Studied Geology in college, but now deal with abstract layers well above the silicon (systems administration). Book of interest to Geologists or Historians: Great Geological Controversies.

Over the years I have created some nifty (to me, anyhow) geology-related utilities. May not work, as were written back in the 1997-1999 timeframe, and thus could contain quite horrid code.
Source code and supporting HTML available.