[1] Pk Canada, Western Canada Serv Ctr, Vancouver, BC V6B 6B4, Canada
[2] Simon Fraser Univ, Sch Resource & Environm Management, Burnaby, BC V5A 1S6, Canada
[3] Simon Fraser Univ, Dept Biol Sci, Burnaby, BC V5A 1S6, Canada
[4] Simon Fraser Univ, Dept Earth Sci, Burnaby, BC V5A 1S6, Canada
[5] Geol Survey Canada, Vancouver, BC V6B 5J3, Canada