Experimental deformation of a glassy basalt

摘要: Abstract Deformation experiments were conducted with the intention of identifying how mechanical behavior and deformation microstructures a basalt are influenced by presence glass that can crystallize to metamorphic minerals or flow. A glassy plagioclase-rich was tested for periods up 649 hours at temperatures 675–875°C, confining pressure 1.0 GPa, strain rates 10−4–10−7 s−1. Over whole range experiments, deformed ductilely in textural steady state. At low (675–775°C), plagioclase crystals microcracking twinning, did not flow into intracrystalline cracks. higher (825–875°C), samples notably weaker, twinning dislocation glide, flowed In all more than 30 hours, neoblasts dark mica quartz crystallized expense K-rich + enstatite H2O. This neomineralization affect strength basalt, presumably because it affected only ~ 50 vol.% each sample. Changes mechanism from fast glide slow rates, may, however, reflect an increase effective caused crystallization glass.