Historical Perspective
Mandy
Falls is a series of flat rocks, over which the water falls
- a beautiful, quiet place. The falls provide water for Trail of
Tears Cherokees that took shelter at Mantle Rock and other nearby
rock shelters as they waited the thawing of the Ohio River at Berry
Ferry. Forced to camp here for several weeks, many dies of
pneumonia from the exposure, lack of food, and insufficient
clothing. Some 250 or 300 people died here.
The falls got its name from Mandy Flanery, who legend goes, was
visiting her married sister in Louisville when the round up took
place, and later moved to southern Illinois and married a Mr.
Flanery. They moved to a house between Mantle Rock and the falls,
and reared their family. Almost nightly, after Mandy got her
work done, she would go to the falls, build a small fire, and keep
vigil all night. When morning came, she would return to the house
and take care of her family.
Geological
Perspective
Mandy
Falls is created by the flow from McGilligan Creek.
The falls has a unique classification. At first glance one
would think that it is Multi-step - A series of waterfalls one
after another of roughly the same size each with its own sunken
plunge pool. But look closer... at one point the fall is
Segmented – distinctly separate flows of water form as it
descends.
Few landforms showcase the power of water better than waterfalls.
Waterfalls provide us a look at local geology that is usually
hidden deep below millenia of rock. The majority of
waterfalls result from layers of rock composed of different degrees
of hardness. Hard layers are more resistant to erosion. Soft layers
are quickly removed. Waterfalls often become undercut as this
soft material is worn away. Eventually, the undercut becomes so
large that the weight of water on the unsupported layer will be
sufficient to collapse the layer and the "cliff" face moves
further up the valley. As long as the hardness differential
remains, the waterfall will persist.
Mandy Falls exposes the
geology of northwestern Livingston County and the Mantle Rock area
for our benefit. Several geological units exist in Livingston
County. But only a few exist in the area of Mandy Falls and Mantle
Rock. These include alluvium, terraced deposits, siltstone,
sandstone, and limestone. The main difference between these
three sedimentary rocks is their
grain
size. In the case of a limestone, it is a crystalline rock
so generally you can't even see the crystals. Limestone will bubble
when a dilute acid like vinegar is applied. The difference
between the other two is purely grain size. On the sandstone we are
dealing with sand size consituents, so you should be able to see
the actual grains. The sandstone will most likely have a rougher
texture when you feel it. With the siltstone, the grains of silt
are very small (probably not able to see them with the naked eye
that clearly), and it will have a pretty smooth texture when you
feel it.
Tasks:
Posted coords will lead you parking for
Mandy Falls. Be sure to pull completely off highway
133.
To get credit for this Earth
Cache:
A.
Visit the falls and email me the answers to the following
questions:
1) Using your GPS,
take an elevation reading between the upper fall and lower
pool.
2) Using the cross
section of for the Golgonda quandrangle and your elevation
readings, determine (by color and abbreviation) the primary
type of strata present at Mandy Falls.
3)
Based on your observations, does the entire waterfall
cut through this strata? If it cuts through other layers as well,
what evidence suggest that there is a difference in the rates of
erosion for these layer(s)? (Extra Credit: What might
this layer be?)
4) How many falls
and pools of water exist at Mandy Falls?
B. OPTIONAL but greatly appreciated: Post a picture
of yourself "in front of" the falls.
