Igneous Rocks: Rocks of fire

Bell Ringer: Please copy in your IAN!Ch.4.2 Igneous RocksDescribe three ways that igneous rock forms.

Explain how the cooling rate of magma affects the texture of igneous rock.

Distinguish between igneous rock that cools within Earths crust and igneous rock that cools at Earths surface.

Igneous Rocks:Rocks of fireIgneous rock begins as magma. there are three ways magma can form:

1) when rock is heated, 2) when pressure is released, 3) or when rock changes composition.

InvestigationToday we will begin our investigation of igneous rocks by creating a visual image that relates to each of the 3 processes.This investigation will take place in the form of a lab called, Fudgeous Rock. Lets take a look at our problem to solve, the background research, and our variables that we will be manipulating today!

Problem: What happens to substances during igneous rock (fudge) formation?Research: Refer to Chapter 4, Section 2 (pgs 98-101) in your text to review information about igneous rocks. Continued rise in temperature can eventually melt any rock until it is molten (called magma). When the molten rock cools it forms an igneous rock. All three main types of rock (igneous, sedimentary, and metamorphic) can be melted to form magma.Independent Variable: (I controlusually in procedure) 5 4 3 2 1 0 _______________________________________________________________________________Dependent Variable: (what I observeanswers the lab problem) 5 4 3 2 1_______________________________________________________________________________Hypothesis: (If + IV + then + DV) 20 15 10 5 0___________________________________________________________So lets take a closer look at our minerals/ingredients that we will turn into magma and igneous rocks1) When magma cools enough, it solidifies to form igneous rock. Magma solidifies in much the same way that water freezes.

2) Liquid magma is a complex mixture containing many melted minerals. Because these minerals have different melting points, some minerals in the magma will freeze or become solid before other minerals do.

Mineral Identification:Now, lets complete a comparison study of a few common minerals/rocks that could resemble todays variables that we will manipulate.Dependent Variable(y)IngredientPhysical Properties(include the phase of matter)Earth Ingredient(what real substance under the surface of the earth does this ingredient remind you of)Final Observation(what did the ingredient look like in the end) Did it change? HOW did it change? (YES or NO) (disappear, melt? include color & phase)sugarevaporated milkbutterMarshmall-owschocolate morsels

KaolinGraphiteBasaltCalciteMarbleSulfurMicaHaliteHow do they form?When hot, liquid rock ________ cools and solidifies.If it cools quickly, it is _____________.If it cools slowly, it is ______________.It takes our fudgeous rock 2 hours to cool and harden. Is that fast or slow? How would we know?Origins of Igneous Rock3 ways magma can form:________________________________________________________Changes composition

It solidifies through freezing. 0 degrees Celsius vs. 1,000 degrees CelsiusSome minerals freeze faster than others. This can give igneous rocks unique texturesComposition and TextureNot all igneous rocks look alike.Cooling rate and mineral compositionLight color = ________ __________ (felsic)Dark color= ________ (mafic rocks)The longer it takes magma to cool, the larger the crystals(demo)

Fine/AboveCoarse/BelowFormation:Weird Science FactSome igneous rocks form from cooling on the surface, but some form ___________________.

Intrusive rock igneous rock that formed when magma hardened beneath Earths surface.Larger Crystals!The most abundant intrusive rock in the part of the crust makes up the continents is granite.Granite forms the core of many mountain ranges.

Originwhere Extrusive are formed

Extrusive rockigneous rock formed from lava that erupted onto Earths surface.Smaller Crystals!The most common extrusive rock is basalt. Look at the rock in the tray.Basalt forms much of the crust, including the crust beneath the ocean floor.

What about obsidian?

Comparing and Contrasting

Materials -granite and basaltWhich parts of the Earths crust are composed mostly of one or the other of these igneous rocks?Basalt -ocean floorGranite -continents

Uses of Igneous Rocks

Hard, dense, and durableThrough history -tools and building materialsCan you think of some uses?

Basalt/GravelObsidian/ToolsGranite/Egyptian StatuesPumice/ExfoliationLAB SummaryNow, lets complete our lab data analysis and our conclusion. Lets compare our knowledge to what we saw yesterday!Dependent Variable(y)IngredientPhysical Properties(include the phase of matter)Earth Ingredient(what real substance under the surface of the earth does this ingredient remind you of)Final Observation(what did the ingredient look like in the end) Did it change? HOW did it change? (YES or NO) (disappear, melt? include color & phase)sugarevaporated milkbutterMarshmall-owschocolate morselsLAB ConclusionConclusion: (Complete the following sentence starters in your OWN paragraph) The data states 10 My data ________________ (supports/does not support) my hypothesis. 10 My conclusion is 10 (What happens to substances during igneous rock (fudge) formation)?

https://www.youtube.com/watch?v=mxbmvG5gpAsRock TypeWhere is it formed?What is its rate of cooling?What is the grain size?IgneousXXIntrusive IgneousExtrusive Igneous