Brimham Rocks, England
On August 10th, 2016; I spent the day at Brimham Rocks, England.
During the last Ice Age, a passing glacier created Nidderdale Valley, creating a deep U-shaped cross-sectional valley. The millstone grit resisted this glacial erosion and was left exposed as the softer rocks wre cut away by the moving ice, before it finally melted about 10 000 years ago. The softer rock and shale was then further eroded by sand-blasting and weather to leave stacks of millstone grit found at “Brimham Rocks”.
Below, I’m pushing on one of the rock formations, (Idol Rock), found at “Brimham Rocks”.
The Dancing Bear (pictured below) and the Turtle are the names of some of the weird millstone grit rock stacks in Nidderdale, Yorkshire. Many area is surrounded with ancients myths, (as indicated from the artist rendition found below).
These rocks are scattered over some 50 acres on the Brimham Moor. The creation of these rocks began in the granite mountains of northern Scotland and Norway.
Between 430 and 380 million years ago, a vast range of mountains as big as the Himalayas lay to the north. These were thrown up when, what is now, North America collided with Europe. Mighty rivers washed loose sand, grit and pebbles down from these mountains and flowed into a delta covering half of Yorkshire. As the water slowed down in the delta, the grit and mud settled on the river beds. The grit included crystal of very-hard quartz and softer crystals of feldspar. Over the millennia these layers compressed and hardened to form layers of rock.
Layers of this grit and sand, along with rock crystals of feldspar and quartz, built up to form a tough sandstone known as millstone grit. Between 80,000 and 10,000 years ago, glaciers eroded these rocks into the bizarre shapes on view today. Millstone grit outcrops can be found all over Pennine Yorkshire, from Sheffield north to Scotch Corner. Parts of it are covered by peat moorland, but in some places like Brimham, the bare rocks are easy to see. Millstone grit is also the main building stone in this area, well able to withstand the winter winds and rains.
Their tiny plinth-like supports, like the one pictured below, were caused by fluvial sandblasting at lower levels which wore away the softer layers of rock.