The Sedimentary Record of Atmospheric Pollution in Jerseyfield Lake, Adirondack Mountains, New York

Abstract

Jerseyfield Lake is a clear water oligotrophic lake of 176 hectare with a watershed of 1,936 hectare. Maximum depth is 28 meters. The present pH is about 4.8-4.9. Portions of the watershed were cut in the 1920’s, 1939–1941, ca. 1955–1961, and since 1981, concurrently with the emplacement of a circum-lake road. The chemistry of a sediment core from Jerseyfield indicates nearly steady state conditions over the period 1600–1850. The only systematic change in sediment chemistry was a persistent decline in MnO content. The cause of this is unknown. Pb, Zn, Cu, and V concentrations and deposition rates started to increase about 1850, 1900, 1925, and 1950, respectively. These changes are interpreted to be caused by increased atmospheric deposition of these metals from polluted air masses. Disturbance of the watershed, indicated by increased deposition of all major elements, occurred from ca. 1910 to 1970. This is followed by a decrease in deposition rates to 1982. Acidification of the lake water starting about 1950 is suggested by a decrease in the Zn and CaO deposition rates. The sharp reversal from Zn accumulation to Zn depletion suggests a rapid change in lake pH. The decline in MnO accelerated slightly starting about 1850. None of these changes appear to be synchronous with increased deposition of sediments, presumably related to concurrent lumbering in the watershed. The trends for changing deposition rates for Pb, Zn, Cu, V, Mn, and Ca appear to be reflective of atmospheric deposition of acids and metals.