Rebecca Pickering
Postdoctoral fellow
Reactive silica fractions in coastal lagoon sediments from the northern Gulf of Mexico
Author
Summary, in English
Continental-margin sediments account for ~ 50% of the oceanic biogenic silica burial despite covering < 10% of its area. In Mississippi Sound, a coastal lagoon in the northern Gulf of Mexico (nGoM), we measured sediment biogenic silica at sites removed from major freshwater discharge sources using the traditional method and a method that has been modified for deltaic systems to quantify other reactive silica pools, specifically those involved in the process of reverse weathering. The magnitude of authigenically-altered biogenic silica during our study was significant and represented, on average, 33% of the total sediment biogenic silica among core depths and sites. Additionally, there was a significant relationship between the degree to which the biogenic silica pool was authigenically altered and the source of the sediment organic matter, with lower modification in sediments corresponding with higher terrestrial organic matter. We observed no positive correlation between the magnitude of authigenic modification and sediment clay content. Thus, our findings suggest that these processes may occur within a variety of sediment compositions and add to a growing body of evidence suggesting that reverse weathering of silica in coastal systems is a significant pathway in the global silica budget.
Publishing year
2017
Language
English
Publication/Series
Continental Shelf Research
Document type
Journal article
Publisher
Elsevier
Topic
- Oceanography, Hydrology, Water Resources
- Geochemistry
Keywords
- Biogenic silica
- Sediment
- Silicon
- Reverse weathering
- Carbon isotopes
- Gulf of Mexico
Status
Published
ISBN/ISSN/Other
- ISSN: 0278-4343