Dislocations in mantle peeidotite nodules
1977; Elsevier BV; Volume: 39; Issue: 1-3 Linguagem: Inglês
10.1016/0040-1951(77)90098-1
ISSN1879-3266
Autores Tópico(s)earthquake and tectonic studies
ResumoDislocation microstructures were investigated in 110 mantle peridotite nodules from basalts and kimberlites. Such an extensive study was made possible by the use of a powerful decoration technique. High voltage electron microscopy has also been used in several cases. Slip planes, dislocation wall spacings and dislocation densities were determined. The most frequent glide system is (010) [100], as expected from extrapolations of experimental deformation data and previous studies. The {110} 〈001〉 system is present in several samples but appears as a result of a late superimposed deformation. The nodules exhibit various degrees of recovery. Dynamic as well as static recrystallization is present. Dislocation densities and wall spacings are on average respectively of 6.106 cm−2 and 100μ for basalt nodules and 107 cm−2 and 16μ for kimberlite nodules. These results indicate a high temperature deformation under stresses in the 100–1000 bars range.
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