Wetlands are
one of the richest biological habitats on Earth. Unfortunately,
they have been viewed for centuries as a physical constraint to
most land uses and they have been drained in order for the land to
be used by the ever growing population. The eradication of wetlands
was a global phenomena, and in the United States, agriculture was
the primary reason for draining wetlands. The Celery Bog area
underwent this trend in the late 1800's when farmers installed a
tile drainage system to dry out the wetland so crops could be grown
in the rich peat soil.
A tract of farmland near the present-day marsh still illustrates
this stage in the Celery Bog's history. Due to difficulties in draining
the lower portions of the wetland, the current marsh formed after
the tile drain system was abandoned in the late 1960's. Without the
drainage system being operated, the water levels quickly rose in
the old wetland area to form our present-day Celery Bog.
Geology of the Celery Bog
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The geology of the
Cuppy-McClure Watershed was largely influenced by the movement of
glaciers through northwestern Indiana. The glaciers deposited
large amounts of till, which is a material composed of a mixture of
various types and sizes of rock fragments. The source of
these rock fragments can be from anywhere along the glaciers path,
and these rocks are broken into fragments by the crushing and
grinding of rocks and sediments in the glacier. There are
four known layers of till underlying the Celery Bog area: the Earl
Park till, the Snider till, the Plainfield till, and the Fairgrange
till (see cross-section below). These different layers correspond
to the advances and retreats made by the glaciers. Layers of sand
and gravel that were deposited by outwash from the glacier exist
between some of the till layers. These layers of outwash deposits
serve as aquifers, which are saturated layers of material that
store and transmit groundwater. The path by which water moves from
shallow, surface aquifers to the deep aquifer is not fully
understood; however, it is believed that sand and gravel pockets
within the tills provide pathways for water to move through the
subsurface.
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Hydrology of the Celery Bog
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The
Hydrologic Cycle around the Celery
Bog:
Water vapor moves through the atmosphere, some of it
condensing (turning to liquid water) to form clouds and
precipitation. When this precipitation reaches land surfaces in and
around the Celery Bog, the water can seep into the soil
(infiltration) or move across the surface (runoff).
Some of the water that infiltrates cannot travel down through the
underlying till (dense glacial sediments) layers, thus it
becomes shallow groundwater that helps keep the marsh
wet in the dry part of the year. However, some of the water
trickles through layers of till with intermingled lenses
of sand and gravel, and eventually the water reaches aquifers
(groundwater).
The water from the Celery Bog is a source for the Wabash (locally
known as Teays) River Valley Aquifer, which provides the water that
the City of West Lafayette and Purdue University utilize every day.
This is a relatively large aquifer that is 6 miles wide and between
200 to 300 feet deep. The water is drawn up from underground via
wellfields, and the aquifer has a capacity of about 18,000,000
gallons. As of 2001, the average amount of water drawn daily was a
little over 10,000,000 gallons. Aquifers have limits too -
and care needs to be taken in the surrounding watersheds to ensure
that both good water quantity and quality continues to feed the
aquifer, our main source of water.
Runoff
can
either travel to an area where it can pass through the soil, or it
enters a body of water such as a marsh (in our case, the
Celery Bog). Surface water can also travel back into the atmosphere
before it has a chance to enter the ground (evaporation).
Similarly, plants use water that infiltrates the soil and then
release some of the water into the atmosphere through a process
called transpiration. One single drop of water is recycled
constantly through the hydrologic cycle by
precipitation, runoff and/or infiltration, evaporation or
transpiration, and again by precipitation.
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The cache
co-ordinates will take you to the Lilly Nature Center at Celery Bog
and the “Who’s Watching Who” bronze sculpture
shown here:
The nature
center is open to the public without charge 10:00 am to 5:00 pm,
Wednesday through Saturday, and 1:00 pm to 5:00 pm on Sunday. It is
staffed by volunteers trained as “Master Naturalists”
to help visitors enjoy the center’s educational displays and
indoor bird and wildlife viewing area.
To get the
best views of the bog, you will need to do a little walking along
the Celery Bog Footpath, a 1 ½ mile network of
wood-mulched-trail-loops connecting the nature area to Lilly Nature
Center. The footpath provides many wildlife viewing opportunities
along the wetland and through the wooded area. Bluebird and bat
houses, waterfowl nesting structures, and two wildlife viewing
decks have been constructed in the nature area. The viewing decks
have become the favorite spots along the footpath to view birds,
frogs, turtles, and other wildlife. There are 5 interpretive
signboards to be found along those trails. To claim this earthcache as a
find, use the information provided by those signs to e-mail us the
answers to the following questions:
- How was the Celery Bog formed, that is, what
specific event or feature led to the formation of
this specific wetland?
- Based on your own observation as well as what
you can learn from the signage, which is cleaner – water
entering Celery Bog or water leaving it? Why is that so?
As
you’re walking the trails, keep your eyes open for what we
have dubbed “the cactus tree”.
(Information and diagram from Purdue
University Earth & Atmospheric Sciences web pages and Celery
Bog Nature Area fact sheet; pictures from Car54.)