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 are corrected Data corrected Direction of axial direction of magnetization DuBois Duluth Gabbro east of NW Equal-area projection ft east ft north ft south ft west geologic dip geomagnetic field FIGURE Grand Portage Greenstone Flow intrusion in sec Ironwood Isle Royale Kearsarge 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 Minnesota nawan Nonesuch Shale north of Lake North Shore Volcanic North-seeking polarization Direction Ontario paleomagnetic data Portage Lake Lava present geomagnetic field quartzite remanent magnetization rhyolite intrusion sedimentary rocks Shore Volcanic Group Sibley Peninsula Sibley Series South Trap Range stratigraphic Strike Strike N upper Keweenawan west of NE