Metamorphic rock the foliation is called "gneissosity"), granoblastic (includes granulite, some marbles and quartzite), and hornfelsic (includes hornfels and skarn). 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
Heat capacity either by adding heat to the system or by the system performing work. Written mathematically we have or For work as a result of an increase of the system volume we may write If the heat is added at constant volume, then the second term of this relation vanishes, and one readily obtains This defines the "heat capacity at constant volume", "C", which is also related to changes in internal energy. Another useful quantity is the "heat capacity at constant pressure", "C". This quantity refers to the change in the "enthalpy" of the system, which is given by A small