Mineralogy of Suizhou shock veins / Минералогия ударных жил Суйчжоу

The shock metamorphic effects observed in meteorites can be described in terms of either deformation or transformation or some combination of the two. As mentioned in Chap. 3, the deformation effects include fracturing, plastic deformation, twinning, and mosaicism within constituent minerals. Planar deformation features (PDFs) have been attributed to deformational processes, but they have also been shown to contain transformed material, either diaplectic glass or high-pressure phases (Xie and Chao 1987; Goltrant et al. 1991; Bowden 2002).

Transformational effects observed in shocked meteorites include shock melting, which commonly result in localized melt veins and pockets, transformation of minerals to high-pressure polymorphs, formation of diaplectic glass, and crystallization of highly deformed material. The high-pressure minerals that occur in shocked meteorites formed by either crystallization of silicate liquids in shock melt veins and pockets (Chen et al. 1996a; Xie and Chen 2009) or solid-state transformation of the constituent minerals in meteorites (Chen et al. 1996a). Solid-state phase transformation can provide important constraints on shock conditions of a  meteorite, but transformation pressures are difficult to calibrate accurately becauseof kinetic effects and the heterogeneous nature of the initial transient shock pressure (Sharp and DeCarli 2006). Crystallization of chondritic melt provides an alternative means of constraining the crystallization pressure, which can be related to the shock pressure of the sample. <...>