Calcilutite (also known as cementstone) is a type 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 wh ...

that is composed of predominantly, more than 50 percent, of either clay-size or both silt-size and clay-size detrital (transported)

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 carbonat ...

grains. These grains consist either of

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

fragments,

ooid Ooids are small (commonly ≤2 mm in diameter), spheroidal, "coated" (layered) sedimentary grains, usually composed of calcium carbonate, but sometimes made up of iron- or phosphate-based minerals. Ooids usually form on the sea floor, mo ...

intraclasts Intraclasts are irregularly shaped grains that form by syndepositional erosion of partially lithified sediment. Gravel grade material is generally composed of whole disarticulated or broken skeletal fragments together with sand grade material of wh ...

, pellets, other grains, or some combination of them. The term calcilutite was originally proposed in 1903 by GrabauGrabau, A.W. (1903) ''Paleozoic coral reefs.'' Geological Society of America Bulletin. vol. 14, pp. 337-352.Grabau, A.W. (1904) ''On the classification of sedimentary rocks.'' American Geologist. vol. 33, pp. 228-247. as a part of his calcilutite,

calcarenite Calcarenite is a type of limestone that is composed predominantly, more than 50 percent, of detrital (transported) sand-size (0.0625 to 2 mm in diameter), carbonate grains. The grains consist of sand-size grains of either corals, shells, o ...

and

calcirudite Calcirudite is a type of limestone that is composed predominantly, more than 50 percent, of carbonate grains that are larger in size than sand (2 mm in diameter). The grains can consist of either fragments of fossils, fragments of older limesto ...

classification system based upon the size of the detrital grains composing a limestone.Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, J.A., eds. (2005) ''Glossary of Geology'' (5th ed.). Alexandria, Virginia, American Geological Institute. 779 pp. Flügel, E. (2010) ''Microfacies of Carbonate Rocks'', 2nd ed. Springer-Verlag Berlin, Germany. 976 pp. In the original classification of limestone according to the dominant grain-size,

calcisiltite Calcisiltite is a type of limestone that is composed predominantly, more than 50 percent, of detrital (transported) silt-size carbonate grains. These grains consist either of the silt-size particles of ooids, fragments of fossil shells, fragments o ...

s were not named and are classified as calcilutite. In this classification, which the majority of geologists follow, a calcilutite consists of both silt- and clay-size, less than 0.062 mm in diameter, grains. It is the carbonate equivalent of a mudstone (not to be confused with a 'mudstone' of the Dunham Limestone classification).Folk, R.L., 1962, ''Spectral subdivision of limestone types. ''. In Ham, W. E.. Classification of carbonate rocks. American Association of Petroleum Geologists Memoir. no. 1, pp. 62-84. Calcilutites can accumulate in a wide variety of marine and

lacustrine A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much larger ...

environments.Scholle, P.A., D.G. Bebout, and C.H. Moore (1983) ''Carbonate Depositional Environments. '' Memoir no. 33. Tulsa, Oklahoma, American Association of Petroleum Geologists. 708 pp.

References

Limestone {{petrology-stub