If water gets into a crack in a rock and then freezes, it expands and pushes the crack further apart. When the ice melts later, water can get further into the crack. When the water freezes, it expands and makes the crack even bigger.

Mechanical weathering, also called physical weathering and disaggregation, causes rocks to crumble. Water, in either liquid or solid form, is often a key agent of mechanical weathering. For instance, liquid water can seep into cracks and crevices in rock. If temperatures drop low enough, the water will freeze.

Mechanical weathering

Scientists have observed a process called freeze-thaw. That process occurs when the water inside of rocks freezes and expands. That expansion cracks the rocks from the inside and eventually breaks them apart. The freeze-thaw cycle happens over and over again and the break finally happens.

The different ways by which rocks are weathered and eroded are discussed e.g. physical weathering by wind, rain, waves, ice, heat from the sun, chemical weathering by acidified run off water and acid rain and biological weathering by plants-roots descriptions etc.

Weathering occurs fastest in hot, wet climates. It occurs very slowly in hot and dry climates. Without temperature changes, ice wedging cannot occur. In very cold, dry areas, there is little weathering.

Which statement best explains why the soil is thicker above the limestone than it is above the quartzite? The limestone is less resistant to weathering than the quartzite.

If a large rock is broken into smaller pieces, weathering happens much more quickly. The rate of weathering increases because the surface area-to-volume ratio of the small rocks is greater than that of the large rock. So, a greater proportion of a smaller rock is exposed to weathering processes.

The larger rock will weather much slower than the severely broken rock. Explanation: A massive body of rock has less surface area for its volume as compared to a small rock.

Slope The steep sides of mountains and hills make water flow down them faster. Fast-moving water has more energy to break down rock than slow-moving water. Therefore, rocks on steep slopes can weather faster than rocks on level ground.

Many lichens contain acids that help break down rock. Furthermore, the mechanical action of the fungal threads of the lichen penetrating the spaces between the rock crystals together with changes in temperature and moisture also help break down rock into soil.

There are some rocks, like limestone, that weather more rapidly. Limestone has the compound calcite. It is the carbonization of calcite that causes the increased rate of weathering of limestone. The material found in sediment grains also affects the rate of weathering.

limestone