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1. |
Continental crustal evolution observations |
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Eos, Transactions American Geophysical Union,
Volume 72,
Issue 48,
1991,
Page 537-541
Walter D. Mooney,
Rolf Meissner,
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摘要:
How has the continental crust evolved? What are the primary processes responsible for its composition, structure, and mode of deformation? What role do fluids play in deep crustal processes? In the last dozen years, geophysicists have obtained images of the deep continental crust that can be used to examine these questions and refine geologic models of crustal evolution. In this report we summarize recent progress in geophysical studies of the deep continental crust and highlight some of the more important implications of deep crustal processes.
ISSN:0002-8606
DOI:10.1029/90EO00380
年代:1991
数据来源: WILEY
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2. |
A new path to magnetic reversals? |
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Eos, Transactions American Geophysical Union,
Volume 72,
Issue 48,
1991,
Page 538-538
Lynn Teo Simarski,
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PDF (175KB)
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摘要:
When the Earth's magnetic field undergoes periodic reversals, does it retain the dipolar (north‐south) character of its stable periods, or does it develop a more complex magnetic character? And during the transition from normal to reverse polarity, or the opposite, does the field show a mysterious “preference” for certain paths to its new state? Fresh evidence gathered from paleomagnetic fossils across the globe, to be aired in sessions at AGU's 1991 Fall Meeting, suggests a possible “yes” to both questions.The Earth's magnetic field has regularly flip‐flopped from normal to reverse polarity and back again throughout the planet's history. The switches, which take a few thousand years to occur, are abundantly recorded in the fossil magnetism of rocks, both sedimentary and volcanic, formed during the times
ISSN:0002-8606
DOI:10.1029/90EO00378
年代:1991
数据来源: WILEY
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3. |
Tectonics‐climate interaction studied |
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Eos, Transactions American Geophysical Union,
Volume 72,
Issue 48,
1991,
Page 539-540
Susan Bush,
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PDF (1536KB)
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摘要:
A growing number of Earth scientists are studying tectonic‐climate interaction, which is reflected in a constantly evolving mountain landscape. Robert S. Anderson, University of California, Santa Cruz, and Michael A. Ellis, Center for Earthquake Research and Information, Memphis State University, describe the field as “one of the most exciting interdisciplinary fields of Earth science.” By studying the landscape, researchers are gaining new insight into the kinematics and dynamics of crustal deformation.Several important feedbacks may exist at the large time and length scales involved in building mountains. Tectonic uplift produces mountains that influence both regional and global climate. At the same time, the evolution of mountain belts is influenced by climatically driven erosion, which transfers crustal mass away from the mountain belt. The distribution and intensity of the erosional process is strongly affected by the uplift, and the transfer of mass affects the stress system in the crust and mantle. It has also been suggested that large regions of uplift (plateaus) may trigger global climate changes through increased weathering rates at high eleva
ISSN:0002-8606
DOI:10.1029/90EO00377
年代:1991
数据来源: WILEY
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