Revision History for USGS Open-File Report 01-480 Margaret A. Keller, Joe H.S. Macquaker, and Paul G. Lillis High Resolution Study of Petroleum Source Rock Variation, Lower Cretaceous (Hauterivian and Barremian) of Mikkelsen Bay, North Slope, Alaska ----------------------------------------------------- Improved PDFs; updated Web style March 16, 2012 (mfd) Migrated to http://pubs.usgs.gov/of/2001/of01-480/ November 16, 2006 (bwr) Posted online on the Geopubs server January 31, 2002 (cad) -----------------------------------------------------