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Metastability, mechanical strength, and the support of mountain belts

J. A. Jackson, H. Austrheim, D. McKenzie and K. Priestley
Metastability, mechanical strength, and the support of mountain belts
Geology (Boulder) (July 2004) 32 (7): 625-628


Exhumed high-pressure rocks from the Caledonian root zone in Norway provide analogues for processes occurring today under southern Tibet, allowing large-scale geophysical observations, from gravity and earthquakes, to be linked with the mechanical properties of metastable rocks under high mountains. Metastability is essential for the survival of thick mountain roots and, hence, of high mountains and is in turn controlled by water. If water is absent, dry granulite, formed from earlier melting episodes, is both stable and strong and likely to survive in the eclogite stability field of deep root zones for hundreds of million years. But if hydrous fluid is introduced, the transformation of granulite to eclogite is relatively rapid and accompanied by a dramatic loss of strength. In Norway, this transformation was initiated by water infiltration along fractures formed by earthquakes. The same process, as marked by deep earthquakes, may be occurring today beneath southern Tibet.

ISSN: 0091-7613
EISSN: 1943-2682
Serial Title: Geology (Boulder)
Serial Volume: 32
Serial Issue: 7
Title: Metastability, mechanical strength, and the support of mountain belts
Affiliation: University of Cambridge, Department of Earth Sciences, Cambridge, United Kingdom
Pages: 625-628
Published: 200407
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 30
Accession Number: 2004-056737
Categories: Solid-earth geophysicsIgneous and metamorphic petrology
Document Type: Serial
Bibliographic Level: Analytic
Annotation: Cambridge Earth Sci. Contrib. ES 7778
Illustration Description: illus. incl. sketch map
N60°00'00" - N61°00'00", E05°10'00" - E05°30'00"
Secondary Affiliation: University of Oslo, NOR, Norway
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
Update Code: 200416
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