Version history for


  Billingsley, George H., and Wellmeyer, Jessica L., 2003, 
       revised 2006, Geologic map of the Mount Trumbull 
       30' X 60' quadrangle, Mohave and Coconino Counties, 
       northwestern Arizona, version 1.1:  U.S. Geological 
       Survey Geologic Investigations Series I-2766, scale 
       1:100,000 [available on the World Wide Web at 
       http://pubs.usgs.gov/imap/i2766/ ].


  Version 1.1, January 1, 2007

  Updated the geodatabase package.  This update 
  incorporates the following changes:

  1) Internal database structure and feature attributes 
     were modified to match other geologic map databases 
     being created for the Grand Canyon region.

  2) One map unit was added because it was mislabeled in 
     the original. Qt (travertine) on the north edge is 
     really Qtr (talus). So we added the Qtr unit to the 
     database to reflect that correction.


  Version 1.0

  January 8, 2004

  Digital and geologic-map errors were corrected and the 
  ARC/INFO coverages were converted to an ArcMap personal 
  geodatabase by Debra Block

  Released online at
  http://pubs.usgs.gov/imap/i2766/


  2003

  Published in paper form