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Geologic Mapping

Geologic mapping is at the core of DGS research activities. Geologic maps provide a map-based representation of our current understanding of the geology of Delaware. Geologic maps can be made at several scales, depending on the level of detail of the underlying data and on intended use of the map. Most maps in the DGS Geologic Map Series focus on surficial geology, but subsurface geologic mapping is also part of our program.

Delaware's growing population and the resulting development make surficial geologic maps a valuable tool, and DGS mapping efforts are directed toward issues and areas of benefit to Delawareans. DGS geologic maps are used for ground-water, land-use, natural hazard, environmental geology, soils/agriculture, and geotechnical engineering applications. Traditionally, DGS geologic maps have been released as paper products. However, to meet the needs of users who employ geographical information systems (GIS), DGS geologic maps. DGS geologic maps are now also made available digitally, either as images or digital data suitable for GIS work.

Of the 57 USGS topographic map quadrangles in Delaware, the DGS has published 1:24,000-scale geologic maps covering fourteen quadrangles since the mid-1990s. Much of this work has been funded through the Statemap Program, a cooperative effort of the Association of American State Geologists and the U.S. Geological Survey. We have also recently completed 1:100,000-scale county surficial geologic maps for New Castle County and Kent County and have a one under construction for Sussex County. The 1:24,000-scale surficial geologic map information is available through the DGS DGIR web site; the 1:100,000-scale geologic information will soon also be available.