Grainstones are the main part of the section, among which the oolites, intraclast limestones and most bioclast limestones are cemented by sparry calcite. 颗粒灰岩在剖面中占绝大多数,其中,鲕粒灰岩、内碎屑灰岩和多数生物碎屑灰岩均为亮晶方解石胶结。
Oolite (egg stone) is a sedimentary rock formed from ooids, spherical grains composed of concentric layers. The name derives from the Ancient Greek word ᾠόν for egg. Strictly, oolites consist of ooids of diameter 0.25–2mm; rocks composed of ooids larger than 2mm are called pisolites. The term oolith can refer to oolite or individual ooids.