This is one of my favourite photos, taken on the granite coast of Brittany, not far from Roscoff. Look at the lovely smooth rock surfaces. This reminds us that not all smooth surfaces are glaciated or wave washed. Here we are about 20m above sea level, on a coastline that was not (as far as we know) ever affected by glacier ice during the Quaternary.
It is sometimes difficult to be sure of the origin of "glaciated slabs" unless there are striae or glacial grooves present. On rock surfaces that have been exposed for thousands or even millions of years, a multitude of processes can operate in smoothing off sharp edges, rounding corners and eliminating rocky projections. The age of a rock surface has a great deal to do with how it looks, as any desert geomorphology textbook will tell you........
Mind you, if a lump of rock in West Wales (or for that matter on Salisbury Plain) is genuinely derived from a Neolithic quarry, around 5,000 - 5,500 years ago, it sure as eggs would not look like this:
Stone 37, courtesy Simon Banton
1 comment:
The Stonehenge stone's photograph you display as " courtesy Simon Banton" - at least Simon Banton is courteous, unlike his friend.
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