Weathering and Soil Horizons Quiz

Which of the following is not an example of mechanical weathering?

• a gopher burrowing in the ground and loosening rock/soil.

• a tree's roots growing in a cracked rock.

• iron oxide weakening and breaking down a rock.

• ice expanding cracks in a rock.

Answer explanation

Iron oxide weakening and breaking down a rock is a chemical weathering process, not mechanical. Mechanical weathering involves physical forces, like gopher burrowing, tree roots growing, or ice expanding cracks.

Which soil horizon contains organic matter on the surface?

• Horizon R

• Horizon C

• Horizon O

• Horizon B

Answer explanation

Horizon O is the top layer of soil, rich in organic matter such as decomposed leaves and other plant material. This horizon is crucial for soil fertility, unlike Horizons R, C, and B, which contain less organic material.

Tags

NGSS.MS-LS2-3

Which layer of the soil profile would be affected the most by weathering and erosion?

• 1

• 2

• 3

• 4

Answer explanation

Layer 1, the topsoil, is most affected by weathering and erosion due to its exposure to the elements. It contains organic matter and is where most biological activity occurs, making it vulnerable to these processes.

Tags

NGSS.MS-ESS2-2

The process that transports rocks, soil and sediments to a different location is called _______.

Answer explanation

The process that transports rocks, soil, and sediments to a different location is called erosion. Deposition, on the other hand, refers to the accumulation of these materials after they have been transported.

Which is NOT an example of weathering?

• Sediment is moved further down the beach

• Acid Rain causes statues to deteriorate

• Water seeps into a rock, freezes, and breaks the rock

• Water dissolves rocks and removes minerals

Answer explanation

The correct choice is 'Sediment is moved further down the beach' because this describes erosion, not weathering. Weathering involves the breakdown of rocks, while erosion refers to the movement of sediment.

Tags

NGSS.MS-ESS2-4

There is a streak of red rust on some rocks. What kind of weathering is this?

• Mechanical Weathering

• Chemical Weathering

Answer explanation

The streak of red rust indicates the presence of iron oxide, which forms when iron reacts with oxygen and moisture. This process is a type of chemical weathering, as it involves a chemical change in the minerals of the rocks.

Tags

NGSS.MS-ESS2-2

The loose weathered material on Earth's surface is called...

• humus

• sediment

• soil

• rust

Answer explanation

The loose weathered material on Earth's surface is called sediment. Sediment consists of particles that have been broken down by weathering and erosion, making it distinct from humus, soil, or rust.

What can be a cause for weathering to happen more quickly (rate of weathering)?

• The soil in an area

• Loam Soil

• The climate in an area

• the type of humus in the soil

Answer explanation

The climate in an area significantly affects weathering rates. Factors like temperature, moisture, and precipitation influence how quickly rocks and minerals break down, making this the primary cause for accelerated weathering.

The grinding away of rocks by other rock particles carried by wind, water, and glaciers (ice) is called...

• drought

• bedrock

• abrasion

• chemical weathering

Answer explanation

The correct answer is 'abrasion' because it specifically refers to the process of rocks being worn down by the friction of other rock particles carried by natural forces like wind, water, and glaciers.

Tags

NGSS.MS-ESS2-2

Which is NOT true of plant roots when it comes to weathering?

• Plant roots can pry/wedge rock apart.

• Plant roots can cause oxidation of the soil.

• Plant roots can produce a weak acid that can chemically break down rock.

• Plant roots hold soil in place so that it won't blow or wash away (erosion).

Answer explanation

Plant roots do not cause oxidation of the soil; rather, they can contribute to physical and chemical weathering through wedging and acid production. Thus, the statement about oxidation is NOT true.