The Western Indian Ocean results from a complex geological history, implying both plate motion since about 180 million years and volcanic hot-spot activity since about 68 million years. This region exhibits a myriad of islands different in nature and origin, including continental remnants (Madagascar, the granitic Seychelles), high volcanic islands (Reunion, Mauritius, Rodrigues, the Comoros), high- and low-lying carbonate reef platforms (the carbonate Seychelles, the French Scattered Island Group, Agalega Islands) and a few submerged reef banks (Geyser, Nazareth, Saya de Malha). This region contains all known types of reefs—fringing, barrier, atoll, platform and bank. The data about reef development history over the Quaternary were gained mainly from two distinct sources: boreholes and emerged outcrops. Reef drilling indicates that modern reefs started regionally to grow from about 10,000–9600 years BP. Rates of vertical reef accretion ranges from 0.2 to about 10 mm/year according to exposure and shape of coral builders. The sea-level curves, reconstructed from vertical reef-accretion and lagoon-deposition curves, express a rapid rise in sea level at rates averaging 6 mm/year between 10,000 and 7500–7000 years BP, with a stabilization at the present position around 2500–3000 years BP. There are significant variations in the composition and distribution of dominant reef-building coral assemblages and facies (framework versus detritus) according to exposure to wave energy. Frameworks composed of robust coral branching assemblages—mainly Acropora robusta, A. humilis groups; Isopora palifera—dominate in higher energy settings, while those with domal and tabular branching forms—mainly Porites, various faviids, Acropora hyacinthus group—are best represented in lower-energy to protected environments. Detritus-reefs are best developed in sheltered sites. The recent contribution of some dominant coral species in modern WIO reefs seem to have resulted from their delayed arrival in the region as controlled by the regional prevailing surface circulation—South Equatorial Current and Agulhas Current—and/or by the competency period of their larvae. Coral-based, geochemical records suggest that, during the mid Holocene, the seasonal variability of sea surface temperatures was lower than today. The reconstruction of the WIO Pleistocene reef history is chiefly based on a limited number of exposed reef remains deposited during the last interglacial MIS 5.5 stage (129,000–125,000 years BP), at present culminating at elevations ranging from − 20 to + 9 m with respect to present mean sea level. Such differences in elevation can be explained by a differential tectonic behaviour of reef-bearing substrates, from stable continental areas to subsiding volcanic islands. The existence of older reef generations (Plio-Pleistocene) was identified from coral-rich inclusions trapped into pyroclastites of Comoro volcanoes.

西印度洋源自复杂的地质历史，这意味着自约1.8亿年以来的板块运动和自约6800万年以来的火山热点活动。该地区拥有无数不同性质和起源的岛屿，包括大陆残余物（马达加斯加，花岗岩塞舌尔群岛），高火山岛（留尼汪岛，毛里求斯，罗德里格斯岛，科摩罗），高低碳酸盐礁平台（碳酸盐岩）塞舌尔群岛，法国分散岛集团，阿加莱加群岛）和一些水下礁石滩（间歇泉，拿撒勒，萨亚德马尔哈）。该区域包含所有已知类型的珊瑚礁-边缘，障碍，环礁，平台和河岸。有关第四纪珊瑚礁发育史的数据主要来自两个不同的来源：钻孔和露头。珊瑚礁钻探表明，现代珊瑚礁从10,000到9600年BP开始在区域内开始生长。根据珊瑚建造者的暴露情况和形状，垂直礁石的积聚速率为每年0.2至约10毫米。从垂直礁石增生和泻湖沉积曲线重建的海平面曲线表示，在10,000至7500–7000年BP之间，海平面以每年6毫米/年的速度快速上升，目前位置稳定在2500年左右–3000年BP。根据暴露于波能的影响，主要的造礁珊瑚组合和相（构架与碎屑）的组成和分布存在显着差异。由坚固的珊瑚分支组合组成的框架-主要是 根据珊瑚建造者的暴露情况和形状，每年2至10毫米。从垂直礁石增生和泻湖沉积曲线重建的海平面曲线表示，在10,000至7500-7000年BP之间，海平面以每年6毫米/年的速度快速上升，目前位置稳定在2500年左右–3000年BP。根据暴露于波能的影响，主要的造礁珊瑚组合和相（构架与碎屑）的组成和分布存在显着差异。由坚固的珊瑚分支组合组成的框架-主要是 根据珊瑚建造者的暴露情况和形状，每年2至10毫米。从垂直礁石增生和泻湖沉积曲线重建的海平面曲线表示，在10,000至7500–7000年BP之间，海平面以每年6毫米/年的速度快速上升，目前位置稳定在2500年左右–3000年BP。根据暴露于波能的影响，主要的造礁珊瑚组合和相（构架与碎屑）的组成和分布存在显着差异。由坚固的珊瑚分支组合组成的框架-主要是 在2500-3000年BP的当前位置保持稳定。根据暴露于波能的影响，主要的造礁珊瑚组合和相（构架与碎屑）的组成和分布存在显着差异。由坚固的珊瑚分支组合组成的框架-主要是 在2500-3000年BP的当前位置保持稳定。根据暴露于波能的影响，主要的造礁珊瑚组合和相（构架与碎屑）的组成和分布存在显着差异。由坚固的珊瑚分支组合组成的框架-主要是鹿角罗布斯塔，A.蒿草组; Isopora palifera-在较高能量的环境中占主导地位，而具有圆顶状和板状分支形式的-主要是Porites，各种收藏夹，Acropora hyacinthus组—以对保护环境的低能耗为最好的代表。碎屑礁最好在有遮盖的地方开发。在现代WIO珊瑚礁中，一些优势珊瑚物种最近的贡献似乎是由于它们受区域主要地表环流（南赤道洋流和Agulhas洋流）和/或幼虫的生存期控制而延迟到达该区域。基于珊瑚的地球化学记录表明，在全新世中期，海表温度的季节性变化低于今天。WIO更新世珊瑚礁历史的重建主要基于在最后一个冰间期MIS 5.5阶段（129,000–125,000年BP）期间沉积的少量暴露珊瑚礁残骸，目前，相对于目前的平均海平面，其最高海拔范围为− 20至+ 9 m。海拔的这种差异可以用从稳定的大陆地区到下沉的火山岛的含礁基质的不同构造行为来解释。从科摩罗火山的火山碎屑岩中捕获的富含珊瑚的包裹体中发现了较老的珊瑚礁世代（上新世）。