Semester of Graduation

Spring 2026

Degree

Master of Science (MS)

Department

Geology and Geophysics

Document Type

Thesis

Abstract

Louisiana’s active deltaic wetlands are indispensable, playing a crucial role in protecting the state’s coastal communities from storms, sequestering carbon, and supporting rich biodiversity. The acceleration of climate change and construction of anthropogenic structures that divert flow along the Mississippi River has caused the Balize Delta, colloquially known as the Bird’s Foot, to experience significant wetland loss through increased relative sea level rise (RSLR) and sediment depletion. These factors heightened wetland vulnerability by intensifying inundation and submergence, while also reducing their natural ability to maintain elevation and sequester carbon. As a result, 374.77 km2 of land was lost between 1932 and 2016 (Couvillion et al., 2017). Since the 1980s, coastal agencies have leveraged the delta’s natural sedimentation and hydrologic processes to build man-made crevasses, which are breaks in channel levees that help disperse sediment by mimicking the natural process of crevassing. To build resilient marsh platforms that sequester carbon effectively, natural and man-made crevasse environments require sustained vertical accretion through inorganic and organic accumulation. It is unknown how well man-made crevasses opened within the last ~30 years mimic the sediment and total organic carbon accumulation dynamics of older, natural crevasses. This research seeks to fill this knowledge gap through analyses of geologic properties (bulk density, organic matter, total organic carbon, and grain size) and 210Pb geochronology of two-meter sediment cores from both natural and man-made crevasses in the Balize Delta. The goal was to develop a validated organic matter to total organic carbon conversion factor and collect geologic and accretion data relevant to these environments. The major conclusions of this study show that man-made crevasses closely resemble natural ones, with no significant (p>0.05) differences in the analyzed geologic properties, indicating their potential as land-building solutions. Both crevasse types display long-term vertical accretion rates that indicate the environments are maintaining elevation relative to RSLR. In the Balize Delta, total organic carbon accumulation rates are more variable than previously reported, highlighting the need for long-term trend analysis to evaluate total organic carbon sequestration efficiency. This information will guide land management decisions in the Balize Delta, and aid broader efforts to restore the Mississippi River Delta.

Date

3-21-2026

Committee Chair

Carol A. Wilson

LSU Acknowledgement

1

LSU Accessibility Acknowledgment

1

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