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.

Oolite or oölite (from Ancient Greek ᾠόν (ōión) ' egg stone ') [1] is a sedimentary rock formed from ooids, spherical grains composed of concentric layers. [2] Strictly, oolites consist of ooids of diameter 0.25–2 millimetres; rocks composed of ooids larger than 2 mm are called pisolites .

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)).

Ooids are small rounded accretionary mineralized bodies. They could be called sand grains, but they are no ordinary sand grains. Just like normal sand grains, ooids have a diameter reaching up to 2 mm (usually less than 1 mm).

: shaped like an egg. : one of the individual spherical concretionary bodies that characterize an oolite. Greek ōioeidēs, from ōi- o- + -eidēs -oid. Expand your vocabulary and dive deeper into …

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 · Here we investigate a rare and beautiful geophysical problem that combines both of these processes; the shape evolution of carbonate particles known as ooids.

OOIDS are a distinctive type of sand that usually form on the sea floor. After they have been buried under additional sediment, such sand grains can be fused into a solid mass of sedimentary rock known as an OOLITE. The unusual name reflects the fact that grains of oolitic sand are highly reminiscent of fish eggs or roe when examined closely.

Common ooid nuclei are peloids and fragments of Halimeda, red algae, and mollusks. You might find these chapters and articles relevant to this topic. Most Upper Jurassic reservoirs are developed in ooid grainstones that originally had porosities of nearly 50%.