Download Igneous Rocks

Rock Notes- 3 types of
Rock
Rock Notes
A) Rock- a mixture of minerals and other materials
1. Mineral- a naturally occurring, inorganic solid with
a crystal structure and definite chemical make up
2. The basic building blocks of rocks are minerals.
B) Rock Classification: Origin- rocks are mainly
classified by how they are formed
1) Igneous rock- forms from the cooling of molten rock
(magma or lava)
(a) Extrusive Rock- igneous rock formed from lava that erupted
onto Earth’s surface; basalt is the most common extrusive
rock
(b) Intrusive Rock- igneous rock that formed when magma
hardened beneath Earth’s surface; granite is the most
common intrusive rock
Igneous Rocks…..
©Texture- depends on the size and shape of the mineral
crystals
(i) Fine-grained- rapid cooling
(ii) Glassy- rapid cooling
(iii) Coarse, large, or medium grained- slow
cooling; the slower magma cools, the larger the
crystals
Sedimentary Rock
(2) Sedimentary rock- forms when particles of other rocks or the
remains of plants and animals are pressed and cemented
together
(a) Processes that turn sediment to rock
(i) Weathering- breaks rock down into sediment
(ii) Erosion- moving of sediment to a new location
(iii) Deposition- dropping of sediment
(iv) Compaction- presses sediment together
(v) Cementation- dissolved minerals crystallize and glue
particles of sediment together
Types of Sedimentary Rocks
• (i) Clastic- a sedimentary rock that forms when rock fragments
squeeze together like shale, sandstone, and conglomerate
• (ii) Organic- forms when layers of plants and animals are deposited
in thick layers like coal and limestone
• (iii) Chemical- form when minerals that are dissolved in a solution
crystallize or from mineral deposits that are left when seas or lakes
evaporate like rock salt
Metamorphic rock
(3) Metamorphic rock- formed when an existing rock is changed by heat
and/ or pressure
(a) Foliated- grains arranged in parallel layers or bands like slate,
schist, and gneiss
(b) Nonfoliated- mineral grains are arranged randomly like marble
and quartzite
Rock Cycle
C) Rock Cycle- forces inside the Earth and at the
surface produce a rock cycle that builds, destroys, and
changes the rock in the crust; the series of processes on
and beneath Earth’s surface that slowly change the rock
from one kind to another
(1) Any rock can change into another type of rock; rocks of
the same type can turn into a new rock of that type
Look at these pictures of rocks.
•How are they different?
•How are they the same?
IGNEOUS
ROCK TYPES
SEDIMENTARY
METAMORPHIC
Igneous Rocks – ‘fire rocks’
Igneous rocks are made either
underground or above ground.
Igneous Rocks – ‘fire rocks’
• Underground: melted
rock, called magma, cools
slowly and becomes
igneous rocks. (Intrusive)
Igneous Rocks – ‘fire rocks’
• Above ground:
volcanoes erupt,
bringing magma to
the earth's surface,
it is called lava. The
lava cools and
becomes igneous
rocks. (extrusive)
Igneous Rocks – ‘fire rocks’
Granite
Basalt
Pumice
Sedimentary Rocks – ‘sandwich rocks’
• For millions of
years, little pieces of
our earth (called
sediments) have
been broken down
by wind and water.
Sedimentary Rock – ‘sandwich rocks’
• These little bits of
our earth are
washed to the
bottom of the
rivers, lakes, and
oceans where they
settle.
Sedimentary Rock – ‘sandwich rocks’
• Many layers of small pieces of earth collect on top
of each other in layers. These layers are pressed
down more and more until the bottom layers
slowly turn into hard rock.
Sedimentary Rock – ‘sandwich rocks’
Limestone
Coal
Sandstone
Metamorphic Rock – ‘changing rocks’
Metamorphic rocks are rocks that have
"morphed" or changed into another kind of rock.
These rocks were once igneous or sedimentary
rocks.
Metamorphic Rock – ‘changing rock’
• Millions of tons of heat and pressure
have made these rocks change.
Metamorphic Rock – ‘changing rock’
Marble
Slate
Quartzite
Igneous rocks
Sedimentary rocks
Metamorphic rocks
Basalt
Limestone
Marble
Granite
Sandstone
Slate
Rhyolite
Coal
Gneiss
Gabbro
Mudstone
Schist