Slip-system and EBSD analysis on compressively deformed, fine-grained polycrystalline olivine

Abstract

A slip-system analysis was performed on two synthetic compressively deformed olivine aggregates, derived from experimental solution-gelation (sol-gel) and natural San Carlos precursors to determine how dislocation density relates to Schmid factor for slip in olivine. Individual grain orientations were measured with electron backscatter diffraction. Using decorated dislocations, grain populations were separated into subsets of high versus low dislocation density. Analysis of preferred orientations and distributions of Schmid factors suggests that there is only weak correlation between Schmid factor and dislocation density, slip on (010)[100] in San Carlos grains but (001)[100] in sol-gel material, with multiple slip or stress heterogeneity in both.