Warm-Up:Describe the texture and composition of each igneous rock.

A B

Definition of A RockA naturally occurring, solid, mixture of one or more minerals or organic matter

Classified into 3 groups based on how they are formed: igneous, sedimentary, and metamorphic

Texture and composition give clues as to how rocks are formed, and are used to classify and identify rocks

Rocks are always changing form in a cycle called the Rock Cycle

Rocks Rock!Rocks Rock!

Igneous RocksExtrusive rocks- formed by cooling lava

Texture Can Be:• glassy • porous • fine-grained

Intrusive rocks- formed by cooling magma

Texture Is Always: • coarse-grained

Formation of Extrusive Igneous Rock

Igneous Features and Landforms

Extrusive Igneous Rock

Formation of Intrusive Igneous Rock

Intrusive Igneous Rock

Yosemite N.P.

Examples of Textures: Pumice

Porous Texture

Basalt

Obsidian

Course Grained Texture

Granite

Porous Texture

Sedimentary Rocks Formed by:

Weathering (breaking down of rock)

Erosion (movement of sediments)

Deposition (collection of sediments)

Compaction & Cementation (sediments bonding together)

Two Types of Weathering1. Mechanical Weathering

Root Action

Frost Action

Moss

Types of Weathering2. Chemical Weathering:

Oxidation (rust) – Oxygen in air reacts with metals in rocks

Acidic rain water

Physical Weathering

Five Agents of Erosion

Gravity (Mass wasting)WindRunning waterGlaciersWaves

Gravity (Mass Wasting)

Slumping

Soil creep

Mass Movements: Five Main Types

Wind

Running Water

Yellowstone Canyon & River

Niagara Falls

Glaciers

Glacial Processes I

Waves

Australia

Examples of Deposition

Lateral moraine

Cape Cod (spit)

Nile River Delta

Compaction & Cementation

Sedimentary Rocks (categorized by composition)

Clastic Rocks (rock fragments) • Conglomerates (pebbles) • Sandstones (sand) • Shales (mud & clay)

Organic Rocks (once living) • Ex: limestone(coral and shells), coal (plants)

Chemical Rocks (evaporation)• Ex: rock salt, limestone, geodes, gypsum

Clastic Sedimentary Rock…Conglomerate

Shale

Sandstone

Organic Sedimentary Rocks…

Coal (plant mateiral) Limestone (shell & coral)

Chemical Sedimentary Rocks…

Limestone

Gypsum rock

Geode

Sedimentary rocks according to texture:

Coarse-grained

Conglomerate

Shale

Sandstone

Fine-grained Medium-grained

Formation of Metamorphic Rock

Types of Metamorphic Rock

1. Foliated - bands or layers Ex: schist, slate, gneiss

Gneiss

Slate

2. Unfoliated - no bands or layersEx: marble and quartzite

Types of Metamorphic Rock

Quartzite

Foliated texture

Unfoliated Texture