Detritus (adjective detrital) is a geological term used to describe particles of rock derived from pre-existing rock through processes of weathering and erosion. Weathering is the decomposition of earth rocks, Soils and their Minerals through direct contact with the planet's Atmosphere. Erosion is the carrying away or displacement of solids ( Sediment, Soil, rock and other particles usually by the agents of currents such as wind Detrital particles can consist of lithic fragments (particles of recognisable rock), or of monomineralic fragments (mineral grains). These particles are often transported through sedimentary processes into depositional systems such as riverbeds, lakes or the ocean forming sedimentary successions. Sedimentary rock is one of the three main rock types (the others being igneous and Metamorphic rock) Diagenetic processes can transform these sediments into rock through cementation and lithification, forming sedimentary rocks such as sandstone. In Geology and Oceanography, diagenesis is any chemical physical or biological change undergone by a Sediment after its initial deposition and during Lithification (from the Greek word lithos meaning 'rock' and the Latin -derived suffix -ific) is the process in which Sediments compact These rocks can then in turn again be weathered and eroded to form a second generation of sediment.