EGU22-9516
https://doi.org/10.5194/egusphere-egu22-9516
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Using OSL dating to constrain the timings of Late Quaternary palaeohydrological activity on the Rustaq alluvial fan system, northern Oman.

Sam Woor1, Julie Durcan1, Sallie Burrough1, Ash Parton2,3, and David Thomas1
Sam Woor et al.
  • 1University of Oxford, School of Geography and the Environment, Oxford, United Kingdom of Great Britain – England, Scotland, Wales (samuel.woor@stx.ox.ac.uk)
  • 2Mansfield College, University of Oxford, Oxford, OX1 3TF, UK
  • 3Human Origins and Palaeoenvironments Research Group, School of Social Sciences, Oxford Brookes University, Gipsy Lane, Oxford, OX3 0BP, UK

Large (1-50 km), coalescing alluvial fan systems extend eastwards from Hajar Mountain catchments to the Batinah Coast of northern Oman, representing an important environment for both sediment transfer and storage. As sediment stores, these alluvial fans have great potential to act as archives of Quaternary palaeohydrological changes in their mountain catchments. This has been shown by work carried out on interior draining fans west of the Hajar (e.g. Blechschmidt et al., 2009; Parton et al., 2013, 2015), which has highlighted the sensitivity of fan systems to periods of intensified Indian Ocean Summer Monsoon (IOSM) rainfall. However, the timing of fluvial activity and fan aggradation on the east of the Hajar Mountains is currently poorly constrained due to limited quantitative geochronology. This is, in part, due to the difficulty of dating Batinah alluvial sediments using luminescence techniques because of their low quartz abundances (Hoffmann et al., 2015).

This study presents new Mid-Late Pleistocene OSL ages from alluvial sediments exposed by incised channel systems in fan-head trenches in the lower reaches of the catchment and one section near the apex of the Rustaq fan. Ages from the upper fan represent the first dates on unconfined fan deposition from the Batinah Coast. The depositional contexts of ages are important for understanding the nature of fan dynamics over time. However, ages will also be considered in the context of regional palaeoenvironmental records to investigate the role of IOSM variability in landscape evolution on the Batinah Coast.  

References

Blechschmidt, I., Matter, A., Preusser, F. and Rieke-Zapp, D., 2009. Monsoon triggered formation of Quaternary alluvial megafans in the interior of Oman. Geomorphology, 110(3-4), pp.128-139.

Hoffmann, G., Rupprechter, M., Rahn, M. and Preusser, F., 2015. Fluvio-lacustrine deposits reveal precipitation pattern in SE Arabia during early MIS 3. Quaternary International, 382, pp.145-153.

Parton, A., Farrant, A.R., Leng, M.J., Schwenninger, J.L., Rose, J.I., Uerpmann, H.P. and Parker, A.G., 2013. An early MIS 3 pluvial phase in Southeast Arabia: climatic and archaeological implications. Quaternary International, 300, pp.62-74.

Parton, A., Farrant, A.R., Leng, M.J., Telfer, M.W., Groucutt, H.S., Petraglia, M.D. and Parker, A.G., 2015. Alluvial fan records from southeast Arabia reveal multiple windows for human dispersal. Geology, 43(4), pp.295-298.

How to cite: Woor, S., Durcan, J., Burrough, S., Parton, A., and Thomas, D.: Using OSL dating to constrain the timings of Late Quaternary palaeohydrological activity on the Rustaq alluvial fan system, northern Oman., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9516, https://doi.org/10.5194/egusphere-egu22-9516, 2022.