Conclusions and Acknowledgments

CONCLUSIONS

The mines in the Illinois portion of the IKFD were active for more than 150 years. Currently, the only fluorspar production in Illinois comes as a by-product of aggregate mining at the Hastie Quarry in the Cave-in-Rock Subdistrict. The demise of this mineral district was due to dwindling shallow reserves and competition from foreign producers. There is active interest in a relatively low-grade mineralization at Hicks Dome. The mineralization is located in the Ordovician Plattin Limestone at depths below 2,000 feet. With the exception of Hicks Dome, very few deeper exploration borings have been conducted to test for additional fluorspar resources. If this district has future potential, it will most likely come from deeper levels that historically have been unexplored.

ACKNOWLEDGMENTS

The authors thank Bob and Don Hastie for their generous access to Hastie Quarry and for allowing the ISGS to scan the historical files of Ozark-Mahoning; Larry Nuelle for his thoughts and insights on Hicks Dome; and Roy Jackson and the American Fluorspar Museum for access to mine maps and other documents. The authors acknowledge the USGS Earth Mapping Resource Initiative for funding part of this research. This project was also funded in part by the USGS National Cooperative Geologic Mapping Program under several USGS STATEMAP awards. The authors further acknowledge the effort of Mike Knapp, who provided layout and graphic arts support; Susan Krusemark, who provided editorial support; Zak Lasemi and Scott Elrick, who reviewed the map and report; and Emily Bunse, who provided cartographic reviews and layout support for the map sheet.

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Circular 604 | Production History | Geology of the Illinois-Kentucky Fluorspar District | Mining Methods | Mineral Subdistricts and Individual Mines | Conclusions and Acknowledgments