 |
| Titel |
Record of the early Holocene deglaciation from the East Antarctic Adélie Land margin: IODP Site U1357 |
| VerfasserIn |
Carlota Escutia, Francisco Jimenez-Espejo, Ariadna Salabarnada, Julia Gitiérrez-Pastor |
| Konferenz |
EGU General Assembly 2015
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250114865
|
| Publikation (Nr.) |
 EGU/EGU2015-15692.pdf |
|
|
|
|
|
| Zusammenfassung |
| Drilling at Site U1357 yielded a 185.6 m section of Holocene continuously laminated diatom ooze as well as a portion of an underlying Last Glacial Maximum diamict. We present sedimentological and geochemical data of the time of the first Holocene deglaciation. The use of CT-Scanner has allowed us to characterize in detail sedimentary facies dominated by iceberg rafted debris, silt layers and biogenic laminations. In addition, geochemical studies have been conducted at ultra-high (seasonal to decadal) resolution using X-Ray Fluorescence scanning, allowing to reconstruct detrital input, paleoproducitivity and redox conditions. Comparison between CT-Scan images and geochemical data show that the intervals with high Ba/Al and Si/Al are associated to poor detrital levels allowing to use these ratios along the entire core as detrital/paleoproductivity proxies. Detrital proxies (e.g., Zr content) anticorrelate with bottom redox conditions proxies (U/Th) pointing to well oxygenated deep waters as generator for silt layers. These preliminary observations point to an unprecedented high resolution ice fjord-like sequence in the studied region with strong water column stratification and pulsational detrital input acting as a main forcing for environmental variations. Ongoing radiocarbon analysis, performed in the bulk fraction and also in compound-specific, will allow us to recognize timing, cylces and if major variations occurred in the reservoir age during the deglaciation. |
|
|
|
|
|
|