Saturday, 2 June 2012

Geodiversity in Suffolk

Where would we be without the land? Geodiversity is the various aspects of the physical landscape, its geology, soils, landforms and water. I think it is impossible truly to understand a place without understanding something of its physical features; life is interwoven with them. Reading the geodiversity of a place is an essential part of what Judith Stark calls 'landscape literacy'.

High Suffolk: a clayland landscape near Creeting Bottoms

Imagine standing on the open clayland plateau of High Suffolk, perhaps at Rattlesden or Worlingworth: the eye travels across a gently undulating plain. Big arable fields contrast with smaller, more intimate vistas as we approach woods, farms and villages. The highest areas are more or less flat, but outwards we encounter shallow valleys, often little more than dips in the land surface. The landscape is like a calm sea freighted with human life and wildlife; church towers stand out for miles; the land shimmers with heat in summer, and is chill and windswept in winter.
But the patterns that we see are as much determined by physical as biological or cultural realities. A key factor linking villages as far apart as Hopton or Clopton is the glacial boulder clay, a legacy of the Anglian glaciation some 450,000 years ago which laid down a thick layer of till (glacial debris) over the land. This geology determines the way crops grow here; its flint, clay and brickearth have been used for building everything from humble cottages to fine churches; the impermeable clay soils necessitate constant drainage and ditching work. The evidence of this glacial story is staring at us out of the plough-soil or from the banks of a local clay-pit; it is written into the shape of the very plateau.

Upper Weybread © Tim Holt-Wilson 2011
A Suffolk boulder clay landscape at Upper Weybread

Reading the geodiversity of a place. We start with geological maps, soil maps and specialist publications, we gain a sense of the way that the rocks, sediments and soils are disposed. Out in the field, we notice landforms and topographical variations, rock outcrops and the stones in the topsoil, and the way that water is moving, above and below ground. Gradually we build up a picture of a place in the context of deep time: its Earth history comes alive, as inscribed in its physical environment. Then we can weave plant, animal and human life into the picture, confident that we have understood an important aspect of the ground we are standing on. It is as much a philosophical as a physical ground.

Weybread beet © Tim Holt-Wilson 2011

To find out more about geodiversity in Suffolk you can read my article 'Geodiversity, Suffolk: an Introductory Excursion'. This was published in 'A Celebration of Suffolk Geology. GeoSuffolk 10th Anniversary Volume' (edited by Roger Dixon; published by GeoSuffolk, Ipswich; 2012; ISBN 0-9508154-7-0).

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