Analysis of variations in major ion chemistry in the Mill River watershed reveals the importance of anthropogenic activities in controlling streamwater chemistry. Average concentrations of NO3- and SO4(2-) show a positive correlation with percent catchment area altered by human land uses, and concentrations of Cl- increase with road density. Water removal from municipal reservoirs increases the downstream concentration of NO3- and SO4(2-) over that predicted by land use changes, showing that removal of high quality upstream water concentrates pollutants downstream. In salt-impacted streams, Cl- exceeds Na- by 10-15% due to cation exchange reactions that bind Na+ to soil. The net effect of nonpoint source pollution is to elevate ANC in the most developed areas, which impacts the natural acidity of a large swamp. The sum of base cations (C(B)) exceeds ANC for all samples. Plotting C(B) against ANC and subtracting Cl- quantifies the impact of road salt from the impact of the addition of strong acids.
Abstract--The clay and bulk mineralogy of soil and till from 26 Adirondack watersheds was studied. The materials consist typically of quartz, K-feldspar, plagioclase, mica, vermiculite, and kaolinite. Talc, smectite, halloysite, and hornblende are present in some samples. The clay fraction of the soils is composed predominantly of vermiculite, likely derived from the transformation of a mica precursor, and kaolinite. The soil vermiculite commonly contains hydroxy-Al interlayers which are especially prevalent in the B-horizon samples. Despite significant variation in the type of bedrock and the composition of heavy mineral assemblages in these watersheds, the clay mineralogy is remarkably uniform. This finding supports earlier suggestions that the occurrence of vermiculite in soils is more dependent on climate than on the nature of the parent material.
Woods and Panther lakes in the Adirondack Mountains of New York respond differently to the same acidic deposition. A mathematical model study has shown that lake water becomes acidic when hydrologic conditions force precipitation to flow to the lakes as surface flow or as lateral flow through the shallow organic soil horizon. Hydrographic data, capacity of flow through inorganic soil horizons, runoff recession curves, and groundwater level fluctuations of Woods and Panther lake basins provide independent evidence to support the thesis that the acidic state of a lake depends on the paths the tributary water takes as it passes thorough the terrestrial system. It is concluded thot Panther Lake is more alkaline than Woods Lake, because a larger proportion of the precipitation falling on the basin passes through deeper mineral soil horizons.
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