Rheology of olivine and the strength of the lithosphere

Journal Article · Mon Jan 01 00:00:00 EST 1990 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/GL017i001p00009· OSTI ID:5480116

Mackwell, S J ^[1]; Bai, Q; Kohlstedt, D L ^[2]

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1. Pennsylvania State Univ. (USA)
2. Cornell Univ. (USA)

In order to throw some light on the rheological behavior of the upper mantle of the Earth, a detailed series of high-temperature deformation experiments has been performed on olivine single crystals at 1 atm pressure under highly controlled thermodynamic conditions. The effects of stress, temperature, oxygen fugacity and orthopyroxene activity on the deformation rate of olivine have been carefully measured for the major high-temperature slip systems. These experimental results have been extrapolated to the pressures and strain rates of the upper mantle to provide new insight into the mechanical behavior of the mantle and a better constrained approach to extrapolation of laboratory deformation data to the conditions present in the upper mantle. The authors suggest that extrapolations in stress provide the most reliable means for extending laboratory creep data to upper mantle strain rates. They also predict that, in the dislocation creep field, the bulk of the strain in olivine in the upper mantle is accommodated by the (010)(100) slip system. In addition, true mantle strengths are probably most accurately modeled using the experimental data for samples oriented favoring the (010)(001) slip system. However, the reliable prediction of mantle strengths requires highly accurate temperature versus depth relationships and good indications of the local oxygen fugacity in the mantle.

• OSTI ID: 5480116
• Journal Information: Geophysical Research Letters (American Geophysical Union); (United States), Vol. 17:1; ISSN 0094-8276
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
58 GEOSCIENCES
EARTH MANTLE
RHEOLOGY
OLIVINE
ATMOSPHERIC PRESSURE
CREEP
DEFORMATION
DEPTH
EXTRAPOLATION
OXYGEN
RESERVOIR PRESSURE
RESERVOIR TEMPERATURE
ROCK MECHANICS
SLIP
STRESSES
TEMPERATURE EFFECTS
VAPOR PRESSURE
ALKALINE EARTH METAL COMPOUNDS
DIMENSIONS
ELEMENTS
IRON COMPOUNDS
IRON SILICATES
MAGNESIUM COMPOUNDS
MAGNESIUM SILICATES
MECHANICAL PROPERTIES
MECHANICS
MINERALS
NONMETALS
NUMERICAL SOLUTION
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SILICATE MINERALS
SILICATES
SILICON COMPOUNDS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
360603* - Materials- Properties
580000 - Geosciences