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Paleomagnetic and 40Ar/39Ar Results from the Grant Intrusive Breccia and Comparison to the Permian Downeys Bluff Sill—Evidence for Permian Igneous Activity at Hicks Dome, Southern Illinois Basin

Description: A report about applying 40Ar/39Ar dating methods, along with other rock techniques, to determine the age of emplacement and the cooling history of the Grant intrusive breccia at Hicks dome in Illinois.
Date: 1997
Creator: Reynolds, Richard L.; Goldhaber, Martin B. & Snee, Lawrence W.
Partner: UNT Libraries Government Documents Department
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Zinc-Lead-Copper Resources and General Geology of the Upper Mississippi Valley District

Description: From introduction: This report discusses the general geology of the Upper Mississippi Valley zinc-lead district, the distribution of ore deposits, and some relations of the ore deposits to the major geologic features.
Date: 1955
Creator: Heyl, Allen V.; Lyons, Erwin J.; Agnew, Allen F. & Behre, Charles H., Jr.
Partner: UNT Libraries Government Documents Department
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Geological and Geophysical Survey of Fluorspar Areas in Hardin County, Illinois

Description: From abstract: Pt 1. The present work seems to confirm the genetic theory previously published, namely that [Illinois Cave in Rock] deposits were formed by ascending solutions. These solutions probably followed minor fissures that connected below with larger fissures, which in turn probably connected with a major fault zone. It is believed that where such minor fissures extended upward only to the shale or other impervious cap rock, or were greatly reduced in size where they penetrated such bed… more
Date: 1944
Creator: Currier, Louis W.; Wagner, Oscar Emil, Jr. & Hubbert, M. King
Partner: UNT Libraries Government Documents Department
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