A spring is a water resource formed when the side of a hill, a valley bottom or other excavation intersects a flowing body of ground water at or below the local water table, below which the subsurface material is saturated with water. A spring is the result of an aquifer being filled to the point that the water overflows onto the land surface. They range in size from intermittent seeps, which flow only after much rain, to huge pools flowing hundreds of millions of gallons daily. Springs are usually at mean annual air temperatures. Spring water usually originates as rain or snow (meteoric water).
The bed rock that Mackinac Island is made of is limestone and Mackinac Breccia limestone. These rocks will fracture over time. Water then finds it's way into these fractures. The water is somewhat acidic and dissolves the limestone. As the water moves through the rock it may move closer to the bedrock's surface. Depending on the soil's depth the water may start to flow on top of the soil. This is the case at this earthcache. If you look closely at the source of the water you'll see that it comes from between a couple pieces of limestone. The soil around the spring has been washed away.
The spring at the posted waypoint is not that large. In fact, it's kind of small, but cute. I would like you to look at the actual point where the water comes to the surface. You should be able to see the limestone rock from which carries the water.
To claim your find please email your answers to the cache's owner by clicking here. Which will open a new email with the questions in the body. Just add your answers. Be carefull walking in this area as the ground can be water logged at times. Let's not leave our foot prints here.
1.) At N45 52.454 W84 38.235 The active spring. What is the elevation your GPS shows?
2.) From the table below, tell me the magnititude at which you feel the spring is flowing. There is no real way to capture the water and measure it directly so give me your best guess.
3.) At N45 52.439 W84 38.221 The inactive spring. What is the elevation your GPS shows?
| Magnitude |
Flow (ft³/s, gal/min, pint/min) |
Flow (L/s) |
| 1st Magnitude |
> 100 ft³/s |
2800 L/s |
| 2nd Magnitude |
10 to 100 ft³/s |
280 to 2800 L/s |
| 3rd Magnitude |
1 to 10 ft³/s |
28 to 280 L/s |
| 4th Magnitude |
100 US gal/min to 1 ft³/s (448 US gal/min) |
6.3 to 28 L/s |
| 5th Magnitude |
10 to 100 gal/min |
0.63 to 6.3 L/s |
| 6th Magnitude |
1 to 10 gal/min |
63 to 630 mL/s |
| 7th Magnitude |
1 pint to 1 gal/min |
8 to 63 mL/s |
| 8th Magnitude |
Less than 1 pint/min |
8 mL/s |
| 0 Magnitude |
no flow (sites of past/historic flow) |
None |
Not required but always a pleasure to see, please post your photographs too.
Click here to find out more info about the Mackinac State Historic Parks.