Igneous, Metamorphic, Igneous, Metamorphic, and Sedimentary Rocksand Sedimentary Rocks

Igneous RockIgneous Rock Igneous rocks come from two major Igneous rocks come from two major

sources: sources: – MagmaMagma – LavaLava

Who can explain the difference between Who can explain the difference between the two?the two?

Magma comes is liquid rock Magma comes is liquid rock beneathbeneath the surface, the surface, it becomes Lava when it reaches the surface of it becomes Lava when it reaches the surface of

the Earth.the Earth.

Igneous rocks formed from magma Igneous rocks formed from magma are formed ________ (where?), and are formed ________ (where?), and they are called they are called plutonicplutonic, or , or intrusiveintrusive igneous rocks.igneous rocks.

Igneous rocks formed from lava are Igneous rocks formed from lava are formed ________, and they are called formed ________, and they are called volcanic,volcanic, or or extrusiveextrusive igneous rock. igneous rock.

Two Major Types of MagmaTwo Major Types of Magma FelsicFelsic – – Composition of mostly feldspar Composition of mostly feldspar

and silica. Slow moving, and solidifies and silica. Slow moving, and solidifies as a as a hard grainy rockhard grainy rock like Granite. like Granite. Most plutonic rocks are Felsic.Most plutonic rocks are Felsic.

MaficMafic – – High composition of High composition of magnesium and iron. It’s hotter, magnesium and iron. It’s hotter, thinner and faster moving. Solidifies thinner and faster moving. Solidifies as a as a dark materialdark material like basalt. like basalt.

TexturesTextures(An overview)(An overview)

Depends on size, shape, and arrangement of Depends on size, shape, and arrangement of crystals.crystals.

Examples: Obsidian – smooth and glossy. Granite is rough Examples: Obsidian – smooth and glossy. Granite is rough and grainy.and grainy.

The The longerlonger magma stays liquid, and the magma stays liquid, and the more more gasgas that is trapped within it, the larger the that is trapped within it, the larger the crystals. (Example: The grains in Granite are crystals. (Example: The grains in Granite are crystals)crystals)

Taking from what you just learned, what type of igneous rock do Taking from what you just learned, what type of igneous rock do you think you’d find the largest crystals? Take a moment and you think you’d find the largest crystals? Take a moment and talk it over with your table!talk it over with your table!

Sedimentary RockSedimentary Rock Who can tell me what sedimentary rock is?Who can tell me what sedimentary rock is?

– Sediments are:Sediments are: Formed by the Formed by the hardeninghardening and and cementingcementing of layers of of layers of

sediments. Consist of rock fragments, plant and animal sediments. Consist of rock fragments, plant and animal remains, or chemicals that form on lake and ocean bottoms.remains, or chemicals that form on lake and ocean bottoms.

Where do the sediments come from?Where do the sediments come from?– WeatheringWeathering is primary cause. They range in is primary cause. They range in sizesize; large pebbles to sand-like grain. Wind, ; large pebbles to sand-like grain. Wind, waves, glaciers, rain, running water, etc. waves, glaciers, rain, running water, etc. What type of rocks could sediment come from?What type of rocks could sediment come from? Are sediments only made up of rock?Are sediments only made up of rock?

3 types of Sedimentary Rock:3 types of Sedimentary Rock:

1) 1) ClasticClastic – Formed from – Formed from fragmentsfragments of of other rocks. (Shale, Sandstone, conglomerate)other rocks. (Shale, Sandstone, conglomerate)

2) 2) ChemicalChemical – formed from – formed from mineral mineral grainsgrains that fall out of a solution, ( that fall out of a solution, (precipitationprecipitation), ), by evaporation or by chemical action. Rock salt by evaporation or by chemical action. Rock salt and some limestone are examples.and some limestone are examples.

3) 3) OrganicOrganic – rocks are formed from – rocks are formed from remainsremains of plants and animals. Coal, and of plants and animals. Coal, and limestone made of shell fragments are examples limestone made of shell fragments are examples

Formation of Clastic Sedimentary Formation of Clastic Sedimentary RockRock

- They form via cementation by - They form via cementation by naturalnatural cement substances such as cement substances such as Calcite (CaCO3), iron oxide (FeO), or Calcite (CaCO3), iron oxide (FeO), or silica (SiO2).silica (SiO2).

- Sometimes, - Sometimes, pressurepressure is enough is enough to bind together sediments.to bind together sediments.

You do not need to know CaCO3, FeO, or You do not need to know CaCO3, FeO, or SiO2. Just be aware that there are natural SiO2. Just be aware that there are natural cements.cements.

Metamorphic RocksMetamorphic Rocks

Formed when rocks that already exist are Formed when rocks that already exist are changed by changed by heatheat and and pressurepressure into new kinds of into new kinds of rocks. rocks. – Examples: Gneiss, slate, marble, quartziteExamples: Gneiss, slate, marble, quartzite– ** Not formed by either magma or sediment!! **** Not formed by either magma or sediment!! **

Gneiss Gneiss resemblesresembles granite, slate granite, slate resemblesresembles shale, marble shale, marble resemblesresembles limestone etc. The limestone etc. The reason for these similarities is because the rocks reason for these similarities is because the rocks that they resemble are the that they resemble are the parentparent rock. rock.

- They are formed through the action of - They are formed through the action of heat, pressure, and chemicals. heat, pressure, and chemicals.

Types of MetamorphismTypes of Metamorphism

Regional MetamorphismRegional Metamorphism - happens over - happens over largelarge areas. Plate tectonics are an excellent source of areas. Plate tectonics are an excellent source of regional metamorphism.regional metamorphism.

Shale: Rock becomes more dense and crystalline, forms Shale: Rock becomes more dense and crystalline, forms slate. If the heat and pressure is more intense, it can create slate. If the heat and pressure is more intense, it can create schist. schist.

Contact MetamorphismContact Metamorphism – Happens when – Happens when magma forces its way into magma forces its way into overlayingoverlaying rock. The rock. The heat of it bakes the rocks that are in contact with heat of it bakes the rocks that are in contact with it. The hot liquids and gases can enter into the it. The hot liquids and gases can enter into the rock and react with the minerals therein. rock and react with the minerals therein.

Review!!Review!!

Igneous comes from _________?Igneous comes from _________?

Sedimentary comes from _______?Sedimentary comes from _______?

Metamorphic comes from ________?Metamorphic comes from ________?

Each of these are Each of these are relatedrelated to each other, and they to each other, and they come together to form the come together to form the ROCK CYCLE!ROCK CYCLE!

Rock Cycle LabRock Cycle LabYou will now create your own rock cycle, and write down You will now create your own rock cycle, and write down how each cycle is related to the other using this handout.how each cycle is related to the other using this handout.

Can I get a volunteer to pass out the handouts please?Can I get a volunteer to pass out the handouts please?

Please listen carefully to the instructions, and I will also Please listen carefully to the instructions, and I will also put them up on the screen for you to read.put them up on the screen for you to read.Please maintain a clean environment to work with. If you Please maintain a clean environment to work with. If you leave a mess, I will hold you after class to help clean up. leave a mess, I will hold you after class to help clean up. You will not receive an excused tardy!You will not receive an excused tardy!Be careful, boiling water will be used, so please do not Be careful, boiling water will be used, so please do not bump, push or horseplay around it. I want NO BURNS!bump, push or horseplay around it. I want NO BURNS!

1.1. Place your newspaper on the desk in Place your newspaper on the desk in front of you. This is your work mat to help front of you. This is your work mat to help you keep things clean!you keep things clean!

2.2. I want you or your partner to come up I want you or your partner to come up and take one sheet of aluminum foil, and and take one sheet of aluminum foil, and 2 to 3 crayons, and ONE plastic knife per 2 to 3 crayons, and ONE plastic knife per group.group.

1.1. This knife is not a weapon or a toy. Anybody caught horse-playing This knife is not a weapon or a toy. Anybody caught horse-playing with it will be given a zero and will be kept after classwith it will be given a zero and will be kept after class

3.3. Peel the crayons. Place them on your foil Peel the crayons. Place them on your foil and look up when you are finished.and look up when you are finished.

4. What type of rock does this crayon resemble? (Think about the size 4. What type of rock does this crayon resemble? (Think about the size of the crystals. Can you see them? Are they grainy, smooth, of the crystals. Can you see them? Are they grainy, smooth, glossy?)glossy?)

5. Choose one of your crayons and scrape a moderate pile onto your 5. Choose one of your crayons and scrape a moderate pile onto your foil. This will be your parent rock. (You do not need to scrape the foil. This will be your parent rock. (You do not need to scrape the entire crayon out of existence)entire crayon out of existence)

6. Now make a secondary pile off of the foil. This pile should be 6. Now make a secondary pile off of the foil. This pile should be smaller.smaller.

What do these two piles represent? From what type of rocks could What do these two piles represent? From what type of rocks could these have come from?these have come from?

7.Mix them together on the center of your foil, and fold the foil together. 7.Mix them together on the center of your foil, and fold the foil together. Apply pressure and flatten the crayon shavings.Apply pressure and flatten the crayon shavings.

8.Open the foil – describe what you see. What type of rock does this 8.Open the foil – describe what you see. What type of rock does this represent?represent?

Make a boat out of your foil now, with your Make a boat out of your foil now, with your sedimentary rock in the center. Make sure sedimentary rock in the center. Make sure no water can leak into it.no water can leak into it.

When you are ready, bring your boat up When you are ready, bring your boat up front, and dip the bottom of it into the hot front, and dip the bottom of it into the hot water. Allow the crayons to melt together, water. Allow the crayons to melt together, and take them out before the colors blend and take them out before the colors blend together completely.together completely.

What type of rock does this represent?What type of rock does this represent?

Ticket out the DoorTicket out the Door

We covered the rock types, and the rock We covered the rock types, and the rock cycle.cycle.

Can you tell me the differences between igneous, Can you tell me the differences between igneous, sedimentary, and metamorphic rock?sedimentary, and metamorphic rock?Can you relate them together in the rock cycle?Can you relate them together in the rock cycle?

Ticket out the door: Relate plate tectonics Ticket out the door: Relate plate tectonics to the rock cycle on a half sheet of paper to the rock cycle on a half sheet of paper with your with your namename on it. on it.