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The first corals appeared, though other reef-building organisms were already present.
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The oceans teemed with the coiled-shelled ammonites, mollusks, and sea urchins that survived the Permian extinction and were quickly diversifying. Earlier failed attempts at the split formed rift valleys in North America and Africa filled with red sediments that today contain the best preserved fossils of Triassic life. The Tethys Ocean filled the C and was the zipper upon which Pangaea began to split apart. Areas near the coast were pummeled by seasonal monsoons, but ocean-circulation patterns kept the isolated and vast interior warm and dry. The giant ocean called Panthalassa surrounded Pangaea. By the end of the period 199 million years ago, tectonic forces had slowly begun to split the supercontinent in two: Laurasia in the north and Gondwana in the south. Almost as soon as the supercontinent formed, it started to come undone. Pangaeaīy the start of the Triassic, all the Earth's landmasses had coalesced to form Pangaea, a supercontinent shaped like a giant C that straddled the Equator and extended toward the Poles. Life that survived the so-called Great Dying repopulated the planet, diversified into freshly exposed ecological niches, and gave rise to new creatures, including rodent-size mammals and the first dinosaurs. Something-a bout of violent volcanic eruptions, climate change, or perhaps a fatal run-in with a comet or asteroid-had triggered the extinction of more than 90 percent of Earth's species.īut it was also a time of tremendous change and rejuvenation. Helen Belyea.The start of the Triassic period (and the Mesozoic era) was a desolate time in Earth's history.
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Around this same time, the GSC employed a third woman Dr. Alice Wilson, the first of these women, lobbied for the inclusion of paleontologist Frances Wagner shortly afterward. The Geological Survey of Canada first began allowing women to conduct fieldwork in the early 1950s. George Mercer Dawson became a staff member in 1875, progressed to assistant director in 1883 and finally to director of the Geological Survey of Canada in 1895. After Aylesworth Perry was appointed as acting librarian in 1881 he prepared the catalogue of reference works on geology, mineralogy, metallurgy, chemistry and natural history. Sterry Hunt joined in the early days and the Survey added paleontological capability in 1856 with the arrival of Elkanah Billings. One of the prominent cartographers and the chief topographical draughtsman was Robert Barlow, who began his work in 1855. In the spring of 1843, Logan established the GSC's headquarters in Montreal (in his brother's warehouse and then in a rented house on Great St. Four months later, Logan arrived in Kingston, Ontario, to compile the existing body of knowledge of Canada's geology. Gaining recommendations from prominent British scientists, Logan was appointed the first GSC director on April 14, 1842. William Edmond Logan was in Montreal at the time and made it known that he was interested in participating in this survey. Geological Survey of Canada building in Montreal, 1852–1874