What is a old river stage?

An old river stage is a term used in geology and paleontology to refer to a former course of a river that is no longer active. These old river stages can be identified by the presence of fluvial deposits such as sand, silt, clay, and gravel, which were laid down by the river over time. The deposits may be found in a variety of locations, such as river valleys, floodplains, and deltas. Old river stages can provide important information about the past climate, hydrology, and geomorphology of an area. They can also be used to identify potential groundwater resources and to assess the risks associated with flooding and other natural hazards.