Journal ArticleDOI
Syntectonic Recrystallization of Olivine and Modes of Flow in the Upper Mantle
TLDR
In this paper, it was shown that syntectonic recrystallization is an important or dominant mode of flow in the upper mantle at temperatures above about 500°C, and that fabrics in olivine tectonites are similar to those produced experimentally.Abstract:
Olivine in dunite, peridotite, and olivine powder has been recrystallized syntectonically during compression tests at temperatures from 950°C to 1350°C, confining pressures from 5 to 30 kb, and strain rates from 10 −3 to 10 −8 /sec. For intragranular recrystallization of the dunite, the orientations of the new grains are controlled by the host orientation. For inter-granular recrystallization and total recrystallization of the dunite and of olivine powder, the orientations of the grains are controlled dominantly by the stress. The fabric produced over the entire range of physical conditions is a [010] maximum parallel to σ 1 and [001] and [100] girdles in the σ 2 = σ 3 plane. With few exceptions, and allowances for the experimental requirement that σ 2 = σ 3 , fabrics in olivine tectonites are similar to those produced experimentally. Such probable upper mantle source materials as ultramafic nodules in diamond-bearing kimberlites and in under-saturated basalts and “Alpine-type” peridotites show these same preferred orientations. We propose, therefore, that Syntectonic recrystallization is an important or dominant mode of flow in the upper mantle at temperatures above about 500°C. The implications of this conclusion, as they bear on seismicity and seismic anisotropy, are considered in light of the two most seriously regarded hypotheses advanced to explain motions of spreading plates of the lithosphere.read more
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Journal ArticleDOI
Stress and temperature in the bending lithosphere as constrained by experimental rock mechanics
C. Goetze,Brian Evans +1 more
TL;DR: In this paper, a limiting yield strength curve, which is primarily a function of temperature, is constructed from data from brittle failure and ductile flow experiments, in order to formulate a more realistic constitutive relation.
Journal ArticleDOI
Lattice preferred orientation of olivine aggregates deformed in simple shear
Shuqing Zhang,Shun-ichiro Karato +1 more
TL;DR: In this article, the results of simple-shear deformation experiments on olivine aggregates, conducted at high temperatures and pressures (~1,500 K and 300 MPa), were described.
Journal ArticleDOI
A review of wave motion in anisotropic and cracked elastic-media
TL;DR: A review of wave propagation in anisotropic media can be found in this paper, where the authors present consistent theoretical formulations for the numerical solution of a number of propagation problems, including body and surface wave polarizations.
Journal ArticleDOI
The Elastic Properties of Composite Materials
TL;DR: In this paper, the problem of determining the elastic properties of composite materials (polycrystals, polycrystals and porous or cracked solids) is approached in several ways, via scattering theory, through variational principles, or by the assumption of specific geometries for the material under consideration.