Stratigraphic column
![Stratigraphic column of the Twin Cities area focusing on the Ordovician Period.](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/full_width/public/thumbnails/image/10%20stratigraphic%20column%20diagram.png?itok=YQVDOXps)
Detailed Description
Stratigraphic column of the Twin Cities area focusing on the Ordovician Period. https://pubs.usgs.gov/gf/201/text.pdf USGS
Sources/Usage
Public Domain.
Stratigraphic column of the Twin Cities area focusing on the Ordovician Period. https://pubs.usgs.gov/gf/201/text.pdf USGS
Public Domain.