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Kriging Fuzzy Logic WLC / OWA Mineral Prospectivity FOSS GIS

Geological Prospectivity Mapping — FOSS Desktop Tool

A multi-criteria mineral prospectivity mapping (MPM) tool built entirely on free and open-source geospatial libraries. Combines Ordinary Kriging, Euclidean distance analysis, fuzzy membership normalisation and weighted linear combination into a guided desktop workflow — no ArcGIS licence required.

Ordinary KrigingGeochem interpolation
WLC / OWAProspectivity model
Fuzzy LinearEvidence normalisation
100% FOSSNo licence required
MPM tool — prospectivity raster output and weighted layer controls

The problem

Mineral prospectivity workflows are traditionally locked inside ArcGIS Pro — a licence dependency that puts systematic targeting out of reach for smaller explorers and independent geologists.

This tool guides a geologist through the full MPM workflow — from raw geological and geochemical inputs through to a continuous prospectivity raster and ranked target list — using only free and open-source geospatial libraries. It was built to replace an existing ArcGIS Pro workflow, removing the licence dependency while preserving the same analytical rigour.

Each evidence layer goes through a consistent normalisation pipeline before being combined in a weighted model. Outputs are GeoTIFF rasters compatible with any GIS platform. A demo of the interface is available at shmit98.github.io/MPM-2026-Redo.

Analytical methods

Ordinary KrigingInterpolates point geochemistry (Au, As, Cu, etc.) to a continuous grid using a spherical variogram model via pykrige
Euclidean Distance AnalysisProximity rasters from geological contacts, structural lineaments and geophysical anomalies — inverted and normalised 0–1
Fuzzy Linear MembershipLinearly rescales each evidence raster to a 0–1 favourability score: (val − min) / (max − min), clipped to [0, 1]
95th Percentile ThresholdingIsolates high-value anomalies in raster datasets before vectorising and computing proximity distance
Slope Analysis (WhiteboxTools)Derives slope rasters for terrain-based constraints; threshold applied as a binary exclusion mask
WLC / OWA Weighted ModelUser-assigned weights (summing to 100%) combined via weighted linear combination or ordered weighted averaging across all normalised evidence layers

Evidence layer pipeline

  1. Geology (polygons) — Lithological or alteration polygons are converted to boundary lines, rasterised, and used to generate a proximity distance raster. Optional per-unit weighting applies relative geological importance before normalisation.
  2. Point geochemistry (CSV) — Sample data projected to GDA94 MGA zone. Ordinary Kriging run independently for each selected element column, outputting a continuous interpolated surface per element.
  3. Structural lineaments (polylines) — Fault or structural polyline shapefiles rasterised and converted to Euclidean distance rasters. Distance clipped to a user-defined cutoff radius, then inverted so proximity = high favourability.
  4. Geophysical / processed rasters — Existing raster datasets (e.g. magnetics, radiometrics) thresholded at the 95th percentile, vectorised, dissolved, and converted to a proximity raster.
  5. Constraints — Hard exclusion masks applied as binary overlays: attribute-based polygon filters, buffer zones, or slope thresholds. Constrained cells are zeroed out of the final model.
  6. Prospectivity model — All normalised evidence layers combined using WLC or OWA. User controls individual layer weights via interactive sliders; output is a continuous 0–1 prospectivity raster exported as GeoTIFF.
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