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Project properties |
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| Title | Constraining peat initiation by OSL-dating the pre-peat landscape |
| Group | Soil Geography and Landscape |
| Project type | thesis |
| Credits | 36 |
| Supervisor(s) | Cindy Quik (SGL) and Jakob Wallinga (SGL, examinor) |
| Examiner(s) | Jakob Wallinga (SGL) |
| Contact info | cindy.quik@wur.nl; jakob.wallinga@wur.nl |
| Begin date | 2019/06/02 |
| End date | |
| Description | Large parts of the Pleistocene sand landscape in the Netherlands were once covered with peat. Most of these organic deposits were lost during peat reclamation and excavation during the past centuries. Many questions regarding the spatio-temporal dynamics of their initiation and lateral development throughout the Holocene remain unanswered. Current research on the Fochteloërveen area, a peat remnant located on the edge of the Drenthe Plateau (the Netherlands), aims to reconstruct peatland palaeogeography and rates of lateral and vertical peat expansion.
Radiocarbon dating is usually the method of choice for organic deposits, but dating peat inception may be problematic as basal peat layers may be poorly preserved due to fluctuating groundwater levels or may be contaminated by the downward flux of young carbon during reclamation. In this project you will test whether Optically Stimulated Luminescence (OSL) dating can be used to date the moment when the sandy landscape became covered with organic deposits. The rationale is that bioturbation processes continuously mixed the upper soil layer, exposing sand grains to light and resetting OSL signals until the sandy surface was covered with peat. Samples for dating will be collected in September 2019 at a large sand ridge located centrally in the Fochteloërveen. The top of the ridge is exposed at the surface and the flanks are covered with peat. At the same locations samples for radiocarbon dating will be collected as part of the ongoing PhD research project at Fochteloërveen, providing a unique opportunity for intercomparison of radiocarbon and OSL results. You will prepare and analyse samples at the OSL laboratory, using cutting-edge feldspar single-grain methods suitable for determining the timing of bioturbation. You will analyse the data, taking into account the particular circumstances at the study site: locally podzols have developed in the underlying sandy deposits prior to peat growth, raising the question whether OSL dates would indicate the moment of peat initiation or cover by a litter layer during podzol formation. To gain more insight in OSL bleaching in podzols, you will also obtain samples from modern (undisturbed) podzol soils. Expected outcome of the project is: 1) insight in the possibilities and limitation of using OSL dating to determine the age of palaeosols; 2) a valuable contribution to the overarching palaeogeographical study of the Fochteloërveen area. |
| Used skills | Literature study, OSL-sample collection in the field, working in the OSL laboratory, data analysis and reporting of project results. |
| Requirements | - Strong motivation and proactive attitude;
- Keen interest in optically stimulated luminescence dating; - Recommended course: SGL-33806 The 4th Dimension in Earth Sciences - Quantifying Past and Future Landscape and Soil Dynamics. |