Word: sedimentation
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Dates: during 1970-1979
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...Geological Survey of Egypt and holds a seat in the Egyptian Parliament, bases his theory on evidence he found while doing test borings for the Aswan High Dam in 1961. In some of his core samples, Said was puzzled to find a layer of alluvial (deposited by running water) sediment at a depth of 450 ft., well below the level of the modern Mediterranean Sea. Convinced that such deposits could not have been left by today's Nile, Said began looking into the possibility that they were traces of an earlier river...
...Egypt's population, it should be noted that this project was not an unmitigated benefit. Although the dam made possible the cultivation of 1.3 million acres of formerly arid land, it stands accused of several disasters. The Egyptian Mediterranean fisheries have been virtually wiped out because the nutritional sediment washing downstream that formerly sustained sea life is now silting up the dam. In addition, salt water is moving upstream in the Delta, eroding farm land or making it saline. There has been an alarming spread of schistosomiasis. Also, a water weed is growing so fast in Lake Nasser behind...
Though this scenario for the beginning of the ice age has been well documented by fossil records, scientists have long been uncertain about what caused the cooling. Now, after studying cylindrical-core samples of ocean sediment dug up by the deep-sea drilling ship Glomar Challenger, two University of Rhode Island researchers have found evidence that may help provide the answer. The telltale position of layers of volcanic ash found in the cores by Geologists James Kennett and Robert Thunell suggests that the first great ice age could have been set off by a worldwide series of volcanic eruptions...
From examination of fossils in the sediment cores found just above the bedrock, the geologists deduced that 150 to 200 million years ago, the Falkland plateau was dry land in a climate similar to that of the Mediterranean today. That evidence fitted in with earlier suggestions by other geologists that there had once been an inland sea in Gondwanaland similar to the Mediterranean and bounded by what are now South America, Africa and Antarctica. Then, as the continents began to separate, the area round the ancient sea gradually sank, reached its present depth about 80 million years ago, and remained...
Last week the Glomar Challenger again made news. Another team of geologists announced that in July a drill lowered from the ship in midocean, about 200 miles southwest of the Azores, had penetrated 1,910 ft. into the earth's hard crust under the Atlantic bottom sediment. It returned core samples from depths never before explored; the previous record penetration was 260 ft. into the submarine crustal rock. Said Geochemist William Melson of the Smithsonian Institution: "It was like probing into the unknown, getting samples we had thought about for years but had never been able to reach...