3 Types of Rocks
How Igneous Rocks Form: When molten rock (lava) cools and becomes solid Intrusive: cools slowly Extrusive: cools quickly
Description of Igneous Rocks: Contains bubble-like holes Hard Bubbly texture Formed above or below earth’s surface
Examples of Igneous Rocks: Granite Basalt Pumice
How Metamorphic Rocks Form: When heat and pressure cause older rocks to change into new types Formed deep in the earth
Description of Metamorphic: Fine texture Has bands or streaks of minerals Usually made of quartz and calcite
Examples of Metamorphic: Marble – comes from limestone Slate – comes from shale Quartzite – comes from sandstone
How Sedimentary Rocks Form: When rocks, plants, and loose material get pressed into layers over time Involves weathering and erosion
Description of Sedimentary: Has layered features Very soft (easily scratched) Contains fossils Made of particles cemented (pressed) together
Sedimentary Examples: Limestone – made from seashells Shale – made from mud Sandstone – made from sand