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Storm deposition induced by hurricanes in a rapidly subsiding coastal zone.
- Source :
-
Journal of Coastal Research . Apr2014 Special Issue, Vol. 70, p308-313. 6p. 1 Color Photograph, 1 Diagram, 1 Chart, 2 Graphs, 3 Maps. - Publication Year :
- 2014
-
Abstract
- To understand the geological processes induced by tropical cyclones, geochemical and sedimentological analyses were performed on a 3 m sediment core (basal 14C date of 940 +/- 50 years BP) extracted from a marsh adjacent to a backbarrier lake along Louisiana's Gulf of Mexico coast (USA). This study was conducted in order to identify the geologic changes within a subsiding coastal region in the light of coastal recession and past hurricane activity. Previous studies show that Bay Champagne, a semi-circular lake near Port Fourchon, Louisiana, is subjected to subsidence rates between 1.0 and 1.2 cm year-1, the highest rate of retreat within the entire northern Gulf of Mexico. Loss-on-ignition (LOI) and X-ray fluorescence (XRF) analyses, employed to generate lithological and geochemical core profiles, identified three distinct sand layers measuring up to 50 cm in thickness deposited by recent hurricanes. LOI shows large decreases in water, organic, and carbonate contents, indicating the occurrence of marine inundation. Within each marine incursion layer terrestrial elemental concentrations as determined by XRF display large depletions. Grain size analysis of a portion of the core (30-86 cm) indicates the presence of two series of sequential high-energy storm deposits followed by intense fluvial flooding within Bay Champagne. These events are attributed to Hurricanes Katrina/Rita in 2005 and Gustav/Ike in 2008. [ABSTRACT FROM AUTHOR]
- Subjects :
- *SEDIMENTOLOGY
*CYCLONES
*MARSHES
*PETROLOGY
*CARBONATES
Subjects
Details
- Language :
- English
- ISSN :
- 07490208
- Volume :
- 70
- Database :
- Academic Search Index
- Journal :
- Journal of Coastal Research
- Publication Type :
- Academic Journal
- Accession number :
- 103594503
- Full Text :
- https://doi.org/10.2112/SI70-052.1