Rocks representing a variety of tectonic and depositional environments outcrop along the canal and towpath and reveal the geologic history of the central Appalachian region from the Mesoproterozoic to Jurassic Period.
This digital map database represents the general distribution of the geology (bedrock and surficial deposits) in San Mateo County. Accompanying text file (*.txt or *.ps) provides current information on the geologic structure and stratigraphy.
Coordinated studies of the effect of historical mining for mercury, origin and composition of metals in groundwaters and surface waters, history of volcanic and intrusive activity, and the complex geological history of this area.
The USGS provides map-on-demand (MOD) printing for selected infrequently requested geologic and other theme map products providing high-quality paper-copy maps as needed. Site links to available map products with thumbnail views and how to order.
Geological mapping carried out by USGS in close cooperation with state, university, and federal partners. Includes general information about geological maps and mapping standards.
Overview of the Pacific Northwest Urban Corridor Geologic Mapping Program concerned with geology and urban hazards with links to online geologic maps, current research, publications, and contacts.
Pennsylvania digital data for watershed boundaries, county geology, and flood mapping in Arc/Info format compressed with gzip utility for downloading plus links to other sources of data.