Word: emiliani
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Dates: during 1960-1960
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...system promises to pinpoint the Pleistocene. Developed at the University of Miami by Dr. John Rosholt of the U.S. Geological Survey and Italian-born Dr. Cesare Emiliani, it depends on the fact that a tiny amount of uranium is dissolved in all sea water. When it slowly decays radioactively, it yields protoactinium 231 and thorium 230, both of which attach themselves to sediment particles and sink slowly to the bottom. There they in turn decay, but protoactinium 231 decays faster than thorium 230. The age of sediment on the ocean floor can therefore be determined by measuring the relative abundance...
...dating the ocean-bottom sediments, Rosholt and Emiliani estimate that the last warm interglacial Pleistocene period extended from 100,000 B.C. to 67,000 B.C., with its temperature peak coming about 93,000 B.C. Since the oldest skull fragments of Homo sapiens (true man) are believed to date from the warmest part of the last interglacial period, this date, 93,000 B.C., can be considered the provisional birth date of the human race...