 The 230‑million-year-old accreted oceanic plateau, Wrangellia in British Columbia and Yukon, has also been searched for nickel, copper, and platinum group metals.The kimberlite diatremes, or pipes, across Canada have also been important economically, because kimberlite magmas are the world's main source of gem-quality diamonds.Kimberlite pipes form when kimberlite magmas rise considerably from depths as great as .