Access to this
earthcache is from the Land Trust Parking Lot on
Bankhead Parkway. From there take the Alms House Trail to the
Wildflower trail, which leads right to the pump house. Some
hill climbing is required.
As a whole, Monte Sano’s history has been
formed by the flow of water. Years of erosion and the
underground water flow have left the
marks of time throughout the area. These marks are both
beautiful and fascinating, with opportunities for viewing
caves, fossils, rock formation, water falls, springs, and so
much more abound. The natural history of this mountain
has often intersected with our American history over the pass
250 years in many ways. The focus of this earthcache is to
look at this intersection at Fagan Cave and spring. A fuller
appreciation of this area can be found by hiking the Old
Railroad Bed Trail, which is not required for this cache, but
highly recommended.
“It is impossible to hike the Old Railroad
Bed Trail without a sense of awe. In the 1880’s, heavy
construction equipment consisted of dynamite, mule-drawn
wagons, picks, and shovels. As you clamber over quarried
rocks that once supported trestles you sense the permanence
of nature and the transience of human handiwork.
The two-mile path is a segment of the short-lived Monte Sano
Railroad that once carried guests to a mountaintop resort.
Maintained by the Land Trust of Huntsville and North Alabama, it
was one of the first 500 rail-trails in America Just fifty yards
into the old-growth forest, towering oaks and shagbark hickories
swallow you. It is hard to believe that you are within the city
limits, in spring and summer colorful wildflowers dot the ground.
In fall, the turning poplars and maples blaze golden on the slopes.
Streams gush over their ancient stone courses. Opportunities for
spiritual reawakening abound. The mountain is gradually reclaiming
its turf. In places the trail detours around the hillside’s
imperceptible march to the valley. The cuts and fills are blending
back into the terrain. The rough surface underfoot is often the
only reminder of the stone roadbed. This story has come full
circle. Rails disappear but their essence remains.”
The posted coordinates
will take you an old pump house built so the railroad could
pump water uphill 40’ to the rail lines. The engine stopped
here right near the cave before heading to Duggin’s Cut
nearby. Just uphill and upstream from the pump house is the
old storage tank. The top was left open so people could get
water from it. The local found their liquid refreshment here,
as did travelers. This was the last opportunity for such a
stop until Cold Spring off the old Toll Gate Road. Uphill and
upstream from the tank, is Fagan Cave. The headwaters of the
spring are flowing right out of the cave. Other
structures used to support the railroad with this spring are
in the area. Can you find them?
LOGGING REQUIREMENTS
You must do requirement #1 and any one of the
other logging requirements. Failure to do so will result in
your log being deleted. The logging requirements have been
updated on 12/8/07. All logs entered after 12/15/07,
must comply with the new requirements. Logs prior may comply
with either the new or old requirements.
1. Post a picture of yourself, with GPSr in hand with the pump
house, the tank or the cave and spring in the background. If you’re
good, you should be able to get a couple of those in a picture.
2. Locate another karst spring on Monte Sano. (Hint all the springs
on Monte Sano I know about are karst springs!) Post a
coordinate and a picture of the spring.
3. In your log, estimate the amount of water that flows through
here in one day. Include in your log how you arrived at your
estimation (NOTE: If you come on a day where the there is no
water flow, then this is not a viable option, so choose something
else. If water is not flowing through the pipe, you can work
with what is coming our of the spring!).
4. Include in your log where you think they pumped the water to
along the railway, by posting a coordinate and picture. What
is the difference in elevation between the pump house and your
location. (Hint: there is some nearby
evidence!)
5. Locate other evidence of
the karst aquafer, such as described below. Post a
coordinate and picture of this feature.
GEOLOGIC
BACKGROUND
Springs are hydrologic features. Maybe
you've visited some of the many cave springs on the mountain,
including Walker Springs, Arrow Springs (pictured below), and Cold
Springs to name a few. So, what's behind
these? Well, it's part of karst topology that typifies
the area. The area is blanketed with sink holes, caves,
and many other karst features. For an earthcache that
focuses on general karst features, checkout The Stone Cuts of
Monte Sano. The feature of focus here is cave
springs. Karst springs discharge water collected
by the many sink holes and sinking streams of the area, which
form succssively larger passages of increasing
flow.
Technical Definition of Karst
Aquifer:
A body of soluble rock that conducts water principally via enhanced
(conduit or tertiary) porosity formed by the dissolution of the
rock. The aquifers are commonly structured as a branching network
of tributary conduits, which connect together to drain a
groundwater basin and discharge to a perennial spring.
Dr. Steve Worthington, independent geologist, personal
communication, 2002
In many karst aquifers a large
percentage of the water stored underground is perched, or
suspended, above the main part of the aquifer in the "epikarst."
The epikarst ("upon the karst") is the interval between the mostly
unaltered bedrock and the topsoil. The water in the epikarst is
stored in enlarged joints and bedding planes, spaces around pieces
of float (rocks that have been detached from the bedrock), porosity
within residual chert rubble, and the smaller conduits in the
bedrock. Sinkholes are a reflection of the development of the
epikarst and are sites of active transport of insoluble sediment
and dissolved rock into the subsurface.
Karst springs occur where the
groundwater flow discharges from a conduit or cave. Karst springs
or "cave springs" can have large openings and discharge very large
volumes of water. The sinkholes and sinking streams that drain to a
large karst spring can be many miles away from the spring.
Frequently, groundwater flow rises to the surface from a completely
water-filled conduit. The depth of the clear water in the spring
pool gives the water a deep blue color so they are termed "blue
holes."
Spring distributaries are
branched conduits or caves that discharge groundwater to multiple
springs, commonly distributed along the bank of a short reach of
the receiving stream. They are quite common in karst systems and
were first described formally and scientifically from springs
discovered along the Green River near Mammoth Cave. As the water
flowing in the conduits nears a permanent surface-flowing stream
into which it discharges, the water seeks the lowest available exit
and is constantly creating new spring openings downstream. During
higher flows the intermittently abandoned openings, or "cave
springs," also discharge water. Along low-gradient streams, several
openings may develop almost simultaneously, resulting in many
springs draining a single groundwater basin.
For
more information on springs, hydrology, or karst(cave) springs,
check out these links!
1. Wikipedia on
Hydrology
2. Issaquah Creek
Valley Ground Water Advisory Committee notes on
Hydrology
3 Introduction
to Karst Groundwater