Open File Report LXXX Scenic Beauty of the Pre-Cambrian.............................13 Pre-Cambrian in Lower Michigan.................................14 GEOLOGY OF MICHIGAN X Paleozoic Era ..............................................................14 by Cambrian Period ..........................................................14 O. F. Poindexter The Michigan Basin ............................................... 14 Economic Products of the Cambrian..................... 15 1934 Formation, Sandstone, Shale, Limestone, Dolomite and Conglomerate ................................................. 15 Sandstone..................................................................15 TABLE OF CONTENTS Shale..........................................................................15 Limestone ..................................................................15 I Introduction and Acknowledgments ............................... 2 Dolomite.....................................................................15 Conglomerate.............................................................15 II Definition of Geology..................................................... 3 Scenic Effects of the Cambrian ............................. 15 III Origin of the Earth and Solar System .......................... 3 Ordovician Period.........................................................16 St. Peter Formation ............................................... 16 IV Composition of the Earth’s Core.................................. 4 Trenton Formation (Trenton-Black River).............. 16 V Composition of the Earth’s Crust.................................. 4 Economic Products of the Trenton.............................16 Cincinnatian Series................................................ 16 VI Minerals and Rocks ..................................................... 5 Economic Products of the Cincinnatian......................16 Minerals ......................................................................... 5 Silurian Period..............................................................17 Rocks............................................................................. 5 Niagaran Series..................................................... 17 Formation of Rocks and Minerals.................................. 5 Economic Products of the Niagaran...........................17 Niagaran Scenery ......................................................17 Igneous rocks...........................................................5 Salina Formation (Salt Beds) ................................ 18 Sedimentary rocks ...................................................5 Economic Products – Salt ..........................................18 Metamorphic rocks...................................................5 Origin of Salt ..............................................................18 Oldest Known Rocks ..................................................... 6 Monroe Group ....................................................... 18 VII Geologic Time Scale................................................... 6 Devonian Period...........................................................19 Correlation of Formations.............................................. 7 Sylvania Formation................................................ 19 Economic Importance............................................ 19 Unconformities............................................................... 7 Detroit River Formation (Upper Monroe)............... 19 VIII Branches of Geologic Study in Michigan................... 7 Economic Products of the Monroe Group ..................19 Discussion of Geologic Formations............................... 8 Salt.............................................................................19 Dundee Formation................................................. 20 IX The Pre-Cambrian ....................................................... 8 Economic Products ....................................................20 Archeozoic and Algonkian............................................. 8 Oil and Gas ................................................................20 Origin and Occurrence of Petroleum and Natural Laurentian Series .......................................................... 8 Gas ............................................................................20 Economic Products of the Archean............................... 8 Nature of the Occurrence of Oil and Gas ...................20 X Proterozoic (Algonkian) ................................................ 9 Brines and Mineral Waters.........................................21 Well Logs and Samples .............................................21 Huronian - Keweenawan Periods.................................. 9 Traverse Formation ............................................... 21 Lower Huronian ............................................................. 9 Economic Products of the Traverse ...........................21 Middle Huronian .......................................................... 10 Limestone ..............................................................21 Water Supplies.......................................................22 Upper Huronian ........................................................... 10 Oil and Gas ............................................................22 Presque Isle Granite.................................................... 10 Scenery in the Traverse .............................................22 Economic Products of the Huronian............................ 10 Antrim Formation ................................................... 22 Iron Ore..................................................................10 Economic Products of the Antrim Shale.....................23 Nature of the Ores .................................................11 Mississippian Period ....................................................23 Origin of the Ores...................................................11 Berea-Bedford Formations .................................... 23 Reserves of Iron Ore in Michigan ..........................11 Economic Products of the Berea-Bedford ..................23 Other Economic Products of the Huronian ............12 Oil and Gas ............................................................23 Brine.......................................................................23 Keweenawan Series.................................................... 12 Shale......................................................................23 Economic Products of the Keweenawan..................... 12 Coldwater-Sunbury Formation .............................. 23 Native Copper ........................................................12 Economic Products ....................................................24 Nature of Occurrence and Origin of the Copper Marshall Formation................................................ 24 Deposits .................................................................13 Economic Importance of the Marshall ........................24 Other Mineral Products of the Keweenawan .........13 Origin of the Marshall Brines......................................24 Life in the Pre-Cambrian.............................................. 13 Sandstone..................................................................24 Oil and Gas ................................................................25 Open File Report LXXX - Geology of Michigan – Page 1 of 35 Marshall Scenery........................................................25 Highest Point in State Grand Rapids Series ................................................... 25 Huron Mountains Michigan Formation ...............................................25 Bayport Formation .................................................25 Irish Coast Economic Products of the Grand Rapids Series ...25 Irish Hills Gypsum (Calcium Sulphate).......................................25 Limestone...................................................................25 Isle Royale Oil and Gas ................................................................25 Pennsylvanian Period.................................................. 25 Keweenaw Fault Saginaw Group ......................................................26 Mount Bohemia Grand River Group (Woodville forrnation) .............26 Permian Period............................................................ 26 Mount Horace Greeley Economic Products of the Pennsylvanian-Permian Mount Houghton Periods...................................................................26 Niagaran Escarpment Extent and Quality of Michigan Coals....................26 Shale......................................................................27 Ocqueoc Falls Sandstone..............................................................27 Water Supplies.......................................................27 Pictured Rocks Salt Brines..............................................................27 Point Aux Barques Pennsylvania Scenery ...........................................27 Porcupine Mountains XII Life of the Paleozoic ................................................. 27 Presque Isle Granite Evidences of Paleozoic Life in Michigan ..................... 27 Post-Paleozoic in Michigan ......................................... 28 Presque Isle Park Pleistocene Period....................................................... 28 Rabbit's Back Peak Centers of Accumulation of Ice ................................... 28 Rainy Falls Other Glacial Features ...............................................