1. METAMORPHIC ROCKS Types of Metamorphism Regional Metamorphism
Form when heat and/or pressure change existing rock into a new rock through recrystallization
Types of Metamorphism
Regional Metamorphism
occurs over a large area where rocks are buried deeply or are caught in a mountain building event
rocks recrystallize due to high T & P
Contact Metamorphism
occurs when rocks are locally exposed to high temperatures in a small area (e.g. under a lava flow, at a meteorite impact site, etc.)

2. classified by texture & origin rock / composition
METAMORPHIC ROCKS
classified by texture & origin rock / composition
Texture
FOLIATED – layered or banded
foliation forms when long mineral crystals line up in response to pressure
or when light and dark minerals separate
NONFOLIATED – not layered or banded
no foliation forms when mineral crystals do not have a long axis
and when only a few similar minerals are present

3. classified by texture & origin rock / composition
METAMORPHIC ROCKS
classified by texture & origin rock / composition
Origin Rock / Composition
origin / parent rock → metamorphic rock
sandstone → quartzite (nonfoliated)
conglomerate → metaconglomerate (nonfloliated)
limestone → marble (nonfoliated)
shale → slate → schist → gneiss (foliated)
granite → schist → gneiss (foliated)
basalt → amphibolite OR schist → gneiss (rock names!) (foliated)