Geological Survey Professional Paper

Ashbed Flow axial dipole component Baraga County circle of confidence component of present Copper Harbor Copper Harbor Conglomerate corrected for geologic Data corrected Direction of axial direction of magnetization DuBois Duluth Gabbro east of NW emu/cm³ Equal-area projection ft east ft north ft south ft west geologic dip geomagnetic field FIGURE Grand Portage intrusion in sec Ironwood Isle Royale Kearsarge Kewee Keweenaw Peninsula Keweenawan lava flows Keweenawan rocks Lake Gogebic Lake Lava Series Lake Superior Lake Superior region lower hemisphere lower Keweenawan magnetization directions Marquette Range Supergroup Mean direction Mean of site-mean middle Keweenawan lava Minn nawan Nonesuch Shale north of Lake North Shore Volcanic North-seeking polarization Direction Ontario paleomagnetic data Portage Lake Lava present geomagnetic field Remanent intensity remanent magnetization rhyolite intrusion rock units sedimentary rocks Shore Volcanic Group Sibley Peninsula Sibley Series South Trap Range stratigraphic Strike U.S. Geological Survey upper Keweenawan west of NE