Weathering and Weathering and ErosionErosion

WeatheringWeathering

The processes that break down rock The processes that break down rock into smaller pieces.into smaller pieces.

SedimentSediment Small pieces of rock Small pieces of rock

Examples of SedimentExamples of Sediment:: GravelGravel Sand Sand Silt Silt Clay Clay

Mechanical WeatheringMechanical Weathering

Occurs when rocks are broken down Occurs when rocks are broken down by physical processes. The rocks get by physical processes. The rocks get smaller, but do not change chemical smaller, but do not change chemical makeup.makeup.

Types of Mechanical WeatheringTypes of Mechanical Weathering

Plants and animals – Examples: tree Plants and animals – Examples: tree roots and burrowing animals roots and burrowing animals

Types of Mechanical WeatheringTypes of Mechanical Weathering

Ice wedging – water gets between Ice wedging – water gets between the cracks in the rocks, freezes and the cracks in the rocks, freezes and breaks them apart. breaks them apart. Example:Example: cracks in sidewalks cracks in sidewalks

Chemical WeatheringChemical Weathering

Occurs when chemical reactions Occurs when chemical reactions dissolve minerals in rocks or change dissolve minerals in rocks or change them into different minerals.them into different minerals.

Types of Chemical WeatheringTypes of Chemical Weathering

Natural acids – break down rocks.Natural acids – break down rocks.

Examples: caves; feldspar turns into Examples: caves; feldspar turns into clayclay

Types of Chemical WeatheringTypes of Chemical Weathering

Plant acids- acids are released from Plant acids- acids are released from plants and dissolve rock over time. plants and dissolve rock over time.

Ex: LichenEx: Lichen

Types of Chemical WeatheringTypes of Chemical Weathering

Oxidation - Metallic minerals exposed Oxidation - Metallic minerals exposed to water and oxygen over time. to water and oxygen over time. Example: rustExample: rust

ErosionErosion

The movement of sediment from one The movement of sediment from one place to another.place to another.

Forces of Erosion: wind, water, ice, Forces of Erosion: wind, water, ice, gravitygravity

DepositionDeposition

The laying down of sediment by The laying down of sediment by water, wind, glaciers or gravitywater, wind, glaciers or gravity

Examples: river delta, glaciersExamples: river delta, glaciers

Forces of ErosionForces of Erosion

Mass movement (mass wasting) - Mass movement (mass wasting) - erosion from gravity moving erosion from gravity moving sediment down a slopesediment down a slope

Types of Mass MovementTypes of Mass Movement

SlumpSlump – when a section of material – when a section of material slips down a slope and breaks off. slips down a slope and breaks off.

Types of Mass MovementTypes of Mass Movement

Rockfall Rockfall – pieces of rock fall and – pieces of rock fall and cause other rocks to fall. Usually cause other rocks to fall. Usually happens in happens in

the winter.the winter.

Types of Mass MovementTypes of Mass Movement

Rock slideRock slide- rocks slide down a slope - rocks slide down a slope at once. Usually happens after at once. Usually happens after heavy rain or during earthquakes heavy rain or during earthquakes

Types of Mass MovementTypes of Mass Movement

Mudflow (mudslide)Mudflow (mudslide)- rain mixes - rain mixes with soil to form mud, slides downhill with soil to form mud, slides downhill

Types of Mass MovementTypes of Mass Movement

CreepCreep- when sediment slowly shifts, - when sediment slowly shifts, trees and other objects lean forward trees and other objects lean forward

WindWind

the less vegetation, the greater the less vegetation, the greater wind can affect erosion.wind can affect erosion.

GlaciersGlaciers

as a glacier moves, sediment moves as a glacier moves, sediment moves with it causing erosion with it causing erosion

WaterWater

rivers and oceans can cause erosion rivers and oceans can cause erosion

AnimalsAnimals

Humans and other animals can Humans and other animals can impact erosion. impact erosion.

Glue these notes in your journal.Glue these notes in your journal. Be sure to label table of contentsBe sure to label table of contents Write a 1 paragraph summary of Write a 1 paragraph summary of

weathering and erosionweathering and erosion