Characterization of Lower and Middle Pleistocene tephra beds in the southern plains of western Canada

Wellsch Valley tephra, near Swift Current, southwestern Saskatchewan, and Galt Island Medicine Hat, southeastern Alberta, have been referenced in the literature since 1970s, but little is available on their physical chemical attributes – necessary information if they are to be recognized elsewhere. This study seeks remedy this situation. Both a calc-alkaline rhyolitic composition with hornblende, biotite, plagioclase, pyroxene, Fe-Ti oxides being dominant. They similar not same. tephra has glass fission-track age of 0.75 ± 0.05 Ma, reversed magnetic polarity, was deposited at close Matuyama Chron. an 0.49 normal during early Brunhes Rich fossil vertebrate faunas occur sediments them. Major- trace-element concentrations shards indicate source Cascade Range Pacific Northwest, USA, differences ratios suggest consanguineous.