Download full USGS poster from http://walrus.wr.usgs.gov/infobank/bear/poly/ak/alaska.cst ILLUSTRATOR PDF (~6 MB)
or http://geopubs.wr.usgs.gov/map-mf/mf2335/ or here (smaller ~1MB jpg) Thanks to Peter Barnes, USGS, Menlo Park, CA

Citation:
Kevin R. Evans, Paul R. Carlson, Monty A. Hampton, Michael S. Marlow, and Peter W. Barnes, 1999, Map of Distribution of Bottom Sediments
on the Continental Shelf, Gulf of Alaska, U.S. Geological Survey, Misc. Field Studies, MF 2335