DO NOW Turn in your video sheet. Pick up the notes sheet.

LOOKING BACK… What evidence did Wegener use to support his theory of Continental Drift? Why wasn’t he taken seriously at the time?

ROCK CYCLE SES1. Students will investigate the composition and formation of Earth systems, including the Earth’s relationship to the solar system. . e. Identify the transformations and major reservoirs that make up the rock cycle

MINERALS BUILDING BLOCKS OF EARTH’S CRUST Minerals are naturally occurring, inorganic, crystalline, homogeneous solids. Two types: Silicates and Non-silicates Most common rock forming minerals: Quartz, Orthoclase, Plagioclase, Muscovite. Biotite, Calcite, Pyroxene, Amphibole, Olivine

ROCKS ARE MADE UP OF MINERALS Made up of a mixture of minerals. May contain a single mineral or a collection of many different minerals. Classified by process of formation. No definite shape or color. 30 common minerals make up most of Earth’s rock. Unique chemical composition (pure substance). Classified by chemical composition. Consistent color and shape.

ROCK CYCLE Earth’s crust is recycled. Ongoing process that forms and recycles rock. Changes caused by tectonic forces, weathering and erosion. Include igneous, sedimentary, and metamorphic rocks.

IGNEOUS ROCK Igneous rock forms when magma rises from the Earth’s interior and cools. Magma is a hot liquid made of melted minerals. Lava is magma that reaches the surface. Igneous means “Born of Fire”.

Did they cool FAST (small) or SLOW (large)? IGNEOUS ROCK Igneous rocks crystallize as they cool. Cooling slowly produces larger crystals. Cooling quickly produces small crystals, or sometimes no crystals. What size are the crystals shown below? Did they cool FAST (small) or SLOW (large)? SMALL Crystals Cooled FAST LARGE Crystals Cooled SLOW

IGNEOUS ROCK: Below or Above the Surface? Extrusive Igneous Intrusive Igneous Cool BELOW the Earth’s surface. Because they cool slowly, they often have large crystals. Examples: Cool ABOVE the Earth’s surface. Because they cool quickly, they often have small or no crystals. Includes Volcanic Rock: Little gas in rock = glassy - obsidian Large amount gas = vesicular – trapped gas in bubbles - pumice Examples:

SEDIMENTARY ROCKS Any exposed rock can become sedimentary rock (igneous, metamorphic or sedimentary). WEATHERING breaks down rocks into sediment, can be: Mechanical - wind, rain and ice Chemical - acid rain or oxidation Sedimentary rocks can contain fossils and tell us what the Earth's surface was like in the geologic past.

SEDIMENTARY ROCKS Broken down rocks are carried away by EROSION. These particles eventually are DEPOSITED. Over a long period of time layers are compressed. Then these layers are CEMENTED or glued together to form sedimentary rock.

SEDIMENTARY ROCKS Cover approximately 80% of the Earth's crust Sediments are often seen in layers . Can be cemented together by minerals. A thin unit of rock with the same characteristics throughout is called a bed. Beds with similar character that were laid down in a continuous sequence is called a formation. Examples of sedimentary rocks include:

Sedimentary Rock Three basic processes: Clastic – forms from deposition and cementation of sediment – deposition determines how particles are sorted. Chemical – forms when minerals precipitate from a solution or settle from a suspension. Organic – forms from remains of living organisms (shells, etc.).

METAMORPHIC ROCK Metamorphic means "to change form“. HEAT and PRESSURE cause the minerals in the rock to become unstable so they reform and the layers rearrange. This process happens because of both heat and pressure, but the rocks do NOT melt!

METAMORPHIC ROCK TYPES Metamorphic rocks can be: Foliated – minerals arranged in layers or bands. Foliated rocks can form by: High pressure and temperature which forms large bands. When minerals with different compositions separate into a series of dark and light bands. Examples:

METAMORPHIC ROCK TYPES Metamorphic rocks can be: Non-foliated – do NOT have layers or bands. Example:

METAMORPHIC ROCK Rocks often contain minerals called geothermometers. These minerals’ presence defines a minimum temperature a rock must have achieved in order to complete the metamorphic process. Staurolite and hornblende are two examples of these.

ROCK CYCLE A.___________________ B.___________________   B.___________________ C.___________________

COMPARING IGNEOUS SEDIMENTARY METAMORPHIC Might have crystals large enough to see May have a bubbly, frothy or glassy texture May be fine-grained, uniform and hard May contain bubble-like cavities that may be lined with minerals It can’t contain fossils. Contains parallel bands of different substances. It is soft enough to be scratched easily. Obviously made up of different particles. May contains fossils. Has a fine, uniform texture. May contain streaks or clumps of minerals. May contain minerals like garnets. Foliations are zig-zags or vein – like It can’t contain fossils.

SCIENCE SONG: THE ROCK CYCLE

REVIEW…. Which type of rock is: Cooled lava? Formed deep within Earth from heat and pressure? Cemented and compressed from sediment?

TO DO Do Review #7.