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
This Heat This Heat This Heat were an English experimental rock band, formed in early 1976 in Camberwell, London by multi-instrumentalists Charles Bullen (guitar, clarinet, viola, vocals, tapes), Charles Hayward (drums, keyboards, vocals, tapes) and Gareth Williams (keyboard, guitar, bass, vocals, tapes). This Heat were active in the ascendancy of British progressive rock and punk rock, but stood apart from those scenes due to a radically inventive approach that touched on numerous different styles and genres, but was always confrontational and politically charged. Their commercial success was limited, but This Heat are widely considered a link between early 1970s music (especially krautrock)