The BGS have put up a nice interactive map of the UK's geology (flash required). You can select and deselect rocks of different geological periods to see where they are distributed around Britain and Ireland, and if you hover over the information symbols it will show you their absolute ages and stratigraphic subdivisions.
It's not as pretty as William Smith's effort, but it's a neat tool, and nicely summarises the larger-scale geological patterns such as the obvious increase in the age of the exposed rocks as you strike northwest from Dover (there's a nice story behind that, which I need to get around to posting one day). The BGS also provides online access to higher resolution data, although the implementation is a bit more fiddly (you have to zoom in a bit before you can display basement geology, too).
(Via the Isles Project)

Chris Rowan is a geologist specialising in the dark arts of paleomagnetism, and getting people to pay him to travel to exotic destinations for fieldwork. Having drilled up New Zealand during his PhD, and South Africa in his first post-doc, he now works at the University of Edinburgh.
Anne Jefferson has a love of all things water-related and blends hydrology, geomorphology, geology, and climate change in her work. She has a Ph.D. from Oregon State University and is now an assistant professor at the University of North Carolina at Charlotte.



Comments
There was a great Hot Topics discussion at GSA about interactive maps, and a guy from BGS was there to talk about their work, and also about the One Geology project. The British maps are great... but the thing that really got me excited was the vision of the director of the Minnesota Geological Survey. He wants to make clickable google-earth style geologic maps in which you can make the upper layers invisible... and show what geologists think is beneath them. He apparently got a mayor of a city in one of the Dakotas asking "how deep are we now?" while demonstrating this... and showed the water board that they were entirely confused about the direction their groundwater flowed.
Really great stuff.
Posted by: Kim | November 13, 2007 8:52 AM
Fan-bloody-tastic! I've been waiting years for something like this! When I was in the US, my geological map of the UK got a lot of attention - it really is one of the prettiest maps around. And, as one rather vacant member of the lab said - "It's so cool that you've got all the geological periods there"...
Posted by: Julia | November 13, 2007 9:06 AM
A "geology" layer on Google Earth would be something; a "geology at 1km depth" layer would be unimaginably cool.
Julia - did you manage to keep a straight face?
Posted by: Chris Rowan | November 13, 2007 11:21 AM
so, is this the kind of format and scale the OneGeology initiative is shooting for?
Posted by: BrianR | November 13, 2007 12:54 PM
That's a cool map! I didn't know that travelling through Britain from Dover to the Outer Hebrides is such a voyage back in time ;-)
Posted by: Stefan | November 13, 2007 1:35 PM
Wow. It's easy to see why the combination of economic and governmental stability, good schools, and perfect geology helped England (and France) basically create modern geology and paleontology. The progression of exposed rock from southeast to northwest neatly shows the broad outlines. My only question would be (and on my work computer I can't tell) is can you go even further into the age breakdowns to see which eras are missing (Mouseterian, etc)?
Posted by: Billy (A Liberal Disabled Vet) | November 14, 2007 10:32 AM
I did just about manage not to giggle, Chris. And I felt it was just ever so slightly too jingoistic to say "Well we did invent the geological column". Plus I'm sure someone would have disagreed with me. Although the Carboniferous Period, I am pleased to report, still confuses the hell out of the less well-read Americans.
Posted by: Julia | November 14, 2007 12:53 PM