National Geological and Geophysical Data Preservation Program

Wisconsin: Mineral Exploration Data and Documents

E.K. Lehmann Mining Collection, Geologic Map, Wisconsin

E.K. Lehmann Document 1126: Geologic Map of River Island and Blockhouse Lake Prospect Area; NGGDPP funds used to preserve Lehmann Collection. (Public domain, courtesy of Wisconsin Geological and Natural History Survey.)

In 2017, the Wisconsin Geological and Natural History Survey (WGNHS) received a NGGDPP grant to inventory, preserve, and publicly expose the Lehmann Collection of documents, maps, data, and analyses. Significant time and money were invested by the private company, Ernest K. Lehmann and Associates, Inc. (ELA), to collect and compile the Lehmann exploration data and documents. The inclusion of these documents in our collection increases the scientific value of our core immensely, providing newly available geologic interpretations. This collection represents an important chapter in the recent history of mineral exploration in Wisconsin, contains irreplaceable original research on the Precambrian bedrock of the state, and can provide detailed information on the region’s mineral-bearing rocks—information that is not available anywhere else. Additionally, recent changes in the laws regulating non-ferrous metallic minerals in Wisconsin make the online publication of this collection timely and relevant.

Mining companies, educators, legislators, environmentalists, and journalists will all benefit from our preservation work on and digital access to this collection because they will be spared the costs of collecting this data. Making the scanned documents accessible online will allow researchers to evaluate the utility of the collection without having to travel to our facility. Building an online platform to display our core collection, beginning with the Lehmann core, drastically improves accessibility for all users.

The study of the documents in the Lehmann collections will ultimately allow a better understanding of the economic and environmental impact of the rocks of northern Wisconsin. Public access to these materials will facilitate research on the natural resources, geology, and mineral resources of Wisconsin. The application and the collection are being well-received and have already been used by researchers at USGS, educators at Western Michigan University, Wisconsin legislative staff, and the Wisconsin Wildlife Federation.

The documents in this collection provide the original data for the recent publication: Theodore DeMatties, Effects of paleoweathering and supergene activity on volcanogenic massive sulfide mineralization in the Penokean Volcanic Belt, northern Wisconsin, Michigan and east-central Minnesota, USA: Implications for future exploration. Elsevier, Ore Geology Reviews, Vol. 95, April 2018, Pages 216-237.

View Lehmann Collection in National Digital Catalog HERE

VIew Mineral Exploration in Northern Wisconsin Application HERE