Ooids (/ ˈoʊˌɔɪd /, [1] from Ancient Greek ᾠόν (ōión) 'egg stone') [2] 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.

Jul 1, 2024 · Ooids are concentrically-laminated, sedimentary grains produced through successive stages of carbonate precipitation and abrasion that typically form above wave base in tropical-to-subtropical carbonate platforms (e.g., Davies et al. (1978)).

Mar 1, 2019 · Ooids are spherical or ovoidal carbonate grains (typically <2 mm in diameter) of smooth, well-laminated cortices that accrete around a nucleus, typically a bioclast, peloid, siliciclastic grain or lithoclast (Fig. 1).

Coated grains include oolites, pisolites, oncoids, and oncolites. oolites (figure below) are formed by a series of concentric layers surrounding a nucleus. They generally form in agitated marine environments including tidal sand bars or tidal deltas between barrier islands.

Jan 29, 2018 · Ooids are rounded, sand-sized particles of calcium carbonate that typically form by mineral precipitation in warm and shallow coastal waters. Their transport by waves and currents gives rise to...

Jul 11, 2020 · Ooids are a common type of carbonate sand grain that form through a combination of constructive and destructive mechanisms: growth via precipitation and diminution via physical abrasion.

Aug 30, 2019 · Ooids, pisoids, oncoids and pelloids comprise the most common non-skeletal component of limestones. The first three are characterized by enveloping laminations that range from perfectly concentric spheres to strongly asymmetric grains.

An ooid is a small rounded sedimentary rock. Like sand grains, ooids have a diameter of 2 mm or less. Larger grains formed the same way as ooids are called pisoids. Rock made of ooids is oolite. [1]

Jan 1, 1980 · Ooids are spherical or subspherical carbonate grains characterized by an internal concentric structure and average dimensions ranging mainly from 0.25 to 1.00 mm.

Feb 22, 2021 · We present a method for making 3D reconstructions by serial grinding and imaging, which enables accurate measurement of the morphology of individual ooids within an oolite, as well as the sorting and porosity of a sample. We also provide three case studies that use the morphology of ooids in oolites to extract environmental information.