VISUALIZING THE GEOLOGY OF THE SOUDAN MINE: A PROPOSED SITE FOR A DEEP UNDERGROUND SCIENCE AND ENGINEERING LABORATORY IN NORTHERN MINNESOTA

Over the past several years, research communities in physics, geosciences, biosciences, and engineering have developed strong scientific arguments for access to facilities deep underground. A key component of these arguments is the geological characterization of candidate sites deep underground, as a means to assess science possibilities and infrastructure layout. The NSF is currently reviewing site proposals from a number of institutions, including a proposal by the University of Minnesota (UMN) to deepen and expand current physics laboratories at the historic iron mine at Soudan, northeastern Minnesota. As part of the UMN proposal, geological data for the Soudan Mine area have been integrated from numerous CAD, GIS, spreadsheet, and geophysical software packages into a single 3D platform (gOcad by Earth Decision Sciences). These data include a detailed (1:2,000) geological map, structural elements and measurements, geochemistry, geophysics, mine workings, and conceptual designs of proposed infrastructure. In addition, the 3D margin of the Laurentide ice sheet has been interpreted from mapped Quaternary landforms.

With the exception of data from within the Soudan Mine, all of these data have been acquired at the surface (and at the scale of the project, essentially in 2D). The 3D tools in gOcad, coupled with integration of 2,000 structural measurements and geophysical data, have lead to a stratigraphically and structurally compatible geological model of the Soudan Mine area down to a depth of >8,000 feet.