Monthly Archives: August 2012

Excursion 2: Barmston

It’s a bright and breezy Sunday morning and there are plenty of people in the low cliff-top carpark at Barmston beach. Sand martins soar high on the winds and plummet into the cliff beneath us.  To the north are the chalk cliffs of Flamborough and the holiday town of Bridlington, while looking south the slight smooth curve of the Holderness coast is visible all the way to its tip.

I’m here with Mike Horne of the University of Hull, who has kindly let me tag along on one of the field trips for his summer Lifelong Learning class, a mixed group of absolute beginners and seasoned regulars. They’ve come to look at how the ice age created this area of land, and to look at the many different erratics brought by the glaciers, which came south primarily from Norway, the Lake District and Whitby. Some of the group are excellent scavengers, finding an impressive variety of rocks and fossils for identification: Frosterley Marble (Carboniferous age coral limestone from Weardale), red flints (perhaps from Denmark), Gryphaea or ‘Devil’s Toe Nail’ (Lower Jurassic Oyster), Arnioceras and Datylioceras (Lower Jurassic Ammonites), Black Flint, New Red Sandstone, garnet schist and jasper. Mike hands me a fist-sized greyish stone: ‘Rhomb Porphyry, from Norway’. It’s good fun, arriving at the beach and simply seeing what gems it has to offer, and then learning from that.

Image courtesy urbanrim.org.uk/Holderness.htm

Mike says it’s his favourite way to teach, and he is an excellent teacher, the beach his chalkboard. Drawing diagrams in the sand, he explains how at the beginning of the Quaternary the coastline was the 70 million year old chalk which now lies about fifteen miles west inland. The area was transformed during the last glaciation, 16 – 18,000 years ago, when the boulder clays (or glacial tills) were deposited and new land was created, extending out into the North Sea.

This is the land that is now being lost to the sea by up to two metres a year.  Two miles has been eroded since Roman times. The artist Anna Kirk-Smith, who is taking the class to inform her work, tells me of a map which shows all of the  villages lost to the sea. Attempts to stop the erosion seem futile, yet they do continue, often, I’m told, with little management or concern for the coast as a whole. Mounds of concrete boulders, planted on the beach by farmers, often simply make the tides worse further south. One of these defences now sits fifteen metres away from the current line of the cliff and will be covered at high tide. Mostly, though, I get a sense of stoicism from the people here: the cliff has been receding all their lives, it’s just something that happens. If climate change is a factor, it was climate change, non-manmade, that led to this situation in the first place. The caravans perched on the cliff are nick-named ‘Roll Backs’: each time part of the cliff falls they simply move them a little further inland.

Caravans at Barmston Sands, with beach in foreground showing range of glacial erratics

The erosion does make the area attractive for geologists, with new questions being thrown up with each landslip. Today, Mike spots a strange fault in the cliff which suggests a glacier which ran from the south to north, rather than the generally perceived north to south direction.  Or did it simply bend north at this stage? The direction of glacier flow can be measured by the direction rocks with a long axis are facing, because all objects will align themselves in water for the path of least resistance…There was a lot to take in and it was all fascinating stuff…. And yes, the best way of telling the difference between silt and clay is to taste it.

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Please note: any inaccuracies are all mine!  For more information about Holderness coastal erosion, there is a good website here.