Question

sedimentary rock is formed from loose grains of minerals or other rock. these loose grains are called sediment, and they are formed through weathering and erosion.
weathering breaks down rocks into sediment. water, wind, ice, and living things can all cause weathering. during weathering, sediment is not moved away from the place where it forms.
however, during erosion, sediment is moved from the place where it formed. erosion happens when water, wind, or ice moves existing sediment, or creates new sediment and moves it somewhere else.
read the examples of how sediment can form. select the example that describes erosion.
as a river flowed over rock, sediment in the river water wore away the rock. this sediment was carried away by the river.
rainwater collected in the cracks of a rock. during cold weather, the trapped water froze. the water expanded as it froze, splitting the rock into smaller pieces.
saltwater sprayed onto a rock. when the water evaporated, salt crystals were left behind. the crystals grew and put pressure on the rock.

Explanation:

Erosion is defined as the process where sediment is moved from its formation location.

• The first example describes river water wearing rock into sediment and carrying that sediment away, which matches erosion.
• The second example is weathering: water freezing splits rock into pieces but does not move the sediment.
• The third example (partial text) describes salt crystals forming and pressing on rock, which is weathering, not movement of sediment.

Answer:

A. As a river flowed over rock, sediment in the river water wore away the rock. This sediment was carried away by the river.