摘要: Anegada is part of the British Virgin Islands, and a low lying limestone island with maximum elevation 8 m. It has extensive salt ponds wetlands. entirely different from rest US Islands Puerto Rico which together form Rican/Virgin microplate. formed as massive coral reef system during last Interglacial highstand 130,000 ± 2k to 119,000 years before present. Its western side comprised dune beach ridge complexes, lagoons mangroves, known Ridge Plain Formation. The eastern distinguished by indurated modified karst topography including solution pits sinkholes. Contiguous Horseshoe Reef these cover approximately 133 km2. reefs have two distinctive facies, high energy front along north-eastern windward island, series patch marked northwest/southeast orientation aligned prevailing wind waves on southern leeward side. width shoreline crest varies widely, 5 m 3 km sandy lagoon abundant seagrasses algae. From tip barrier extends 14 southeastwardly an area where horseshoe shape turns almost 90 south. As many in Caribbean, heavy mortalities Acropora (and Diadema) greatly reduced live 1980s. considerable resiliency ability adjust both extreme events conditions including, perhaps, those introduced climate change. Although coastline displays alternating areas erosion accumulation sand up 300 change, long-term result been counter-clockwise rotation island.