Metamorphic Rocks Flashcards
Metamorphic aureole:
Area where contact meta is felt; always localised.
More intense metamorphism results in
Longer crystal size.
Sedimentary to meta May include the
Loss of water and gases.
During meta, little or no
Material transfer occurs.
The nature of minerals formed is
Dependent of those in the individual original rocks.
Usually occurs in a
Solid state, without melting.
Contact metamorphism:
Occurs adjacent to an intruded magma body due to high magma temps baking the surrounding rocks.
Regional metamorphism
Has a larger area. Increase in pressure and temp, may be caused by tectonic activity.
Minerals that tend to form from regional meta produce
A ‘layering’ characteristic of regional meta. (Except marble and quartz which only have a single crystal)
Meta rocks contain interlocking crystals, often
In layers.
Slate:
Dark grey, signs of original structure; contains clay, mica and quartz.
Schist:
Coarse grained, light grey, glossy/white. Contains mica, quartz garnet.
Gneiss:
Interlocking crystals - glassy and shiney. Pale and dark bands. Contains mica, quartz, feldspar.
Marble:
Granular texture. Interlocking calcite crystals.
Quartzite:
Granular texture. Interlocking crystals.
