April 27 th Review Drill: You find an igneous rock with both coarse and fine grains. Describe how this rock could have formed. Objective: SWBAT review basic concepts of the Rock Cycle in order to prepare for the test.

Rocks Igneous: Formed by molten material either lava or magma. Sedimentary: Created from compaction and cementation of layers of sediment and remains of organisms. Metamorphic: When a rock undergoes extreme heat and pressure causing it to change forms.

Sedimentary Rocks Formed over millions of years. Compaction: Pressure from layers (and/or oceans) above. Cementation: Minerals dissolved to form materials that bind the sediment together. ****Fossils normally found in this type of rock. ****Typically rock forms in layers

Types of Sedimentary Rocks Clastic: Larger pieces of sediment that form rocks under pressure. Organic: Rocks formed from living materials Chemical: Rocks that are “glued” together through mineral solution.

Comparing Rocks Texture: Grain Size Coarse vs. Fine Grain Shape Smooth & rounded Rough & jagged Grain Pattern Flat layers Wavy, swirling Rows of beads No pattern No Visible Grain Mineral Composition: Microscope Acid test Magnetic Origin: Igneous Sedimentary Metamorphic

Igneous Formed from volcanic material Intrusive: Formed from magma in the Earth Extrusive: Formed from lava on top of the layers. Grain size is determined by cooling rate.

Metamorphic Rocks Form from existing rock exposed to extreme heat and pressure. Folliated: Rock arranged in layers or bands. Non-folliated: Random pattern Contact Metamorphism: Rock comes in contact with an intrusion of magma Fault metamorphism: Rock exposed to extreme pressure from plate movement.

Rock Cycle Rocks can change from one type to another through a series of events. Weathering and Erosions – Sediment – Compaction/Cementation = Sedimentary rocks. Melting – magma – cooling = Igneous rock Extreme Heat and Pressure = Metamorphic