Changing sea levels, or a reconfiguration of the oceans, are sometimes to be found in the most surprising of places. Anyone holidaying in Shropshire, about as middle of southern Britain as you can get, cannot help but be impressed by such geological formations as The Wrekin or Wenlock Edge. Another interesting feature is the Long Mynd, a very long piece of upland that stands out of the Shropshire plain like a huge boil. It is quite high – enough to be covered in moor like habitat rather than the rich farmland below. A natural place for sheep – and some of those sheep can become quite tame, even to the extent of coming up to cars looking for a snack. Once upon a time ago I had a labrador dog and he was headbutted by a sheep at Long Mynd, when both of them went for some potato crisps one of my children had dropped. I collapsed in a fit of laughter and the dog's face, it was a picture to behold. He wasn't at all pleased- but I was helpless with mirth and unable to take the picture. Anyway, it seems Long Mynd has something even more interesting than the Stipper Stones (which is where most people head when they climb to the top and nibble at the bilberries). It has several circular outcrops of sandstone completely surrounded by Silurian shallow water deposits (Cambrian or Precambrian in origin). These were laid down, it is thought, at a coastline location which featured sea stacks (and the circular sandstone formations are the remnant of those sea stacks). These curious formations can be seen on the western side of Britain (the Hebrides) and Ireland (Kerry), often with grass and vegetation growing on the top. Hermits and monks have been known to live on them in more aesthetic times – when truly zealous religious adherents gave up the comforts of normal life (unlike the folk in the church of climatology). Of course, they didn't have to be particularly tall, like some of them you see, as they are temporary geological features – in the process of being eroded away. Hence, we may wonder why sea stacks from millions and millions of years ago have been preserved on Long Mynd – and why the coastline was at that point. Presumably the sea level/position changed rapidly in order to preserve the geology as an intact feature of Long Mynd.
The Long Mynd
27 November 2013Geology