How much do we know about Stonehenge? Less than we think. And what has Stonehenge got to do with the Ice Age? More than we might think. This blog is mostly devoted to the problems of where the Stonehenge bluestones came from, and how they got from their source areas to the monument. Now and then I will muse on related Stonehenge topics which have an Ice Age dimension...
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Saturday, 31 August 2013
Now for some spotted rhyolite......
Up on Carningli today I found several boulders of the rock which I call rhyolite -- it is typically very fine-grained and even glassy in appearance, and has this typical grey-blue colour. The weathered surface of rhyolite boulders is often cream or white. But this one is distinctly spotty, rather like the famous spotted dolerites.
There are some spotted dolerites on Carningli too. There are also quite wide expanses where rhyolites outcrop at the surface-- but I'm note sure where this one has come from. The whole mountain is littered with erratics, many of which have come from within a mile or so of the place where they are now found.
I'm not sure if there are any spotted rhyolites at Stonehenge -- maybe Myris knows.....
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