Transcript Apostle Islands National lakeshore

By Jack Gamble
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Sea Caves
Centuries of wave action, freezing, and thawing have sculpted
shorelines throughout Apostle Islands National Lakeshore. Some of
the Great Lakes' most spectacular scenery occurs where these forces
interact with sandstone of the Devils Island Formation to create sea
caves.
Ice caves
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By February, an ice bridge might connect Sand Island to the mainland.
The lake surface is usually a frozen white expanse. Lakeshore cliffs form
a crimson red border to this arctic landscape. Pillars of ice extend to the
cliff tops where waterfalls have hardened in place. Frozen lake water
encrusts the base of the cliffs. Inside the caves awaits a fairyland of
needlelike icicles. The formations change from chamber to chamber and
from day to day.
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Sand Scapes
More than mere beaches, sand scapes are a range of features from barren sand bars to
dune habitats that support plant and animal communities.
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Lake Superior Sandstone
This sandstone that is mostly red or brown in color comes primarily form the
Bayfield Group of sedimentary rocks that are found near Bayfield, Wisconsin
and on the Apostle Islands in Lake Superior. The bass Island Sandstone is
one example. the sandstone of choice in this group is mostly a red
feldspathic (has feldspar as a dominant mineral) sandstone deposited as the
final stage of the infilling if the Keweenaw Rift. It is presently considered to
be the last Precambrian event in Wisconsin which makes it about 1040
million years old.
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Athelstane and Amberg Granites
These granites come from nearby towns in northeastern Wisconsin, just south of the Michigan
border. They are similar in grain size, but the Amberg is more gray, whereas the Athelstane is
more pink. They both formed as intrusive bodies of rock that formed the core or subsurface of
volcanic islands some 1840-1890 million years ago, when northern Wisconsin looked more
like the Japanese Islands do today. These granites were a few of many granites quarried in
Wisconsin. In fact Red Granite is the State rock.
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Fire, air and water pollution, erosion, and storms are all issues, but they
change the land. Erosion destroys sandstone pillars that hold up caves. air
and water pollution weakens stone structures. And fire destroys forests, but
all of this changes the land, shaping the park.
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Solar panels are used
LED lighting is used
Compact fluorescents lights are used
Web sites used:
http://www.google.com/imgres?imgurl=http://www.reisenett.no/map_collection/National_parks/Apos_87.jpg&imgrefurl=http:
//www.reisenett.no/map_collection/National_parks/National_parks.html&usg=__BncXXzTzhV3wDdtAMaZSjSrTbt8=&h=144
1&w=1249&sz=283&hl=en&start=1&um=1&itbs=1&tbnid=ivDRow0tLVh6JM:&tbnh=150&tbnw=130&prev=/images%3Fq%
3Dtopographical%2BMap%2Bof%2BApostles%2Bisland%26um%3D1%26hl%3Den%26sa%3DG%26tbs%3Disch:1
http://www.nps.gov/apis/index.htm
http://en.wikipedia.org/wiki/Apostle_Islands
http://www.ohranger.com/apostleislands/geology