The aim of this thesis is to examine the spatial and temporal characteristics of the <sup>14</sup>C marine reservoir effect (MRE) in the North Atlantic over the Holocene. The MRE is a variable offset in the <sup>14</sup>C age of carbon within the atmospheric and surface ocean reservoirs at any point in time where ocean <sup>14</sup>C is depleted relative to the coeval atmosphere. The MARINE04 calibration curve is produced by modelling the oceanic response to fluctuations in atmosphere <sup>14</sup>C and provides a time-series of MRE corrections for the global average ocean. In a specific ocean area however, MRE values may deviate from this global average as a function of specific local oceanographic and climatic variables. This deviation (known as ΔR) is determined by empirical measurement of local samples and modern (pre-bomb) ΔR values show considerable spatial variations. The overall results demonstrate observable spatial and temporal variability in ΔR within the study over the past c.8000 years that can be related to climate and oceanographic changes previously identified as potential mechanisms for producing variation in ΔR. These variations were as follows: 1. In the Early Holocene (c.6480-1940 BC) ΔR values were greater relative to the present day. 2. During the periods c.400 BC-90 AD and c.1000-1200 AD, ΔR values were reduced relative to those of the present day. 3. During the period c.1200-1400 AD, ΔR values were higher compared to the present. 4. In addition, there is evidence for spatial variation in ΔR within the study area over the Holocene. The results of this study have important implications for our understanding of the MRE and the effective application of correction values to marine samples for <sup>14</sup>C measurement within both paleoenvironmental and archaeological research.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:641093 |
| Date | January 2006 |
| Creators | Ascough, Philippa |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/29463 |
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