One year has passed since I first wrote a post for this occasional blog. Now, 12 months, 22 posts and 7500 page views later, here’s a quick look back. For me, this has been a way of using some of my back catalogue of field photographs, of fleshing out a bit of context around papers I have been working on, and adding a little commentary on some more topical aspects. I am pleased with the results so ...[Read More]
Sea-floor spreading, on land
One piece of evidence that helped to establish the theory of Plate Tectonics in the early-1960’s was the recognition of patterns of magnetisation in the basalts of the seafloor that were symmetrical about the global oceanic ridge system. Fred Vine and Drummond Matthews recognised that this pattern had to be fixed in place as the lavas, that were erupted along the ocean ridge, cooled through ...[Read More]
Polygons, columns and joints
Over on her Georney‘s blog, Evelyn Mervine has recently posted a nice piece with some spectacular images of columnar jointing. This seemed like a good opportunity to dust off some field photos, with some more examples of polygonal joint sets in lavas from a variety of settings, to illustrate the diversity of forms that cooling-contraction joints may take in volcanic rocks. The first example ...[Read More]