Geology: Erosion and Weathering Quiz

Questions and Answers

What happens to the surface area when a rock is cleaved three times?

Decrease the surface area

Approximately quadruple the surface area

Increase the surface area (correct)

Approximately halve the surface area

Approximately double the surface area (correct)

Match the following weathering processes to their types:

Root wedging = Physical Weathering Frost wedging = Physical Weathering Abrasion = Physical Weathering Dissolution = Chemical Weathering Oxidation = Chemical Weathering Hydrolysis = Chemical Weathering

As rocks are weathered by moving water, what happens to the individual grains?

Grains become smaller and more rounded

The order of sediment classification from smallest to largest is: clay, ___, sand, pebbles, cobbles, boulders.

silt Signup and view all the answers

What is the order of the images of a desert landscape from least eroded to most eroded?

The ones that are fully filled to the top with sand is the first, slightly lower is the second, less sand is the third, and the last one is the least amount of sand. Signup and view all the answers

Which features are more common in downcutting river systems?

Waterfalls Signup and view all the answers

In the image provided, select the part where erosion is most common in a river's course.

Towards the plane of longitudinal profile Signup and view all the answers

Select the images that were predominately created by wind erosion.

Black rock, yardang, multiple hills split in the middle, individual rocks, and hills straight down next to water. Signup and view all the answers

Strong rocks like thickly bedded sandstones tend to form _, whereas weaker rocks like thinly bedded shales tend to form gentler _.

cliffs, slopes Signup and view all the answers

Label the image of a yardang with the appropriate terms:

On top = Strong rocks and sandstone On the bottom = Weak rocks and shale Signup and view all the answers

Which units are made of rocks that are resistant to weathering in the desert?

Third unit Signup and view all the answers

Where would you expect to find shale in the Grand Canyon image?

The first two on the left side Signup and view all the answers

What are the three most likely causes of erosion of the barrier island?

Strength and direction of ocean currents Signup and view all the answers

What was the rate of coastal retreat from 1993 to 2012 in meters/year?

14 meters/year Signup and view all the answers

What was the annual rate of coastline retreat between 2012 and 2017?

220 meters/year Signup and view all the answers

Based on the erosion rate, how long will it be until your family home is lost to the ocean?

A little over three and a half years Signup and view all the answers

Which techniques could be employed to try to extend the amount of time the home would be livable?

Build a groin Signup and view all the answers

Study Notes

Weathering Processes

Chemical weathering targets exposed rock surfaces, working alongside physical weathering which breaks rock apart and increases surface area.
Physical weathering examples include root wedging, frost wedging, and abrasion, leading to increased rock fragmentation.
Chemical weathering involves processes like dissolution, oxidation, and hydrolysis.

Erosion and Sediment Transport

Moving water causes rock grains to become smaller and more rounded over time.
Sediments are classified by grain diameter: clay (smallest), silt, sand, pebbles, cobbles, and boulders (largest).
Rivers can exhibit both downcutting (erosion) and aggrading (deposition) phases, depending on water flow and sediment load.

Erosion Patterns in Landscapes

In desert environments, the degree of erosion can vary significantly; landscapes can be ranked from least to most eroded based on sand volume.
Some river systems may have areas of both erosion and deposition; erosion primarily occurs upstream, while sediment accumulation is seen in floodplains and oxbow lakes.

Wind Erosion Features

Eroded landscapes shaped predominantly by wind can include formations like yardangs and unique individual rock structures.

Rock Composition and Resistance

Rock strength determines erosion patterns; strong, thickly bedded sandstones form cliffs, while weak, thinly bedded shales or siltstones create gentler slopes.
Yardangs, also known as "mushroom boulders," arise from selective weathering of weaker rocks.

Coastal Erosion Factors

Erosion of barrier islands is influenced by ocean currents, wave activity, and storm frequency; mining and seawater temperature changes have no direct impact.
Notable coastal retreat measured from 1993 to 2012 was 270 meters, averaging a rate of 14 meters per year.

Future Erosion Projections

A further retreat of the barrier island from 2012 to early 2017 totaled 1100 meters, translating to an annual rate of 220 meters per year.
A family home built 2 km from the shore that has eroded to 800 meters away may be lost to the ocean in just over three and a half years.

Mitigation Strategies

To prolong home viability against erosion, strategies include building further inland post-damage, constructing seawalls, groins, or employing beach nourishment.
Inaction is not recommended as an effective strategy against erosion.

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Description

Test your knowledge on the concepts of erosion and weathering with this focused quiz. Explore the processes of chemical and physical weathering and understand how they interact to shape the Earth's landscapes. This quiz is designed to help reinforce key geological concepts.