Lakehead University Geology - Journal Yearbook (Thunder Bay, Ontario Canada)

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Modern mining exploration requires more than a pick and a pan Cominco offers world markets an increasingly diversified product range which requires the successful development of new sources of metals and industrial minerals. Extensive and aggressive exploration is required to meet future needs and replace the ore which Cominco is currently mining at approximately seven million tons each year. To accomplish this Cominco spends several million dollars annually in exploration programs in Canada, the United States and overseas. ENplorabion TCommco 34

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Roy Shegelski Experience: Economic Geology Limnology - 1969-70 Canada Centre for Inland Waters GENERAL STRATIGRAPHY AND Fe Mn BEARING BEDS OF THE SEDIMENTS OF THUNDER BAY, LAKE SUPERIOR R. J. Shegelski In the summer of 1970, a reconnaissance survey was done of the bottom sediments of Thunder Bay. This was generally done with a Boston Whaler using a Phleger corer and a Ponar grab sampler and 147 sample points were done in this manner. Three sonar traverses were also made in the Bay. Samples were brought back to the laboratory for analysis. Cores were split and lithologies were recorded. Samples from cores were analysed by x-ray diffractometer, thin and polished sections were made of various parts and certain layers were analysed for iron and manganese. Results of analyses indicate that the sediments in Thunder Bay can be divided into five categories. (1) Varved Clay. (2) Weathered Varved Clay. (3) Intermediate Clay. (4) Upper Deltaic Sediment. (5) Upper Trough Sediment. Through correlation of the cores and sonar runs, the stratigraphy has been established as such. The Varved Clay is the oldest, the Weathered and Intermediate Clays are the second oldest and the Upper Sediments are the youngest and over- lies the previous types. An areal distribution is shown in the accompanying map. Results of the iron and manganese analyses indicate that the Upper Sediments contain anomalously high concentrations of iron and manganese. It has been proposed that upward migration of connate waters rich in iron and manganese has produced highly concentrated layers of iron and manganese near the top of the Upper Sediments. The proposed mechanisms of concentration are precipitation, burial subsequent resolution and upward migration causing redeposition at an appropriate Eh, (pH) interface. CONGRATULATIONS AND BEST WISHES to the Graduates M. W. Bartley Associates Ltd. Geologists 204 Toronto - Dominion Bank Bldg. Thunder Bay, Ontario 36