Graphite and vermiculite found under forest cover in southern Ontario
Fingerprint maps trained on six known outcrops pointed field crews to new graphite and vermiculite zones in terrain not known for either, confirmed by trenching in 2023 and 2024.
The challenge
A private explorer held claims in southern Ontario, where mature forest, wetlands and lakes cover most of the ground and neither graphite nor vermiculite had been a traditional target. Within a 10 km² focus area they had found four graphite and two vermiculite occurrences, and wanted to know where else to look across a much larger district.
Our approach
We surveyed 3,000 km² using ASTER thermal (LWIR) mineral mapping and Sentinel-2 shortwave (SWIR) data, choosing a November 2021 scene when the deciduous canopy was bare. The six known outcrops were used to train our predictive fingerprint models, which scored every pixel of the survey area for the same graphite and vermiculite signatures.
The result
Prospecting, sampling and trenching in 2023 and 2024 found significant new graphite and vermiculite zones at the locations the maps predicted. A 125 m graphite trench returned continuous mineralization, including 2.36% Cg over 30 m, within a zone interpreted at about 750 m by 300 m. A vermiculite trench averaged 16% vermiculite over 35 m, and every soil site and trench tested along the 5 km vermiculite target was mineralized, with coarse vermiculite up to 24%.
- NOV 2021Leaf-free satellite scene selected
- 2023Prospecting and first trenches
- 2024Trenching confirms both targets