Dunnet Bay in Caithness, Northern Scotland was chosen as a study site to look at the relationship between dune stability and climatic change during the late Holocene in Northern Scotland. The surviving drift deposits of Dunnet Bay consist of aeolian and organic soils overlying the shelly till which forms mounds and ridges beneath the overlying deposits. The surviving drift deposits have been deposited within the last 10,000 years. The oldest date acquired is from the lower inter-tidal peat which was dated to approximately 7,720–7,580 yrs BP. The aeolian sediment which makes up the bulk of the main dune ridge and a large percentage of the central links area is of very recent origin and was deposited rapidly during storm events in the Little Ice Age climatic event. An unconformity between the upper aeolian recent sands and older sediment was found. The unconformity occurs between approximately 250–1900 yrs BP and exists in the main dune sequence and links The depositional phases interpreted from the study can be associated with those found in other dune studies and proxy data. The timings of the depositional phases can be partially associated with levels of chloride found in the GISP2 core and storm circulation index data produced from a proxy ice core from Greenland (Mayewski & White, 2002), however some inconsistencies exist. These inconsistencies imply that the ice core record may not completely mirror timings of dune instability in Northern Scotland. Similar studies in the UK and around the North Atlantic basin show only partial correspondence with the transition timings at Dunnet. Coastal dune and sediment stratigraphy can therefore be seen as a low resolution localised record of coastal change of which climate plays a major role but not sufficiently consistent over regional areas to provide a clear regional pattern. A thin foraminifera rich shelly sand layer found beneath the inter-tidal peat may be the result of an extreme run-up event caused by the Storegga slides approximately 8,200 yrs BP. The thesis provides a detailed look at the development of the sedimentary history of Dunnet Bay.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:521338 |
| Date | January 2009 |
| Creators | Mcilvenny, Jason Daniel |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
Page generated in 0.014 seconds