Revision History for USGS Scientific Investigations Map 3177 Kenneth L. Tanaka and Corey M. Fortezzo Geologic Map of the North Polar Region of Mars ----------------------------------------------------- Corrupted GIS zip file replaced July 2, 2014 Minor formatting correction to map sheet November 1, 2012 Version 1.1 Reference corrected in online pamphlet Posted online at http://pubs.usgs.gov/sim/3177/ October 2, 2012 Version 1.0 Initial release of pamphlet in print form August 2012 -----------------------------------------------------