Topic 4

Rocks

Minerals- the building blocksMinerals- the building blocks

• Naturally occurring

• Inorganic

• Crystalline structure

• Specific chemical composition

Halite crystal (salt)

Source: Photograph © The McGraw-Hill Companies, Inc./Bob Coyle, photographer.

Galena (lead and sulfur)

Source: Photograph © The McGraw-Hill Companies, Inc./Doug Sherman, photographer.

RockRock

• A naturally occurring solid aggregate of one or more minerals or mineral materials

The Rock CycleThe Rock Cycle

• Plate tectonics and weathering drive the rock cycle

• 3 types of rocks on Earth– Igneous– Sedimentary– Metamorphic

The Rock CycleThe Rock Cycle

The Rock CycleThe Rock Cycle

• Igneous Rocks– Formed by the crystallization/solidification

of magma– Granitic or Basaltic

– Instrusive: solidified inside Earth– Extrusive: solidified on Earths surface

Granite

(intrusive)

Source: Courtesy of Carla W. Montgomery.

Obsidian

(extrusive)

Source: Photograph © The McGraw-Hill Companies, Inc./Bob Coyle, photographer.

Basalt

Source:Courtesy of Carla W. Montgomery.

The Rock CycleThe Rock Cycle

• Sedimentary Rocks– Chemical precipitation

• Limestone (carbonate)

– Sedimentation• Sandstone (conglomerate), shale

Limestone

Source: Photograph by I.J. Witkind, USGS Photo Library, Denver, CO.

Shale

Source: Photograph © The McGraw-Hill Companies, Inc./Bob Coyle, photographer.

Sandstone

Source: Photograph © The McGraw-Hill Companies, Inc./Doug Sherman, photographer.

The Rock CycleThe Rock Cycle

• Metamorphic Rocks– Changed form– Heat, pressure

Marble