1	Rocks and the Rock Cycle (Set up for Cornell Notes)
2	What are rocks? Rocks are made of a mixture of minerals & other materials video
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4	Igneous Rocks (a bit more detail) Formed from lava or magma (Both are molten or liquid rock) Magma= underground Lava = above ground 2 basic types of igneous rock Intrusive/Plutonic– form when magma cools Large crystals (coarse-grained) Extrusive/Volcanic– form when lava cools Small crystals (fine-grained) Think: Why are the crystal sizes different?
5	Intrusive Igneous Rock Rocks form from magma cooling beneath Earth’s surface Takes a long time to cool and harden Coarse (large) grained Crystals form and grow (granite)
6	Intrusive Igneous Rock Rocks crystallize from cooling magma
7	Extrusive Igneous rocks Forms from magma that is brought to Earths surface (lava) Lava cools more rapidly so crystals do not have time to form or are small and difficult to see Fine grained or lacking crystals like Obsidian
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9	Are there other kinds of Igneous Rock? Yes. But they are still classified as intrusive or extrusive.
10	Are there other kinds of Igneous Rock? Yes. But they are still classified as intrusive or extrusive.
11	Sedimentary rocks (more about ‘em) Formed from compressed (squeezed) or cemented layers of sediment There are 3 types Clastic – formed from mechanical weathering debris or pieces of other rocks that are glued together. (ex. Sandstone) Chemical – formed by precipitation of different elements dissolved in water. Organic – formed from remains of living things
12	How sedimentary rock is formed Like soil or dirt, they are products of weathering that form at or near Earth’s surface. Weather or nature is the major factor here. For example: Water Rivers cutting through Ice Rain Earthquakes
13	How it becomes Sedimentary rock The rock is formed from weathered debris that is carried from one place to another, redeposited, buried, and then hardened into rock. Sediments are compressed from the weight above the forming rock.
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17	Sedimentary rock Rocks that contain fossils are sedimentary rock. Why will you only find fossils in sedimentary rock?
18	Metamorphic Rock A rock that forms from other rocks as a result of intense heat, pressure, or chemical processes.
19	Metamorphic Rock Some examples: Limestone à marble
20	The Rock Cycle! Animation! http://www.classzone.com/books/earth_science/terc/content/investigations/es0602/es0602page02.cfm
21	Evidence of Ancient Life Fossils are usually found in sedimentary rocks Paleontologists are scientists who study fossils
22	Kinds of Fossils Petrified: minerals replace tissue of dead/buried organism Mold: hollow impression left by an organism Cast: copy of organism’s shape (fits the mold) Carbon film: thin layer of carbon left by organism (looks like a drawing)
23	"Trace Fossil:" Trace Fossil: fossilized evidence of an organism’s activities Preserved remains: remains of life w/little or no change
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25	Fossils and Past Environments Fossils help scientists understand how the Earth’s climate, environment, and life forms have changed through time
26	Finding the Relative Age & Absolute Age of Rocks Relative age is a comparison. “older” and “younger” Absolute age is a number.
27	Position of Rock Layers Law of superposition: In horiz. layers of sed. rocks, the oldest layer is at the bottom, and higher layers are younger than the layers beneath them.
28	Other Clues to Relative Age Igneous intrusions are always younger than the layers of rock that surround them Index fossils tell the relative age of the rock layer they are found in
29	Absolute Ages from Radioactive Dating Scientists use the rate of radioactive decay to determine the absolute age of an igneous rock layer (Why only igneous?) Radioactive decay has been used to determine that the Earth is at least 4.6 billion years old
30	Igneous Rock Concept Map Word List Igneous Rock Intrusive Extrusive Fine Grained Silica Course Grained Magma Lava Light Colored Dark Colored
31	Sedimentary & Metamorphic Rock Concept Map Word List Clastic Chemical Organic Precipitation Sediment Water Ice Earthquakes