Travertine - cave or hydrothermal deposits. Dolomite - formed when magnesium in seawater replaces some of the calcium in limestone. Chert Microcrystalline silica Also flint, jasper, agate Biochemical sediment from skeletons of radiolarians in the oceans. In geodes - precipitates of silica in volcanic areas. Evaporites From evaporation, supersaturation and precipitation in shallow, enclosed seas.
Many sedimentary environments can exist at the same time over a broad area.
Gradual lateral changes in the type of sedimentary rock can occur within a single layer. Each facies grades laterally into another that formed at the same time but in a different environment. Bedding planes - interfaces between the strata. Generally form in a horizontal configuration, but there are exceptions. Termination of a set of strata by another set of inclined layers.