Some samples were analyzed at the DGGS Geochemical Laboratory for copper, zinc, lead, silver, antimony, molybdenum, cadmium, and arsenic using Atomic Absorption Spectroscopy after HCl:HNO3 (3:1) acid digestion. Other samples were analyzed for copper, zinc, cobalt, nickel, iron, manganese, cadmium, chromium using Inductively Coupled Plasma - Atomic Emission Spectroscopy after HCl:HNO3 (3:1) acid digestion. Some results may be below the lower limit for that element and method. Bondar-Clegg performed analyses on 118 stream sediment samples for copper and zinc using Atomic Absorption Spectroscopy.