Experimental deformation of polycrystalline pyrite; effects of temperature, confining pressure, strain rate, and porosity

摘要: Triaxial, compression experiments were conducted to establish the effects of temperature (from 20 degrees 400 C), confining pressure 1 bar 3 kb), and strain rate 10 (super -4) -7) sec -1) ) on mechanical behavior dry, natural, polycrystalline pyrite high porosity ( nearly equal 8%). Additional deformation performed a similar but less porous 1%) aggregate at pressures from 2 kb, C strain-rate X -5) . The aggregates tested by Lang (1968) determined used supplement results present study.Strength depends strongly directly is inversely dependent upon porosity. Strength independent only slightly temperature. Macroscopic ductility enhanced increasing temperature, pressure, or rate.When deformed under conditions corresponding upper km earth's crust, much stronger ductile than galena, chalcopyrite, pyrrhotite, Solnhofen Limestone.The above properties reflect fact that deforms exclusively cataclasis.The influence strength related energy requirements for fracture. Porosity influences macroscopic providing local stress relief favoring development intensely comminuted zones bounding more stable regions.It suggested relatively fast laboratory rates are adequate evaluate dry undergoing cataclastic slower geological fracture density may significantly structures in deforming deposits facilitating "flow".Plastic be possible temperatures sulfur vapor partial pressures.