No, not something in Colorado or some other location from a forgotten cowboy film, but our very own ‘wild west’, just a short trip out from Cambridge (or Huntingdon, or St Neots for that matter). With attractive villages, plenty of walks, excellent views (particularly across the Cam Valley), and some welcoming country pubs, its an area worth exploring, especially if you want to get to know the geology of southern Cambridgeshire. Underlying the area are a variety of Jurassic and Cretaceous rocks including clays, sandstones (the Woburn Sands of the Lower Greensand) and chalk and these outcrop in several places resulting in a small scale mosaic of habitats. These rocks can often be seen in the local building stones of churches and other historic buildings. Springs are good indicators of a change in the bedrock and the streams produced by them often cut down into the bedrock, revealing the underlying layers. The Dean Brook between Waresley and Gransden Woods is a good example – water flowing off the impermeable Gault Clay has eroded the softer Cretaceous Woburn Sands forming a small valley that reveals the Jurassic Ampthill Clay below.
Spring is a good time to visit the area to enjoy several of its nature reserves – not least for the locally characteristic Oxslips that favour the soils of the ‘boulder clay woodlands’ found here. The Glacial Till (boulder clay) that covers much of the plateau seems to provide what these beautiful relatives of the primrose need to give some of the best displays in the country. Lords-n-ladies, wood anemones and bluebells can also be found and it’s a good time to hear and see woodpeckers and treecreepers before too many leaves appear on the trees. For information on Hayley Wood, Gamlingay Wood, Waresley and Gransden Woods and the area in general look at the Wildlife Trust’s website page on the West Cambs Hundreds. More information is on the ‘Western Plateau’ page of our website.
If you have a smart phone, you can arm yourself with the free British Geological Survey app iGeology (easily downloadable) giving you detailed geology maps as you go (keep an eye on your data allowance included in your charging plan).