Named as a group in Keweenawan Supergroup. Named for town of Bergland, Ontonagon Co., northwestern MI (Upper Peninsula). Consists of Portage Lake Volcanics and Porcupine Volcanics (new). Group designation for this thick volcanic succession is consistent with what other workers have done with similar packages of volcanic units assigned to a group. Good exposures are abundant in type area north and northeast of Bergland, in T49N, R42W, where group is exposed in a north-facing monoclinal section about 9000 m thick. Upper contact is depositional surface at base of Copper Harbor Conglomerate. Basal contact is tectonic; Keweenaw fault forms south margin of Portage Lake Volcanics outcrop belt and juxtaposes the Portage Lake on the north side and younger Jacobsville Sandstone on the south. Report includes geologic map and correlation chart. Age is Middle Proterozoic.

Source: GNU records (USGS DDS-6; Reston GNULEX).