pyrometamorphism
/ˌpʌɪrəʊmɛtəˈmɔːfɪz(ə)m/Geology
noun
Metamorphism of rock caused solely by extreme heat, especially that resulting from contact of the rock with magma.
Origin
Mid 19th century; earliest use found in Samuel Haughton (1821–1897), geologist and physiologist. From pyro- + metamorphism.