A study of the Slocan Series of South Eastern British Columbia along the three related paths of Lithology, Biology and Tectonics is made. The Lithotopes studied are mainly microscopic, though some megascopic characters are used to determine bottom conditions. The microscopic work was done on slides made from specimens taken at random on a cross-section of these sediments from near Zincton B.C. along the valleys of Seaton and Carpenter Creeks, to New Denver, B.C. The specimens indicated an increase of grain size and feldspar content from the bottom of the section towards the top. This is correlated with an increase in sediment supply and rate of subsidence. The fossils found by Cairnes show that these sediments were laid down in marine waters. A study of lithologic assemblages and types leads to some hypotheses. These, taken with a study of the Windermere geosynclinal assemblage, and theoretical considerations based on the orogenic cycle, allow a history of the area to be made. This history indicates that the Slocan Series, while the result of a separate downwarp of the crust, is probably part of the complex Purcell-Windermere geosynclinal sequence. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate