Mineral Exploration Beneath Temperate Forests: The Information Supplied by Tree

Exploration & Mining Geology, Vol. 4, No. 3, 1995

COLIN E. DUNN, Geological Survey of Canada, Ottawa, Ontario, Canada, K1A 0E

Plants have a remarkable ability to select, use and store metals derived from the substrate. Each species is unique in its requirements for and tolerances to the full spectrum of chemical elements in the Periodic Table. Studies to de?ne the chemical characteristics of common trees and shrubs of the temperate forest are providing insight to their use for exploration, i.e., biogeochemical exploration. Examples of surveys over gold deposits in British Columbia show the effectiveness of sampling various tissues from different species in a range of biogeoclimatic environments. At the Nickel Plate mine in the Montane-Spruce zone, outer bark of Lodgepole pine was effective in de?ning a large area of metal enrichment; at the Carolin mine in the zone of Coastal Mountain Hemlock, analysis of twigs of western hemlock and Paci?c silver ?r provided an exploration target considerably larger than that de?ned by lithogeochemistry; at the Mount Washington gold deposit in the Mountain Hemlock zone, twigs of mountain hemlock and rhododendron were used to outline the mineralization; and in the Interior Douglas-?r zone at the QR deposit analysis of Douglas-?r tops collected by helicopter provided a rapid and effective method of identifying a gold-rich area
Mots Clés: Exploration, Mineral exploration, Temperate Forests, Plants, Biogeochemical exploration