Boulder clay

Boulder clay, also known as till, is a type of soil that is formed by the action of glaciers. It is a mixture of clay, silt, sand, gravel, and boulders, which are deposited by the melting ice of a retreating glacier.

Formation

Boulder clay is formed during the process of glaciation. When a glacier moves over the land, it picks up rocks and soil, grinding them down and mixing them together. This mixture is then deposited as the glacier melts, forming a layer of boulder clay. The size and shape of the particles in boulder clay can vary greatly, from fine clay and silt to large boulders.

Characteristics

Boulder clay is typically unsorted, meaning it contains a wide range of particle sizes. This is due to the fact that glaciers are not selective in the material they pick up and deposit. The clay is often dense and compact, with a bluish or grayish color. It can be very difficult to work with in construction due to its high clay content and the presence of large boulders.

Distribution

Boulder clay can be found in many parts of the world that have been glaciated, including North America, Europe, and Asia. In the United Kingdom, it is particularly common in the northern and eastern parts of the country, where it forms the basis of much of the agricultural land.

Uses

Despite its challenges, boulder clay has been used in construction, particularly for the building of roads and foundations. It is also used in agriculture, where it can provide a rich source of nutrients for crops.

See also

• Glacier
• Glaciation
• Soil
• Clay