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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Sunday, 7 September 2014
Half Dome, Yosemite
A fine collection of images from the Yosemite National Park -- all showing Half Dome, one of the most famous natural features in North America. We can see from the top image that this is a pretty spectacular glacial trough, deepened during several glacial episodes. Half Dome, the summit of which is over 1400 m above the valley floor, is not actually half a dome at all -- it is a granite "plug" which has been resistant to erosion, and which has lost about 20% of its mass to erosive processes (glacial erosion and cliff collapses) on the flank of the trough.
By the way, the cliff in the second to bottom photo is that of El Capitan, some way up-valley from Half Dome.
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