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Raymond Thorsteinsson
Raymond Thorsteinsson, (January 21, 1921 – April 23, 2012) was a Canadian geologist who focused on the geology of the high Arctic. He was a Fellow of The Arctic Institute of North America, primarily known for his contribution to the geology of the Proterozoic and Paleozoic rocks. Biography Thorsteinsson was born in Wynyard, Saskatchewan of Icelandic heritage. He obtained a BSc in geology at the University of Saskatchewan (1944) and an MSc in geology at the University of Toronto. In 1955, he earned a PhD from the University of Kansas. Thorsteinsson began work in the Canadian Arctic Archipelago, in 1947, as a summer field assistant. One of his assignments included an epic canoe trip with Dr. Y.O. Fortier to perform geological reconnaissance in the centre of the largely unknown Arctic region. He began his lifelong career with the Geological Survey of Canada in 1952. He spent most of his time studying the Arctic. At first, his fieldwork was completed on foot and by dog te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canadian Arctic Archipelago
The Arctic Archipelago, also known as the Canadian Arctic Archipelago, is an archipelago lying to the north of the Canadian continental mainland, excluding Greenland (an autonomous territory of Denmark). Situated in the northern extremity of North America and covering about , this group of 36,563 islands, surrounded by the Arctic Ocean, comprises much of Northern Canada, predominately Nunavut and the Northwest Territories. The archipelago is showing some effects of climate change, with some computer estimates determining that melting there will contribute to the rise in sea levels by 2100. History Around 2500 BCE, the first humans, the Paleo-Eskimos, arrived in the archipelago from the Canadian mainland. Between 1000–1500 CE, they were replaced by the Thule people, who are the ancestors of today's Inuit. British claims on the islands, the British Arctic Territories, were based on the explorations in the 1570s by Martin Frobisher. Canadian sovereignty was originally (1870â ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arctic Institute Of North America
The Arctic Institute of North America is a multi-disciplinary research institute and educational organization located in the University of Calgary. It is mandated to study the North American and circumpolar Arctic in the areas of natural science, social science, arts and the humanities. In addition, it acquires, preserves and disseminates information on environmental, physical, and social conditions in the north. The institute was created in 1945 by a Canadian act of Parliament as a non-profit membership organization, and also incorporated in the state of New York. History The idea of the institute began in the early 1940s when a group of Canadians discussed ways that Canada could increase administrative, scientific and technical expertise in the Arctic. By 1944, a binational organization that included Canada and the United States, with room for Greenland, Newfoundland, and Labrador was established. Offices were opened at McGill University in Montreal, Quebec, Canada. Geophysicis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Royal Society Of Canada
The Royal Society of Canada (RSC; french: Société royale du Canada, SRC), also known as the Academies of Arts, Humanities and Sciences of Canada (French: ''Académies des arts, des lettres et des sciences du Canada''), is the senior national, bilingual council of distinguished Canadian scholars, humanists, scientists and artists. The primary objective of the RSC is to promote learning and research in the arts, the humanities and the sciences. The RSC is Canada's National Academy and exists to promote Canadian research and scholarly accomplishment in both official languages, to recognize academic and artistic excellence, and to advise governments, non-governmental organizations and Canadians on matters of public interest. History In the late 1870s, the Governor General of Canada, the Marquis of Lorne, determined that Canada required a cultural institution to promote national scientific research and development. Since that time, succeeding Governor Generals have remained involved w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permian
The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleozoic Era; the following Triassic Period belongs to the Mesozoic Era. The concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison, who named it after the region of Perm in Russia. The Permian witnessed the diversification of the two groups of amniotes, the synapsids and the sauropsids ( reptiles). The world at the time was dominated by the supercontinent Pangaea, which had formed due to the collision of Euramerica and Gondwana during the Carboniferous. Pangaea was surrounded by the superocean Panthalassa. The Carboniferous rainforest collapse left behind vast regions of desert within the continental interior. Amniotes, which could better cope with these drier conditions, rose to dominance in place of their am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pennsylvanian (geology)
The Pennsylvanian ( , also known as Upper Carboniferous or Late Carboniferous) is, in the International Commission on Stratigraphy, ICS geologic timescale, the younger of two period (geology), subperiods (or upper of two system (stratigraphy), subsystems) of the Carboniferous Period. It lasted from roughly . As with most other geochronology, geochronologic units, the stratum, rock beds that define the Pennsylvanian are well identified, but the exact date of the start and end are uncertain by a few hundred thousand years. The Pennsylvanian is named after the U.S. state of Pennsylvania, where the coal-productive beds of this age are widespread. The division between Pennsylvanian and Mississippian (geology), Mississippian comes from North American stratigraphy. In North America, where the early Carboniferous beds are primarily marine limestones, the Pennsylvanian was in the past treated as a full-fledged geologic period between the Mississippian and the Permian. In parts of Europe, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Principle Of Faunal Succession
The principle of faunal succession, also known as the law of faunal succession, is based on the observation that sedimentary rock strata contain fossilized flora and fauna, and that these fossils succeed each other vertically in a specific, reliable order that can be identified over wide horizontal distances. A fossilized Neanderthal bone will never be found in the same stratum as a fossilized Megalosaurus, for example, because neanderthals and megalosaurs lived during different geological periods, separated by many millions of years. This allows for strata to be identified and dated by the fossils found within. This principle, which received its name from the English geologist William Smith, is of great importance in determining the relative age of rocks and strata. The fossil content of rocks together with the law of superposition helps to determine the time sequence in which sedimentary rocks were laid down. Evolution explains the observed faunal and floral succession pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ostracoderm
Ostracoderms () are the armored jawless fish of the Paleozoic Era. The term does not often appear in classifications today because it is paraphyletic (excluding jawed fishes) (may also be polyphyletic if anaspids are closer to cyclostomes) and thus does not correspond to one evolutionary lineage. However, the term is still used as an informal way of loosely grouping together the armored jawless fishes. An innovation of ostracoderms was the use of gills not for feeding, but exclusively for respiration. Earlier chordates with gill precursors used them for both respiration and feeding. Ostracoderms had separate pharyngeal gill pouches along the side of the head, which were permanently open with no protective operculum. Unlike invertebrates that use ciliated motion to move food, ostracoderms used their muscular pharynx to create a suction that pulled small and slow moving prey into their mouths. Swiss anatomist Louis Agassiz received some fossils of bony armored fish from Scotland ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinct
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence. More than 99% of all species that ever lived on Earth, amounting to over five billion species, are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryote globally, and possibly many times more if microorganisms, like bacteria, are included. Notable extinct animal species include non-avian dinosaurs, saber-toothed cats, dodos, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graptolites
Graptolites are a group of colonial animals, members of the subclass Graptolithina within the class Pterobranchia. These filter-feeding organisms are known chiefly from fossils found from the Middle Cambrian (Miaolingian, Wuliuan) through the Lower Carboniferous ( Mississippian). A possible early graptolite, ''Chaunograptus'', is known from the Middle Cambrian. Recent analyses have favored the idea that the living pterobranch ''Rhabdopleura'' represents an extant graptolite which diverged from the rest of the group in the Cambrian. Fossil graptolites and ''Rhabdopleura'' share a colony structure of interconnected zooids housed in organic tubes (theca) which have a basic structure of stacked half-rings (fuselli). Most extinct graptolites belong to two major orders: the bush-like sessile Dendroidea and the planktonic, free-floating Graptoloidea. These orders most likely evolved from encrusting pterobranchs similar to ''Rhabdopleura''. Due to their widespread abundance, plantkonic l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Society Of Canada
The Royal Society of Canada (RSC; french: Société royale du Canada, SRC), also known as the Academies of Arts, Humanities and Sciences of Canada (French: ''Académies des arts, des lettres et des sciences du Canada''), is the senior national, bilingual council of distinguished Canadian scholars, humanists, scientists and artists. The primary objective of the RSC is to promote learning and research in the arts, the humanities and the sciences. The RSC is Canada's National Academy and exists to promote Canadian research and scholarly accomplishment in both official languages, to recognize academic and artistic excellence, and to advise governments, non-governmental organizations and Canadians on matters of public interest. History In the late 1870s, the Governor General of Canada, the Marquis of Lorne, determined that Canada required a cultural institution to promote national scientific research and development. Since that time, succeeding Governor Generals have remained involved w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratigraphy
Stratigraphy is a branch of geology concerned with the study of rock (geology), rock layers (Stratum, strata) and layering (stratification). It is primarily used in the study of sedimentary rock, sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithostratigraphy (lithologic stratigraphy), biostratigraphy (biologic stratigraphy), and chronostratigraphy (stratigraphy by age). Historical development Catholic priest Nicholas Steno established the theoretical basis for stratigraphy when he introduced the law of superposition, the principle of original horizontality and the principle of lateral continuity in a 1669 work on the fossilization of organic remains in layers of sediment. The first practical large-scale application of stratigraphy was by William Smith (geologist), William Smith in the 1790s and early 19th century. Known as the "Father of English geology", Smith recognized the significance of Stratum, strata or rock layering and the importance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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