Study Guide for Test on Friday, October 17th Rocks and Minerals Study Guide for Test on Friday, October 17th

Continental Drift Remember that Wegener’s Theory of Continental Drift states that the continents were once joined together as a super-continent called Pangaea.

Besides the puzzle-like fit of the continents, the best evidence for his theory includes similar types of rocks and fossils, the remains of a plant or animal that have been cast in rock.

Minerals Minerals are: Naturally occurring Inorganic (nonliving) Solid Things that have a definite chemical composition and crystalline structure

You try! SALT Vs. SUGAR Solid Solid Crystal Structure Crystal Structure Inorganic Organic (comes from something living)

Answer: Salt is the mineral. It meets all the requirements in the definitions of mineral. Sugar is NOT a mineral. It does not meet one of the requirements to be a mineral. Sugar is organic because it comes from a plant.

Minerals are identified by using their properties: Color Luster – the way in which a mineral reflects light

Streak – the color of the powder of a mineral Cleavage – the splitting of a mineral along smooth, flat surfaces Fracture – the manner in which a mineral breaks along either curved or irregular surfaces

Hardness – a measure of the ability of a mineral to resist scratching; Diamond is the hardest mineral; Talc is the softest mineral

Density – the ratio of the mass of a substance to the volume of a substance; “how much stuff is packed into a certain amount of space”

Graphite is used to make pencil lead. Minerals Jam http://www.youtube.com/watch?v=-F0IA21bgmM

Rocks The most useful way to identify a rock is by its mineral content. Different colors in rocks are due to the different minerals in them.

Rocks are classified by how they are formed, and there are three types of rocks – sedimentary, igneous, and metamorphic. One type of rock can be changed into another by undergoing the rock cycle. When old rock is changed into new rock during the cycle, it takes a very LONG time. Not all rocks go through the entire cycle.

Rock Cycle Clip http://www.youtube.com/watch?v=pm6cCg_Do6k

Sedimentary Rocks Sedimentary rocks are formed by weathering (when wind, water, and ice break down rocks into sediment), erosion (when soil and sediment is moved from one place to another), and deposition (the process in which material is laid down).

Layers of sediment are pressed and cemented together to form sedimentary rock. Most fossils are found in sedimentary rock. Sandstone is an example of a sedimentary rock.

Sedimentary Rocks form in areas of deposition.

See how individual pieces of sediment and sand have stacked on top of each other and pressed down so tightly it hardened into a solid rock.

Sedimentary Rock Animation Interactives . The Rock Cycle . How Rocks Change

Igneous Rocks Igneous rock forms when hot, liquid rock, or magma, cools and solidifies. (Magma is formed underground, but it is called lava when it reaches the surface.) Volcanos are associated with igneous rocks.

Intrusive vs. Extrusive Rock Intrusive igneous rock is formed beneath the Earth’s surface. Because of the slow cooling time, large crystals are formed. Extrusive igneous rock is formed on the Earth’s surface, and since it cools quickly, very small or no crystals are formed.

Intrusive igneous rocks have time to form large crystals. Granite

An underground cave in Mexico- magma cooled very slowly- lots of time for crystals to form.

Mount Rushmore is carved from granite in the Black Hills of South Dakota. Stone Mountain is made of Granite, an igneous rock.

Extrusive Igneous Rocks Cool quickly on the outside of the volcano- little or no crystals! BASALT: Basalts are dark colored, fine-grained extrusive rock. The mineral grains are so fine that they are impossible to distinguish with the naked eye or even a magnifying glass. They are the most widespread of all the igneous rocks. Most basalts are volcanic in origin and were formed by the rapid cooling and hardening of the lava flows. Some basalts are intrusive having cooled inside the Earth's interior. PUMICE: Pumice is a very light colored, frothy volcanic rock. Pumice is formed from lava that is full of gas. The lava is ejected and shot through the air during an eruption. As the lava hurtles through the air it cools and the gases escape leaving the rock full of holes. Pumice is so light that it actually floats on water. Huge pumice blocks have been seen floating on the ocean after large eruptions. Some lava blocks are large enough to carry small animals. Pumice is ground up and used today in soaps, abrasive cleansers, and also in polishes. GRANITE: Granite is an igneous rock that is composed of four minerals. These minerals are quartz, feldspar, mica, and usually hornblende. Granite forms as magma cools far under the earth's surface. Because it hardens deep underground it cools very slowly. This allows crystals of the four minerals to grow large enough to be easily seen by the naked eye. Look at the photo of granite above, notice the different crystals in the rock. Granite is an excellent material for building bridges and buildings because it can withstand thousands of pounds of pressure. It is also used for monuments because it weathers slowly. Engravings in the granite can be read for hundreds of years, making the rock more valuable. Granite is quarried in many places in the world including the United States. The State of New Hampshire has the nickname "Granite State" because of the amount of granite in the mountains of that beautiful state. The Canadian Shield of North America contains huge outcroppings (surface rocks) of granite.

Animation of 2 Types of Igneous Rocks Interactives . The Rock Cycle . How Rocks Change

Metamorphic Rocks Metamorphic rocks are rocks in which the structure, texture, or composition have changed. Metamorphic rocks are formed by extreme heat and pressure.

Marble is an example of a metamorphic rock.

Animations Observe an animation of metamorphic rocks forming. Interactives . The Rock Cycle . How Rocks Change

Rock Cycle Song http://www.youtube.com/watch?v=lE3jR_RhxO4

Rock Cycle Song (Sing to the tune of "Row, Row, Row Your Boat") SEDIMENTARY rock Has been formed in layers Often found near water sources With fossils from decayers. Then there's IGNEOUS rock Here since Earth was born Molten Lava, cooled and hardened That's how it is formed. These two types of rocks Can also be transformed With pressure, heat and chemicals METAMORPHIC they'll become.

“We Will Rock You” http://www.youtube.com/watch?v=hAMBkoLhTBY

Fossils Studying fossils helps us learn how the Earth’s environment has been changed. In large sections of sedimentary rock, the oldest fossils will be found in the bottom layer.

Sometimes fossils from ocean animals are found on tops of mountains Sometimes fossils from ocean animals are found on tops of mountains! That means that the mountain was once covered by the ocean a very long time ago and the mountain was raised up due to the movement of lithospheric plates.

Fossil Fuels Fossil fuels can be obtained by surface mining, strip mining (removing long strips of overlying soil and rock), and drilling wells. The energy found in fossil fuels originally came from the Sun.

Petroleum and natural gas form mainly from decayed sea organisms. Smog is the photochemical base formed when sunlight acts on industrial pollutants and burning fuels.