Minnesota's GeologyU of Minnesota Press, 1982 - 255 pages Have you ever wondered how the Mississippi River was formed? Or why shark teeth have been found in the Iron Range of the Upper Midwest? Towering mountain ranges, explosive volcanoes, expansive glaciers, and long-extinct forms of both land and sea life were an important part of Minnesota's ancient history. Today the evidence of this remarkable heritage is revealed in the state's rocky outcroppings, stony soils, and thousands of lakes. |
From inside the book
Results 1-5 of 91
Page 3
Sorry, this page's content is restricted.
Sorry, this page's content is restricted.
Page 4
Sorry, this page's content is restricted.
Sorry, this page's content is restricted.
Page 8
Sorry, this page's content is restricted.
Sorry, this page's content is restricted.
Page 10
Sorry, this page's content is restricted.
Sorry, this page's content is restricted.
Page 11
Sorry, this page's content is restricted.
Sorry, this page's content is restricted.
Contents
The Briefing | 3 |
Minnesotas Place in Geologic History | 15 |
Early Precambrian Time 4500 to 2500 Million Years Ago | 23 |
Middle Precambrian Time 2500 to 1600 Million Years Ago | 35 |
Late Precambrian Time 1600 to 600 Million Years Ago | 47 |
PostPrecambrian Time 600 to 2 Million Years Ago | 63 |
The Quaternary Period 2 Million Years Ago to the Present | 97 |
Metallic Minerals | 125 |
Nonmetals Fuels and Water | 151 |
Other editions - View all
Common terms and phrases
abundant basalt basin bedrock beds belts beneath Cambrian carbonate Chapter contain County Cretaceous Croix crust deposits dikes dolomite Duluth Complex earth eroded erosion exposed fault Figure Fond du Lac formed fossils G. B. Morey gabbro geologic map geologists Geology of Minnesota Glacial Lake Glacial Lake Duluth glaciers gneisses grains granite greenstone Highway iron iron-formation kilometers Lake Agassiz Lake Superior Lake Vermilion lava flows layers limestone Lower Precambrian mafic magma margins meltwater Mesabi Range metamorphic Middle Precambrian million years ago minerals mining Minnesota Geological Survey Minnesota River Mississippi River Moines Lobe Moraine nesota North America North Shore northeastern Minnesota Ordovician outcrops P. K. Sims Paleozoic Park Portage Precambrian Precambrian rocks quarry quartz Rainy Lake River Warren rock types rock units sand sandstone sedimentary rocks sediments shale Soudan streams Superior Lobe surface taconite thick Thomson Formation uranium Vermilion district volcanic rocks weathering Wisconsin zone