Revised geologic time scale indicating the ages of the lower bounds of chronostratigraphic and geochronologic units as they are currently known. Modifications to those ages made since the previous time scale was released (2007) are clearly marked.
Links to standards prepared under the National Mapping Program to produce and maintain top quality mapping and geospatial data products. Documents may be viewed and downloaded in PDF and HTML formats with links to related information.
Summary of protocols describing procedures for laboratory analysis of algae samples collected by the U.S. Geological Survey's National Water Quality Assessment Program (NAWQA). Includes full document to be downloaded in PDF format.
Branch of Quality Systems monitors the consistent collection and reporting of water-quality data with documentation of field and laboratory methods and proficiency testing. Links to standard reference samples and quality assurance standards.
Site for the Optical Science Laboratory specializing in expert calibration of aerial mapping cameras with links to fees, scheduling cameras for calibration, historical camera database files, USGS aerial camera specifications, and how to visit.
Homepage for ISGS Spatial Data Transfer Standard (SDTS) information with links to software, FTP site, standard, and data available on line, USGS mass conversion schedule, meetings, and related web sites.