This vector data set contains the data points used to generate rock unit polygons for the surficial geology in the Delaware Coastal Plain covered by DGS Geologic Map Series No. 24 (Millington, Clayton and Smyrna Quadrangles). This point file supplements DGS Geological Map Series No. 24 (Millington, Clayton and Smyrna Quadrangles) by showing the locations, depths and surficial geologic picks for hand auger holes, drill holes, and wells used to generate the surficial geologic unit polygons. The geological history of the surficial units of the Clayton, Smyrna, and the Delaware portion of the Millington Quadrangles are the result of deposition of the Beaverdam Formation and its modification by erosion and deposition of the Columbia Formation during the early Pleistocene. These units were then modified by the Lynch Heights and Scotts Corners Formations as a result of sea-level fluctuations during the middle to late Pleistocene. The geology is further complicated by periglacial activity that produced Carolina Bay deposits in the map area, which modified the land surface. This map supersedes Geologic Map of New Castle County, Delaware (Ramsey, 2005) and Geology of the Geologic Map of Kent County, Delaware (Ramsey, 2007).
This data is accessible as a map service on Delaware FirstMap.
Additionally, this and other services are available in the ArcGIS Online DGS Map Viewer
+/- 1 foot. Drill holes and hand auger holes have been averaged together to get this value.
+/- 20 feet. Boring sites are located on topographic base maps and aerial photography. Spot checking of these locations using GPS has verified this accuracy.
University of Delaware
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Newark, DE 19716
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