the florida state university college of arts and sciences evolution of ...

Objectives
CHAPTER 1
INTRODUCTION AND GEOLOGICAL BACKGROUND
Coastal features, such as barrier islands, marine terraces, raised beaches etc, are products
of sea-level change. This investigation focuses on barrier islands. Beach ridges, which represent
paleo-shoreline positions, are often preserved on the surface of these features. Beach ridges can
provide a detailed record of the response of barrier islands to sea-level change. The purpose of
this project was to investigate the age, origin and evolution of a well-developed and well-
preserved barrier island beach ridge plain in the northern Gulf of Mexico. St. Vincent Island, a
coastal barrier island located near the mouth of the Apalachicola River in northwest Florida
(Figure 1.1), has been actively evolving and prograding over the past 4,000+ years. The
organization of the island’s ridges into distinct sets (Figure 1.2) separated by erosional
truncations indicates a history of episodic progradation. This episodicity is likely related to sea-
level change. The primary objective of this investigation was to use the occurrence of multiple
beach ridge sets on the island to investigate the relationship that ridge ages and mean ridge set
heights have to regional sea-level history.
The goals of this project are:
1) To develop a better understanding of the late Quaternary history of the northern Gulf of
Mexico coast and its response to sea-level change, including abrupt sea-level changes
during the mid to late Holocene.
2) To gain insight into the impact of short-term changes in sea level on coastal evolution
and geomorphology on stable continental margins.
3) To obtain direct evidence for mid- to late Holocene sea-level fluctuations, including
stillstands and possible highstands in the northern Gulf of Mexico.
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