Soil
Bedrock on Isle Royale is basalt or sandstone and conglomerates on the 1100 million year old Midcontinent Rift. Most of the island is covered with a thin layer of glacial material. A number of small native copper mines were active in the 1800s but mining was never really prosperous. Recent analyses by the USGS of both unmineralized basalt and copper-mineralized rock show that a small amount of naturally-occurring mercury is associated with mineralization.
Read more about this topic: Isle Royale National Park
Famous quotes containing the word soil:
“An underground grower, blind and a common brown;
Got a misshapen look, it’s nudged where it could;
Simple as soil yet crowded as earth with all.”
—Richard Wilbur (b. 1921)
“Forever float that standard sheet!
Where breathes the foe but falls before us,
With Freedom’s soil beneath our feet,
And Freedom’s banner streaming o’er us!”
—Joseph Rodman Drake (1795–1820)
“This fair homestead has fallen to us, and how little have we done to improve it, how little have we cleared and hedged and ditched! We are too inclined to go hence to a “better land,” without lifting a finger, as our farmers are moving to the Ohio soil; but would it not be more heroic and faithful to till and redeem this New England soil of the world?”
—Henry David Thoreau (1817–1862)