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 of older limestones and dolomites, intraclasts, pellets, other carbonate grains, or some combination of these.
[1][2] Calcisiltites can accumulate in a wide variety of coastal, lacustrine, and marine environments.
[2][3] The term calcisiltite was not an original part of the calcilutite, calcarenite and calcirudite classification system for limestones, which Grabau[4][5] proposed in 1903.
Instead, the term calcisiltite was created by Kay[6] in 1951 for limestone consisting predominantly of detrital silt-size, 0.062 to 0.002 mm, grains.