Metamorphic Rock-rocks buried deep in the Earth that are changed by heat (not melting),
pressure, and chemical reactions
Origin of
Greek “metamorphosis” to change form
word
Contact
Rock that changes when it comes in contact (touches) an igneous intrusion.
metamorphism
Minerals can be changed by the increase in temperature.
Regional
Metamorphism that occurs over a large area. 1)Heat and pressure build up
metamorphism
deep in the Earth where deformation and chemical change occurs 2)Where
large pieces of Earth’s crust collide or move past each other.
Index mineral
a mineral that forms at only certain temperatures and pressure (depth).
Helps geologists determine the temperature and pressure at which a rock
containing an index mineral was formed
Foliated
“Folia” from Latin for leaves. Pressure and heat cause crystals to change
Metamorphic
position and sometimes chemical composition, causing banding or stripes in the
Rock
rock
Examples of
Slate – from sedimentary rock, shale
Foliated
Metamorphic
Rock
Schist – from igneous rock granite
Gneiss – from igneous rock granite
Nonfoliated
Rock changed by heat and pressure. Rock has no banding or stripes, but the
Metamorphic
crystals may have enlarge during metamorphism.
Rock
Examples of
Nonfoliated
Metamorphic
Rock
Marble - from sedimentary limestone
Quartzite – from sedimentary sandstone
Hornfels - fine-grained. Hornfels is a rock that was "baked" while near a
heat source such as a magma chamber, sill or dike.
Deformation
Change in shape of a rock caused by a force placed on it such as stretching
or squeezing.