Title: Revisions of stratigraphic nomenclature within the Keweenawan supergroup of northern Michigan
Subjects: Rhyolite, Stratigraphic Geology, Volcanic ash, tuff
Places: Bergland Group (Mich.), Copper Harbor Conglomerate (Mich.), Keweenaw Peninsula, Michigan, Porcupine Volcanics (Mich.), Portage Lake Volcanics (Mich.)
Time periods: Proterozoic