Transcript Rocks and the Rock Cycle

Rocks and the Rock Cycle
Igneous, Sedimentary, Metamorphic
The Rock Cycle
As you may recall the rock cycle is the changing of
rocks from one kind to another over long periods
of time.
But what are
these igneous,
sedimentary, and
metamorphic
rocks anyway?
Igneous Rocks
Extrusive – rocks formed from lava exposed to
the Earth’s surface (example: basalt)
Extrusive rock
cools quickly
Igneous Rocks
Intrusive – rocks formed deep within the Earth
(example: granite)
Intrusive rock
cools slowly
Sedimentary Rocks
Clastic – rocks made from fragments of previously
existing rock
(example: conglomerate)
Sedimentary Rocks
Organic – rocks made from material that was
once living
(example: limestone, coal)
Sedimentary Rocks
Chemical – rocks made when a sea or lake dries
up leaving large amounts of minerals to be
deposited (example: gypsum, rocksalt)
Metamorphic Rocks
Foliated – rocks with parallel layers or bands
(example: slate, schist, gneiss)
Metamorphic Rocks
Unfoliated – rocks not banded into layers
(example: marble, quartzite)