ABSTRACT

In the literature, relative sea level rise in southern Florida averaged only about 4.0 m/100 years since 3,000 YBP to the present. It is generally thought that this gradual slow rate of continued relative rise permitted many coastlines to stabilize or begin expanding seaward and many shallow marine environments to build upward to present sea level.

However, an analyses of sediment cores taken in southern Big Cypress National Preserve, Estero River, and Estero Bay, in eastern Collier and western Lee counties, southwestern Florida, shows that a sharp transgression and regression, ranging from about 5 m above NGVD to 3 m below NGVD, occurred about 3,000 YBP based on previous Everglades and Florida Bay core dating. The cores indicate a possible series of high-frequency oscillations; that is, a stillstand followed by a rapid rise which was followed then by a rapid lowering. This transgression lasted about 200-400 years in duration and was about 0.5 m to 2 m in amplitude. The cores also indicate that the Estero bay was well into its regressive phase of sedimentation by 2,200 YBP and had completed forming by about 1,200 YBP. In Estero Bay, this regressive sedimentation following the rapid transgression caused marine sediment bodies to be reworked and transferred to more stable sites within the bay.