What is an Artesian Well?
Firstly, artesian groundwater is the same as any other type of groundwater the only difference is how it gets to the surface. An artesian well is simply a well that doesn’t require a pump to bring water to the surface; this occurs when there is enough pressure in the aquifer. The pressure forces the water to the surface without any sort of assistance. Chemically and physically, artesian groundwater is not different than other groundwater, but it comes to the surface differently. Perhaps your drinking water from a well that taps an aquifer that is "confined". This aquifer is water-bearing rock (the pores and cracks between rock particles are filled with water) that is surrounded by other rock or material that does not allow water to pass through. So, the water in this aquifer is squeezed by the other rocks, creating pressure in the water-bearing aquifer. When an artesian aquifer is tapped by a well the pressure pushes the water up the well, sometimes all the way to the surface, creating a flowing well. Imagine it as a very wet sponge contained in a closed plastic bag. Put a straw through the bag into the sponge, hold the bag tightly around the straw, and SQUEEZE - that would be artesian water squirting you in the face.
Where did Artesian Wells Originate?
The first Artesian well on record was drilled in 1126 by a group of Monks in the French province of Artois, hence the name Artesian well.
Back then they didn’t have the luxury of a fully operation drilling rig like we use today and the aquifer was reached by brute force and a sharp rod known as a bore. The percussive drilling technique they used eventually broke through the rock and the water rose to the surface. Because it had seeped through many layers of porous rock in the aquifer many of the contaminants had been filtered out, providing a much safer and cleaner form of drinking water when compared with surface or river water.
An aquifer is a geologic layer of permeable and porous rock such as sandstone or limestone and that provides the water source for the artesian well. The aquifer absorbs and stores water and in an artesian well the porous stone is sandwiched between a top and bottom layer of impermeable rock such as shale or clay. This causes positive pressure.
This Healing Fountain is located at point where groundwater flows out of the ground, and is thus where the aquifer surface meets the ground surface. A Man-made pipe has been inserted in the aquifer to help bring that water up in a controlled way so that visitor may drink some or take some with them. This unique Fountain Is said to have an added spiritual healing from the Guardian Angle
Dependent upon the constancy of the water source for this spring (rainfall or snowmelt that infiltrates the earth), it might be considered ephemeral (intermittent) or perennial (continuous).
Water issuing from the spring rises to a higher elevation than the top of the confined aquifer from which it issues. When water issues from the ground it may form into a pool or flow downhill, in surface streams. Sometimes a spring is termed a seep.
Minerals typically become dissolved in the water as it moves through the underground rocks. This may give the water flavor and even carbon dioxide bubbles, depending upon the nature of the geology through which it passes. This is why spring water is often bottled and sold as mineral water, although the term is often the subject of deceptive advertising. Springs that contain significant amounts of minerals are sometimes called 'mineral springs'. Springs that contain large amounts of dissolved sodium salts, mostly sodium carbonate, are called 'soda springs'. Many resorts have developed around mineral springs known as spa towns. But in the case of this spring, there is no significant minerals present. That is why the water has no taste or smell of any kind.
How are springs formed?
Springs may be formed in any sort of rock. Small ones are found in many places. In North Carolina, the largest springs are formed in limestone and dolomite in the karst topography of the region. Both dolomite and limestone fracture relatively easily. When weak carbonic acid (formed by rainwater percolating through organic matter in the soil) enters these fractures it dissolves bedrock. When it reaches a horizontal crack or a layer of non-dissolving rock such as sandstone or shale, it begins to cut sideways, forming an underground stream. As the process continues, the water hollows out more rock, eventually admitting an airspace, at which point the spring stream can be considered a cave. This process is supposed to take tens to hundreds of thousands of years to complete.
This Spring in particular flows through the native limestone, a sedimentary rock composed of calcium carbonate and is a rock of marine origin derived from the lime mud and ooze that accumulated on calm, shallow sea floors millions of years ago.
Water flow from springs
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 spring.
The scale of magnitude is as follows:
0 Magnitude - no flow (sites of past/historic flow)
1st Magnitude - > 100 cubic feet per second (cfs)
2nd Magnitude - 10 -100 cfs
3rd Magnitude - 1 ? 10 cfs
4th Magnitude - 100 gal/min (gallons per minute) - 1 cfs (448 gal/min)
5th Magnitude - 10 to 100 gal/min
6th Magnitude - 1 to 10 gal/min
7th Magnitude - 1 pint to 1 gal/min
8th Magnitude - Less than 1 pint/min
In order to claim this EarthCache, (WITHOUT REVEALING THE ANSWERS IN YOUR LOG). You must submit a picture of yourself at the EarthCache and email me with the answers to these questions:
1) What is the magnitude of this spring?
2) Is this spring ephemeral (intermittent) or perennial (continuous)?
3) There is a plaque at the sorce. What book is the reading on this plaque from?
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