Weathering, Erosion, Deposition

Weathering

Breakdown of rocks at or near the Earth's surface

Physical Weathering

Breaking down of rocks into smaller pieces (sediments) without chemical change

Chemical Weathering

Changes the chemical composition of the rock

Frost Action

Water seeps into cracks, freezes, and expands

Abrasion

Rocks rub and become smaller and rounder in a stream or wind

Root Action

Roots grow into rocks and pry them apart as they grow

Exfoliation

Surface rock "peels" off due to temperature and pressure changes

Oxidation

Iron combines with oxygen to make iron oxide

Carbonation

Carbonic acid causes minerals to dissolve away

Hydration

Water weakens the rock, causing it to crumble

Erosion

Movement of sediments

Gravity

Primary force driving agents of erosion

Stream

Body of water with a current

Discharge

Volume of water flowing past a fixed point in a period

Oxbow Lake

Cut-off meander in a stream

Meander

Curve in a stream

Youth Stage of a Stream

Steep slope, straight channel, high energy, lots of erosion

Mature Stage of a Stream

Gentler gradient, slower moving water, meanders develop

Old Age Stage of a Stream

Almost flat land, levees form, has oxbow lakes

Drainage Patterns

Dendritic, Radial, Annular, Rectangular

Mass Movement

Downward sliding of rock material

Barrier Island

Long, narrow island parallel to the mainland, made of sand

Glaciers

Large, slow-moving mass of ice

Esker

Long winding ridge of sorted sands and gravel

Moraine

Material left behind by a moving glacier

Kettle Lake

Water-filled pothole left by a receding glacier

Deposition

Dropping or stopping of sediments after erosion

Delta

Triangular shape of deposited sediment at the mouth of a river

Watershed

Area where rainwater flows into a river

Tributary

Creek or stream that flows into a larger body of water

Types of Weathering

Physical and Chemical

What does physical weathering do?

Creates more surface area

Chemical weathering is most dominant in /

warm, moist conditions

Where does chemical weathering occur?

On the surface of rock materials

What is the key to chemical changes?

Water

As particle size decreases / surface area increases and the rate of weathering increases 

Resistant layers of rock stick out and form

cliffs or escarpments 

Chemical weathering will occur most rapidly when rocks are exposed to the

hydrosphere and atmosphere 

Soil develops because of

weathering and biological activity over long periods of time

Residual soil  

soil that formed and stayed in the place – same substance of the underlying bedrock 

Transported soil / made up of completely different material than the underlying bedrock 

made up of completely different material than the underlying bedrock 

Soil that contains large quantities of calcium was most likely formed by the weathering of

limestone

The 5 Agents of Erosion

Water, Glaciers, Wave Action, Wind, & Mass Movements

Stream valleys are

V-Shaped

Most of the surface materials in NY State can be classified as

transported soils

By which processes are rocks broken up and moved to different locations?

Weathering and erosion

The faster the water moves

the larger the particles it can transport

As water slows down /

the larger, rounder more dense particles settle out first

Stream velocity depends on

gradient (steepness or slope) and volume (amount) of water

The outside of a meander bend is

fast and erodes (elbow)

The inside of the meander bend is

slow and deposits (dent)

Dendritic Pattern

looks like branches on a tree

Radial Pattern

occurs when stream flows away from a high point and looks like spokes on a wheel

Annular Pattern

occurs on an eroded dome and has a circular pattern with small tributaries going into each circle 

Rectangular Pattern

occurs were drainage flows along folds and faults

Evidence of gravity erosion is

unsorted and angular (sharp) rocks at base of cliff

After mass movement rocks look

rough and angular

Which process describes the downward sliding of the rock material?

Mass movement

A landslide is an example of

mass movement

Wave action round sediments because of

abrasion

Shores are protected by

barrier islands

Beaches are formed by the

weathering of continental & oceanic rocks

Longshore drift moves

sand along the beach in the direction of the ocean current

Barrier Islands are made by the action of

wave currents and wind that distributes the sand which protects the mainland from erosion

Jetties and Groins are

beach protection structures that protect against longshore drift

Gravity causes a glacier to move

downhill

Glacial landscapes show

U-Shaped Valleys, erratic (large boulders), kettle lakes, moraines, drumlines and scratched bedrock (striations)

Glacial and gravity deposition is

unsorted (all mixed up called till)

Glaciers form in

high latitudes and high elevation

Terminal Moraine

moraine ridge that makes the marks the maximum limit of glacial advance

Recessional Moraine

small ridges left as a glacier pauses during its retreat

Outwash Plains form as

a glacier melts and rivers carry small sediments (sorted) away from the glacier

Drumlins

hills of sediment that have been streamlined by glacier flow

Kames

moundlike hill of poorly sorted drift deposited at or near the end of a glacier

Glaciers advance from the

north, formed Long Island, left sand and gravel (moraines)

Wind Erosion creates

sand dunes, the windward side of a sand dune has a gentle slope

Round, large, more dense particles settle out

faster than angular, small and less dense particles

Sorted sediments settle out in a

distinctive order

Unsorted sediments are dropped in

no particular order

Water and wind deposits are

sorted and layered

Glacial and gravity deposits are

unsorted and not layered

Horizontal Sorting

occurs when a stream enter a large body of water , velocity slows down, larger particles settle out first

Vertical Sorting

sorting of sediments from bottom to top, large round and dense particles settle out first at the bottom

When a river enters the ocean

it slows down, deposits and forms a delta

Drainage Basin

area where water flows downhill into one large body of water

Deltas form when

deposition is greater than erosion