Virginia geologic map overlay for Google Earth -- you can click on the different units and it will tell you what rock type/formation they are. Pretty cool. Kind of clunky when I loaded it up on my home computer this morning, though.

Hat tip to Kyle House's Geologic Frothings blog for the alert.

Other states available too.

Also worth noting is an interactive Potassium-Argon age date map. In Virginia, you can use it to find the age of the lamprophyre dikes at the upstream end of Mather Gorge (~369 Ma) or find Alleghenian-aged pegmatites, or look at Triassic diabase ages contemporaneous with supercontinent breakup.

Labels: art, geology, google, isotopes, maps, tech, virginia