Subject: Pennsylvanian Geologic Period / Year: 1999 - Yale University Library GeoBlacklight Search Results

Start Over Subject Pennsylvanian Geologic Period Year 1999

1. The lower Pennsylvanian unconformity in the central Appalachian Basin [cartographic material]

1999. 2002-06-01T04:00:00Z. 2016-07-16T21:16:14Z. Geological Survey (U.S.). U.S. Geological Survey ; For sale by U.S. Geological Survey, Information Services. English. cartographic image. Public. Appalachian Basin, United States, and Appalachian Basin. Pennsylvanian and From 280 to 310 million years ago.