading backwards. Among such rocks, time moves in and out and up and down as well as by. “It’s a real schlemazel,” Anita said. “Not by accident is geology called geology. It’s named for Gaea, the daughter of Chaos.” Among the west-dipping Silurian formations of the Delaware Water Gap, one might project but could not reasonably expect Devonian rock to westward. It would be there if the stratigraphic package was intact and had not been overturned. The rock of that first big Pennsylvania roadcut was early Devonian in age. Leaving it, we moved seven miles west along the interstate and twenty million years up the co-working space utrecht time scale, where we stopped at a roadcut of middle Devonian marine siltstones and shales, so rich in organic residues that it was black as carbon, with corals that had been sliced by dynamite and resembled sections of citrus. Cambrian, Ordovician, Silurian, Devonian-for this crunched and shuffled country we were experiencing remarkable consistency in an upward voyage through time. And now in the silken muds of these Devonian seafloors we were seeing the final stages in the long tranquil interval between the Taconic and Acadian revolutions.

Adzes of granite

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They made adzes of granite, basalt, argillite, even siltstone, from sources closer to home. They went to Berks County, in Pennsylvania, for gray chalcedony and brown jasper. They used glacial-erratic hornfels. They made arrowheads and spear points of Deepkill flint. They made drills and scrapers of Onondaga chert. Flint, chert, and jasper are daughters of chalcedony, which in turn is a variety of quartz. The Eastern flint belt runs from Ontario across New York State and then south to the Minisink. The Indians did not have to attend the Freiberg Mining Academy to be able to tell you that. They understood empirically the uniform bonding of cryptocrystalline quartz, which cannot be separated along flat planes but fractures conchoidally, by percussion, and makes a razor’s edge. The forests were alive with game on the sides of what the Lenape called the Endless Mountain. There were eels, shad, sturgeon in the river. The people lived among maize fields in osier cabins. They worshipped light and the four winds-all the elements of nature, orchestrated by the Great Manito. The flexplek huren rotterdam burial grounds of the Minsi display the finest vistas in the Minisink. As the dead were placed in the earth, they began their final journey, through the Milky Way. Indians first appeared in the Minisink about a hundredth of a million years ago. The carbonate rocks in the valley before us were close to five hundred million years old. They were one-ninth as old as the earth itself. For their contained conodonts, they were of special interest to Anita, and after the interstate dropped to the valley floor we stopped at roadcuts to collect them. The roadcuts suggested the ruins of blocky walls built by Hellenic masons. They were on both sides of the interstate and in the median, too. There were bluish-white and pale-gray limestones, dolomites weathered buff. Rock will respond to weather with varieties of color-rusting red in its own magnetite, turning green from trace copper. Its appearance can be deceiving. Geologists are slow to identify exposures they have not seen before. They don’t just flexplek huren utrecht cruise around ticking off names at distances that would impress a hunter. They go up to outcrops, hit them with hammers, and look at the rock through ten-power lenses. If the possibilities include the carbonates, they try a few drops of hydrochloric acid. Limestone with hydrochloric acid on it immediately forms a head, like beer.

Celestial navigation

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Now when she goes up Fifth Avenue-as she did with me that summer day-she addresses Fifth Avenue as the axis of the trough of a syncline. She knows what is underfoot. She is aware of the structure of the island. The structure of Manhattan is one of those paradoxes in spatial relations which give geologists especial delight and are about as intelligible to everyone else as punch lines delivered in Latin. There is a passage in the oeuvre of William F. Buckley, Jr., in which he remarks that no writer in the history of the world has ever successfully made clear to the layman the principles of celestial navigation. Then Buckley announces that celestial navigation is dead simple, and flexplek huren amsterdam that he will pause in the development of his present narrative to redress forever the failure of the literary class to elucidate this abecedarian technology. There and then-and with intrepid, awesome courage-he begins his explication; and before he is through, the oceans are in orbit, their barren shoals are b1ight with shipwrecked stars. With that preamble, I wish to announce that I am about to make perfectly clear how Fifth Avenue, which runs along the high middle of a loaf of rock that lies between two rivers, runs also up the center of the trough of a syncline. When rock is compressed and folded, the folds are anticlines and synclines. They are much like the components of the letter S. Roll an S forward on its nose and you have to the left a syncline and to the right an anticline. Each is a part of the other. Such configurations in rock compose the flexplek huren eindhoven structure of a region, but will not necessarily shape the surface of the land. Erosion is the principal agent that shapes the surface of the land; and erosion-particularly when it packs the violence of a moving glacier-can cut through structure as it pleases. A carrot sliced the long way and set flat side up is composed of a synclinal fold. Manhattan, embarrassingly referred to as the Big Apple, might at least instructively be called the Big Carrot. River to river, erosion has worn down the sides, and given the island its superficial camber. Fifth Avenue, up on the high ground, is running up the center of a synclinal trough. On the upper West Side that afternoon, Anita drew her rock hammer and relieved Manhattan of some dolomite marble, which she took from an outcrop for its relevance to her research in conodonts. She found the marble “overcooked.” She said, “To get that ldnd of temperature, you have to go down thirty or forty thousand feet, or have molten rock nearby, or have a high thermal gradient, which can vary from place to place on earth by a factor of four. This marble is so cooked it is almost volatilized. This-you better believe-is hot rock.”

Drifting continents

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“I didn’t grow up with the idea of drifting continents and seafloor spreading. But I tell you, when you look at the way pieces of tl1e northeastern portion of the African continent seem to fit together, separated by a narrow gulf, you could make a believer out of anybody.” Schmitt was one of the eighty per cent who were changing their minds about the new global theory. In addition to his astronaut’s training, he had a Ph.D. in geology, and he would bring back from the moon a hundred kilos of rock
Twenty miles out of Winnemucca, and the interstate is dropping south toward the Humboldt Range. A coyote runs along beside the road. It is out of its element, tongue out, outclassed, under minimum
speed. Deffeyes says that flexplek huren rotterdam most ranges in the Basin and Range had one or two silver deposits in them, if any, but the Humboldts had five. We have also entered the bottomlands of the former Lake Lahontan. The hot-springs map shows more activity in this part of the province. Extension of the earth’s crust has been somewhat more pronounced here, Deffeyes explains, and hence there are more ore deposits. He feels that when a seaway opens up, the spreading center will be somewhere nearby. Or possibly back in Utah, in the bed of Lake Bonn’eville. “But this one has better connections.” “Connections?” “Death Valley. Walker Lake. Carson Sink.” An Exxon map of the western United States is spread open on the seat between us. He runs his finger from Death Valley to Carson Sink and on northward to cross the interstate at Lovelock. “The ocean will open here,” he repeats. “Or in the Bonneville basin. I think here.” A few miles off the flexplek huren utrecht road is the site of a planned community dating from the nineteen-sixties. It was to have wide streets and a fountained square, but construction was delayed and then indefinitely postponed. Ghostless ghost town, it had been named Neptune City. With the river on our right, we round the nose of the Humboldt Range, as did the Donner party and roughly a hundred and sixtyfive thousand other people, in a seventeen-year period, heading in their wagons toward Humboldt Sink, Carson Sink, and the terror of days without water.

The province

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The ash was from elsewhere, from outside the province, punctuation brought in on the wind. It had come from volcanoes standing, probably, in what is now the Snake River Plain, two hundred miles away. Settling into the basin lakes-long-gone Miocene, Pliocene lakes-much of it had turned into zeolites. Among the zeolites, Deffeyes had found in Jersey Valley three million tons of a variety called erionite, which is named for wool, and is fibrous, and when it gets into the linings of human lungs causes mesothelioma. There are more millions of tons of erionite throughout the Basin and Range, passively causing zakelijke energie nothing. But if twenty-five valleys of the province were to be filled up with forty-six hundred concrete shelters for MX missiles, as the Defense Department had proposed, wind would present extraordinary hazards during the process of construction. It would be difficult to overestimate the amount of fine material that can be borne long distances by the wind. The largest single layer of ash that Deffeyes found in Jersey Valley was ten feet thick. He once showed it to Howel Williams, of the University of California at Berkeley, whom he regarded as “the greatest of volcanologists.” Deffeyes asked Williams what might have been the size of a volcano that from two hundred miles away could send out such an explosion of ash. Williams just stood there impressed, shaking his head. On a shelf above us was a pile of sticks of a size that in moister country could well have been collected by a beaver. “Hawk,” Deffeyes said. “Note the southern exposure. The hawk went solar long ago. The sun incubates the eggs and the hawk is free to soar.” Running his eye over zakelijke energie vergelijken the sequence of sediments revealed in the slope before us, he decided to begin his work right there. He was carrying in his hand a device of his own invention with which he hoped to accomplish the delicate operation of removing paleomagnetic samples from unconsolidated lake sediments.

The stages and ages

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The stages and ages, as they are called-the subdivisions of all of the epochs and eras-read like a roll call in a district council somewhere in Armenia. Berriasian, Va langinian, Hauterivian, Barremian, Bedoulian, Gargasian, Aptian, Albian, Cenomanian, Turonian, Coniacian, Santonian, Campanian, and Maastrichtian, reading upward, are chambers of Cretaceous time. Actually, the Cretaceous has been cut even finer, with zakelijke energie about fifty clear time lines now, subdivisions of the subdivisions of its eighty million years. The Triassic consists of the Scythian, the Anisian, the Ladinian, the Camian, the N orian, and the Rhaetian, averaging seven million years. What survived the Rhaetian lived on into the Liassic. The Liassic, an epoch, comes just after the Triassic and is
the early part of the Jurassic. Kazanian, Couvinean, Kopaninian, Kimmeridgian, Tremadocian, Toumaisian, Tatarian, Tiffanian … When geologists choose to ignore these names, as they frequently do, they resort to terms that are undecipherably simple, and will note, typically, that an event which occurred in some flooded summer 34i.27 million years ago took place in the “early late-middle Mississippian.” To say “middle Mississippian” might do, but with millions of years in the middle Mississippian there is an evident compunction to be more precise. “Late” and “early” always refer to time. “Upper” and “lower” refer to rock. “Upper Devonian” and “lower Jurassic” are slices of time expressed in rock. In the middle Mississippian, there was an age zakelijke energie vergelijken called Meramecian, of about eight million years, and it was during the Meramecian that the Tonka-the older of the formations in the angular unconformity in Carlin Canyon, Nevada-was accumulating along an island coast. The wine-red sandstone and its pebbles may have been sand and pebbles of the beach. The island was of considerable size, apparently, and stood off North America in much the way that Taiwan now reposes near the coast of China.

Fresh mountain range

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You would first have had the rock of the lower strata lying flat-a conglomerate with small b1ight pebbles like effervescent bubbles in a matrix red as wine. Then the forces that had compressed the region and produced mountains would have tilted the red conglomerate, not to the vertical, where it stood now, but to something like fortyfive degrees. That mountain range wore away-from peaks to hills to nubbins and on down to nothing much but a horizontal line, the bevelled surface of slanting strata, eventually covered by a sea. In the water, the new sediment of the upper formation would have zakelijke energie accumulated gradually upon that surface, and, later, the forces building a fresh mountain range would have shoved, lifted, and rotated the whole package to something close to its present position, with its lower strata nearly vertical and its upper strata aslant. Here in Carlin Canyon, basin-and-range faulting, when it eventually came along, had not much affected the local structure, further tilting the package only two or three degrees. Clearly, if you were going to change a scene, and change it again and again, you would need adequate time. To made the rock of that lower formation and then tilt it up and wear it down and deposit sediment on it to form the rock above would require an immense quantity of time, an amount that was expressed i? the clean, sharp line that divided the formations-the angular unconformity itself. You could place a finger on that line and touch forty million years. The zakelijke energie vergelijken lower formation, called Tonka, formed in middle Mississippian time. The upper formation, called Strathearn, was deposited forty million years afterward, in late Pennsylvanian time. Cambrian, Ordovician, Silurian, Devonian, Mississippian, Pennsylvanian, Permian, Triassic, Jurassic, Cretaceous, Paleocene, Eocene, Oligocene, Miocene, Pliocene, Pleistocene . . . In the long roll call of the geologic systems and series, those formations-those discrete depositional events, those forty million years-were next-door neighbors on the scale of time. The rock of the lower half of that hill dated to three hundred and forty million years ago, in the Mississippian, and the rock above the unconformity dated to three hundred million years ago, in the Pennsylvaniad. If you were to lift your arms and spread them wide and hold them straight out to either side and think of the distance from fingertips to fingertips as representing the earth’s entire history, then you would have all the principal events in that hillside in the middle of the palm of one hand.

The earth is moving

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The earth is moving. The faults are moving. There are hot springs all over the province. There are young volcanic rocks. Fault scars everywhere. The world is splitting open and coming apart. You see a sudden break in the sage like this and it says to you that a fault is there and a fault block is comiAg up. This is a gorgeous, fresh, young, active fault scarp. It’s growiIDg. The range is I lifting up. This Nevada topography is what you see during mountain building. There are no foothills. It is all too zakelijke energie vergelijken young. It is live country. This is the tectonic, active, spreading, mountain-building world. To a nongeologist, it’s just ranges, ranges, ranges.” Most mountain ranges around the world are the result of compression, of segments of the earth’s crust being brought together, bent, mashed, thrust and folded, squeezed up into the sky-the Himalaya, the Appalachians, the Alps, the Urals, the Andes. The ranges of the Basin and Range came up another way. The crust in this region between the Rockies and the Sierra-is spreading out, being stretched, being thinned, being literally pulled to pieces. The sites of Reno and Salt Lake City, on opposite sides of the province, have moved apart sixty miles. The crust of the Great Basin has broken into blocks. The blocks are not, except for zakelijke energie simplicity’s sake, analogous to dominoes. They are irregular in shape. They more truly suggest stretch marks. Which they are. They trend nearly northsouth because the direction of the stretching is roughly east-west. The breaks, or faults, between them are not vertical but dive into the earth at angles that average sixty degrees, and this, from the outset, affected the centers of gravity of the great blocks in a way that caused them to tilt. Classically, the high edge of one touched the low edge of another and formed a kind of trough, or basin. The high edge-sculpted, eroded, serrated by weather-turned into mountains.

Paleomagnetic samples

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For that matter, geologists have done their share to bust up these roadcuts. “They’ve really been through here!” They have fungoed so much rock off the walls they may have set them back-a foot. And everywhere, in profusion along this half mile of diabase, there are small, neatly cored holes, in no way resembling the shot holes and guide holes of the roadblasters, which are larger and vertical, but small horizontal borings that would be snug to a roll of coins. They were made by geologists taking paleomagnetic samples. As the magma crystallized and turned zakelijke energie solid, certain iron minerals within it lined themselves up like compasses, pointing toward the magnetic pole. As it happened, the direction in those years was northerly. The earth’s magnetic field has reversed itself a number of hundreds of times, switching from north to south, south to north, at intervals that have varied in length. Geologists have figured out just when the reversals occurred, and have thus developed a distinct arrhythmic yardstick through time. There are many other chronological frames,
of course, and if from other indicators, such as fossils, one knows the age of a rock unit within several million years, a look at the mineral compasses inside it can narrow the age toward precision. Paleomagnetic insights have contributed greatly to the study of the travels of the continents, helping to show where they may have been with respect to one another. In the argot of geology, paleomagnetic specialists are sometimes called paleomagicians. Enough paleomagicians have been up and down the big roadcuts of the Palisades Sill to prepare zakelijke energie vergelijken what appears to be a Hilton for wrens and purple martins. Birds have shown no interest. Near the end of the highway’s groove in the sill, there opens a broad, forgettable view of the valley of the Hackensack. The road is descending toward the river. At an even greater angle, the silltilting westward-dives into the earth. Accordingly, as Karen Kleinspehn continues to move downhill she is going “upsection” through the diabase toward the top of the tilting sill. The texture of the rock becomes smoother, the crystals smaller, and soon she finds the contact where the magma-at 2000 degrees Fahrenheit-touched the country rock. The country rock was a shale, which had earlier been the deep muck of some Triassic lake, where the labyrinthodont amphibians lived, and paleoniscid fish.