The D platinum-chromite showing occurs at the confluence of Britton (Eagle) Creek with the Tulameen River, 10.5 kilometres west-southwest of the town of Tulameen.

This occurrence is hosted in the dunite-rich core of the Early Jurassic Tulameen Ultramafic Complex, a zoned Alaskan-type intrusive complex. Mineralization occurs in a serpentine breccia zone containing fragments of dunite/peridotite cemented by a matrix of serpentine. The zone is 180 metres long, up to 155 metres wide and lies mostly north of the river, on either side of the creek.

Chromite occurs in the breccia and the surrounding dunite in areas of stronger magnesium alteration, mostly along Britton Creek. The mineral forms irregular lenses up to 20 centimetres long and 10 centimetres wide, fracture fillings up to 2 centimetres wide and primary layers of magmatic origin up to 15 centimetres thick.

Platinum occurs in elevated values in the breccia and in the surrounding dunite/peridotite. Two samples from the breccia assayed 2.150 and 4.400 grams per tonne platinum (Assessment Report 17170, page 5). Values of up to 0.481 gram per tonne platinum occur west and south of the breccia zone, in peridotite with little visible chromite (Assessment Report 17170, Figure 3).

The breccia zone is noted to be practically free of sulphides (Assessment Report 17170), yet earlier reports suggest the presence of chalcopyrite and millerite. Magnetite, sperrylite and asbestos have also been reported in the past.

The showing was mapped and sampled by Imperial Metals Corporation, Newmont Exploration of Canada and Tiffany Resources between 1984 and 1987.