Floatstone is a type of

carbonate A carbonate is a salt of carbonic acid (H2CO3), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word ''carbonate'' may also refer to a carbonate ester, an organic compound containing the carbonate ...

rock. The original

Dunham classification The Dunham classification system for carbonate sedimentary rocks was originally devised by Robert J. Dunham in 1962, and subsequently modified by Embry and Klovan in 1971 to include coarse-grained limestones and sediments that had been organical ...

(Dunham, 1962) of

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms w ...

s did not consider the separate classification of coarse grained carbonate lithologies. In an attempt to rectify this, Embry & Klovan (1971Embry, A.F. and Klovan, J.E. (1971) A Late Devonian reef tract on Northeastern Banks Island, NWT. Bull. Can. Pet. Geol., 19, 730–781.) introduced the terms rudstone (grain supported) and floatstone (matrix supported) for coarse-grained allochthonous limestones. This definition of a floatstone was most recently clarified as "a carbonate-dominated rock where more than 10% of the volume is grains larger than 2 mm and the fabric is supported by the component that is 2 mm and smaller".

References

Limestone {{petrology-stub