Hydrogeology (hydro-meaning water and geology-meaning the study of
the Earth) is an area of geology that deals with the movement and
distribution of groundwater within the rocks of the Earth’s
crust such as in aquifers.
An aquifer is an underground layer of water-bearing permeable rock
or unconsolidated materials such as gravel, clay, silt or sand,
from which groundwater is contained and transmitted.
Groundwater makes up about twenty percent of the Earth’s
fresh water supply. Groundwater is water located beneath the ground
surface in voids or fractures of underground layers of rock. A unit
of rock or an unconsolidated deposit is called an aquifer when it
can yield a usable quantity of water The depth at which fractures
and voids in rock become completely saturated with water is called
the water table. Groundwater is naturally replenished by surface
water from streams, rivers and precipitation and eventually flows
to the surface naturally when it reaches the water table. This
natural discharge often results in springs.
A spring is any natural occurrence where water flows onto the
surface of the earth from groundwater contained below the surface
of the Earth, basically where an aquifer surface meets the ground
surface.
The amount of water that flows from springs depends on many
factors, including the size of the caverns within the rocks, the
water pressure in the aquifer, the size of the spring basin, and
the amount of rainfall. Human activities also can influence the
volume of water that discharges from a spring, ground-water
withdrawals in an area may reduce the pressure in an aquifer,
causing water levels in the aquifer system to drop and ultimately
decreasing the flow from the stream.
Springs are classified by the volume of the water they discharge.
The largest springs are called "first-magnitude," defined as
springs that discharge water at a rate of at least 100 cubic feet
of water per second, down to eighth magnitude where less than one
pint per minute flows. Zero magnitude is reserved for past sites
with no current flow.
1st Magnitude - > 100 cubic feet per second
2nd Magnitude - 10 -100 cubic feet per second
3rd Magnitude - 1 - 10 cubic feet per second
4th Magnitude - 100 gallons per minute – 1 cubic feet per
second
5th Magnitude - 10 to 100 gallons per minute
6th Magnitude - 1 to 10 gallons per minute
7th Magnitude - 1 pint per minute to gallons per minute
8th Magnitude - Less than 1 pint per minute
0 Magnitude - no flow (sites of past/historic flow)
Magnolia Springs is a natural spring where you can witness
hydrogeology and view the beauty that results when the groundwater
of an underground aquifer meets the surface of the Earth.
Magnolia Springs State Park is a 1071 acre park located near
Millen, Georgia. The park has a unique history. It was known as
Camp Lawton during the Civil War, at which time it was used as a
prison. The park still houses remnants of the ten-thousand prisoner
camp. The park also offers wildlife viewing and recreational
opportunities. There is also a newly remodeled freshwater aquarium
($1.00 admission fee.) However, the cool spring is the most
important part of the park. The spring is so important that the
park and the nearby town of Millen may have never developed without
the spring. In inland areas a viable water source is vital to
sustain the population and development. The posted coordinates for
this earthcache lead you to a beautiful spot about 20 feet from
this most important park feature.
Magnolia Springs is situated below the fall line (which separates
Georgia’s upland region from the coastal plain), where the
spring flows from an underground aquifer through an area mostly
comprised of limestone, a sedimentary rock composed of calcium
carbonate, riddled with sinkholes. Most of the water from the
spring is naturally delivered from a great depth, which results in
water with an average temperature of 72 degrees Fahrenheit
throughout the year. Millions of years of geology and hydrogeology
have resulted in the beautiful natural springs you see here today.
The park is open daily from 7:00 AM to 10:00 PM. The park office is
open from 8:00 AM to 5:00 PM.
In order to prove your visit and show that you have learned an
“earth lesson,” you will need to email answers to the
following questions to me and upload a photo with your “found
it” log.
1. What is the magnitude classification of Magnolia Springs? (The
posted sign will help you figure this out. A bit of math will be
needed.)
2. From what aquifer does the spring flow?
3. How deep is Magnolia Springs from limestone bedrock to surface
water? (No need to measure, see the sign.)
4. From what depth is most of the water delivered?
5. What color is the water of Magnolia Springs?
6. What wildlife do you see at the time of your visit?
(You’ll definitely see wildlife here.)
As always, a photo of you with your gpsr is appreciated as proof of
your visit. If you have the ability to take and download a photo,
please do so. If, however, you do not have this ability, don't let
that prevent you from visiting the park, learning a bit about its
geology and logging this earthcache.
I hope you enjoyed your visit. Remember to always practice Leave No
Trace Outdoor Ethics and Cache In Trash Out.
Congratulations to tombstone1, Ollie46, British Hummnbyrde
(and two little Byrdes) and Cach'n Chria for being the First to
Find.