The listed coordinates will bring you to the entrance of Fox Ridge
State Park. In order to complete this Earthcache you will have to
visit six locations and do a little quick research. Though you do
NOT have to exit your car to acquire the necessary information I
urge you to go for a walk on one of the many walking trails. And
there are a couple of traditional caches in the area too!
The phenomena you will be searching for came into being during
the Late Wisconsinan period, which is the most recent part of
Pleistocene time, during which the latest continental ice sheet
covered most of northeastern Illinois (25,000 years ago, give or
take 10,000 years).
The two geological phenomena you will be introduced to are glacial
erratics and end moraines. A glacial erratic is a piece of
rock that deviates from the size and type of rock native to the
area in which it rests; the name "erratic" is based on the errant
location of these boulders. These rocks were carried to their
current locations by glacial ice, often over hundreds of miles.
Erratics can range in size from pebbles to large boulders such as
Big Rock (16,500 tons) in Alberta, Canada. An end
moraine is a ridge of unconsolidated debris deposited at the
end of the glacier. Glaciers act much like a conveyor belt carrying
debris from the top of the glacier to the bottom where it deposits
it in end moraines. End moraine size and shape is determined by
whether the glacier is advancing, receding or at equilibrium. The
longer the end of the glacier stays in one place the more
accumulation there will be. Got it?
Fox Ridge State Park is a great place to find erratics; they can
often be found along the walking trails in stream beds. The
erratics I want you to find, however, have been moved by park
personnel and are being used as markers and/or barriers. At each of
the four erratic stops you need to count how many erratics there
are within five yards.
Erratic 1 (Front of Ranger Station): N 39° 24.140 W 88°
08.239
Erratic 2 (Kile Field backstop): N 39° 24.206 W 88°
08.980
Erratic 3 (Small tree): N 39° 24.101 W 88°
09.554
Erratic 4 (No Parking Sign): N 39° 23.983 W 88°
09.274
Fox Ridge State Park exists because the Wisconsinan glacial
advance ended here. The end moraine -- called the Shelbyville end
moraine -- is a great example of this phenomena as there is such a
great elevation difference between the top and the bottom of the
end moraine. At the two moraine stops you need to take note of the
elevation.
Moraine 1 (Top): N 39° 23.791 W 88° 09.725
Moraine 2 (Bottom): N 39° 23.743 W 88° 09.726
To fulfill the requirements of this EarthCache post a photo in
your online log of you and/or your group in front of the largest
erratic you find, and email me both the total number of erratics
you found at the four erratic stops and the difference in elevation
between the two moraine stops. Please do NOT include the answers in
your online log.
For more information on EarthCaches please click here.
Enjoy your time at Fox Ridge State Park!
FTF HONORS GO TO
G..P.A.M.!!!
