IGNEOUS ROCK Volcanoes eject molten rock Molten rock=magma Flows when hot and becomes a solid when it cools Hardened, cooled magma is called igneous rock.

Magma Temperatures of magmas range from about 650° to 1,200°C, depending on their chemical compositions and pressures exerted on them. Earth’s heat to melt rocks comes from interior Radioactive decay of elements is main source of heat. Magma is less dense than surrounding rock, which forces it upwards When magma reaches Earth’s surface and flows from volcanoes, it is called lava.

Instrusive Rocks Atoms and compounds in the liquid rearrange into new crystals called mineral grains, when magma cools Rocks form when mineral grains grow together. Rocks from magma below the surface are called intrusive igneous rocks.

Extrusive Igneous Rock Extrusive Rock forms when magma cools on Earth’s surface Magma exposed to air and water, thus cools quickly.

Volcanic Glass Pumice, obsidian, and scoria are examples of volcanic glass. Rocks cooled so quickly few or no mineral grains formed. Pumice and scoria, gases become trapped in the gooey molten material as it cools.

Basaltic Rock Basaltic igneous rocks are dense, dark-colored rocks. Rich in iron and magnesium and poor in silica. FE and MG gives them dark color Basaltic Lava is fluid and free flowing. http://www.youtube.com/watch?v=r3HyGTrgt7k

Granitic and Andesitic Rock Granitic igneous rocks are light-colored rocks of lower density than basaltic rocks. Thick and stiff magma, high in silica, and low in Mg and FE. Andesitic igneous rocks have mineral compositions between those of basaltic and granitic rocks

Igneous rock is formed by __________. A. cooling of hot magma B. change in pressure C. compression of loose materials D. pressure from watery fluids

What is the difference between intrusive and extrusive igneous rock? Intrusive igneous rocks form from magma below Earth’s surface. Extrusive igneous rocks form from lava flowing at Earth’s surface.

Which of the following is a volcanic rock that contained trapped gases during its formation? A. marble B. pumice C. sandstone D. slate

Igneous Rock Venn Diagram (22) Create a Venn Diagram comparing and contrasting Basaltic, Andesitic, and Granitic Rock. Draw a picture to illustrate the difference between the different igenous rocks. Write a level 1 or 2 question and its answer for EACH of the following ideas: Igneous Rock Lava Instrusive rock Extrusive rock Volcanic glass