Analysis of 38 chemical elements in five peat cores from the mid-continent to the eastern coast of North America shows that the concentrations and rates of accumulation of chemical elements supplied by atmospheric deposition to Sphagnum bog peats vary greatly with geographic location, which determines the relative importance of emissions to the atmosphere from the soil (e.g., Al, La, Th) and the sea (e.g., I., Br, Cl, Na). Biological uptake also has a considerable effect upon certain elements (e.g., C, N, K, P). The concentration/depth profiles of several lithophilic and biophilic elements reveal greater concentrations in fen than in bog peats, and in surficial than in deeper bog peats, but only in some sites. Some mobile elements are lost to a marked degree from the peat column (Na, K) or are influenced by upward migration from fen peat into the bog peat above it (Ca, Fe, Mn). No single chemical element, or elemental quotient (e.g., Ca/ Mg, C/N), clearly distinguishes the transition from fen to bog peat in all sites.