Pennsylvania Geological Survey: Digital Bedrock Geology

Department of Conservation and Natural Resources

Geologic Maps Map 61 Open File Topographic
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Digital Bedrock Geology of Pennsylvania

Overview

In 1980, the Bureau of Topographic and Geologic Survey published Map 1, Geologic Map of Pennsylvania, by T. M. Berg and others. This map, which was compiled and printed at 1:250,000 scale, has had widespread use for regional applications and remains a popular source of the bedrock geology of the state as a whole. Although the hard-copy edition of Map 1 is no longer available, images of the map can be viewed, downloaded, or printed from its online version.

Responding to numerous requests from governmental agencies and the private sector, the Bureau has used GIS technology to prepare a digital version of the regional bedrock geology of the state, based on the 1980 published map and source materials used for that map. It was beyond the scope of the project to include new mapping done since the 1980 map was compiled; however, limited updates and changes were made where they could be easily incorporated. Newer mapping will be included in future editions.

There are two datasets, one for geologic units and faults, and the other for dikes. The datasets are available for downloading below in both ArcInfo export format and shapefile format. Separate files containing metadata (information about the datasets and how they were prepared) and other explanatory information are also available below.

We welcome feedback from users regarding these datasets. Please contact Michael Moore with your comments, recommendations, and suggestions.

Downloading and Viewing the Datasets

Before downloading the files, please read the distribution liability statement. To download, select either seamless files for the entire state, or files for 30- by 60-minute quadrangles.

The datasets cannot be viewed with a web browser. They must be used with a software program that is capable of importing an ArcInfo export file or ArcView shapefile. Free software for viewing the shapefiles may be obtained from the ESRI web site.

The files have been compressed to assist the user by limiting the time needed for downloading. The compressed files have a “.zip” extension after their names.** Sizes of these compressed files, as well as the sizes of the uncompressed files contained in each compressed archive, are listed below.

The dataset files do not contain color tables or map explanations. However, colors and symbols for the map units may be assigned by the user through available symbology styles.

Note on Projection: The datasets are in a geographic coordinate system. Units are decimal degrees. The datum is NAD 1927.

Datasets for Entire State

Digital bedrock geology layers

Download the GIS files below by selecting the desired format for the statewide files.

ArcInfo Export Files for Entire State
pageoexp.zip (28.6 MB) Contains the following files when uncompressed:

pageo.e00—Bedrock geologic units and faults (ArcInfo export format)
padike.e00—Dikes (ArcInfo export format)
pagmeta.htm—Metadata (HTML format)
credits.pdf—Credits for sources, geologic work, and digital work (PDF format)
references.pdf—Reference citations for published and unpublished sources (PDF format)
changes.pdf—List of general changes made in the datasets to geologic names, map
symbols, and ages from those shown on the 1980 state geologic map (PDF format)
explanation.pdf—Explanation containing a brief geologic description of the map units in the dataset, largely derived from the 1980 state geologic map (PDF format)
polyattrib.pdf—A list of the polygon attributes for each geologic unit in the dataset for geologic contacts and faults (PDF format)
dikeattrib.pdf—A list of the arc attributes for each dike line in the dataset for dikes
(PDF format)

ArcView Shapefiles for Entire State
pageoshp.zip (65.5 MB) Contains the following files when uncompressed:

pagpoly—Bedrock geologic units and faults, polygons (ArcView shapefile format)
pagarc—Bedrock geologic units and faults, arcs (ArcView shapefile format)
padike—Dikes, arcs (ArcView shapefile format)
pagmeta.htm—Metadata (HTML format)
credits.pdf—Credits for sources, geologic work, and digital work (PDF format)
references.pdf—Reference citations for published and unpublished sources (PDF format)
changes.pdf—List of general changes made in the datasets to geologic names, map
symbols, and ages from those shown on the 1980 state geologic map (PDF format)
explanation.pdf—Explanation containing a brief geologic description of the map units in the dataset, largely derived from the 1980 state geologic map (PDF format)
polyattrib.pdf—A list of the polygon attributes for each geologic unit in the dataset for geologic contacts and faults (PDF format)
dikeattrib.pdf—A list of the arc attributes for each dike line in the dataset for dikes
(PDF format)

Datasets for 30- by 60-minute Quadrangles

Click on a quadrangle on the index map or in the list below to view files available for downloading.

Allentown…..Ashtabula…..Bradford…..Carlisle…..Clearfield…..Cumberland…..East Liverpool…..Erie…..Hagerstown Harrisburg…..Honesdale…..Indiana…..Jamestown…..Johnstown…..Middletown…..Morgantown…..Moundsville Oil City…..Pittsburgh East…..Pittsburgh West…..Reading…..Scranton…..State College…..Sunbury…..Towanda…..Trenton Tyrone…..Warren…..Wellsboro…..Williamsport East…..Williamsport West…..Wilmington…..York…..Youngstown

Download by selecting the desired file underlined in blue. Please note that the metadata and related files are the same for all of the quadrangles.

ALLENTOWN QUADRANGLE
ArcInfo Export File aleexp.zip (443 KB) Contains the following file when uncompressed:

Bedrock geologic units and faults

ArcView Shapefiles aleshp.zip (723 KB) Contains the following files when uncompressed:

Bedrock geologic units and faults, polygons
Bedrock geologic units and faults, arcs