The Ten Thousand Islands (TTI) are a myriad of low-relief mangrove islands that lie along the low energy, subtropical southwest Florida coast. The region has been subjected to a relative rise in Holocene sea level, which has continuously decelerated to its present rate. Data derived from surface and subsurface sampling indicate that the Holocene sediment package of the TTI area consists of two sediment sequences. The lower sequence is transgressive and was generated as coastal salt marsh and/or terrestrial environments were submerged and replaced by a shallow coastal marine setting. The upper sediment sequence consists primarily of 1) biogenic shallowing upwards sequences or 2) thickened mangrove peat layers, reflecting island emergence and shoreline stabilization, respectively. Based on coastal stratigraphy and 14C dates, the formation of this transgressive/regressive sediment sequence is directly related to changing rates of Holocene sea-level rise, reported to have occurred between 3500 and 3200 yr BP. -from Author
