Download Earth Systems 3209 – Common Metamorphic Rocks Slate (parent

Earth Systems 3209 – Common Metamorphic Rocks
Slate (parent – shale)
Slate is a fine-grained, foliated metamorphic rock that is created by
the alteration of shale or mudstone by low-grade regional
metamorphism.
Phyllite (parent – shale, slate)
Phyllite is a foliate metamorphic rock that is made up mainly of very
fine-grained mica. The surface of phyllite is typically lustrous and
sometimes wrinkled. It is intermediate in grade between slate and
schist.
Schist (parent – shale, slate , phyllite)
Schist is metamorphic rock with well developed foliation. It often
contains significant amounts of mica which allow the rock to split into
thin pieces. It is a rock of intermediate metamorphic grade between
phyllite and gneiss.
Earth Systems 3209 – Common Metamorphic Rocks
Gneiss (parent – granite or shale, slate , phyllite ,schist)
Gneiss is a foliated metamorphic rock identified by its bands. Gneiss
usually forms by regional metamorphism at convergent plate
boundaries. It is a high-grade metamorphic rock in which mineral
grains recrystallized under intense heat and pressure.
Gneiss can form in several different ways. The most common path
begins with shale, which is a sedimentary rock. Regional metamorphism can transform shale into slate,
then phyllite, then schist, and finally into gneiss.
Intense heat and pressure can also metamorphose granite into a banded rock known as "granite gneiss."
This transformation is usually more of a structural change than a mineralogical transformation.
Marble (parent – limestone)
Marble is a nonfoliated metamorphic rock that forms when limestone
is subjected to the heat and pressure of metamorphism. Being
composed of calcium carbonate, marble will react in contact with
many acids.
Quartzite (parent – sandstone)
Quartzite is a nonfoliated metamorphic rock composed almost
entirely of quartz. It forms when a quartz-rich sandstone, is altered by
the heat, pressure, and chemical activity of metamorphism. These
conditions recrystallize the sand grains and the silica cement that
binds them together. The result is a network of interlocking quartz
grains of incredible strength.