E.S. 6: Rocks and Rock Cycle

SMS Earth Science

Things to know:

Rocks can be identified on the basis ofmineral content and texture.

The process by which rocks are formeddefine the three major groups.

The rock cycle is the process by whichall rocks are formed and how basicEarth materials are recycled throughtime.

Rock Cycle

Igneous Rocks Igneous rocks form from molten rock

that cools and hardens either below oron Earth’s surface.

Types of Igneous Rock Extrusive igneous rocks cool quickly on

Earth’s surface.– Small or no crystals in rock, smooth

texture.– Examples: pumice, obsidian, and basalt.

Types of Igneous Rock Intrusive igneous rocks cool slowly

below Earth’s surface.– Large crystals and coarse texture.

Examples: granite

Sedimentary Rocks Sedimentary rocks

form from compactionand cementation ofsediment.

Materials:1. rock fragments

2. organic matter

3. chemical precipitation.

Types of Sedimentary Rocks

Clastic sedimentary rocks are made upof fragments of other rocks.– Examples: sandstone, conglomerate, and

shale.

Sandstone Conglomerate Shale

Types of Sedimentary Rocks

Non-clastic sedimentary rocks thatprecipitate from a solution.– Examples: limestone and rock salt.

Limestone Rock salt

Metamorphic Rocks Metamorphic rocks form when any rock

is changed by heat and pressure.

Types of Metamorphic Rock

Foliated metamorphic rocks have bandsof different minerals.

Examples: slate, schist, gneiss.

Slate Schist Gneiss

Types of Metamorphic Rock

Unfoliated metamorphic rocks have littleor no banding and are the samethroughout.

Examples: marble and quartzite.

marble quartzite

End