Metamorphic rock Metamorphic rock Metamorphic rocks arise from the transformation of existing rock types, in a process called metamorphism, which means "change in form". The original rock (protolith) is subjected to heat (temperatures greater than 150 to 200 °C) and pressure ( or more), causing profound physical or chemical change. The protolith may be a sedimentary, igneous, or existing metamorphic rock. Metamorphic rocks make up a large part of the Earth's crust and form 12% of the Earth's land surface. They are classified by texture and by chemical and mineral assemblage (metamorphic facies). They may be formed simply by being deep beneath
Heat capacity ratio Heat capacity ratio In thermal physics and thermodynamics, the heat capacity ratio or adiabatic index or ratio of specific heats or Poisson constant, is the ratio of the heat capacity at constant pressure () to heat capacity at constant volume (). It is sometimes also known as the "isentropic expansion factor" and is denoted by (gamma) for an ideal gas or (kappa), the isentropic exponent for a real gas. The symbol gamma is used by aerospace and chemical engineers. where is the heat capacity, and the specific heat capacity (heat capacity per unit mass) of a gas. The suffixes and