LEGEND SILURIAN 7 GUELPH FORMATION: dolomite 6 LOCKPORT FORMATION: dolomite 5 MANITOULIN FORMATION: dolomite. WINGFIELD FORMATION: shale. DYER BAY FORMATION: dolomite. CABOT HEAD FORMATION: shale ORDOVICIAN 4 KAGAWONG FORMATION: dolomitic limestone. WEKWEMIKONGSING FORMATION: shale with limestone interbeds 3 SHEGUIANDAH FORMATION: shale. COLLINGWOOD FORMATION: shale 2 TRENTON GROUP: limestone. BLACK RIVER GROUP: limestone, shale, sandstone PRECAMBRIAN 1 Not subdivided Gravel Road Geological boundary (defined, approximate, assumed) Structure contour on top of Trenton Group (interval 50 feet above and below sea-level) Well (location only) ••••••••••••••••••• Well (show of oil) ••••••••••••••••••• Well (show of gas) ••••••••••••••••••• Well (location uncertain) ••••••••••••••••••• Group of wells ••••••••••••••••••• Well number, referred to in Memoir. 72 Oil spring •••••••••••••••••• SOURCES OF INFORMATION Areal geology and structure contours by M. Y. Williams, 1935. Base-map prepared from published maps of the Department of Mines and Resources. Printed at the office of the Surveyor General and Chief, Hydrographic Service, Ottawa, 1938 N 46°00' P. Detour Channel Above Sea-level SEA-LEVEL Cockburn Island Polama Bay Ros 5 Thompson Pt. Below Sea-level 6 Magoay Boom Pt. 45° INTERNATIONAL BOUNDARY UN 83°30' 45°30' 85° Alberta R. James Rupert R. Moosonee Mistassini R. Mistassini 50° Hearst Nipissing R. Cochrane Amos Quebec L Rouyn ONTARIO Sudbury Manitoulin R. Lake Huron Haliburton Timiskaming North Bay Mont Launier Penbrooke Three Falls Hull C.P.S. Ottawa 85° Scale. 1 Inch to 200 Miles