An ooid forms as a series of concentric layers around a nucleus. The layers contain crystals arranged radially, tangentially or randomly. The nucleus can be a shell fragment, quartz grain or any other small fragment. Most modern ooids are aragonite, a polymorph of calcium carbonate; some are composed of high … See more Ooids (from Ancient Greek ᾠόν (ōión) 'egg stone') are small (commonly ≤2 mm in diameter), spheroidal, "coated" (layered) sedimentary grains, usually composed of calcium carbonate, but sometimes made up of See more Ooids with radial crystals (such as the aragonitic ooids in the Great Salt Lake, Utah, US) grow by ions extending the lattices of the radial crystals. The mode of growth of ooids with tangential (usually minute needle-like) crystals is less clear. They may be … See more Sometimes fossils are included in ooids, often forming the nuclei. This taphonomic process is termed ooimmuration (Wilson et al., 2024). The … See more Whether ooids become calcitic or aragonitic can be linked to strontium/calcium substitution within the crystalline structure. This has been shown in some examples to be due … See more There are several factors that affect ooid growth: supersaturation of the water with respect to calcium carbonate, the availability of nuclei, agitation of the ooids, water depth, and the … See more • Ooid Formation at the Wayback Machine (archived 20 June 2013) See more WebOoids most often form in shallow, wave-agitated marine water. Are ooids fossils? Oids (also known as olites or oliths) are sand-size spheres of calcium carbonate mud concentrically …
Ooid - Wikipedia
WebOoids form in a wide variety of modern depositional settings. Most form in shallow, tropical marine settings of moderate to high wave activity, at depths <10 m (often ≤2 m), where the water is supersaturated with respect to calcium carbonate. Well-studied areas of modern marine ooid formation include the Great Bahama Bank and the Persian Gulf. WebJun 27, 2024 · Iron-bearing goethitic (limonitic) ooids are probably formed out of volcanic pyroclastic (volcanic ash) material deposited in sea. Concentric layering in iron-bearing ooids is thought to result from … ironton library ohio
The formation of ooids - DAVIES - 1978 - Wiley Online Library
WebMembranes form concentric shells which act as growth surfaces for carbonate and also induce the periodicity in carbonate precipitation. Ooids exhibiting a tangential orientation of batten-like crystals have been synthesized under conditions of agitation, supersaturation and without the intervention of organic processes during the precipitation. WebIn their model, which obviates the role of microbes in the synthesis of organic membranes, ooid growth begins in the agitation phase, where precipitation is triggered by turbulence, a … WebJan 1, 1980 · Chemically ooids are formed almost completely of CaCO 3 and may be distinguished as (a) concentric ooids with cortical envelopes in which the individual … ironton low profile creeper