Abstract:
With the removal of phenocrysts, fluids become less and less and the viscosity increases during slow cooling and crystallization. Once the fluids become a plastic mass, there will appear effects of stress on early phenocrysts, thus bringing about oriented arrangement and plastic or brittle deformation. Meanwhile relict plastic masses occurring among the phenocrysts will form mineral aggregates with a fine-grained mosaic crystalloblastic texture and elongated and venlike plastic quartz; moreover the elict plastic mass will be exsolved to form fine-grained rhythmic layerring due to pressure filtration, and even the usefull components will be further concentrated under the oriented pressure to form a mineral deposit.