LICHENS AND ROCKS - A REVIEW

Lichens, especially saxicolous (rock-inhabiting) lichens, are encounte red almost daily by the field geologist. Despite the difficulties in r eadily identifying lichens, there is increasing evidence that many spe cies have a preference for some rock types, and that certain species c an chemically modify their substrate. There is also increasing evidenc e that certain lichens, some of which change colour based on absorbed metal content, may make effective indicator plants in mineral explorat ion, particularly in areas such as the Northwest Territories.