Holocene coral reef on Kauai, Hawaii; evidence for a sea-level highstand in the central Pacific

Evidence of a late Holocene sea-level high stand has been found on the Island of Kauai, Hawaii. A fossil reef complex in growth position is exposed approximately 500 m inland in the Hanalei River estuary at a maximum elevation of + or - 1.8 m above present sea level. A fossil reef flat is also exposed in the adjacent Waioli Stream. Radiocarbon ages (uncalibrated) of corals within the reef complex range from 4.2 to 3.23 ka. The coral species identified imply a shallow-water environment. Although buried by fluvial sediments, the paleoshoreline should be several tens of meters landward of the study site. The elevation and age of the Kauai reef support recent geophysical models of the last deglaciation and indicate an emergence approximating that in French Polynesia and the Cook Islands. It is proposed that as the relative sea level retreated to its present position, the Hanalei River built a delta that buried the fossil reef with unconsolidated alluvium.