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:
“Ah! never shall the land forget
How gushed the life-blood of her brave—
Gushed, warm with hope and courage yet,
Upon the soil they fought to save.”
—William Cullen Bryant (1794–1878)
“Most subject is the fattest soil to weeds.”
—William Shakespeare (1564–1616)
“There will be mud on the carpet tonight
and blood in the gravy as well.
The wifebeater is out,
the childbeater is out
eating soil and drinking bullets from a cup.”
—Anne Sexton (1928–1974)