The Poly property is underlain by the west-northwest striking, north to northeast dipping Sediment-Sill Unit of the Paleozoic Sicker Group. The succession of interbedded chert, cherty tuff, siltstone argillite and slaty argillite interbedded with tuffwacke is intruded by locally 'flower porphyritic' diabasic sills compositionally similar to Karmutsen Formation basalts. These rocks are unconformably overlain by conglomerates and shales of the Upper Cretaceous Nanaimo Group. A manganese-oxide showing occurs in bedded cherts and a crosscutting quartz vein. At this location very light pink and green rhodonite lenses occur.