Browsing by Author "Tye, A. M."

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    How the composition of sandstone matrices affects rates of soil formation
    (Elsevier, 2021-07-10) Evans, Daniel L.; Quinton, John Norman; Tye, A. M.; Rodés, Á.; Rushton, J. C.; Davies, J. A. C.; Mudd, S. M.
    Soils deliver multiple ecosystem services and their long-term sustainability is fundamentally controlled by the rates at which they form and erode. Our knowledge and understanding of soil formation is not commensurate with that of soil erosion, in part due to the difficulty of measuring the former. However, developments in cosmogenic radionuclide accumulation models have enabled soil scientists to more accurately constrain the rates at which soils form from bedrock. To date, all three major rock types – igneous, sedimentary and metamorphic lithologies – have been examined in such work. Soil formation rates have been measured and compared between these rock types, but the impact of rock characteristics on soil formation rates, such as rock matrices and mineralogy, have seldom been explored. In this UK-based study, we used cosmogenic radionuclide analysis to investigate whether the lithological variability of sandstone governs pedogenesis. Soil formation rates were measured on two arable hillslopes at Woburn and Hilton, which are underlain by different types of arenite sandstone. Rates were faster at Woburn, and we suggest that this is due to the fact that the Woburn sandstone formation is less cemented that that at Hilton. Similarly, rates at Woburn and Hilton were found to be faster than those measured at two other sandstone-based sites in the UK, and faster than those compiled in a global inventory of cosmogenic studies on sandstone-based soils. We suggest that the cementing agents present in matrix-abundant wackes studied previously may afford these sandstones greater structural integrity and resistance to weathering. This work points to the importance of factoring bedrock matrices into our understanding of soil formation rates, and the biogeochemical cycles these underpin
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    The role of post UK-LGM erosion processes in the long-term storage of buried organic C across Great Britain – a ‘first order' assessment
    (Elsevier, 2022-08-09) Tye, A. M.; Evans, Daniel L.; Lee, J. R.; Robinson, D. A.
    Increasing consideration is being given as to whether and how the subsoil can be utilised as a resource to store greater quantities of organic carbon through a range of ‘frontier' technologies. However, recent work suggests ‘priming’ effects may occur when fresh soil organic carbon (SOC) is mixed with older organic carbon (OC). Combined with increasing intensity of land use and perturbation of the surface environment there is potential for buried organic carbon (OC) to be re-incorporated into the active global C cycle. Therefore, understanding the nature of existing buried organic carbon (OC) within Soil Parent Material (SPM) and landscapes is increasingly important. A major OC burial route within landscapes is via erosion and deposition processes. This paper aims to provide a ‘first order' overview of the role erosion processes have made since the UK Last Glacial Maximum (UK-LGM) in the burial of OC in Great Britain. Using collated information, Monte-Carlo simulations were used to produce ‘first-order' estimates of the mass of OC buried within three deposit types; Devensian Till, Devensian Glacio-fluvial deposits and Holocene Alluvium. Combined median estimates for these three deposit types alone suggest, that 385 MT of OC has been buried in these deposits across Great Britain, demonstrating the importance of post UK-LGM erosion processes in long-term sequestration of OC. The paper provides a basis of a framework to describe where buried OC may be found within UK SPM and landscapes, whilst identifying gaps in our knowledge base. Whilst focusing on Great Britain, the processes are relevant to many countries, each of which will have experienced erosion processes unique to their own history of geology, geomorphology and climate.