Boerboom, T., Holm, D., Woodruff, L., Cannon, B., & Wirth, K. (2005). The Western Margin of the Keweenawan Midcontinent Rift System: Geologic Highlights of Archean, Paleoproterozoic, Mesoproterozoic, and Paleozoic Bedrock in Eastern Minnesota and Northwestern Wisconsin. Minnesota Geological Survey Guidebook. https://oaks.kent.edu/node/1978
Boerboom, Terrence, Daniel Holm, Laurel Woodruff, Bill Cannon, and Karl Wirth. 2005. “The Western Margin of the Keweenawan Midcontinent Rift System: Geologic Highlights of Archean, Paleoproterozoic, Mesoproterozoic, and Paleozoic Bedrock in Eastern Minnesota and Northwestern Wisconsin”. Minnesota Geological Survey Guidebook. https://oaks.kent.edu/node/1978.
Boerboom, T., D. Holm, L. Woodruff, B. Cannon, and K. Wirth. The Western Margin of the Keweenawan Midcontinent Rift System: Geologic Highlights of Archean, Paleoproterozoic, Mesoproterozoic, and Paleozoic Bedrock in Eastern Minnesota and Northwestern Wisconsin. Minnesota Geological Survey Guidebook, 1 Jan. 2005, https://oaks.kent.edu/node/1978.