USING FORAMINIFERA TO IDENTIFY OVERWASH DEPOSITS IN ST VINCENT ISLAND, FLORIDA, IN THE WAKE OF HURRICANE MICHAEL

Major hurricanes have geomorphic and stratigraphic impacts in coast environments that can be used to identify and characterize the storms. One of the approaches to identify storm impact is by studying assemblage of foraminifera, small organisms that live primarily in marine environments with some species living in marshes, in coastal marshes or ponds, with the assumption that storm-induced overwash flooding brings marine species ashore. Hurricane Michael made landfall ~40 km northwest of St Vincent Island (SVI), Florida, on October 10, 2018, as a Category 5 storm. The storm surge of Michael inundated a large part of SVI, which offers a rare opportunity to investigate foraminifera assemblage of overwash deposits caused by an extremely powerful landfalling hurricane. In this study, samples from a sediment core taken from a marsh pond in SVI were analyzed for foraminifera assemblage. The ongoing analysis focuses on core top sediment interpreted as the Michael event layer, additional deeper sandy layers similar in grain size to the core top sediments, and clayed pond deposits. Preliminary data of representative samples show that the core top sediment contains a higher proportion of foraminifera species originated from the bay east of SVI in comparison to the clayed pond deposits. It suggests that foraminifera assemblage in the pond sediment may complement grain-size analysis for paleotempestite identification in SVI. The full analysis result will be presented.