Would a sink hole from a collapsed limestone cave work as an EarthCache?

[Nick - Cacher]

I am curious if something like this would be an appropriate earthcache? : There is a place called Peter Sinks. It's a collapsed limestone cave which creates a sink hole. Peter Sinks is famous for having the second lowest recorded temperature in the lower 48 states, being a sink hole up in the mountains it acts as a dam for cold air which sinks down into it during the winter and makes it super cold. Of course being an earthcache, I'd focus on the geology aspect of being a collapsed limestone cave. I just think it's interesting how geology also has an impact on the temperature.

 

Do you think something like this would be an appropriate EarthCache?

[+Carbon Hunter]

I am sure it would - check out, Tawi Atyar (Oman); Bapsfontein (South Africa) & Taiq (Oman) - sorry I am travelling so I can not provide the hyperlinks right now.

[+terratin]

Sounds like a good topic for an EC. I would only look if there's no similar EC in the neighborhood already.

 

Mrs. Terratin

[+GEO WALKER]

The next time I head out to visit family I plan on checking this one out, GC3MREV. Just a reminder keep it safe...

[BlueRajah]

Here is a photo of the sinks...

 

It is not a regular sinkhole and you cannot simply look at it and say that what it is.

 

You could have a few issues in your logging tasks. Trying to keep them on topic. Good luck

[Nick - Cacher]

Here is a photo of the sinks...

 

It is not a regular sinkhole and you cannot simply look at it and say that what it is.

 

You could have a few issues in your logging tasks. Trying to keep them on topic. Good luck

 

If proving they were at the sinkhole may be a problem: After having a cache page providing educational information about sinkholes and the particular type at Peter Sinks, I could have a multiple choice questionnaire, where I say although underneath used to be limestone caves, what type of rock is at the surface at a particular coordinate area, then list options A through F of various rock types. They have to email with the correct type. Then maybe it could be turned into a geology learning experience of stratification.

 

Another possibility I was thinking of for their logging task to prove they were actually there is to have them use their GPS to see at what elevation in this collapsed cave the treeline stops (since trees can't grow down in the sink hole), and then where the shrubs stop. They could either use their GPS elevation estimation all GPSr have regardless if they have an altimeter, or if they happen to have an altimeter to use that, or if they have a map with topo lines on their GPS they could use that.

 

I wonder if I could have them measure how far across the deeper collapsed hole is within the Peter Sinks, by measuring their GPS track distance. There are multiple smaller sink holes inside the Sinks Valley area.

[BlueRajah]

Altitude and measurements are pretty frowned upon because they are so easy to grab online. I can look at a satellite map, then switch to a topo and have the answer. Same with the "measure the distance from x to y.

[Nick - Cacher]

Altitude and measurements are pretty frowned upon because they are so easy to grab online. I can look at a satellite map, then switch to a topo and have the answer. Same with the "measure the distance from x to y.

 

What about the possibility of a multiple choice question asking about rock type, dealing with stratum? I went to Google Maps and it's not clear enough to see rocks from the satellite imagery.

Edited July 10, 2012 by Nick - Cacher

[+junglehair]

Altitude and measurements are pretty frowned upon because they are so easy to grab online. I can look at a satellite map, then switch to a topo and have the answer. Same with the "measure the distance from x to y.

 

What about the possibility of a multiple choice question asking about rock type, dealing with stratum? I went to Google Maps and it's not clear enough to see rocks from the satellite imagery.

 

To me, that would make your EarthCache about rock types rather than the sinkhole unless there is some correlation between the two. I'd prefer to see questions that directly relate to the topic. If there is debate about whether this is a sinkhole or not, you could have people examine a few things at the site and give their opinion on how the area formed and describe what they saw. What supports that theory? What doesn't?

[BlueRajah]

Digging through some geology maps... I was not convinced that this sink was caused by a limestone cavern. It is really big, and near the peaks of mountains.

 

I found a fault map of the area.

Peter Sinks by firennice, on Flickr

 

I think what you are looking at is a high altitude Graben and Horst

 

If you look at the photo you see the high mountain that is listed on the picture. There is a fault on both sides, that would be the Horst. The Sinks Have a fault on the East and West side. They are pulling apart and the sinks drop down into them. There are a ton of little east-west faults that are most likely caused by this being near where those two larger faults are pulling apart and their meeting just south of there. I do not believe there are many graben Earthcaches for a ways from there, so you might do it on that.

Edited July 13, 2012 by BlueRajah

[+terratin]

The geology seems to be limestone, thus a sinkhole is very well possible. It looks to be about 1x2.5km large, which is very large indeed. Maybe the elongated shape and the size are indeed related to faulting in the area such that water could penetrate the linestone more easily. Alternatively, the faults could have been sealing and the water had more difficulties leaving the area, thus leading to a large area of solution due to this. A map which really shows the hole relative to faults might be interesting!

 

Mrs. terratin