Simple Lithology

metamorphic rock

definition Rock formed by solid-state mineralogical, chemical and/or structural changes to a pre-existing rock, in response to marked changes in temperature, pressure, shearing stress and chemical environment. more like this
buchite more like this
fulgurite more like this
narrower amphibolite
broader metamorphic rock
chlorite actinolite epidote metamorphic rock
broader metamorphic rock
broader metamorphic rock
foliated metamorphic rock
broader metamorphic rock
glaucophane lawsonite epidote metamorphic rock
broader metamorphic rock
broader metamorphic rock
broader metamorphic rock
broader metamorphic rock
broader metamorphic rock
broader metamorphic rock
broader metamorphic rock
note Robertson (1999) defines the boundary between diagenesis and metamorphism in sedimentary rocks as follows: “…the boundary between diagenesis and metamorphism is somewhat arbitrary and strongly dependent on the lithologies involved. For example changes take place in organic materials at lower temperatures than in rocks dominated by silicate minerals. In mudrocks, a white mica (illite) crystallinity value of < 0.42D.2U obtained by X-ray diffraction analysis, is used to define the onset of metamorphism (Kisch, 1991). In this scheme, the first appearance of glaucophane, lawsonite, paragonite, prehnite, pumpellyite or stilpnomelane is taken to indicate the lower limit of metamorphism (Frey and Kisch, 1987; Bucher and Frey, 1994; Frey and Robinson, 1998). Most workers agree that such mineral growth starts at 150 ± 50° C in silicate rocks. Many lithologies may show no change in mineralogy under these conditions and hence the recognition of the onset of metamorphism will vary with bulk composition.” more like this
source Jackson 1997 more like this
broader composite genesis rock
narrower metamorphic rock
in scheme simplelithology
is primary topic of metamorphic rock