Geologic Maps

Geologic maps cover all parts of Pennsylvania, and are used to understand the rock type and structure of the earth.

Statewide coverages are available in different formats: a digital bedrock geology layer, a page-sized map, and a wall-sized paper version called Map 1.

The maps above are links to the digital bedrock geology coverage (left) and the page-sized geologic map* of Pennsylvania (center).

The digital GIS coverage (1:250,000 scale) is actually two digital data sets, one for geologic units and faults and the other for dikes. Regional coverages or the entire state may be downloaded. The coverages, in general, closely correspond to those shown on the 1980 Geologic Map of Pennsylvania (Berg, T. M., Edmunds, W. E., Geyer, A. R., and others, compilers, 1980, Pennsylvania Geological Survey, 4th ser., Map 1, scale 1:250,000).

Map 1, the 1980 map, is out of print. See our list of map publications for citation information.

Map 63 (above right), Rock types of Pennsylvania, is available as an image. Map scale is 1:500,000.

Other geologic maps are available for many areas of Pennsylvania; many maps are printed in full color. They may be examined in Repository Libraries or purchased from the sales office of the State Bookstore as instructed in the List of Publications,* which includes an index map showing the locations and the publication numbers of Pennsylvania's geologic publications on page 37. The online geologic maps page provides links to geologic maps across the state. Some specific publications including geologic maps can be viewed online and efforts are being made to add to that list.

Historical geologic maps of Pennsylvania

• First Pennsylvania Geological Survey maps
  • 1858 State Geological Map
  • 1858 Anthracite Fields of Pennsylvania map
• Second Pennsylvania Geological Survey maps
  • 1893 State Geological Map
  • County geologic maps and descriptions

Online open-file reports

Map 61

The out-of-print publication Map 61 contains 623 uncolored, page-sized geologic quadrangle maps; it is available here by clicking on Map 61.

National Geologic Map Database

The National Geologic Map Database is a searchable database of geologic maps by the U.S. Geological Survey. Many publications of the Pennsylvania Geological Survey are included with this database. If digital maps are available, online links are provided. Geographic searches also can be made at this web site. In addition, a lexicon of geologic names is included along with locations of new geologic mapping across the country.

Other digital images of Pennsylvania geology

In cooperation with the Penn State University Libraries, hundreds of geologic maps and other publications are available as digitally scanned files. See “Pennsylvania Geology” at their web site. These are scanned images of geologic maps, many of which were produced by the Pennsylvania Geological Survey.

*You will need the Acrobat Reader 6.0 or later to successfully view/print some information. This program can be downloaded to your computer for free; simply click on the "Get Acrobat Reader" button at right to download now.