Stable sulfur isotopes of sulfate in precipitation and stream solutions in a northern hardwood watershed

Stable S isotopes of SO2-4 in precipitation, throughfall, and stream water solutions in a northern hardwood watershed (Bear Brook Watershed, Maine) were examined to determine sources of stream SO2-4 and to identify watershed processes that may affect atmospherically deposited SO2-4 prior to reaching the streams. Similarity among temporal patterns in δ34S of precipitation, throughfall, stream SO2-4 indicate that the δ34S values of stream SO2-4 are controlled principally by atmospheric deposition. Lack of correlation between δ34S of stream SO2-4 and stream [SO2-4total], elevational position, and stream discharge supports the interpretation that fractionation of stable S isotopes within the watershed appears to have, at most, a minor influence on δ34S of stream SO2-4