Download Intrusive Igneous Rocks

3.2
Igneous Rocks
3 Families
Granite – forms from felsic lava
Basalt – forms from mafic
lava, rich in iron
Large crystals From
slow cooling
Deep underground
Plageoclase feldspar & augite
Diorite – medium-colored rocks made up of plageoclase
feldspar, hornblende, augite, and biotite mica
Intrusive Igneous Rocks
Cools deep in the earth; Large grains
Granite – most common;
forms from felsic lava
Gray = quartz
Pink = feldspar
Black = biotite mica
Diorite
Intrusive rock formations
Batholith “deep rock” –
over 100 square miles; form
the core of many mountain
ranges
Laccolith –
meaning “lake
of rock”
Sill– sheet of magma flows
Dike– follows
between rock layers
existing vertical
fractures
Extrusive Igneous Rocks
Little to no crystal growth!
Rapid cooling Small grains
Obsidian
volcanic glass
Pumice
Shiprock, New Mexico
Andesite
Rhyolite
Volcanic neck
Lava flows...
and Lava plateaus
Sedimentary Rock
Stratification – changes in type of sediment creating stripes in the rock.
Erosion from wind & water
1. Clastic – cemented rock fragments
Conglomerate
Breccia
Sedimentary Rock
2. Chemical – minerals once dissolved in
water
Halite - salt
Limestone
Gypsum
Sedimentary Rock
Special examples...
Geodes
Fossils
Crystal caves
Metamorphic Rock
Change of one type of rock into another by
heat, pressure, and/or chemical processes.
Foliated – has visible layers or bands
Unfoliated – w/out visible layers