Chapter 14Ch. 14: The Rock Cycle•Rock a naturally occurring solid mixture of one or more minerals or organic matter.

•Rock Cycle- The Process by which new rock is made by old rock

Chapter 14 Section 1 The Rock Cycle

Chapter 14The Value of Rock Ancient and modern civilizations have used rocks as construction materials.

Rock is also an important ingredient in concrete and plaster, used in todays construction

Section 1 The Rock Cycle

Chapter 14Processes That Shape the Earth

• Weathering- process in which water, wind, ice, and heat break down rock.

• Weathering is important because it breaks down rock into fragments of which sedimentary rock is made.

Section 1 The Rock Cycle

Chapter 14• The process by which wind, water, ice, or gravity transports soil and sediment from one location to another is called erosion.

• The process in which sediment moved by erosion is dropped and comes to rest is called deposition.

Section 1 The Rock Cycle

Chapter 14Break !

Chapter 14

• Heat and Pressure Sedimentary rock can also form when buried sediment is squeezed by the weight of overlaying layers of sediment.

• If the temperature and pressure are high enough, the rock can change into metamorphic rock.

• If the rock gets hot enough to melt, this creates the magma that eventually cools to form igneous rock.

Section 1 The Rock Cycle

Chapter 14• How the Cycle Continues Buried rock is exposed at the Earth’s surface by a combination of uplift and erosion.

• Uplift is the movement within the Earth that causes rocks inside the Earth to be moved to the surface.

• When uplifted rock reaches the Earth’s surface, weathering, erosion, and deposition begin.

Section 1 The Rock Cycle

Chapter 14• Composition is the chemical makeup of a rock. Composition can describe either the minerals or other materials in the rock.

• Texture is the quality of a rock that is based on the sizes, shapes, and positions of the rock’s grains.

Section 1 The Rock Cycle

Chapter 14Rock Classification

Rock can be three main classes based on how the rock is formed:

Igneous rockMetamorphic rockSedimentary rock

Section 1 The Rock Cycle

Chapter 14Igneous Rock• Igneous rock forms when hot, liquid rock, or magma, cools and solidifies.

Section 2 Igneous Rock

Chapter 14• When magma intrudes, or pushes, into surrounding rock below the Earth’s surface and cools, the rock that forms is called intrusive igneous rock.

• Intrusive igneous rock usually has a coarse-grained texture because it is well insulated by surrounding rocks and cools very slowly.

Section 2 Igneous Rock

Chapter 14Section 2 Igneous Rock

Chapter 14• Igneous rock that forms from magma that erupts, or extrudes, on the Earth’s surface is called extrusive igneous rock.

• Extrusive igneous rock, commonly found around volcanoes, cools quickly on the surface and contains very small crystals or no crystals.

Section 2 Igneous Rock

Chapter 14Sedimentary Rock• Wind, water, ice, sunlight, and gravity all cause rock to physically weather into fragments.

• Through erosion, these rock and mineral fragments, called sediment, are moved from one place to another.

Section 3 Sedimentary Rock

Chapter 14Break 2!

Chapter 14• The most noticeable feature of sedimentary rock is its layers, or strata.• Stratification is the process in which sedimentary rocks are arranged in layers.

Section 3 Sedimentary Rock

Chapter 14Composition of Sedimentary Rock

Clastic sedimentary rock is made of fragments of rocks cemented together by a mineral such as calcite or quartz.

• Clasitc sedimentary rocks can have coarse-grained, medium-grained, or fine-grained textures.

Section 3 Sedimentary Rock

Chapter 14• Chemical sedimentary rock forms from solutions of dissolved mineral and water.

• As rainwater slowly makes its way to the ocean, it dissolves some of the rock material it passes through.

• Some of this dissolved material eventually crystallized and forms the mineral that make up chemical sedimentary rock.

Section 3 Sedimentary Rock

Chapter 14• Organic sedimentary rock is made up of the skeletons and shells of sea animals. These remains collect on the ocean floor and eventually become cemented together.

• Coal is a type of organic sedimentary rock that is formed when decomposed plant material is buried beneath sediment and is changed by increasing heat and pressure.

Section 3 Sedimentary Rock

Chapter 14

Break 3: Devils Tower

Chapter 14Metamorphic Rock

• Metamorphic rocks are rocks in which the structure, texture, or composition of the rock have changed.

Section 4 Metamorphic Rock

Chapter 14• Foliated Metamorphic Rock The texture of metamorphic rock in which the mineral grains are arranged in planes or band is called foliated.

• Foliated metamorphic rock usually contains aligned grains of flat minerals, such as biotite mica or chlorite.

Section 4 Metamorphic Rock

Chapter 14• Nonfoliated Metamorphic Rock The texture of metamorphic rock in which the mineral grains are not arranged in planes or band is called nonfoliated.

• Nonfoliated metamorphic rocks are commonly made of one or only a few minerals.

• During metamorphism, crystals of these minerals may change in size or the mineral may change in composition in a process called recrystallization.

Section 4 Metamorphic Rock

Chapter 14• Metamorphic rock has features that indicates its history. These features are caused by deformation.

• Deformation is a change in the shape of a rock caused by a force placed on it.

• These forces may cause a rock to be squeezed or stretched. Folds, or bends, in metamorphic rock are structures that indicate a rock has been deformed.

Section 4 Metamorphic Rock