Author ORCID Identifier

Date Available


Year of Publication


Degree Name

Master of Science (MS)

Document Type

Master's Thesis


Arts and Sciences


Earth and Environmental Sciences (Geology)

First Advisor

Dr. Kevin M. Yeager


Coastal wetlands along the Northern Gulf of Mexico (NGOMx) are critically important but threatened environments which provide significant and diverse economic, social, and environmental value. These environments are essential components to the global carbon cycle, serving as one of the most efficient terrestrial carbon sinks. Since onset of the Industrial Revolution increasing rates of coastal wetland loss have been documented due to a variety of anthropogenic activities, neotectonic processes, subsidence, and rising sea-levels. This research utilized an array of methods and sedimentological analyses to test the hypothesis that growth-fault induced changes at Earth’s surface affects the delivery to, and storage of particulate organic carbon (POC) within near-surface sediments in coastal wetlands. Objectives were focused on understanding the environmental controls (i.e., sediment supply, surface elevation gradients, relative marsh age) on organic carbon fluxes and near and long-term inventories within coastal marshes. Four marshes with contrasting depositional environments along the NGOMx were studied.

It is shown that growth-faulting, surface elevations, and marsh ages all act as significant controls on POC storage and fluxes. Relative marsh age is identified as having a positive effect on the rate of delivery and storage of POC, with older, established marshes displaying the most efficient accumulation and storage of POC. Surface elevation contrasts due to growth-faulting also act as a control of POC inventories, showing contrasting relationships between “developing” and “established” marshes. In “developing” marshes, POC inventories increase with increasing elevation, while in “established” marshes, POC inventories increase with decreasing elevation. These findings contribute to the growing literature on organic-carbon functioning in coastal wetlands. With climate change, relative sea-level (RSL) rise, among other anthropogenic effects projected to accelerate in the near future, understanding the changes these environments may experience is essential to protecting their efficiency and overall sustainability.

Digital Object Identifier (DOI)