chapter 6 sedimentary rocks
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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 - PowerPoint PPT PresentationTRANSCRIPT
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