Editing Coral reef (section)

===Platform reef===
[[File:Plattformriff.png|thumb|Platform reef]]
Platform reefs, variously called bank or table reefs, can form on the [[continental shelf]], as well as in the open ocean, in fact anywhere where the seabed rises close enough to the surface of the ocean to enable the growth of zooxanthemic, reef-forming corals.<ref name=Leser>{{cite encyclopedia |editor=Leser, Hartmut |year=2005 |title=Wörterbuch Allgemeine Geographie |language=de |edition=13th dtv |location=Munich, DE |page=685 |isbn=978-3-423-03422-7}}</ref> Platform reefs are found in the southern Great Barrier Reef, the Swain<ref>{{cite journal |vauthors=Scoffin TP, Dixon JE |title=The distribution and structure of coral reefs: one hundred years since Darwin |journal=Biological Journal of the Linnean Society |year=1983 |volume=20 |pages=11–38|doi=10.1111/j.1095-8312.1983.tb01587.x }}</ref> and Capricorn Group<ref>{{Cite journal|url=https://espace.library.uq.edu.au/view/UQ:10881 |access-date=2018-06-28 |vauthors=Jell JS, Flood PG |title=Guide to the geology of reefs of the Capricorn and Bunker groups, Great Barrier Reef province |journal=Papers, Department of Geology |volume=8 |issue=3 |at=pp.&nbsp;1–85, pls.&nbsp;1–17 |date=Apr 1978}}</ref> on the continental shelf, about 100–200&nbsp;km from the coast. Some platform reefs of the northern [[Mascarenes]] are several thousand kilometres from the mainland. Unlike fringing and barrier reefs which extend only seaward, platform reefs grow in all directions.<ref name=Leser/> They are variable in size, ranging from a few hundred metres to many kilometres across. Their usual shape is oval to elongated. Parts of these reefs can reach the surface and form sandbanks and small islands around which may form fringing reefs. A lagoon may form In the middle of a platform reef.

Platform reefs are typically situated within atolls, where they adopt the name "patch reefs" and often span a diameter of just a few dozen meters. In instances where platform reefs develop along elongated structures, such as old and weathered barrier reefs, they tend to arrange themselves in a linear formation. This is the case, for example, on the east coast of the [[Red Sea]] near [[Jeddah]]. In old platform reefs, the inner part can be so heavily eroded that it forms a pseudo-atoll.<ref name=Leser/> These can be distinguished from real atolls only by detailed investigation, possibly including core drilling. Some platform reefs of the [[Lakshadweep|Laccadives]] are U-shaped, due to wind and water flow.