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Origin of Archean granitoids and continental evolution |
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Eos, Transactions American Geophysical Union,
Volume 72,
Issue 20,
1991,
Page 225-229
R. P. Rapp,
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摘要:
The origin of a stable, permanent crust is inextricably linked to granitoid genesis. The oldest terranes on Earth contain abundant granitoids, presumably representing the low density material that buoyed the crust and prevented its recycling into the mantle. The question of the origin of these rocks is thus fundamental to understanding Earth history: What was their source material, and what processes caused it to melt? Analogies with modern felsic magma genesis are tempting but not necessarily applicable, first because there are obvious reasons to doubt that present conditions characterized the early Archean (modern geotherms, well‐established subduction zones, massive stable continental crust, and others), and also because early granitoids differed in detail from most of their modern counterparts.In this article, R.P. Rapp, who has done extensive experiments on the moderate‐to‐high‐pressure melting behavior of mafic rocks, presents a decidedly non‐uniformitarian view of the origin of the tonalite‐trondhjemite‐granodiorite suite that characterizes the early Archean crust.—Calvin Miller, “Friends of Granite” editor, V
ISSN:0002-8606
DOI:10.1029/90EO00171
年代:1991
数据来源: WILEY
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More Arctic research needed |
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Eos, Transactions American Geophysical Union,
Volume 72,
Issue 20,
1991,
Page 226-226
Susan Bush,
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摘要:
The desire to achieve a balance between Arctic and Antarctic study was the message of the Senate Committee on Commerce, Science, and Transportation, which heard testimony on the need for more Arctic research on April 24. Ted Stevens (R‐Alaska) noted that since 1986, study in the area has not increased as the National Science Foundation has claimed, but rather, owing to inflation, has merely kept pace.Robert Correll, assistant director of geosciences at NSF and chair of the Interagency Arctic Oceans Working Group, gave several reasons why the Arctic is an important area for study by the scientific community. Its unique environment, he said, makes it a natural laboratory. And due to its environmental sensitivity, it may provide one of the earliest indicators of global climate change. Also, its geographic location makes it a “window on space,” some of the world's largest mineral and petroleum resources are in the Arctic, and the region has great strategic and military impor
ISSN:0002-8606
DOI:10.1029/90EO00173
年代:1991
数据来源: WILEY
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1989 AGU Salary Survey published |
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Eos, Transactions American Geophysical Union,
Volume 72,
Issue 20,
1991,
Page 227-227
Charles Blue,
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PDF (158KB)
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摘要:
According to1989 Salaries: Society Membership Survey,a report by the American Institute of Physics, there is a good chance that you work for a university and your regular salary is somewhere around $55,200. This statistical portrait of the AGU membership was taken from a random sampling of one‐sixth of the U.S. membership of AIP's member societies, including AGU. Each year since 1979, AIP has been conducting surveys of its member societies. Respondents have been asked to provide a wide range of biographical data, including information on their annual salary and occupatio
ISSN:0002-8606
DOI:10.1029/EO072i020p00227-02
年代:1991
数据来源: WILEY
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