Weathering, Erosion and Deposition

Water gets into cracks and joints in bedrock. When the water freezes it expands and the cracks are opened a little wider. Over time pieces of rock can split off a rock face and big boulders are broken into smaller rocks and gravel.

When water in a river or stream moves quickly, it can lift up rocks from the bottom of that body of water. When the rocks drop back down they bump into other rocks, and tiny pieces of the rocks can break apart.

Roots of plants growing into cracks may put pressure on the surrounding rock, eventually breaking rocks apart as the roots grow.

Each area has varying temperature and pressure conditions. This fluctuation leads to the constant expansion and contraction in rocks. This reduces the strength of the rocks, which further breaks them down.

Lichens cling to the surface of the rocks. They can produce organic chemicals which cause break down of the rocks.

Wind carries sand particles while traversing from one place to another. These particles are abrasive in nature. They hit the rocks, thus imparting shape to them.

The Colorado River flowed over rock for prolonged periods, eventually forming the Grand Canyon.

Water comes in contact with granite and the feldspar crystals inside the granite react chemically, forming clay minerals. The clay weakens the rock, making it more likely to break.

When oxygen reacts with iron, iron oxide (rust) is formed. Rust changes the color of the rocks, plus iron oxide is much more fragile than iron, so the region becomes more susceptible to breakage.

Carbonic acid, a weak acid, is produced when carbon dioxide reacts with water. Carbonation is an important process in the formation of many caves and sinkholes. Calcite in limestone dissolves under acidic conditions, leaving open spaces.

A storm brings heavy rain to an area. On the hillside, the soil is washed away with the rain.

Waves carry sand and, when they crash on the shore, they leave some of that sand on the shore.

Soil and sediments being carried by a river accumulate over time. Eventually, a delta is formed where the river flows into a slower moving body of water.

Wind carries sand from a desert to new locations.

Glaciers drag across landforms and scrape off the top layer of rock.