CHAPTER 6 SEDIMENTARY ROCKS

Chapter 6 Section 1 Objectives Sequence the formation of sedimentary

rocks Explain the process of lithification Describe features of sedimentary rocks

Weathering Types Mechanical/

Physical Breakdown of rock Does not change the

rock’s composition Only changes size

and shape

Chemical Changes the

chemical composition of rocks Acid rain, rust, calcite*

Formation of Sedimentary Rocks Weathering and Erosion

Breakdown of rocks = weathering Small particles of rocks = sediments

Particles range from really small to very large Movement of sediments = erosion Deposition

Sediments have been carried then deposited Larger sediments deposit first

Lithification Sediments are turned into sedimentary

rocks Compaction

Particles pushed together due to more and more deposition

Water and air gets squeezed out Cementation

Minerals grow and cement compressed particles together

Sedimentary Features Bedding

The making of layers that go horizontal in the rocks

Graded bedding Small particles layer at the top of a layer Larger particles layer are at the bottom layer

Cross bedding

Ripple marks Small ridges made by wind, waves or river

current Sorting and Rounding

Harder minerals generally take long to break apart

When sediments move they break apart and get rounded

Chapter 6 Section 2 Objectives Describe the types of clastic

sedimentary rocks Explain how chemical sedimentary

rocks form Describe biochemical sedimentary rocks

Types of Sedimentary rocks Clastic

Rocks made of particles of other rocks Coarse grained

Gravel sized particles Medium grained

Sand sized particles Fine grained

Silt/clay size particles

Chemical and Biochemical Result due to evaporation and precipitation

of minerals Chemical Sedimentary Rocks

Crystals precipitate out due to saturation Crystals settle on the bottom Called evaporites

Biochemical Formed from the remains of once living things Shells settle on bottom are buried Lithification then occurs Water gets pushed out Rocks like limestone are made

Chapter 6 Section 3 Objectives Compare and Contrast the different

types and causes of metamorphism Distinguish among metamorphic

textures Explain how mineral and compositional

changes occur during metamorphism Apply the rock cycle to explain how

rocks are classified

Recognize metamorphic rocks Metamorphism = to change Changes result due to heat and pressure High heat needed for metamorphism comes

from the earths interior

Metamorphic Textures Foliated

Rocks that have undergone great pressure Cause mineral to be compressed This compression causes rocks to have layers

Non-Foliated Rocks that have undergone great pressure and

heat

Types of Metamorphism Regional

High temperatures and pressure affect an entire area

Contact metamorphism Magma comes into contact with already

existing rocks changes the existing rocks Hydrothermal metamorphism

Hot water reacts with rocks Gold, copper, zinc, and lead are formed this

way

Economic Importance of Metamorphic Rocks Trade materials…Gold, silver, copper and

lead Building materials…marble, slate