Let’s take a closer look. What Are Rocks? Let’s take a closer look.
Rocks Rocks are a mixture of minerals and other materials. Basically, rocks are pieces of the crust. Three types of rock: Igneous, Sedimentary, and Metamorphic
Processes of Rock Changes Weathering Erosion Compaction Cementation Melting Cooling (Freezing?)
Rock Cycle
Igneous Rocks What first comes to mind when I say igneous? Rock formed from magma or lava when it cools.
Igneous Rock Three types of Igneous: Basaltic, Andesitic, Granitic Formed inside Earth- Intrusive rock Formed at or above crust- Extrusive rock
Sediments Weather- break down of rock. Spectacular Demonstration of Weather Erosion carries broken down rock to other locations.
Sedimentary Rock Sediments precipitate out of solutions to form strata. The sediments are compacted and compressed in a process called lithification.
Fossils and Law of Superposition What is a fossil? The trace or remains of an organism that lived long ago, most commonly preserved in sedimentary rock What is the Law of Superposition? Younger rocks lie above older rocks if the layers have not been disturbed
Index Fossils
Relative Age Dating and Index Fossils What is relative age dating? Determining whether an event or object is older or younger than other events or objects. What is an index fossil? A fossil that is used to establish the age of the rock layers. It is found in the rock layers of only one geologic age. It is found in rock layers around the world. ex Trilobites
Metamorphic Rock Conversion of rock from one form to another by heat and pressure. As you decrease in depth 1 km temperature rises 300 C. Two types of Metamorphic: Foliated- Stripped or banding (slate, gneiss) Nonfoliated- plain with no banding (marble)