Calcareous tufa is a geological term used to describe a porous rock formation that is composed of calcium carbonate. This type of rock is commonly referred to as travertine, and it is often found in areas where groundwater is present. Other synonyms for calcareous tufa include limestone rock, sedimentary rock, carbonate rock, and calcium carbonate deposits. These terms are useful for scientists and geologists studying the earth's history and geology, as well as for anyone looking to understand the makeup of certain rock formations. Overall, the synonyms for calcareous tufa help to paint a more complete picture of the complexities of the natural world.