The Estimation of Deformation Temperature of Sodic Plagioclase

The variation diagram of △131-11 with An content and temperature was first proposed by Christie. Based on new experiments, another diagram was suggested by Smith. Assuming a linear correlation between angle of rhombic section (σ) and △131-11, a variation diagram of σ and An content with temperature was advanced by Zhang. Both angle of rhombic section thermometer and △131-11 thermometer are deformation thermometers. The new diagram is compiled based on those three diagrams (Fig.1).