Abstract extracted from page 1 of Report 252 Vol.1:
ABSTRACT (first two paragraphs) A regional geochemical survey was conducted during 1985-1987 on drill samples of buried Rainy lobe glacial drift over two separate areas in the Precambrian shield of northern Minnesota. A primary objective was to test this method to search for large, mining-camp scale targets of base and precious metal mineralization or alteration. In order to thus evaluate the mineral potential and to foster further exploration, a framework of regionally-based data for glacial drift stratigraphy, glacial drift geochemistry, and limited geophysics was assembled.
The surveys were conducted over Superior Province Archean bedrock terrane in two areas: nine townships near Orr (in Koochiching and St. Louis counties) of typical Archean supracrustal layered bedrock and ten townships around Littlefork (in Koochiching county) over Vermilion Granitic Complex bedrock. The favorable glacial drift for geochemical exploration here is the Wisconsinan Rainy lobe (Labradorean provenance) which is lying on bedrock but buried beneath 50 to 100 feet of Des Moines lobe (Keewatin provenance) clayey till and/or lake sediments. In the 9 townships of the Orr area, 37 holes were drilled for an average of 4 holes per township. Similarly near Littlefork, 30 holes were drilled, or 3 holes per township. A total of 304 glacial drift samples of 5 to 10 foot composites were processed for heavy mineral concentration, and 383 similar composites were dry screened to obtain the silt plus clay fraction for analysis. Those two types of glacial drift plus 58 bedrock samples and 124 (out of the above 304) HMC magnetic fraction samples make up the regional geochemical database...
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Report 252 Volume 1: 1988; Regional Survey of Buried Glacial Drift Geochemistry Over Archean Terrane in Northern Minnesota; 9 Twps in Koochiching & St. Louis counties
(83 pages, 8.5 x 11 inches, 3.90 MB)
Authors: D.P. Martin, G. Meyer, T.L. Lawler, V.W. Chandler, and K.L. Malmquist
Report 252 Volume 2: 1988; Regional Survey of Buried Glacial Drift Geochemistry Over Archean Terrane in Northern Minnesota; 9 Twps in Koochiching & St. Louis counties
(427 pages, 11 x 17 inches, Large File Size 29.54 MB)
Authors: D.P. Martin, G. Meyer, T.L. Lawler, V.W. Chandler, and K.L. Malmquist
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Map plates available
Auxiliary Plates 1-2: Reside on map sheets in the MN DNR Hibbing office.
Author: MN DNR, Lands and Minerals Division
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Report 252 digital data now available for use in GIS applications.
In June of 2012 the MN DNR's Lands and Minerals Division converted DNR Project's 252, Regional Survey of Buried Glacial Drift Geochemistry Over Archean Terrane in Northern Minnesota, original data files (.asc) into ESRI spatial and tabular datasets. Listed below is a zip file with the original tabular data in .asc file format and the converted GIS data of drill holes, samples, and assay data for Report 252. The two reports (volume 1 and volume 2) for Report 252 should be used regarding the metadata for the original .asc data files as well as the converted spatial data which used the original data files. The data is designed to be used as a supplement to the report and plates.
Report 252 Digital Data (zip, 9 mb)
Report 252 Georeferenced Map Figures (zip, 5 mb, June 2016)
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