Dr Andrew Carr
Lecturer in Physical Geography
Contact Details
- Tel: 0116 252 3851
- Email: asc18@le.ac.uk
- Fax: 0116 252 3854
- Office: Bennett Building F43
Research Interests
My research interests focus on palaeoenvironmental changes within the tropics and low latitudes over timescales of centuries to millions of years. The ultimate goal of such work is to improve our understanding of the responses of biological and landscape systems to environmental perturbations. Much of my research uses geomorphic and sedimentological evidence preserved in the landscape to interpret past environmental changes. I am also interested in palaeoecological change, particularly the use of plant biomarker and stable isotope evidence. A significant proportion of my work has focussed on Quaternary (last c. 2.5 million years) environmental changes in the dryland and coastal environments of southern Africa; a region currently occupying an important transitional zone between the sub-tropical and temperate latitudes. More recent work is focussed on the tropical environments of northern South America. Two key approaches underpin much of this work:
- Geochronology: This primarily involves the use of optically stimulated luminescence (OSL) dating techniques, which provide depositional age estimates for quartz and feldspar minerals. In my research this is typically used to construct chronologies of sediment deposition and landscape change, particularly phases of past aeolian (dune) sedimentation.
- Stable isotopes: Stable isotope analyses are currently employed in a number of projects. These include the analysis of fossil marine bivalves and terrestrial gastropod shell carbonates (δ13C and δ18O), and the analysis of organic matter within lake sediment records (bulk and compound specific δ13C) to infer past ecological changes.
I am a member of the Leicester Quaternary Palaeoenvironments Research group. More detailed information on our work and projects I am currently working on can be found in the Research page.
Recent and Ongoing Projects
Novel Biomolecular insights into dryland ecosystem dynamics
This project, funded by the Leverhulme Trust (2010-2012) is investigating the composition and fate of organic matter in semi-arid environments. The work is multifaceted, comprising three key elements:
- The analysis of organic matter sources (primarily plant leaf waxes and cuticles)
- Molecular characterisation 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.
The project will involve a range of techniques, including lipid biomarker analysis, compound specific stable isotope analyses and py-GC/MS techniques for the elucidation of macromolecular organic matter composition.
This work is being carried out with Professor Mike Meadows (University of Cape Town) and Dr Brian Chase (CNRS, Montpellier); along with Dr Arnoud Boom at Leicester.
The application of plant biomarker approaches to palaeoecological reconstruction in southern Africa
In conjunction with Dr Arnoud Boom, director of the Leicester Environmental Stable Isotope Laboratory, Dr Brian Chase (CNRS, Montpellier), Dr Dave Roberts (Council for Geoscience, South Africa), Lynne Quick (University of Cape Town), and others we are developing new approaches to palaeoecological reconstruction in southern Africa. We have focused on the application of lipid biomarkers and stable isotope evidence, as well as the analysis of macromolecular organic matter using pyrolysis GC/MS techniques. Materials analyzed range from Quaternary age wetlands from the southern Cape coastline, to hyrax middens from Namibia. The resulting data provide insights into vegetation composition and the processes of organic matter degradation/preservation through time, which ultimately may be linked to palaeoclimatic changes. More recent work, funded by the Palaeontological Scientific Trust (PAST) is investigating Neogene lignites from the south coast of South Africa, and is providing insights into more ancient palaeoecological change in the region.
Palaeoenvironmental change in the South American Tropics
New research at Leicester in conjunction with Dr Arnoud Boom and Dr Juan-Carlos Berrio focuses on:
- Geomorphic evidence of Quaternary palaeoenvironmental change in the northern tropics of South America. This includes the development of new OSL-derived chronologies of aeolian dune accumulation in the tropical savannas of eastern Colombia. This is being carried out in collaboration with Dr Simon Armitage (Royal Holloway) and Professor Bibiana Bilbao (Universidad Simón Bolivar (Caracas)).
- The palaeoecology of the Miocene Pebas Formation, including the isotopic analysis of fossil gastropods.
External Activities
I am a member of the Southern African Society for Quaternary Research and the Quaternary Research Association (QRA).
PhD Students
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
Most Recent Publications
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
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
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 doi:10.1016/j.yqres.2009.08.006
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 doi:10.1016/j.palaeo.2009.11.029
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 doi:10.1016/j.palaeo.2008.09.009
