The area is underlain by Jurassic to Tertiary Coast Plutonic Complex rocks consisting of diorite and tonalite. The intrusives host roof pendants consisting of sedimentary and volcanic rocks. The sedimentary pendant rocks are commonly limestone containing numerous dykes. Sulphide mineralization occurs in skarn developed in the limestone near intrusive contacts.
The Florence deposit comprises an intensely sheared and brecci- ated, northwest trending crystalline limestone pendant within tona- lite. The pendant is generally 30 to 60 metres wide but locally is 106 metres wide and appears to be caught up in a fault zone striking 320 degrees. Banding in the limestone indicates a northerly strike with an 85 degree east dip. The limestone contains numerous mafic, felsic and tonalite dykes which are crosscutting and also conformable to bedding. Many of the dykes are located along shear zones and several terminate against faults. They contain varying amounts of pyrrhotite and pyrite with minor amounts of chalcopyrite. Epidote- garnet skarn is developed in the limestone at or near the intrusive dyke contacts and also within the intrusive rocks. Some large plugs or sill-like pipes of diorite are exposed underground in the main deposit zone and are mineralized with significant amounts of pyrite, pyrrhotite, chalcopyrite and minor sphalerite.
The skarn is usually a siliceous, epidote-garnet rich mass. The Florence deposit varies in width up to approximately 36 metres and is more than 152 metres long. Mineralization consists mainly of lenses and large pods of massive banded sphalerite ranging from a honey resin to black colour; bornite and chalcopyrite is disseminated or occurs as fine fracture-fillings. Disseminated sphalerite also occurs towards the flanks of the main deposit mass. Minor amounts of galena, tetrahedrite and native copper have also been observed. A grab sample from the adit assayed 32.87 per cent zinc, 9.26 per cent copper, 320.86 grams per tonne silver, 0.16 per cent cadmium and 0.68 grams per tonne gold (Assessment Report 4961).
Past work includes approximately 260 metres of underground development consisting of drifting and crosscutting. Numerous surface cuts and pits are also evident. Records indicate that 39 tonnes were mined in 1928 and a further 8 tonnes in 1935. From this a total of 6221 grams of silver, 2,149 kilograms of copper and 4,781 kilograms of zinc were produced.
