Oncoid-limestone

A limestone composed almost entirely of oncoids.

Used synonymously with oncolite, which is also synonymous with Oncoid. See: https://www.mindat.org/mesg-646228.html

The SEPM site (Society for Sedimentary Geology) says:
“Pisolites, oncoids, and oncolites are enveloped by irregular layers. All these grains are frequently larger than ooids and commonly are over a centimeter in diameter. Pisolites form by the precipitation of calcium Carbonate around nuclei trapped in sediment within the vadose zone of soils or marine tidal flats (Figure 24). Oncoids form on the surface of intertidal and supratidal flats where Carbonate precipitates from salt water spray and marine flood waters (left figure). Though these grains are termed oncoids, in Limestones they probably cannot be distinguished from pisolites. Finally, other grains resembling pisolites but termed oncolites are formed by accretions of blue-green algae and trapped sediment around a nucleus in moderately protected marine environments (figure below). “ This suggests that these three terms may be differentiated in sediments but maybe not in lithified rocks. Probably we need a broader term when we don’t know the origin?