If available, access to physical samples is described in the "WR CMG Sample Distribution Policy" at: <http://walrus.wr.usgs.gov/infobank/programs/html/main/sample-dist-policy.html>
Physical materials are under controlled on-site access.
Some USGS information accessed through this means may be preliminary in nature and presented without the approval of the Director of the USGS. This information is provided with the understanding that it is not guaranteed to be correct or complete and conclusions drawn from such information are the responsibility of the user.
This information is not intended for navigational purposes.
Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.