Abstract
Changes in neritic carbonate production and sediment transport off platforms are related to climate variations, sea-level fluctuations and tectonic processes. Canyon systems marking the platform slopes represent critical source-to-sink pathways transporting shallow-water sediments basinward. However, these export systems and related processes are primarily studied on platform slopes in humid to tropical climate settings. A newly discovered canyon system on the leeward margin of the Al Wajh platform (north-east Red Sea) represents the ideal laboratory to investigate source-to-sink pathway dynamics in an arid climate that prevailed since the Late Pleistocene. A high-resolution bathymetry map was established to characterize the slope morphology. The system displays a U-shaped, 10 km long main channel dominantly sourced by the north-west/south-east running outer channel and two smaller 2 to 3 km long canyons. The latter are positioned perpendicular to the main canyon. A 4 km wide head scarp at the reef edge and dozens of amphitheatre-shaped scarps along the mid to lower slope suggest significant slope failures over time. The analysis of four sediment cores collected on a profile down the canyon revealed sedimentation rates of 26 cm/ka at the mid-slope to 9.4 cm/ka in the basin. Three main sediment-export processes were identified: (i) sandy and neritic component-poor turbidites; (ii) winnowing of strontium-rich carbonate fines through surface currents; and (iii) remobilized carbonate fines on the upper slope. As of the Last Glacial, turbidites are predominantly deposited during times of significant sea-level instability, both rises and falls, whereas their flat-topped-tropical counterparts show a higher turbidite frequency during highstands. Strontium-rich carbonate fines are exported similarly through time in both climate settings. Overall, sediment export is controlled by: (i) the platform morphology (flat-topped versus rimmed lagoon); (ii) variations in sediment production; (iii) sea-level variations (exposure or flooding of sediment production areas); and (iv) the interaction between the sedimentary system and atmospheric changes (sediment production and delivery).
| Original language | English |
|---|---|
| Pages (from-to) | 2241-2271 |
| Number of pages | 31 |
| Journal | Sedimentology |
| Volume | 70 |
| Issue number | 7 |
| Early online date | 20 Jun 2023 |
| DOIs | |
| Publication status | Published - Dec 2023 |
Bibliographical note
Funding Information:This study was financed by faculty baseline funding to V. Vahrenkamp and the King Abdullah University of Science and Technology (KAUST) Endowment. The stable isotope analysis and sample trips for core sampling were funded through baseline funding to J.J.G. Reijmer, Carbonate Sedimentology Group at the College of Petroleum Engineering & Geosciences (CSG@CPG) of the King Fahd University of Petroleum & Minerals. Captain Yuri Brovka and the crew and KAUST CMOR team members Brian C. Hession, Francis L. Mallon and Pulahinge J. Kumara Rodrigo are thanked for their outstanding support during the Al‐Wajh II cruise. Indah Putri, Manuel Fuentes and Rangelys Sorrentino are acknowledged for field assistance and Arnoud Slootman for help with describing and sampling the cores. Moreover, the authors would like to thank Red Sea Global (RSG) for providing the lidar‐multibeam data set and permits to operate in their area. This research used data acquired at the XRF Core Scanner Lab at the MARUM – Center for Marine Environmental Sciences, University of Bremen, Germany. We also thank Suzanne Verdegaal‐Warmerdam (Vrije Universiteit Amsterdam) for running the stable isotope measurements and Bouk Lacet (Vrije Universiteit Amsterdam) for thin‐section preparation. The authors would also like to thank the reviewers Jody Webster and John Counts, Associated Editor Christian Betzler, and Chief Editor Alex Brasier who helped to improve this manuscript with constructive suggestions and comments. R/V THUWAL
Publisher Copyright:
© 2023 International Association of Sedimentologists.
Funding
This study was financed by faculty baseline funding to V. Vahrenkamp and the King Abdullah University of Science and Technology (KAUST) Endowment. The stable isotope analysis and sample trips for core sampling were funded through baseline funding to J.J.G. Reijmer, Carbonate Sedimentology Group at the College of Petroleum Engineering & Geosciences (CSG@CPG) of the King Fahd University of Petroleum & Minerals. Captain Yuri Brovka and the R/V THUWAL crew and KAUST CMOR team members Brian C. Hession, Francis L. Mallon and Pulahinge J. Kumara Rodrigo are thanked for their outstanding support during the Al-Wajh II cruise. Indah Putri, Manuel Fuentes and Rangelys Sorrentino are acknowledged for field assistance and Arnoud Slootman for help with describing and sampling the cores. Moreover, the authors would like to thank Red Sea Global (RSG) for providing the lidar-multibeam data set and permits to operate in their area. This research used data acquired at the XRF Core Scanner Lab at the MARUM – Center for Marine Environmental Sciences, University of Bremen, Germany. We also thank Suzanne Verdegaal-Warmerdam (Vrije Universiteit Amsterdam) for running the stable isotope measurements and Bouk Lacet (Vrije Universiteit Amsterdam) for thin-section preparation. The authors would also like to thank the reviewers Jody Webster and John Counts, Associated Editor Christian Betzler, and Chief Editor Alex Brasier who helped to improve this manuscript with constructive suggestions and comments. This study was financed by faculty baseline funding to V. Vahrenkamp and the King Abdullah University of Science and Technology (KAUST) Endowment. The stable isotope analysis and sample trips for core sampling were funded through baseline funding to J.J.G. Reijmer, Carbonate Sedimentology Group at the College of Petroleum Engineering & Geosciences (CSG@CPG) of the King Fahd University of Petroleum & Minerals. Captain Yuri Brovka and the crew and KAUST CMOR team members Brian C. Hession, Francis L. Mallon and Pulahinge J. Kumara Rodrigo are thanked for their outstanding support during the Al‐Wajh II cruise. Indah Putri, Manuel Fuentes and Rangelys Sorrentino are acknowledged for field assistance and Arnoud Slootman for help with describing and sampling the cores. Moreover, the authors would like to thank Red Sea Global (RSG) for providing the lidar‐multibeam data set and permits to operate in their area. This research used data acquired at the XRF Core Scanner Lab at the MARUM – Center for Marine Environmental Sciences, University of Bremen, Germany. We also thank Suzanne Verdegaal‐Warmerdam (Vrije Universiteit Amsterdam) for running the stable isotope measurements and Bouk Lacet (Vrije Universiteit Amsterdam) for thin‐section preparation. The authors would also like to thank the reviewers Jody Webster and John Counts, Associated Editor Christian Betzler, and Chief Editor Alex Brasier who helped to improve this manuscript with constructive suggestions and comments. R/V THUWAL
| Funders | Funder number |
|---|---|
| Center for Marine Environmental Sciences | |
| King Abdullah University of Science and Technology | |
| King Fahd University of Petroleum and Minerals | |
| Universität Bremen | |
| MARUM – Zentrum für Marine Umweltwissenschaften |
Keywords
- Carbonate mineralogy
- carbonate slope
- Last Glacial
- oxygen isotope
- slope failure
- X-ray fluorescence core data