Abstract |
Stable S isotopes of SO4(2-) in precipitation, throughfall, and stream water solutions in a northern hardwood watershed (Bear Brook Watershed, Maine) were examined to determine sources of stream SO4(2-) and to identify watershed processes that may affect atmospherically deposited SO4(2-) prior to reaching the streams. Similarity among temporal pattern in Delta(34)S of precipitation, throughfall, stream SO4(2-) (range: +3.4 to 9.4%), and (SO4(2-)(marine))/(SO4(2-)(total)) of stream SO4(2-) (5-10%) indicated that the Delta(34)S of stream SO4(2-) were controlled principally by atmospheric deposition. Lack of correlation between Delta(34)S of stream SO4(2-) and stream (SO4(2-)(total)), elevational position, and stream discharge supported the interpretation that fractionation of stable S isotopes within the watershed appeared to have, at most, a minor influence on Delta(34)S of stream SO4(2-). (Copyright (c) 1992, American Geophysical Union.) |