Lake Erie Islands
Formed nearly 7,000-32,000 years ago, the Great Lakes of the
United States and Canada are the largest system of freshwater in
the world. Home to many species of wildlife, the Lake Erie Islands
have become one of the greatest scientific spectacles of all time,
scarred with many years of history.
During the Pleistocene Epoch, or the “Ice Age”,
temperatures on the Earth remained very low without warming trends
which allowed for massive amounts of snowfall. Over time, the snow
built up and created massive amounts of weight which compressed the
lower layers of snow into ice. These sheets of ice are known as
Glaciers. Some of the glaciers in this region were over 10,000 feet
thick!
During this time the glaciers pushed southward moving billions of
tons of soil and rock. The sheer power of this movements can been
seen all through the Erie Islands region including Kelley’s
Island, South Bass Island, and Marblehead via Glacial striations,
or more commonly known as glacial grooves. This southward push
created the depths of the great lakes, depositing the soil into
lower Ohio.
Following the Pleistocene Epoch, the region experienced a warming
trend that caused the glaciers to melt overtime, filling in these
carved depths as we now know as Lake Erie.
During geologic times, there was an uplifting of the earth which
created a raised area of land known as the Cincinnati Arch. This
uplifting affected the present day positioning of the islands. You
can see evidence of this in the island region by looking at the
types of rock found on the islands. There are two types of primary
rock found on the islands: older Dolomite and younger Limestone.
Dolomite will appear white in color for layers that are above the
water levels, and darker in color for areas that are washed by the
lake currents. Limestone will appear more sandy in color for areas
that are above water levels, and almost mud color for areas that
are at or below water level.
To gain credit for this Earthcache, you must perform and
answer the following items. Any logs posted without the following
tasks completed will be deleted by the cache owner. Please send
your answers to the Earthcache owner via email. Photos should be
posted on the Earthcache page. Please do not post your answers in
your log:
1.) Travel to the posted coordinates and take a photo of
yourself with your GPSr (or just your GPSr) showing the cliffs in
the background.
2.) Estimate the height of the cliff from the waters edge at the
highest point. You can easily judge this by using your height as a
reference.
3.) The cliffs in front of you are very old and showing signs of
erosion from wave action. Based on the research you have done
above, do you believe the rock formations in these cliffs are
primarily of older Dolomite or the younger Limestone, and how did
you come to this conclusion?
4.) Which glacier carved out Lake Erie and the Islands region? (A
quick search on the internet should be able to answer this question
easily)
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