what are two causes of mechanical weathering ice wedging and _____

http://www.ux1.eiu.edu/~cfjps/1300/weathering.html

Water and temperature

To identify the second cause of mechanical weathering, we can start by understanding what mechanical weathering is. Mechanical weathering refers to the breakdown of rocks and minerals into smaller pieces without changing their chemical composition. It occurs due to various physical forces that act on rocks.

One common cause of mechanical weathering is ice wedging, also known as frost wedging. This process occurs in cold regions when water seeps into cracks and crevices in rocks. When the temperature drops, the water freezes and expands, exerting pressure on the surrounding rock. Over time, this repeated freezing and thawing weakens the rock, causing it to fracture and break apart.

Another significant cause of mechanical weathering is called abrasion. Abrasion happens when rocks and other particles rub against each other, resulting in the physical wearing down of surfaces. This process can occur in different ways. For example, moving water in rivers and streams can carry sediment that grinds against rocks, wearing them down over time. Similarly, wind-driven sand and particles can erode rocks through constant collision and impact. Glacial activity, where ice and rocks scrape against each other, is another form of abrasion that occurs in areas covered by glaciers.

In summary, ice wedging and abrasion are two common causes of mechanical weathering. Ice wedging is primarily associated with cold climates, while abrasion can occur through the actions of water, wind, and ice.