Ontario occurrences of float, placer gold and other heavy minerals / Месторождения плавучего, россыпного золота и других тяжелых минералов в провинции Онтарио

Mineral exploration has long been an active pursuit of both individuals and mining companies in Ontario. In recent years there has been a resurgence of interest in prospecting by individuals as a full time occupation, but more especially as “weekend prospectors’’. Accordingly, it was thought appropriate to collect together the reported instances of mineralized fragments dislodged from their bedrock source so that the techniques of tracing such fragments to their source as well as the locations of known fragments would be available to those interested in mineral exploration. 
Loose pieces of rock or vein materials that have been separated from the bedrock by weathering and erosion are called ‘float’ and if the material has been transported and deposited by glacial action the float boulders generally occur in ‘till’ of ‘glacial drift’. Glacial erosion of ore deposits that in most cases have been deeply weathered by a long, previous erosion cycle produces a train of fragments ranging in size from boulders to clay-sized particles. An age-old method of prospecting, that has been used since mining first began, has been tracing mineralized float, in order to locate the bedrock source of the mineralization. Recently the concept has been expanded to include all size fractions and to include geochemical determinations of the content of metal ions adsorbed to the surfaces of silt and clay particles. This broadening of the exploration technique has resulted in a renewed interest in float boulders as the possible starting point of an exploration program. <...>