Western Brecon Beacons Monday August 10th 2009

For a couple of years I've made periodic forays into Geographing. This is a project to photograph every Ordnance Survey 1 km grid square in the U.K. http://www.geograph.org.uk/ . You can find me in the drop down list of contributors and see the photographs I have submitted, three of which were taken today.

It's a challenge to put together an interesting walk that takes in some grid squares that don't yet have an image, and today proved to be very successful.

Another element to the walk was to find a rock exposure that I remember visiting with students more than 25 years ago - I could remember what it looked like and the fact that I found a fine fossil coral, about 10cm across.

The juxtaposition of remains from a tropical sea and the cold heights of the Brecon Beacons made for a good teaching point about plate tectonics. After wandering off track looking for the exposure I found it: a sink hole much higher than I remembered, marking the lower edge of the limestone.