Mineral-Potential Mapping for MVT Deposits with Limited Data Sets Using Landsat Data and Geological Evidence in the Borden Basin, Northern Baffin Island, Nunavut, Canada |
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Authors: | Bahram Daneshfar André Desrochers Paul Budkewitsch |
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Institution: | (1) Ottawa-Carleton Geoscience Centre, Department of Earth Sciences, University of Ottawa, 140, Louis Pasteur St., KIN 6N5 Ottawa, Ontatio, Canada;(2) Canada Centre for Remote Sensing, 588 Booth Street, K1A 0Y7 Ottawa, Ontario, Canada |
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Abstract: | Posterior probabilities of occurrence for Zn-Pb Mississippi Valley Type (MVT) mineralization were calculated based on evidence
maps derived from regional geology, Landsat-TM, RADARSAT-1, a digital elevation model and aeromagnetic data sets in the Borden
Basin of northern Baffin Island, Canada. The vector representation of geological contacts and fault traces were refined according
to their characteristics identified in Landsat-TM, RADARSAT-1, DEM, slope, aspect, and shaded relief data layers. Within the
study area, there is an association between the occurrence of MVT mineralization and proximity to the contact of platformal
carbonates and shale units of the adjacent geological formation. A spatial association also tends to exist between mineralization
and proximity to E-W and NW-SE trending faults. The relationships of known MVT occurrences with the geological features were
investigated by spatial statistical techniques to generate evidence maps. Supervised classification and filtering were applied
to Landsat-TM data to divide the Society Cliffs Formation into major stratigraphic subunits. Because iron oxides have been
observed at some of the MVT occurrences within the Borden Basin, Landsat-TM data band ratio (3/1) was calculated to highlight
the potential presence of iron-oxides as another evidence map. Processed Landsat-TM data and other derived geological evidence
maps provided useful indicators for identifying areas of potential MVT mineralization.
Weights of evidence and logistic regression were used independently to integrate and generate posterior probability maps showing
areas of potential mineralization based on all derived evidence maps. Results indicate that in spite of the lack of important
data sets such as stream or lake sediment geochemistry, Landsat-TM data and regional geological data can be useful for MVT
mineral-potential mapping. |
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Keywords: | MVT deposits potential mapping weights of evidence logistic regression posterior probability Borden Basin |
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