Science Weathering & Erosion

A cave can form in two ways. Explain how a cave can form underground through the process of chemical weathering.

When slightly acidic water reacts with limestone rock, it dissolves the rock and can form a cave.

A sinkhole is a hole in the ground (a cave) that usually forms in limestone rock. Which process below would have made the sinkhole?

chemical weathering

The diagram shows a cave within a limestone formation. How could this have formed?

chemical weathering

From the options below, what climate would result in the slowest rate of chemical weathering?

cold & dry because a cold environment would likely have fewer animal and plants living there which contribute to weathering and a dry environment would not have as much water which weathers rock quickly.

What type of plant is usually responsible for the chemical weathering of rocks?

moss

Weathering

Break rocks into smaller pieces

The picture below shows the process of ice-wedging. Using the pictures, describe in words how the process of ice-wedging works.

First water seeps into a small crack. Then, the water freezes and expands causing the crack to get bigger. Eventually the piece of rock breaks off.

Give an example of an agent of erosion that transports sediments very slowly.

A Glacier

Explain how a cave can form on the side of a cliff near a body of water through the process of physical/mechanical weathering.

A cave can form on the side of a cliff from water continually hitting and weathering softer areas of rock over time.

What is formed when sediment is deposited at the opening of a river?

A delta

Explain the process of how a delta forms. Be sure to use the terms sediment and deposition in your answer.

A delta forms when flowing water in a river slows down when it hits an ocean and as a result, it deposits (drops off) sediment. The sediment piles up forming a delta.

Explain how a plant can mechanically/physically weather a rock.

A plant can physically break a rock with its roots.

Deposition

Leaves broken rocks behind after the ice melts

Is ice wedging an example of mechanical weathering or chemical weathering?

Mechanical weathering

Typically, plants help slow the rate of erosion. However, plants can also contribute to erosion. Which option below shows how plants can contribute to erosion?

Plant roots grow in rocks, breaking the rocks.

Erosion

Pushes broken rocks

A farmer has a steeply sloping pasture that is eroding. What should the farmer do to stop the topsoil from eroding?

The farmer should grow some plants there. The plants will help prevent the soil from moving and eroding.

Students observed a large crack found in a boulder with a tree growing out of it. Describe what may have caused a crack in the rock and what affect the tree may have on the rock. (Always relate this answer back to causes of weathering)

The tree roots likely caused the crack. Over time, the root will make the crack bigger. This is an example of physical weathering because the rock is getting broken with the force from the roots.

Before rock can become soil, it must undergo certain processes. One process in the formation of soil involves plants. How can plants chemically change rocks into soil?

They weather rocks with acid.

Give an example of an agent of erosion that transports sediments quickly.

Water

Water is a very important part of the physical weathering of rock. Which of these properties of water is MOST important in causing some of the physical weathering of rock?

Water expands when it freezes.