In a karstic area, concretions include all forms resulting from the precipitation of carbonates which have been dissolved and transported by water. The majority of these are composed of calcite or aragonite. Depending on their form and position, these are divided into stalactites, tubular stalactites, curtains, stalagmites, stalagmitic columns, stalagmitic masses, stalagmitic floors etc. The generic term for underground concretions is speleothem. In northern latitudes, concretions developed during climatic optimums (interstadial, interglacial, Holocene etc.). They can be dated by isotopic analysis (U/Th).