Regional Till Geochemical Survey of the Western Vermilion Greenstone Belt, Minnesota
2004
Loading...
Persistent link to this item
Statistics
View StatisticsJournal Title
Journal ISSN
Volume Title
Title
Regional Till Geochemical Survey of the Western Vermilion Greenstone Belt, Minnesota
Authors
Published Date
2004
Publisher
University of Minnesota Duluth
Type
Technical Report
Abstract
This report presents results of a reconnaissance-scale fine-fraction (silt and clay; -250
mesh, <63μm) till geochemical survey of the western Vermilion Greenstone Belt (VGB).
Survey results provide information on the background concentrations of a suite of precious, base
metal, and pathfinder elements in till. The survey has identified a number of areas with elevated
to anomalous precious and base metal concentrations in till associated with bedrock
mineralization in the greenstone belt. The dataset provides a framework for interpretation of the
significance of results of future regional and property-scale till geochemical surveys.
The survey has identified a number of areas with anomalous precious and base metal
concentrations. A prominent zinc anomaly (up to 266 ppm) is present down-ice of Fivemile
Lake, underscoring the potential for significant undiscovered zinc mineralization in this area.
Highly anomalous copper (314 ppm), gold (54 ppb), molybdenum (26 ppm), and zinc (368 ppm)
are present in till in near Needleboy and Armstrong Lakes, suggesting the presence of significant
mineralization in an essentially unexplored area. Anomalous gold concentrations suggest
significant unidentified gold mineralization exists within the greenstone belt, most notably in the
Bass Lake sequence between the Mud Creek shear zone and Vermilion Fault, where gold values
up to 940 ppb were identified. Using the results of this survey as a baseline, higher density
follow-up till sampling promises to more clearly define and determine the significance of
anomalies, as well as determine the location of potential source rocks.
Interpretation of mixing of exotic granitic with local greenstone lithologies indicate that
over 50% of the fine-fraction material has been transported less than 3 km. Flow direction,
transport distance, and probability sector data indicate most geochemical anomalies identified by
this survey are correlative with previously identified areas with high potential for bedrock
mineralization.
This survey demonstrates that till composition in the VGB systematically reflects both
bedrock composition and economic mineralization. Results suggest drift exploration methods in
general and fine-fraction till geochemical surveys in particular, can be successfully incorporated
into an integrated exploration program in the VGB. Higher density sampling is recommended to
determine the significance of anomalies and more precisely define source rocks. Further work is
recommended to test the applicability till geochemistry to property-scale investigations and of
heavy mineral surveys.
Description
The files attached to this record include the report (TR-2004-23.pdf), two versions of Figure 3 (Fig3 NRRI-TR-2004_23.doc [Microsoft Word 97-2003 document] and TR-2004-23_Figure3.tif), and the digital files found on the CD-ROM accompanying the report (vermilion_till_geochem.xls [Microsoft Excel 97-2003 spreadsheet], vermilion_till_geochem.csv [comma separated values file], and the zipped ArcView Files file that contains 20 .avl, .dbg, .dbf, .prj, .sbn, .sbx, .shp, and .shx files). Please note that the readme.txt file listed on page v of the report was NOT found on the accompanying CD-ROM.
Related to
Replaces
License
Collections
Series/Report Number
Funding information
Isbn identifier
Doi identifier
Previously Published Citation
Suggested citation
Larson, Phillip C. (2004). Regional Till Geochemical Survey of the Western Vermilion Greenstone Belt, Minnesota. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/187140.
Content distributed via the University Digital Conservancy may be subject to additional license and use restrictions applied by the depositor. By using these files, users agree to the Terms of Use. Materials in the UDC may contain content that is disturbing and/or harmful. For more information, please see our statement on harmful content in digital repositories.