Weathering, Erosion and Deposition
Acid rain is caused by
burning fossil fuels
permeable
penetrable; porous; allowing liquids or gas to pass through
unloading/exfoliation
removal of overlying sediment and rock
root wedging
roots growing under rocks causing it to break
Hydrolysis
the chemical breakdown of a compound due to reaction with water.
What type of erosion is considered to be the weakest form?
Wind Erosion
Erosion is caused by these forces
Wind, Water, Ice and Gravity
How does wind abrasion work?
Wind-blown sediment strikes a surface of a rock and chips at the rock breaking off small pieces
The formation of stalactites and stalagmites in a cave as water mixed with carbon dioxide creates carbonic acid, which dissolves away the limestone, is an example of
Chemical weathering - Carbonation
A metal (copper) statue slowly turning green after years of being outside is an example of:
Chemical weathering - oxidation
How is chemical weathering different from mechanical weathering?
Chemical weathering changes the chemical composition of rocks; mechanical weathering does not.
How is mechanical weathering different from chemical weathering?
Chemical weathering changes the chemical composition of rocks; mechanical weathering does not.
Martha has a garden in her yard. During a heavy rainstorm some of the soil is washed away. Which term best describes the movement of soil from one place to another?
Erosion
High-energy environments are most likely to deposit which one of the following?
Larger sediment
What is rust?
A chemical reaction when iron comes in contact with oxygen
Glacier Erosion typically forms?
"U" Vallys
Water Erosion typically forms?
"V" Vallys
Runoff is increased by
A steeper gradient Wet Land A lack of vegetation
Rocks that were made smooth by wind blowing smaller rock particles across their surface. This is an example of:
Abrasion
Carbon dioxide (CO2) combines with water as raindrops fall through the atmosphere. This makes a weak acid, called carbonic acid. Carbonic acid is a very common in nature, where it works to dissolve rock. Pollutants, such as sulfur and nitrogen from fossil fuel burning, create sulfuric and nitric acid. Sulfuric and nitric acids are the two main components of acid rain, which speeds up chemical weathering.This statue was probably destroyed by _____.
Acid Rain
How does slope affect mass wasting?
An increased gradient means the sediment can get carried away faster
action of animals
Animals that burrow in the ground loosen and break apart rocks in the soil
Describe how animals that burrow into the ground are a source of mechanical weathering.
As animals dig, move, claw, and walk they break and chip away at rocks through their actions
Water erosion begins at what point?
As runoff
How can rocks be weathered as trees continue to grow over it?
As tree grow their roots wedge their way into the cracks of rocks and over time slowly break the rock apart
Lichens (small green plants) growing on a large boulder release enzymes and other acids that slowly break the rock apart. This is an example of
Chemical Weathering - Living organisms
Chemical weathering breaks down existing rocks by?
Changing them chemically, but not physically
Mechanical weathering breaks down existing rocks by?
Changing them physically, but not chemically
Rocks that have slowly broken down and turned a blackish color due to the action of:
Chemical Weathering - Acid Rain
What formation results when a river deposits sediment and it slows down as it enters a large body of water?
Delta
What are the different ways mechanical weathering can break down rocks?
Freezing and Thawing, Unloading, Root Wedging, Actions of Animals, Abrasion
What ways can sediment be deposited
Glaciers Water Wind Gravity
Deposition by Gravity (Mass Movement)
Is caused when water and ice causes rock, soil, snow, or other material to move downhill and pile up at the base of the mountain.
lichen
Live on rocks release chemicals that accelerate the chemical weathering of rocks
What can change the size and shape of rock structures?
Mechanical Weathering
What is the weathering process in which rocks are broken down into smaller pieces (sediments) and do not change the rock composition?
Mechanical Weathering
Rocks along a riverbed that are smoothed from continuously moving water and sediment rubbing against them is an example of:
Mechanical Weathering - Abrasion
Potholes forming in the road after a cold winter is an example of:
Mechanical Weathering - Freezing and Thawing
Weeds growing into the cracks in a sidewalk and the sidewalk begins to crumble is an example of:
Mechanical Weathering - Root Wedging
Oxidation is a chemical reaction that takes place when oxygen reacts with another element. Oxygen is very strongly chemically reactive. The most familiar type of oxidation is when iron reacts with oxygen to create rust. Which chemical creates rust?
Oxygen
What factors affect deposition?
Particle Size - How big the sediments are. Shape - Round or flat Density - Weight and composition Settling rates - How fast things settle
Deposition
Process in which sediment is laid down in new locations.
Erosion
Processes by which rock, sand, and soil are broken down and carried away by ice, water, wind and gravity
Large rocks near rivers and streams have large crack running in them. How did weathering most likely cause this rock to crack?
Rocks close to the water have water seep into the cracks of rocks then when the water freezes when temperatures drop then this causes the cracks in the rocks to widen
How does vegetation affect mass wasting?
Root systems help keep the soil in place. It also allows more water to be absorbed into the soil.
Crops are often grown on floodplains because the floodplains are usually very fertile. What is the main reason the floodplains are fertile?
Sediment is deposited on the plain each time it floods.
when Carbonic acid dissolves bedrock what can form?
Sinkholes
In a low energy environment such as the middle of a large lake, the most likely sediment size to accumulate is:
Smaller sediment
Describe how freezing and thawing mechanically weathers earth materials.
When water seeps into cracks of rocks then freezes when temperatures drop causing the cracks in the rocks to widen
In a parking lot at a school or store you will notice many cracks in the asphalt. What process could happen this winter to enlarge these cracks?
The cracks are caused by freezing and thawing
Abrasion
The grinding away of rock by other rock particles carried in water, ice, or wind
Chemical Weathering
The process in which rock is broken down by changes in its chemical makeup
What is mechanical weathering?
The process that breaks down rocks physically into smaller pieces by forces of nature.
What two factors determine the rate of chemical weathering is:
The type of rock and climate
Mechanical weathering (physical weathering)
The type of weathering in which rock is physically broken into smaller pieces
How do the actions of animals and plants break down rock
Through chemicals they release as they go through their lives
Rocks that are found in a small creek/stream bed are smooth. Describe how weathering made the rocks so smooth.
Through the action of abrasion the rocks are worn smooth by rock particles carried by water
mass wasting (mass movement) is impacted by?
Vegetation Slope
What is the largest agent of erosion?
Water erosion
A student hiking in a rock area on a mountain notices that wide, deep cracks have formed in some of the large rocks. Some of the cracks are so large that the rocks have broken apart. Which process most likely caused these rocks to crack and creak?
Water freezing and thawing
glacier erosion occurs by?
When sediment is deposited when the glacier melts or retreats backwards
freezing and thawing (ice wedging)
a type of mechanical weathering where water freezes in a crack and expands causing the crack to become larger
Carbonation weathering
carbon dioxide dissolved in oxygen turns the water into weak carbonic acid solution chemical
A marble statue is left exposed to the weather. Within a few years, the details on the statue have begun to weather away. This weathering probably is caused by...
carbonic acid in rainwater
Oxidation
changes the color of the rocks while making the rock more fragile and easier to break.
acid rain effects
kills trees and plants; wears away stone buildings and statues
Storms can cause major changes to barrier islands by removing sand from the island. Which of the following would be expected to remove the most sand during a storm?
large waves crashing on the island
Water Deposition
occurs as water slows down and drops the sediment it was carrying
Glacial Deposition
occurs when glaciers move to a lower altitude or the climate in the area becomes warmer, glaciers begin to melt. During the melting, sediment is often left behind.
Wind Deposition
occurs when smaller pieces of sediment carried by the wind eventually falls to the ground. Wind deposition can form sand dunes.
mass wasting (mass movement)
occurs when soil and rock moves down a slope under the force of gravity
Acid Rain
rain containing nitric and sulfuric acids
Wind picks up sediment from the ground and carries it. As the wind slows down, it deposits the sediment in other places. Which type of sediment will be dropped first as the wind slows?
the heaviest pieces
Deflation
the process by which wind removes surface materials