Structure Sensitivity and Elastic Anisotropy within Peridotites

摘要: Peridotites derived from the uppermost mantle consist dominantly of olivine and subsequently pyroxene, spinel, garnet, plagioclase. Crystal-plastic flow rocks results in various types structure within peridotite being developed to varying degrees, depending upon sensitivity different mineral phases. Plastic deformation leads simultaneous development shape-preferred orientations crystal-preferred orientations. A orientation is expression average flattening (foliation) elongation (lineation) directions, as defined by individual grains. (CPO) crystallographic grains rock, via dislocation creep recrystallization. During intense homogeneous plastic a composed minerals with dominant slip system, preferred plane direction tends coincide direction, respectively. Recently, new CPO classification (A, B, C, D, E types) has been proposed Karato co-workers illustrate roles stress water content controlling factors systems. An additional type (AG) also recognition its common occurrence nature. Given that other constituent peridotites contain intrinsic elastic anisotropies, during gives rise seismic anisotropy upper mantle. Thus, anisotropic properties 100 km mantle, such Ichinomegata xenoliths northeast Japan arc, have calculated applied aim understanding Earth's