Skip to main content
U.S. flag

An official website of the United States government

Factors controlling the major ion chemistry of streams in the Blue Ridge and Valley and Ridge physiographic provinces of Virginia and Maryland

January 1, 1992

Principal component analysis was used to examine regional patterns in stream chemistry and to examine the degree to which the chemistry of low-order streams is controlled by the bedrock upon which they flow. Streams clustered into regionally isolated groups strongly related to bedrock type, with SO42- and HCO3- the chemical variables of most importance. Sulphate concentrations appear to be strongly controlled by climate and hydrology, and sorption in the soils within the watershed. Much of the atmospherically derived SO42- accumulates in watersheds during the growing season and is later flushed out. Weathering reactions were found to be particularly important in the production of HCO3-, accounting for 91% on an annual basis, and export of divalent cations from these watersheds, accounting for 48-50% on an annual basis. About half of non-anthropogenic Na+ was derived from weathering of silicates, whereas nearly all K+ was identified with leaching by SO42-. Water chemistry was strongly related to the rock type in the watershed and the weatherability of the component minerals. -from Authors

Publication Year 1992
Title Factors controlling the major ion chemistry of streams in the Blue Ridge and Valley and Ridge physiographic provinces of Virginia and Maryland
Authors L.J. Puckett, O.P. Bricker
Publication Type Article
Publication Subtype Journal Article
Series Title Hydrological Processes
Index ID 70017222
Record Source USGS Publications Warehouse