Igneous Rocks 6th Grade Science Mrs. Pancake Contact Teacher Summer 2003

So, What’s the difference? How are they formed? Lava Magma So, What’s the difference?

Lava Magma Magma: molten material inside the earth’s surface. Lava: molten material outside the earth’s surface.

Intrusive Rocks Magma Gabbro Diorite Granite Peridotite

When magma underneath the surface cools, Intrusive Rocks are formed When magma underneath the surface cools, Intrusive Rocks are formed. They cool slowly, allowing visible crystals to form.

Texture Large,Visible Crystals Coarse-Grained Close up of Granite Close up of Diorite Coarse-grained texture can also be called phaneritic texture.

Extrusive Rocks Lava

When the lava from a volcano cools and hardens, Extrusive rocks are formed. The lava cools too quickly for visible crystals to form.

Texture 1. Very rapid cooling a. No Crystals---Shiny---Glassy b. No Crystals---Holy---Vesicular rapid gas escaping Close-up of Obsidian

Texture Close-up of Basalt 2. Quick Cooling a. Small crystals---fine grained Close-up of Rhyolite

Credits Basalt image, Pumice image, Rhyolite image, Obsidian image: http://volcano.und.nodak.edu/vwdocs/vwlessons/lessons/Igrocks/Igrocks1.html Magma image: http://www.iss.k12.nc.us/schools/ems/falcons/Goldrick%20Science/Igneous%20Rocks.htm Granite image: http://sln.fi.edu/fellows/payton/rocks/expert/granite.htm Volcano: http://volcano.und.nodak.edu/vwdocs/vwlessons/lessons/Igrocks/Igrocks3.html Lava image: http://www.zero-kelvin.com/hi02/000204.php :

Igneous rock creation image: http://www.geocities.com/RainForest/Canopy/1080/ igneous_formation.htm Diorite image: http://geology.csupomona.edu/alert/igneous/iddiorite.htm Gabbro image: http://geology.csupomona.edu/alert/igneous/idgabbro.htm Peridotite image: http://geology.csupomona.edu/alert/igneous/idperidotite.htm Magma image: http://pubs.usgs.gov/gip/volc/types.html Phaneritic texture image: http://geology.csupomona.edu/alert/igneous/texture.htm

Close-up of Rhyolite: http://www. geolab. unc Close-up of Basalt: http://www.geolab.unc.edu/Petunia/IgMetAtlas/volcanic-micro/vesicles.X.html Close up of Obsidian: http://www.geolab.unc.edu/Petunia/IgMetAtlas/volcanic-micro/vitrophyre.X.html Close up of Diorite: http://www.geolab.unc.edu/Petunia/IgMetAtlas/plutonic-micro/sieve.X.html Close up of Granite: http://www.geolab.unc.edu/Petunia/IgMetAtlas/plutonic-micro/poikilitic1.X.html