Rocks

Rock Cycle Magma cools and solidifies through crystallization. Igneous rocks form. If exposed to the surface, igneous rocks go through weathering and become sediment. Sediment then goes through a process called lithification. This allows them to become sedimentary rock.

Types of Rocks Metamorphic Rocks Igneous Rocks Sedimentary Rocks

Sedimentary Rocks How They are Made Wind and water break down the earth Bits of earth settle in lakes and rivers Layers are formed and build up Pressure and time turn the layers to rock

Sedimentary Rocks Compacted and cemented sediment; solid material settles out of the fluid; sediment accumulates over time and is deposited by water into spaces.

Sedimentary Rocks continued… Classifying sedimentary - detrital (solid particles from weathered rocks; which is particle size and component grains) - chemical (weathering) - biochemical origins * These kinds of rocks help geologists determine Earth’s history.

Types of Sedimentary Rocks Sandstone Limestone Gypsum Conglomerate Shale

Metamorphic Rocks What are They? Rocks that have changed They were once igneous or sedimentary Pressure and heat changed the rocks

Metamorphic Rocks - means to “change form” - agents of change include heat, pressure and chemically active fluids. Classifying metamorphic rocks: Foliated (fine-grained) Non-foliated (coarse)

Types of Metamorphic Rocks Schist Gneiss

Igneous Rocks What are They? Fire Rocks Formed underground by trapped, cooled magma Formed above ground when volcanoes erupt and magma cools

Igneous Rocks Extra Igneous rocks are formed by fire. They form as magma cools and crystallizes. Lava – gas has escaped from the magma Texture of Igneous Rocks – (fine-grained, coarse-grained, porphyritic and glassy) Igneous rocks are named by classifying their structure and mineral composition.

Types of Igneous Rocks Scoria Granite Pumice Obsidian

Rocks Have Been Used For Many Years and For Many Things