Which type of igneous rock forms on
the surface of Earth from lava?
Intrusive
OR
Extrusive


Metamorphic rocks form from other rocks due
to intense heat and pressure***. There can be
NO melting!
Metamorphic rocks are from recrystallization
of unmelted material over a long period of
time. This forms larger, denser crystals.
1.
Regional – formed by forces acting over large
areas, at great depth where extreme
temperature*** and pressure exist.


High Pressure: caused by collisions of plates
A great region to find metamorphic rock is in
mountains!


Foliation: reorientation of mineral grains
Banding: concentration of minerals into
zones of light and dark colors
Contact – occurs at regions where magma
comes into contact with pre-existing rock.
2.

High temperature changes the rock without melting
1.

2.

Foliated
Examples: Slate, Gneiss, Schist,
Phyllite
Non-Foliated
Examples: Hornfels, Marble, Quartzite
1.
2.
3.
4.
Check for foliation
Check for grain size
Check composition
Use ESRT (page 7)
1.
Marble – metamorphic form of limestone
2.
Quartzite – from sandstone
3.
Slate – usually from metamorphism of shale

Phyllite – further metamorphism of slate

Schist – foliated – contains layering, is easily
broken
Gneiss – highly distorted – contains banding
6.

Usually from granite

Science Review Game- Mixed Rock