The New Springfield occurrence is situated east of Miller Creek, on the main road leading from Sandon to Wild Goose Basin. The underground workings are on the New Springfield Crown grant (Lot 5363). Development of the property began prior to 1900, and in 1902 the claim was Crown-granted to the Miller Creek Mining Company.
Workings consist of 4 adits, now mostly inaccessible. The Uppermost or No. 1 shaft opens on the left bank of Miller Creek, and the others on the opposite side. The best ore was found in a shoot extending from No. 2 level to the surface, a vertical distance of about 14 metres. This shoot had a maximum length of 30.4 metres and has been mostly stoped out above the level. Below the level a winze was sunk for 12 metres at the downward continuation of the orebody and is said to have encountered a much higher proportion of sphalerite than that from above the level. In 1957 the owner E.H. Paterson raised 3 metres in the west drift of this adit. Sorted ore from this work was sent to the Trail smelter.
The main or No. 3 adit crosses a lode 16.7 metres from the portal. Drifts follow this lode 15.2 metres to the southeast and 77.7 metres to the west where in both instances the drifts are caved. The last recorded work on this level was in 1947, when the adit was reopened. A small adit 8.2 metres above No.3 adit is 15.2 metres long and its face in vertically above the lower drift 9.1 metres west of the crosscut.
Regionally, the area lies on the western margin of the Kootenay Arc, in allochthonous rocks of the Quesnel Terrane. In the vicinity of the occurrence, the Quesnel Terrane is dominated by the Upper Triassic Slocan Group, a thick sequence of deformed and metamorphosed shale, argillite, siltstone, quartzite and minor limestone. Rocks of the Slocan Group are tightly and disharmonically folded. Early minor folds are tight to isoclinal with moderate east plunging, southeast inclined axial planes and younger folds are open, southwest plunging with subhorizontal axial planes. The sedimentary sequence has been regionally metamorphosed to lower greenschist facies.
South of the occurrence, the Slocan Group has been intruded by the Middle Jurassic Nelson intrusions which comprise at least six texturally and compositionally distinct phases ranging from diorite to lamprophyre. The most dominant phase is a medium to coarse grained potassium feldspar porphyritic granite. Several feldspar porphyritic granodiorite dikes, apparently related to the Nelson intrusions, also cut the sedimentary sequence near the occurrence (Paper 1989-5).
The occurrence consists of a fissure vein hosted by argillite and quartzite cut by a large sill of quartz porphyry. The strata generally strike north and dip 40 to 60 degrees east. The vein strikes 085 degrees, dips almost vertical and has been explored with at least four adits and a small shaft. Within the workings the vein averaged about 40 centimetres and was continuous for about 30 metres along strike and 15 metres updip. The vein is vertically zoned with galena being more abundant in the upper levels and sphalerite being the dominant sulphide in the lower levels of the mine. Gangue minerals are quartz and siderite.
Production from the New Springfield occurrence between 1897 and 1984 yielded 303,349 grams of silver, 48,792 kilograms of lead and 29,533 kilograms of zinc from 186 tonnes mined. See also Elkhorn (082FNW042).
