How does the surficial geology map relate to a significant aquifers or coastal landslide hazards map?
Both significant sand and gravel aquifers and coastal landslide hazards maps are “derivative” maps which use a subset of the surficial geology information to create a specific map on a different topic. Sand and gravel areas shown on the surficial geology map are the starting point for interpreting the extent of significant sand and gravel aquifers. Areas of Presumpscot Formation (marine clay) are a key element in determining the landslide risk along Maine’s coastal bluffs and along river and stream bluffs.
