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1. |
Locating the K/T boundary impact crater(s) |
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Eos, Transactions American Geophysical Union,
Volume 71,
Issue 48,
1990,
Page 1819-1819
Susan M. Bush,
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摘要:
Stratigraphic, mineralogical, chemical and isotopic evidence have led to the large (˜10‐km) asteroid or comet impact theory as the cause of the Cretaceous period coming to an end. However, a suitable crater has not yet been found. Although the crater may have been destroyed because half of what was then the ocean floor has since been subducted, researchers are still hot on the trail of the impact site(s).A. R. Hildebrand and W. V. Boynton, Department of Planetary Sciences, University of Arizona, Tucson, believe that locating the original crater(s) would resolve the volcanism versus impact debate over what ended the Cretaceous period. Based on a large concentration of shocked mineral grains and the largest grains occurring in North America, and impact‐wave deposits at the K/T boundary only from the Caribbean and southern North America, they suggest that the K/T boundary impact occurred between North and South America. They suggest the 300‐km‐diameter buried basement structure in the Columbia Basin as a possible K/T impact crater. The location of impact‐wave deposits and possibly seismically triggered slumps also helped the two decide that impact(s) musthave occurred in the Caribb
ISSN:0002-8606
DOI:10.1029/EO071i048p01819-01
年代:1990
数据来源: WILEY
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2. |
Collaborative Research Opportunities: Capabilities for Measuring Physical and Chemical Properties of Earth Materials at Lawrence Livermore |
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Eos, Transactions American Geophysical Union,
Volume 71,
Issue 48,
1990,
Page 1820-1823
W. B. Durham,
A. G. Duba,
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PDF (740KB)
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摘要:
The Experimental Geophysics Group of the Earth Sciences Department at Lawrence Livermore National Laboratory (LLNL), Livermore, Calif., has experimental equipment that measures a variety of physical properties and phase equilibria and kinetics on rocks and minerals at extremes of pressure (to 500 GPa) and temperature (from 10 to 2800 K). These experimental capabilities are tabulated in this report, and some of the experimental equipment is described in detail.Experimental geophysics began at the LLNL in the early 1960s as an outgrowth of the Plowshare program, whose purpose was to develop peaceful applications for nuclear explosives. Research activity in rock mechanics expanded rapidly shortly thereafter when underground nuclear testing began. We needed to know the mechanical properties of specific Nevada Test Site rocks at high pressure in order to contain our own texts, and of rocks in general in order to interpret the seismic information emanating from nuclear tests by other countries. Several large testing frames, pressure vessels, and pumping capabilities were acquired at this time. The equipment base left behind by the nuclear test containment and seismic‐monitoring programs allowed us to broaden our research horizons, in turn allowing us to further expand our research capabilities. We now pursue a very diverse program of study of the physical and chemical behavior of rocks and minerals under extremes of pressure and temperature for a wide variety of Earth‐science applicati
ISSN:0002-8606
DOI:10.1029/90EO00358
年代:1990
数据来源: WILEY
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3. |
Mineral Physics Committee Chairman's Report |
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Eos, Transactions American Geophysical Union,
Volume 71,
Issue 48,
1990,
Page 1822-1823
Steve Kirby,
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摘要:
I take on the chairmanship of a committee that has had a solid record of accomplishment during the last 2 years under the vigorous leadership of Bill Bassett of Cornell University, Ithaca, N.Y. A major reassessment of the progress and research opportunities for mineral physics was made by the committee in the 1989 report,Frontiers in Mineral Physics. The report resulted from a 1988 workshop convened by Tom Ahrens of the California Institute of Technology, Pasadena. Copies may be obtained by writing to the Customer Service Department of AGU, 2000 Florida Ave., N.W., Washington, DC 20009 or by calling 800‐966‐A
ISSN:0002-8606
DOI:10.1029/90EO00388
年代:1990
数据来源: WILEY
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4. |
Mineral Physics Student Award |
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Eos, Transactions American Geophysical Union,
Volume 71,
Issue 48,
1990,
Page 1823-1823
Anonymous,
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PDF (151KB)
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摘要:
AGU announces the opening of nominations for the second Mineral Physics Student Award to be given at the Spring 1991 Meeting. This cash award is intended to recognize outstanding student research accomplishments and to encourage students to choose mineral physics as a research specialty. Nominations and supporting letters and materials should be sent to William Bassett, Chairman of the Awards Subcommittee, Department of Geological Sciences, Snee Hall, Cornell University, Ithaca, NY 14853. Eligibility will close March 1.
ISSN:0002-8606
DOI:10.1029/EO071i048p01823
年代:1990
数据来源: WILEY
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