Dr Andrew Carr
Lecturer in Physical Geography
- Tel: 0116 252 3851
- Email: email@example.com
- Fax: 0116 252 3854
- Office: Bennett Building F43
My research interests focus primarily on palaeoenvironmental changes, particularly within the tropics and low latitudes. The main areas of interest are:
Palaeoenvironmental change in southern Africa
A significant proportion of my work has focussed on Pleistocene environmental changes in dryland and coastal environments of southern Africa. This area represents lies within an important transitional zone between the sub-tropical and temperate latitudes, and as a result, it appears to have been very sensitive to past global climatic change. This work has taken various forms and has variously included the development of chronologies for relict aeolian (wind-blown) landforms, the analysis of fossil pollen from wetland and lake sediments, and the application of various stable isotope and biomarker proxy techniques. Currently, I am a member of an international team of researchers that makes up European HYRAX research project. This project seeks to develop detailed records of past environmental change in this region using a remarkable source of evidence – the ancient latrines of the Rock Hyrax.
Chase, B.M., Boom, A., Carr, A.S., Meadows, M.E., Reimer, P.J. (2013). Holocene climate change in southernmost South Africa: rock hyrax middens record shifts in the southern westerlies. Quaternary Science Reviews 82, 199–205
Truc, L., Chevalier, M., Favier, C., Cheddadi, R., Meadows, M.E., Scott, L., Carr, A.S., Smith, G.F., Chase, B.M. (2013). Quantification of climate change for the last 20,000 years from Wonderkrater, South Africa: implications for the long-term dynamics of the Inter-tropical Convergence Zone. Palaeogeography Palaeoclimatology Palaeoecology 386, 575-587
Valsecchi, V., Chase, B.M., Slingsby, J., Carr, A.S., Quick, L.J., Meadows, M.E., Cheddadi. R., Reimer. P.J. (2013). A high resolution 15,600-year pollen and microcharcoal record from the Cederberg Mountains, South Africa. Palaeogeography Palaeoclimatology Palaeoecology 387, 6-16.
Chase, B.M., Scott, L., Meadows, M.E., Gil-Romera, G., Boom, A., Carr, A.S., Reimer, P.J., Truc, L., Valsecchi, V., Quick. L.J. (2012). Rock hyrax middens: a palaeoenvironmental archive in southern African drylands. Quaternary Science Reviews 56, 1-19.
Carr, A.S. Boom, A., Chase B.M. (2010) The potential of plant biomarker evidence derived from rock hyrax middens as an indicator of palaeoenvironmental change. Palaeogeography Palaeoclimatology Palaeoecology 285, 321–330
Stable isotopes and organic matter (biomarker) palaeoenvironmental proxies
This work focuses on the analysis of organic matter composition (biomarkers) and the use of stable isotope analyses as palaeoenvironmental proxies. A key project: “Novel Biomolecular insights into dryland ecosystem dynamics”, which was funded by the Leverhulme Trust (2010-2012,) specifically investigated the composition and fate of organic matter in semi-arid environments. A goal of this was to consider the nature and preservation of terrestrial organic matter in this region and the implications for the interpretation of biomarker/stable isotope records from sedimentary archives. This work involves lipid biomarker analysis, compound-specific stable isotope analyses and py-GC/MS techniques for the elucidation of macromolecular organic matter composition, including
- The analysis of organic matter sources (primarily plant leaf waxes and cuticles)
- Characterisation of the macromolecular composition of organic matter in dryland soils with a view to understanding the mechanisms and rates of (selective?) OM degradation in arid environments
- The fate and preservation of organic matter in long-term (Quaternary) sedimentary archives, and associated implications for palaeoenvironmental reconstructions.
Carr, A.S., Boom, A., Chase, B.M., Meadows, M.E., Roberts, Z.E. Britton, M.N., Cumming, A.M.J. (2013). Biome-scale characterisation and differentiation of semi-arid and arid zone soil organic matter compositions using pyrolysis-GC/MS analysis. Geoderma 200-201, 189 – 201.
Carr, A.S., Boom, A., Chase, B.M., Roberts, D.L., Roberts, Z.E. (2010). Molecular fingerprinting of wetland organic matter using pyrolysis-GC/MS: an example from the southern Cape coastline of South Africa. Journal of Paleolimnology 44 (4), 947-961.
Berrío, J.C., Wouters, H., Hooghiemstra, H., Carr, A.S., Boom, A. (2012). Using paleoecological data to define main vegetation dynamics along the savanna-forest ecotone in Colombia: implications for accurate assessment of human impacts. In: R. Myster (ed.), Ecotones between forest and grassland, p209-228, Springer, New York
Drivers of Quaternary landscape change
One approach to reconstructing the nature of past environmental changes is to consider evidence with the landscape and sedimentary record. Linking in with my interest in luminescence dating, some of this work has sought to use records of past landscape change to infer past climatic shifts. A large proportion of my work in this area has, however, focused more specifically of the responses of landscapes to environmental change, particularly the coastal regions of southern Africa. Here we have sought to understand how coastal landscapes responded to long-term cycles (glacial-interglacial) of sea-level change driven by the waxing and waning of the ice-sheets during the middle and late Pleistocene. From this periods during which sea-levels were higher than the present have also been identified, which has important implications for understanding global ice volumes during periods of relative climatic warmth.
Bateman, M.D., Carr. A.S., Holmes, P.J., Dunajko, A., McLaren, S.J., Marker, M.E., Roberts, D.L, Murray-Wallace, C.V., Bryant, R.G. (2011). The evolution of barrier dune systems: A case study of the Middle-Late Pleistocene Wilderness barrier dunes, South Africa. Quaternary Science Reviews 30, 63-81
Carr, A.S., Bateman, M.D., Roberts, D.L., Murray-Wallace, C.V., Jacobs, Z., Holmes, P.J. (2010) The last interglacial sea-level highstand on the southern Cape coastline of South Africa. Quaternary Research 73, 351-362
Roberts, D.L., Bateman, M.D., Murray-Wallace, C.V., Carr, A.S., Holmes, P.J. (2009) West Coast Dune Plumes: climate driven contrasts in dunefield morphogenesis along the western and southern South African Coasts. Palaeogeography Palaeoclimatology Palaeoecology 271, 34-48
The chronological framework underpinning much of my research has been based on the application optically stimulated luminescence (OSL) dating techniques. This technique provides depositional (burial) age estimates for quartz and feldspar minerals and is typically used to construct chronologies of sediment deposition and landscape change, particularly phases of past aeolian (dune) sedimentation. In 2012 I was involved in the set up the new luminescence dating facility at the Department of Geography at Leicester. This now includes bespoke preparation facilities and a new Risoe DA20 OSL/TL system with an accompanying single grain reader. Past research projects have used the single grain technique to consider the potential effects of bioturbation (post-depositional disturbance) on the reliability of OSL age estimates.
Bateman, M.D., Carr, A.S., Murray-Wallace, C.V., Holmes, P.J., Roberts, D.L. (2008). A dating inter-comparison study on Late Stone Age Midden deposits, South Africa. Geoarchaeology, 23, 715-741.
Telfer, M.W., Bateman, M.D., Carr, A.S., Chase, B.M. (2008) Testing the applicability of a large Standardized Growth Curve (SGC) data set: Kalahari dunes, South African coastal dunes and Florida dune cordons. Quaternary Geochronology 3, 137-142
Bateman M.D., Boulter C., Carr, A.S., Frederick C.D., Wilder, M., Peter, D. (2007.) Preserving the palaeoenvironmental record in drylands: Bioturbation and its significance for luminescence dating derived chronologies. Sedimentary Geology 195, 5-19.
Carr, A.S., Bateman, M.D., Holmes, P.J. (2007). Developing a 150 ka luminescence chronology for the barrier dunes of the southern Cape, South Africa. Quaternary Geochronology 2, 110-11.
Research Areas for PhD Supervision
The Neogene evolution of the Benguela upwelling system: bivalve stable isotope records; Terrestrial gastropods as archives of late Neogene palaeoenvironment in the Western Cape Province of South; Quaternary environmental change; dryland and aeolian geomorphology; geochronology; luminescence dating, stable isotopes, plant biomarkers as palaeoenvironmental proxies.
Enquiries: If you are interested in studying for a PhD in one of these research areas, please make informal enquiries via geogPhD@le.ac.uk
Other representative publications
Carr, A.S., Botha, G.A. (2012). The Coastal Geomorphology of southern Africa. In Holmes, P.J., Meadows, M.E. (Eds). Southern African Geomorphology: Recent Trends and New Directions. Sun Media, Bloemfontein.
Chase, B.M., Meadows, M.E., Carr, A.S., Reimer, P.J. (2010). Evidence for progressive Holocene aridification in southern Africa recorded in Namibian hyrax middens: implications for African Monsoon dynamics and the 'African Humid Period'. Quaternary Research 74, 36-45.
Carr, A.S., Boom, A., Dunajko, A., Bateman, M.D., Holmes, P.J., Berrio, J.C., (2010) New Evidence of the Age and Palaeoecology of the Knysna Formation, South Africa. South African Journal of Geology, Volume 113.3 Page 241-256. doi:10.2113/Gssajg.113.3.241