The American Journal of Science, Band 250

absorption Ajibic basin bedrock beds biotite Bull Cambrian carbonate chemical Cherry Valley chert clastic conglomerate contains County crystal curve deposits depth diabase diagram dikes diorite district dolomite Dundas Harbour erosion evidence faunas feet figure fine-grained formation fossils geology glacial Glacier grains granite gray Guyot Horry clay Huronian igneous inches indicate iron Island Jour laccolith Lake lava layer limestone lower magnetite marine material microcline microns miles mineral moraine Mount Garibaldi Mountain Negaunee North occur orbicules peat pebbles pegmatite perthite plagioclase plants plate Pleistocene Pliocene poles pollen Precambrian present quartz monzonite quartzite radium radium content reef region ridges River rocks samples sand sandstone schist sedimentary sediments shale shonkinite shows silicate slope soil solubility solution species specimens stratigraphic structure surface syenite temperature thick tion tuff-breccia U. S. Geol uplift upper uranium volcanic weathering zone