Sandstone uplift EarthCache

This earthcache is put together at the request of the Missouri Department of Conservation, this is also my 90^th earthcache. This earthcache is designed to be a fairly simple one to complete with only a couple questions. Most of the area geology lesson is in the write up. This area was pointed out to me by Kevin Hedgpeth of the Missouri Department of Conservation, a wildlife management biologist and the areas land manager.

*** Be safe ***

1. Make sure you wear hunter orange during the hunting seasons CLICK HERE
2. Do be careful around the sinkholes and don’t enter them.

Geology:

This area is a small “strip” sandstone glade that was created from three different sources. First the uplift in the sandstone, second because of this uplift within the sandstone it has created a steep enough grade that dirt has a hard time accumulating and thirdly human activity of clear-cutting for the power lines has permanently made this little “strip” into a glade area.

Because this area is now a glade area, it allows us to see the underlying rocks and some of the “filtration system” and “plumbing” that the earth does on a daily bases. Missouri is loaded with caves and more are being created daily, while this GPS location does not have a developed cave, it is making one. This conservation area does have a developed cave system on its property to the south of here, see GC5HXQ1.

The sinkhole:

At the posted coordinates you will observe a sinkhole within the bottom part of the sandstone uplift. This sinkhole is fenced off for your safety, so don’t cross it. As you look into the sinkhole do you notice any water in the bottom? Where do you think this water is coming from, if there is any water at the time of your visit? Do you see any spilling over the edge of the sinkhole into the bottom? Or is the water coming from uphill somewhere? The answer is the majority of the water is coming from somewhere uphill. While yes on rainy days there can be water flow going over the edge, but the majority of the water is coming from uphill. This means that there is a cave tunnel, probably very small, that meanders its way under the rock up the hill.

Erosion:

Now just a little bit downhill you will find an outflow of water. This is connected to the sinkhole and the forming cave system above. Caves depend on water to “live” without water caves dry up and no longer continue to grow bigger. On a good day this cave system is growing, “fast” in geological time that is, and on a dry spell this cave system stops growing. I hope that you get to see this earthcache while water is flowing through it. One thing that I noticed when I was on site was the amount of flow going through the sinkhole was considerably less than the outflow amount. This could mean a couple of things. One the sinkhole is deeper than you think and the collapsed cave roof material is obstructing the view. Or two there is multiple cave tunnels all culminating at the outflow area.

Glade Erosion:

Glades develop because of different reasons most are natural and some are caused because of humans. This glade “strip” is caused primary because of human causes. I say “primarily” because if the land was a flat forest and humans clear-cut the forest for power lines; trees would grow back because the soil would stay in place. However because of most likely an earthquake millions of years ago, this area has a steep uplift region. It is because of this uplift and the actions of clear-cutting years ago that has created this glade area. Once the trees were gone there was nothing left that would trap the dirt in place for new trees to grow. When it rained “sheet erosion” was started and with the steep grade it would not have taken long to create this glade you see today.

**Logging requirements**
DO NOT POST ANSWERS IN YOUR LOG.
Send the following answers to me via email.

1. The text "GC5KZJ8 Sandstone uplift" on the first line
2. How deep is the sinkhole?
3. Take elevation readings at both “Glade Rock” waypoints now find the “grade” percentage of this glade, what is it?

Math Help:

When calculating elevation grade percentage, it is important to ensure that vertical distance and horizontal distance are measured in the same units. For example, if an incline rose 70 meters vertically over 700 meters of horizontal distance, then its grade percentage would be (70 meters/700 meters)*100% = 70 percent grade.