Rudites

Rudites is a term used in geology to describe a sedimentary rock that is composed primarily of clasts, or fragments, larger than 2 millimeters in diameter. These clasts are typically rounded or sub-rounded, indicating they have been transported and abraded by natural processes such as running water or ice. The material filling the spaces between these larger clasts is generally finer-grained, such as sand, silt, or clay.

The most common type of rudite is conglomerate, which is characterized by the presence of rounded pebbles and cobbles. If the clasts are angular rather than rounded, the rock is classified as a breccia. Rudites form in environments where there is sufficient energy to transport and deposit large fragments. These environments include riverbeds, alluvial fans, glacial outwash plains, and the bases of mountain slopes.

The study of rudites can provide valuable information about the geological history of a region. The size, shape, and composition of the clasts can indicate the source of the sediment, the distance and mode of transport, and the conditions under which the rock was deposited. For example, the presence of well-rounded clasts suggests long-distance transport, while angular clasts point to deposition closer to the source area. The specific rock types that make up the clasts can also help geologists identify the underlying bedrock that was eroded to form the sediment.