Jasper, agate, sardonyx and calcite crystals are reported to have been found on Sooke beaches. The area is underlain mainly by pillow basalt, breccia and tuff of the Tertiary (Eocene and older) Metchosin Volcanics. Intrusions of the coeval Sooke Gabbro cut the country rock. The stratigraphy in the area of the beach is overlain by deposits of sand, gravel, silt and clay of the Quaternary Capilano Sediments.