GEOCHEMICAL ASSESSMENT OF TOPSOIL AND ROCK FORMATIONS FROM LEBANON, CT

Bedrock weathering and soil formation are important geological processes associated with the release of trace elements into the environment. In addition, various human activities further provide anthropogenic release of trace elements to the environment. This project examined concentrations of major and trace elements in topsoil and rock Formations from Lebanon, CT northeastern USA, with the goals of determining: i) weathering rate of rock Formations; ii) relationship between different rock Formations and topsoil geochemistry; and iii) element mobility and their overall impact on the surrounding hydrologic systems. In order to address these goals, rock samples were collected from different rock Formations that include Hebron gneiss, Scotland schist, Brimsfield schist, Lebanon gabbro, Canterbury Gneiss, and Tatnic Hill Formation. In addition, topsoil samples were collected around each rock Formation up to a depth of about 10 cm below the surface. In the laboratory, both soil and rock samples were acid digested and later analyzed for trace and major elements concentrations using both ICP-OES and PW2400 X-Ray Fluorescence Machines. Results indicate a weak to no statistical correlation between rock Formations and topsoil chemistry. Calculation of weathering indices, and a A-CN-K ternary plot showed weak to intermediate weathering rates suggesting a dominant influence of anthropogenic activities on topsoil chemistry.