Key Terms: weathering, mechanical weathering, chemical weathering, sediment, erosion, deposition, compaction, cementation.

SedimentPlease turn to page 52 in your textbook.Sedimentary rocks form from sediment.

Sediment is any small solid piece of material that come from: pre-existing rock broken down into smaller

pieces remains of living things (organic material)

such as shells, bones, leaves, dead wood, etc.

crystallized dissolved minerals. Stop :Complete Formation of Sedimentary Rocks

Activity Worksheet Number 1Before Continuing

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WeatheringWeathering is the process that breaks down

rock and other substances at Earth’s surface.The process of mountain building thrusts

rock up to the Earth’s surface.There the rock becomes subject to

weathering.There are two types of weathering

Mechanical WeatheringChemical Weathering

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Mechanical WeatheringMechanical weathering occurs when rock is

broken down into smaller pieces by physical changes.

The forces of mechanical weathering that breaks rock into pieces are Freezing and thawing (frost wedging)Release of pressureGrowth of PlantsActions of animalsAbrasion

These forces are called the agents of mechanical weathering.4

Chemical WeatheringChemical weathering occurs when rock is

broken down through chemical changes.The agents of chemical weathering that

break down rock areWaterOxygenCarbon dioxideLiving organismsAcid Rain

Stop :Complete Formation of Sedimentary Rocks

Activity Worksheet Number 2, 3, and 4 Before Continuing

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From Sediment to RockDifferent processes occur in a specific order

that turn sediment into sedimentary rock.Erosion- the movement of sediment.

Deposition- the depositing of the sediment.

Compaction- pressing the sediment together.

Cementation- binding the sediment.

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ErosionErosion occurs when sediment is moved.

Sediment can be moved by:GravityRivers and StreamsGlaciersWindWaves

These are known as agents of erosion. Stop :

Complete Formation of Sedimentary Rocks Activity Worksheet Number 5Before Continuing

DepositionDeposition is the process by which sediment settles out of the agent of erosion that had been carrying it.

Sediment is deposited in:Horizontal layers

layers become very thick after a long periods of time.

Oldest layers on the bottomLaw of Superposition.

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Erosion and Deposition AnimationObserve how sediment is eroded and deposited

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CompactionAfter being deposited, thick layers of sediment build up.

These layers are heavy and press down on the layers beneath them.

Compaction then occurs.Compaction is the process that presses sediments together.

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CementationMinerals are dissolve in water.The water containing the dissolved minerals

seep into the spaces between the sediment.The water evaporates, leaving behind the

crystallized minerals.Cementation then occurs.Cementation is the process in which

dissolved minerals crystallize and glue particles of sediment together.

Often takes millions of years for compaction and cementation to transform loose sediments into solid sedimentary rock.

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Compaction and Cementation Animation

Observe how sediment is compacted and cemented.

Stop :Complete Formation of Sedimentary Rocks

Activity Worksheet Number s 6 and 7Before Continuing

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Classifying Sedimentary RockGeologists classify sedimentary rock

according to the type of sediment that make up the rock.

Clastic Sedimentary RockSediment type: Rock fragments

Organic (Biochemical) Sedimentary RockSediment type: Remains of Biological/Organic

material. Mainly fossil shells or plant fragments.Chemical Sedimentary Rock

Sediment type: dissolved mineral crystallization. Mainly chemically precipitated crystals

Stop:Complete Formation of Sedimentary Rocks Activity Worksheet Number 8 and turn in your activities sheet when finished.13