Ordovician sea

Afbeeldingsresultaat voor site:ilocate.nl Deffeyes said, “Let’s Richter the situation,” and he got out and crossed the road. With his hammer, he chipped at the rock, puzzled the cut. He scraped the rock and dropped acid on the scrapings. Tilted by the western breeze, the snow was dipping sixty degrees east. The bedding planes were dipping twenty degrees east; and the stripes of Deffeyes’ knitted cap were dipping fifty degrees north. The cap had a big tassel, and with his gray-wisped hair coming out from under in a curly melange he looked like an exaggerated elf. He said he thought he knew what had caused “that big goober” in the rock, and it was almost certainly not a manifestation of some major tectonic event-merely local violence, a cashier shot in a grab raid, an item for an inside page. The cut was mainly limestone, which had collected as lime mud in an Ordovician sea. The goober was dolomite. Limestone is calcium carbonate. Dolomite is calcium carbonate with magnesium added. Together they are known as the carbonate rocks. Deffeyes was taught in college that while it seemed obvious to infer that magnesium precipitating out of water changes limestone into zakelijke energie dolomite there was no way to check this out errlpirically because dolomite was forming nowhere in the world. Deffeyes found that impossible to believe. Deffeyes was already a uniformitarian-a geologist who believes that the present is the key tol the past, that if you want to understand how a rock is formed you go watch it forming now. Watch basalt flows at Kilauea. Watch the festooned crossbeddings of future sandstones being sketched by the currents of Hatteras. Watch a flooding river blanket the tracks of a bear. Surely, somewhere, he thought, limestone must be changing into dolomite now. Not long after graduate school, he and two 1 others went to Bonaire, in the Netherlands Antilles, where they found a lagoon that was concentrating under the sun and “making a jNice very rich in magnesium.” The juice was flowing through the limJstone below and changing it into dolomite. They presented the news in zakelijke energie vergelijken Science. When the rock of this big Utah roadcut had been the limy bottom of the Ordovician sea, the water had been so shall0w that the lime mud had occasionally been above the surface and had dried out and cracked into chips, and then the water rose and tHe chips became embedded in more lime mud, and the process happened again and again so that the limestone now is a self-containing breccia studded with imprisoned chips-an accident so lovely to the eye you want to slice the rock and frame it.

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