1 Rock Concept Map

2 Igneous Rocks ESRT page 6

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4 1. Igneous rocks form from the cooling and solidification of magma (melted rock)

5 LIQUID HOT MAGMA 2. Magma is a mixture of liquid rock, crystals, and gas 3. Magma is less dense than surrounding rocks, and will therefore move upward

6 B. Types of Igneous Rocks1.The cooling rate of magma differs, causing the crystal size to also differ

7 a. intrusive igneous rocksForms by the slow cooling of magma underground “IN” –trusive / “IN” the ground Also known as PLUTONIC

8 Because underground cooling is SLOWER:Rock crystals are LARGER & have a coarse texture

9 gabbro pegmatite granite

10 Granite Mineral Composition

11 b. Extrusive igneous rocksFast cooling of LAVA (magma that has reached earth’s surface)

12 Lava flows forming extrusive igneous rocks (obsidian)

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14 Because the lava Cools QUICKLY (exposed to colder air), rock crystals are SMALL and rocks have a fine/glassy texture

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16 Rate of Cooling Activity- DO NOT WRITEWhen I say “Go” try to find other students in the class who have the same color that you have- PLEASE WALK! When I say “Stop”, stop exactly where you are and do not move until I say “GO” again What happened as I gave you a longer amount of time to find each other?

17 Pumice is an Extrusive Igneous Rock that is VESICULAR (has gas pockets). Because pumice formed so quickly, the rock formed around the pockets of gas, creating “holes” in the rock. This allows the rock to float in water because of its lower density

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20 All light in color, low in density, made up of the same minerals, and felsic in composition…. What’s the difference? COOLING TIME!

21 -Rock texture is by SIGHT/SIZE, not by TOUCHKey idea: -The texture of the igneous rock is determined by the size, shape, and arrangement of the mineral crystals NOT if it is smooth or bumpy -Rock texture is by SIGHT/SIZE, not by TOUCH

22 types of magma FELSIC MAGMA MAFIC MAGMA Light coloredThick (high viscosity) Contains high amounts of silica Ex. Granite MAFIC MAGMA Dark colored Thin (low viscosity) Contains high amount of magnesium & iron Ex. Basalt

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24 Mafic or Felsic?

25 the “bells & whistles” for identifying an IGNEOUS rockObvious crystals in a random order Glassy texture Air pockets

26 Igneous Rock Video Watch the video and write down 3 noteshttps://www.youtube.com/watch?v=Uvft8XI4nao