Transcript Rocks


*observe color and texture to determine mineral
composition

Texture- look & feel of rock’s surface






Grains- particles of minerals or other
rocks.
Size
Shape
Pattern
No visible grain

Origin
• Igneous
• Sedimentary
• Metamorphic
 *Most
abundant on Earth
 *Formed
from cooling of molten rock
 *Classified
as intrusive or extrusive
Animation
http://www.classzone.c
om/books/earth_scienc
e/terc/content/investiga
tions/es0603/es0603pa
ge05.cfm
 Intrusive
 *Cooling
of magma below Earth’s surface
 *slow rate of cooling
 *Large mineral crystals
 *Coarse-grained texture
 *Examples: granite, gabbro, diorite,
pegmatite
 Extrusive
 *Cooling
of lava on Earth’s surface
 *Fast rate of cooling
 *Small or no mineral crystals
 *fine-grained texture if small crystals
 *glassy texture if no crystals
 *Examples: basalt, obsidian, pumice,
scoria, rhyolite
 *Some
rocks begin to cool deep
underground when suddenly magma is
forced to the earth’s surface. This rock
will have large mineral grains
surrounded by fine mineral grains. This
texture is called porphyry.
 *lava
low in silica usually forms darkcolored rocks such as basalt
 *magma
that is high in silica usually
forms light-colored rocks such as granite
 http://player.discoveryeducation.com/in
dex.cfm?guidAssetId=24F28C84-AB7F4F93-92376FA426079138&blnFromSearch=1&produ
ctcode=US
 Sediment-
small, solid pieces of material
that come from rocks or living things.
1. Rock fragments and sediments are
moved by erosion.
2. Erosion slows down and sediments
are deposited.
3. Layers of sediments build up and they
become compacted into rock.
4. Minerals in the rock dissolve in water.
The dissolved minerals seep into
spaces between the sediments and act
like a glue, cementing them together.
http://www.classzone.com/books/earth_science/terc/
content/visualizations/es0605/es0605page01.cfm?ch
apter_no=visualization
1. clastic- formed when rock fragments
are squeezed together.
 shale- clay particles
Sandstone
 sandstone- sand
 comglomerate- mixture of rock
fragments of different sizes
Conglomerate
Shale
2. organic- from remains of living
matter.
 coal- swamp plants
 limestone- shells or skeletal remains of
living things
Limestone
Coquina
Coal
3. chemical- form when minerals
dissolved in solution crystallize.

limestone

rock salt (halite)
Limestone
Halite
 http://player.discoveryeducation.com/in
dex.cfm?guidAssetId=36566049-E79142CF-8FE2494F33FA9983&blnFromSearch=1&produ
ctcode=US
 *Formed
from heat and pressure deep beneath
Earth’s surface.
 *Form
from igneous, sedimentary or other
metamorphic rocks.
 *Results
in a change in
a rocks texture,
crystal structure &
mineral content.
 *Heat
comes from rock being pushed down
close to the mantle at converging plate
boundaries, or by magma rising through the
crust.
 *The
deeper the rock, the more pressure.
 *Classified
by the arrangement of the
grains in the rock (foliated or nonfoliated)
 *Foliated-
mineral grains are arranged
Animation
in parallel bands
 Ex: slate, gneiss
http://www.classzone.com/books/earth_science/terc/content/visu
alizations/es0607/es0607page01.cfm?chapter_no=visualization
Shale
Slate
Gneiss
Granite
 *Nonfoliated-mineral
grains are arranged
randomly.
 Ex: marble, quartzite
Limestone
Marble
Quartzite
Sandstone
 http://player.discoveryeducation.com/in
dex.cfm?guidAssetId=CDDA0692-8F8B461C-9F0486D58B7A2A03&blnFromSearch=1&prod
uctcode=US
 Rock
Cycle- series of processes on
Earth’s surface and inside the planet that
slowly change rocks from one kind to
another.
 Constructive
and destructive forces move
rocks through the cycle.
 http://player.discoveryeducation.com/in
dex.cfm?guidAssetId=4B67887F-E1F14992-A9E11FC91726A237&blnFromSearch=1&prod
uctcode=US
 http://www.classzone.com/books/earth_
science/terc/content/investigations/es06
02/es0602page02.cfm
 http://www.phschool.com/atschool/phsc
iexp/active_art/rock_cycle/index.html