Because eskers are often raised topographic features, much of their resources can be gotten before encroaching on the water table. Once the volume of an esker's resources was determined, estimates were made for the amounts of those materials that could not be exploited because they coincided with sterilized areas, such as stream or road buffers, previous quarrying, housing, or other permanent construction. This was done by determining the area that had beeen sterilized, estimating the thickness of the eskers in that area, calculating the volume of the gravel resources in the sterilized area, and subtracting that volume from the total for the esker. In this way, the total exploitable sand and gravel resources were found for each esker. These totals are shown in the table below.
Number denotes the esker number in the table below.
Photograph of the north face of an esker being consumed for sand and gravel resources in the Loudon, NH, quadrangle. About 1,000 ft of the esker have been removed. Resources below the horizontal surface at the foot of the esker have been sterilized because they are encroaching the water table. Return to top Estimated in-place and sterilized sand and gravel resources in esker deposits in the Soucook River Valley part of the Loudon quadrangle. The geologic map was used to define the area expected to contain glaciofluvial gravel resources, which was mostly the footprint of glacial Lake Hooksett.