Every continent has a core of very ancient metamorphic rocks. The Superior Upland Province is the southern extension of the Laurentian Upland Province, part of the nucleus of North America called Canadian Shield. - USGS
Every continent has a core of very ancient metamorphic rocks. The Superior Upland Province is the southern extension of the Laurentian Upland Province, part of the nucleus of North America called Canadian Shield. - USGS
Place | AsNotedIn | Type |
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Place | AsNotedIn | Type |
Apostle Islands National Lakeshore | ||
Isle Royale National Park | ||
Voyageurs National Park |
Physiographic | Type | AsNotedIn |
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Laurentian Mountain System | Mountain System |
The Superior Upland of Wisconsin and Minnesota is the largest U.S. surface exposure of the ancient (2.6 to 1.6 billion years old) core of the North American continent, known geologically as the Canadian Shield. Even older rocks have been recognized in northwest Canada. Now an area of low topographic relief, these metamorphic rocks once themselves formed mountains- located at the margin of a continent, just as the Appalachian and Rocky Mountain ranges were in their turn. Some of these highly altered rocks have been important sources of iron, copper, and other industrial minerals. - USGS
Physiography | |
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Physiographic Region | Physiographic Province |