mud

Mud is a slimy, wet mixture of solid material, typically earth, with water. It is a fundamental component of geology, forming sedimentary rocks like mudstone, which is composed of clay or silt-sized particles. Mudrocks, including siltstone, claystone, and mudstone, are abundant, making up nearly 80 percent of Earth's sedimentary rock column.123

Mud can form in various environments, such as river floodplains, lakes, and the deep ocean, often requiring weak currents for deposition. It can also be associated with volcanic activity, forming from the mixture of volcanic ash and water, sometimes resulting in hot flows known as volcanic mud. Mud volcanoes are geological formations where mud is heaved up through overlying sediments, sometimes due to hot-spring activity or the release of gases in oil-field regions.345