Dinah Smith, PhD Student

The Holocene Palaeoenvironmental Change in the Fenland of Eastern England.

Supervisors: Dr Jan Zalasiewicz, Dr Mark Williams, Dr. I.P. Wilkinson (BGS)

Dinah Smith
Dinah Smith

The Fenland of Lincolnshire and Cambridgeshire is the largest area – some 4000 square kilometres - of Holocene deposits in Britain, and the deposits, which are up to 15 m thick, show evidence of a complex palaeoenvironmental history. 

A major part of the work is the analysis of the sedimentational history of the roddon network, with particular reference to relations with associated transitions between peat and salt marsh clays.  These sedimentological changes represent profound regional environmental changes:  it is uncertain whether they were gradual or were sudden/catastrophic and a prime aim of this research will be to constrain infill mechanisms and causal agents.

Roddon Drain
Roddon and overlying peat seen along cleaned fenland drain near to Dog and Doublet Bridge, Whittlesey, Cambs

The infilling of the roddon networks with sediment, for instance, may have coincided with the change from salt marsh to reed swamp, perhaps by restricting access to the influx of tidal waters.

The stratigraphy in detail comprises a succession of interbedded clays (broadly representing marginal marine salt marsh environments) and peats (representing freshwater reed swamps), representing greater and lesser amounts of marine influence over an interval of ca 6000 to 2000 BP.  

Rodden Image2.jpg
Microfossils found in roddon sediments

The salt marsh clays contain these striking, exceptionally preserved networks of silt/sand-filled tidal creeks, known locally as roddons, of at least two main generations, and these were mapped in broad outline during the most recent British Geological Survey mapping of the region.

There are wider implications, in that the Fenland during its sedimentation, was populated by human communities, who built major constructions, including the well-known archaeological site of Flag Fen.  Elucidation of the palaeoenvironmental changes will, in turn, provide significant constraints to the interpretation of the course of human history in the region. 

Roddon Undulations
Roddons seen as undulations in fields at Plash Drove, Wisbech St Mary, Cambs

The project thus entails significant collaboration with archaeological researchers working in this region.  There are significant implications too, for future regional environmental change associated with anthropogenic global warming. 

Four Recent Publications 

  • “Rise of the Roddons” – article for the Thorney History Society
  • Abstract: Coastal Palaeoenvironmental Change: the evidence of the Fenland roddons (Poster- All at Sea Conference, Loughborough)
  • Abstract: Past and Future of the Fenland: The story of the roddons. (Poster - conference (Durham University)
  • Smith, D.M., et al .2010. Holocene drainage systems of the English Fenland: roddons and their environmental significance. Proceedings of the Geologists’ Association 121,256-269.

Four Recent Presentations

  • 2011 - Displayed posters at University of Cambridge Geology Club seminar
  • 2011 - Presentation at Cambridge Geology Club
  • 2011 - Presentation to the Ostracod Group of the Micropalaeontology section of TMS
  • 2010 - 8. BGS Thursday Lunchtime talk to NIGL group


  • University of Leicester Geology Department – awarded jointly – John Whitaker Award for 2010.
  • Geologists’ Association Richardson Award for the best paper for year 2010;
    “Holocene drainage systems of the English Fenland: roddons and their environmental significance.”


  • Demonstrated for:- Dynamic Earth, Interpreting the Stratigraphical Record, Sedimentary World.
  • Have helped with supervision of 3rd year students and their dissertations involving the sedimentary  elements/ microfossil work of their project

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