Holocene lagoonal sedimentation at the latitudinal limits of reef growth, Lord Howe Island, Tasman Sea

摘要: Abstract The southernmost limit to coral reef growth occurs on Lord Howe Island (33°30′S, 159°05′E) where a discontinuous fringing flanks the western side of island. Coring and radiocarbon dating indicate that carbonate sediments were first deposited within lagoon around 6500 years BP coincident with sea level reaching close its modern level. High-energy conditions dominated robust branching corals dominating developing reef. Growth crest between 6000 5000 yr is inferred have caused reduction in energy resulting mud deposition. During this period, sedimentation occurred at average rates 5 mm/yr, though locally up 10 mm/yr, which infilled almost all available accommodation space lagoon. By 4000 yr most had accreted very floor having accumulated over 11 m sediment northern part possibly 30 m south. Sediments younger than 3000 yr form thin veneer these older units main deposition being confined embayments, coastal plain infilling blue-hole depressions. appear developed their present primarily during phase luxuriant mid-Holocene.