geochemical researchers are gradually

  • 1Earth Sciences — ▪ 2009 Introduction Geology and Geochemistry       The theme of the 33rd International Geological Congress, which was held in Norway in August 2008, was “Earth System Science: Foundation for Sustainable Development.” It was attended by nearly… …

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  • 2Silurian Period — Interval of geologic time, 443–417 million years ago. The third period of the Paleozoic Era, the Silurian follows the Ordovician Period and precedes the Devonian. It marks the first appearance of land plants and jawed fishes. The continents were… …

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  • 3Life Sciences — ▪ 2009 Introduction Zoology       In 2008 several zoological studies provided new insights into how species life history traits (such as the timing of reproduction or the length of life of adult individuals) are derived in part as responses to… …

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  • 4geology — /jee ol euh jee/, n., pl. geologies. 1. the science that deals with the dynamics and physical history of the earth, the rocks of which it is composed, and the physical, chemical, and biological changes that the earth has undergone or is… …

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  • 5Earth and Space Sciences — ▪ 1996 Introduction GEOLOGY AND GEOCHEMISTRY       In 1995 significant developments took place in the realm of geologic mapping, which provides the foundation for the presentation and comparison of data in the Earth sciences. The most important… …

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  • 6Mathematics and Physical Sciences — ▪ 2003 Introduction Mathematics       Mathematics in 2002 was marked by two discoveries in number theory. The first may have practical implications; the second satisfied a 150 year old curiosity.       Computer scientist Manindra Agrawal of the… …

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  • 7human evolution — Evolution of modern human beings from nonhuman and extinct hominid forms. Genetic evidence points to an evolutionary divergence between the lineages of humans and the great apes (Pongidae) on the African continent 5–8 million years ago. The… …

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  • 8meteorite — meteoritic /mee tee euh rit ik/, meteoritical, meteorital /mee tee euh ruyt l/, adj. /mee tee euh ruyt /, n. 1. a mass of stone or metal that has reached the earth from outer space; a fallen meteoroid. 2. a meteoroid. [1815 25; METEOR + ITE1] * * …

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  • 9climate change — Introduction  periodic modification of Earth s climate brought about as a result of changes in the atmosphere as well as interactions between the atmosphere and various other geologic, chemical, biological, and geographic factors within the Earth …

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  • 10Earth exploration — Introduction   the investigation of the surface of the Earth and of its interior.  By the beginning of the 20th century most of the Earth s surface had been explored, at least superficially, except for the Arctic and Antarctic regions. Today the… …

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