Geology Commons^™

Sedimentology And Shallow Groundwater Responses Of A Coastal Marsh Along A Salinity Gradient: A Case Study In Grand Bay National Estuarine Research Reserve, Mississippi, James Thompson

Master's Theses

Climate change and relative sea level rise is resulting in saltwater intrusion and inundation of coastal marshes. This study investigates factors affecting marsh hydrology, including sediment composition, seasonal variability, and coastal storms in Grand Bay National Estuarine Research Reserve (NERR) near Pascagoula, Mississippi. Analysis of sediment includes color, organic matter, carbonate, magnetic susceptibility, and particle size. Shallow groundwater hydrologic trends between Summer 2015 and Fall 2016 are established along a salinity gradient at four sites using water levels, temperature, and conductivity monitored at the surface and in piezometers at depths of 0.75m, 1.5m, and 2.25m.

Sediment analysis indicates reducing conditions …

Stromatolitic Knobs In Storrs Lake, San Salvador, Bahamas: Insights Into Organomineralization, Alexandre J. Fowler

Master's Theses

Storrs Lake, a hypersaline lake on the east coast of San Salvador Island, Bahamas, contains well-developed microbial mats, some of which have developed calcified structures called microbialites. Many of these microbialites are laminated, and therefore classified as stromatolites. This study focuses on small stromatolitic knobs located in the southern portion of Storrs lake, which are still actively forming, to gain insights into the early stages of stromatolite formation. These knobs appear to be forming as the result of in situ micritic precipitation mediated by both photosynthetic and heterotrophic microbial metabolisms. By comparing these small stromatolitic knobs to larger stromatolitic heads …