Browse the Collection

This website is designed to provide online access to the geologic research of the Lake Superior Division of the USGS, 1882–1922. The collection contains:
  • more than 30,000 hand samples (metadata records)
  • over 13,000 thin sections (photographed in plane- and cross-polarized light)
  • 467 field notebooks (321 of which have been scanned)
  • 67 maps
Click here to read more about items in the collection. Browse, filter, and search using these pages:


For 40 years, beginning in 1882, the Lake Superior Division of the USGS in Madison, Wisconsin documented the geology of the Lake Superior area. The division primarily worked in Wisconsin, Minnesota, Michigan’s Upper Peninsula, and Ontario. Over the course of its work, the division produced a number of publications on the region’s Precambrian geology. R.D. Irving, the first director, did pioneering work in the field of microscopic petrography and was the first to use thin sections in a large-scale survey. Read more about the history...


This work has been supported by the Wisconsin Geological and Natural History Survey with grants from the USGS National Geological and Geophysical Data Preservation Program (NGGDPP). Field notebooks and maps were scanned by the University of Wisconsin-Madison Digital Collections.
Please see our list of full acknowledgments