Numerical model of geochronological tracers for deposition and reworking applied to the Mississippi subaqueous delta
Links
- More information: Publisher Index Page (via DOI)
- Open Access Version: Publisher Index Page
- Download citation as: RIS | Dublin Core
Abstract
Measurements of naturally occurring, short-lived radioisotopes from sediment cores on the Mississippi subaqueous delta have been used to infer event bed characteristics such as depositional thicknesses and accumulation rates. Specifically, the presence of Beryllium-7 (7Be) indicates recent riverine-derived terrestrial sediment deposition; while Thorium-234 (234Th) provides evidence of recent suspension in marine waters. Sediment transport models typically represent coastal flood and storm deposition via estimated grain size patterns and deposit thicknesses, however, and do not directly calculate radioisotope activities and profiles, which leads to a disconnect between the numerical model and field observations. Here, observed radioisotopic profiles from the Mississippi subaqueous delta cores were directly related to a numerical model that represented resuspension and deposition using a new approach to account for the behavior of short-lived radioisotopes. Appropriate selection of parameters such as the biodiffusion coefficient, sediment accumulation rate, and radioisotopic source terms enabled a good match between the modeled and observed cores. Comparisons of modelled profiles with geochronological analytical models that estimate accumulation rate and flood layer thickness revealed potential avenues for refining these tools, and highlight the importance of constraining the biodiffusion coefficient.
Study Area
| Publication type | Article |
|---|---|
| Publication Subtype | Journal Article |
| Title | Numerical model of geochronological tracers for deposition and reworking applied to the Mississippi subaqueous delta |
| Series title | Journal of Coastal Research |
| DOI | 10.2112/SI85-092.1 |
| Volume | Special Issue 85 |
| Year Published | 2018 |
| Language | English |
| Publisher | Coastal Education and Research Foundation |
| Contributing office(s) | St. Petersburg Coastal and Marine Science Center |
| Description | 5 p. |
| First page | 456 |
| Last page | 460 |
| Country | United States |
| Other Geospatial | Gulf of Mexico, Mississippi River Delta |
| Google Analytic Metrics | Metrics page |