Backgrounds and Baselines

Overview

A geochemical base of information is required to define the natural abundance and spatial distribution of chemical elements in the Earth's surface and subsurface environment to which changes caused by human activities (for example, urbanization, agriculture, mining, waste disposal and industrial pollution) or natural processes (for example, volcanic eruptions, floods, hurricanes, and dust storms) can be compared. This project developed this information base through studies ranging in scale from site-specific to regional and national. The resulting databases and interpretive products (including geochemical maps) are available for use by Federal, State, and local land management and environmental protection agencies to determine predevelopment geochemical backgrounds and current geochemical baselines for various sample media both at the surface (soils, stream sediment, and water) and in the subsurface (water and rocks). The information is available for use to detect and measure the magnitude of change in the chemistry of these materials caused by anthropogenic or natural processes. The preparation of these multi-element, multi-media geochemical baselines and their representation as geochemical maps was an essential first step for assessing and monitoring the state of the Earth's land surface.

Project Tasks

• Baseline Characterization and Monitoring of Minerals-Related Mitigation Sites and Undeveloped Mineral Deposits
• Leadership in IUGS/IAGC Working Group on Global Geochemical Baselines
• Three Dimensional Backgrounds and Baselines
• Environmental Behavior of Mineral Deposits in Alaska's National Parks
• Regional Geoscience Baseline Studies of the Fortymile and Goodpasture River Watershed, Alaska
• Sources and Cycling of Hg in Lakes and Reservoirs in the Central Region, USA
• Environmental Geochemistry in Joshua Tree National Park (JTNP), California