The Tod Inlet deposits are located south of Brentwood Bay on the east shore of Saanich Inlet, 18 kilometres northwest of Victoria. Limestone was produced from three quarries in this area between 1905 and 1921.

The region is underlain by the Paleozoic Wark Gneiss and Lower Jurassic Bonanza Group volcanics which are intruded by granodiorite and quartz diorite of the Early to Middle Jurassic Island Plutonic Suite (formerly the Island Intrusions). The Wark Gneiss was formed, probably from mainly Sicker Group rocks, as a result of metamorphic events coeval with the emplacement of the Island Plutonic Suite. A discontinuous carbonate horizon extends from Cordova Bay northwestward across Saanich Inlet to the east shore of Shawnigan Lake, just south of Strathcona. Its generally fine-grained, massive character and its association with greenstones and magnetite-sulphide skarns suggests that this horizon is correlative with the Upper Triassic Quatsino Formation, Vancouver Group.

The Tod Inlet deposit comprises a series of limestone bodies, part of the carbonate horizon, that are up to 76 metres in width and 150 metres in length. The limestone bodies are arranged in an "en echelon" manner, hosted in greenstone and are intruded by mafic dykes. These bodies probably formed a single northwest trending limestone bed that was later repeatedly offset by a series of strike-slip faults. The limestone strikes 150 degrees and dips between 30 and 90 degrees southwest.

These bodies generally consist of fine-grained, dark bluish grey to white high calcium limestone. Small masses of magnesian limestone are reported from the number 2 and 3 quarries. A well developed joint pattern strikes northwest parallel to the formation and dips 70 degrees southwest. Limestone in the number three quarry is extensively fractured and veined with white calcite. An average analysis of the purer limestones from the numbers 1 and 2 quarries contained 97.5 per cent CaCO3, 1.1 per cent SiO2, 0.8 per cent Fe2O3 and a trace of MgO (Geological Survey of Canada Memoir 13, page 62). A 15-metre chip sample across the north end of the number 3 quarry contained 54.07 per cent CaO, 0.58 per cent MgO, 1.42 per cent SiO2, 0.21 per cent Al2O3, 0.31 per cent Fe2O3, and 0.02 per cent sulphur (CANMET Report 811, page 142, Sample 5).

Approximately 836,971 tonnes of limestone were produced from the 3 quarries between 1905 and 1921. The numbers 1 and 2 quarries, located next to the plant on Tod Inlet, were largely exhausted. The Butchart Gardens presently encompass this site. The number 3 quarry was situated 1.1 kilometres east of the plant.

On the west shore of Tod Inlet a 6 to 30 metre thick high calcium limestone bed striking 150 degrees for at least 46 metres and dipping 30 to 35 degrees west remains undeveloped.