Mae On Cave, what is the geological explanation?

[LarryBird]

If you haven't been to the 'Tam Muang On' out in Mae On, it's a pretty cool adventure. It's just before the three way intersection for the San Kam Paeng Hot Springs..

I was just wondering if there are any geologists out there that could explain it in layman's terms if possible. And, also, is that what most of the mountains around here are like in the middle?

Thanks, LB.

[daoyai]

Karst off ya dirty spelunker.

[IMA_FARANG]

I don't know that cave.....but most caves are due to a vein of limestone or such rock and a nearby stream with slightly acidic water that over a long period of time erodes the limestone and gradually opens up the cave by eroding the limestone passage until a larger passage is opened that you can walk or crawl through.

That is a kind of Generic "How to make a cave" description with enough time to do it.

Edited September 6, 2015 by IMA_FARANG

[LarryBird]

Karst off ya dirty spelunker.

Number of people who will laugh or chuckle at that: 0.

Number of people who won't laugh: As many as view the thread.

Edit: sorry, I missed the pun. Definitely a little funny. Lol.

Edited September 6, 2015 by LarryBird

[cooked]

Karst off ya dirty spelunker.

Number of people who will laugh or chuckle at that: 0.

Number of people who won't laugh: As many as view the thread.

Edit: sorry, I missed the pun. Definitely a little funny. Lol.

I thought it was an unfunny joke.

[daoyai]

Karst off ya dirty spelunker.

Number of people who will laugh or chuckle at that: 0.

Number of people who won't laugh: As many as view the thread.

Edit: sorry, I missed the pun. Definitely a little funny. Lol.

I thought it was an unfunny joke.

More of a clue to google all about the karst geology of the region. .... than a joke.

[pgrahmm]

I'm still trying to figure out how a place with no snowfall or high country lakes/dams coupled with water shortages has so many actively free flowing high volume waterfalls....

But am betting the answers could be related.....

[richard_smith237]

This is a general explanation - without knowing the area:

Karstified Limestone - Caves are formed by erosion, the result of underground drainage.

The Calcium Carbonate in the Limestone dissolves into solution with (acidic) subsurface drainage water over millennia this forms caves and sinkholes.

Once the caves are formed the Calcium carbonate often precipitate out as Stalactites and Stalagmites (the tites come down, the mites go up !).

In similar Geological settings its likely there are other cave networks in the area.

[richard_smith237]

I'm still trying to figure out how a place with no snowfall or high country lakes/dams coupled with water shortages has so many actively free flowing high volume waterfalls....

But am betting the answers could be related.....

The erosion occurs over millions of years. A timescale almost incomprehensible to our human minds. These rocks can hold water for 10,000's of years.

Without looking any deeper into the subject (I'm guessing!) its possible that the Limestones of this area are Permian (Geological Age).

This Age Ranges from about 300 to 250 million years ago.

In Comparison - the Chicxulub Meteor resulting in the End of Cretaceous Mass Extinction event (which people will more commonly understand as the end of the Dinosaurs) occurred some 66 million years ago.

Edited September 6, 2015 by richard_smith237

[LarryBird]

Richard, have you been in the cave? Does your explanation explain the smooth surfaces? I understand limestone will tend to be smooth, but also the shape, it makes it look like there was a big bubble in there or something....

[richard_smith237]

Richard, have you been in the cave? Does your explanation explain the smooth surfaces? I understand limestone will tend to be smooth, but also the shape, it makes it look like there was a big bubble in there or something....

No, I've not been in the Cave - hence my explanation was more general.

If the surfaces are more rounded, you also mentioned a 'big bubble' shape to the cave its likely that the cave held water for many many years.

Edited September 6, 2015 by richard_smith237

[LarryBird]

Mr. Smith, thanks. Is it possible there was a gas that was emitted and trapped?

I have no experience with any other caves, so have nothing else to compare it too. Maybe I can venture into the one in Chiang Dao.

[richard_smith237]

Mr. Smith, thanks. Is it possible there was a gas that was emitted and trapped?

I have no experience with any other caves, so have nothing else to compare it too. Maybe I can venture into the one in Chiang Dao.

Yes, its possible that there could've been trapped Gas (hydrocarbon) in the Cave at some point in time.

All it takes is a source, a migration route and a trapping mechanism (its actually a lot more complex than that, but for the purposes of this discussion...)

That said - If there was any trapped gas at some point I'd very much doubt that it had any impact on the cave Geometry which I'd suggest is solely down to Ground Water Erosion over millions of years.

[Chicog]

It is possible that a large bubble of superheated gas formed under a molten layer, which then solidified.

But I think a geologist who knows the area would be best placed to tell you.

Apparently Chiang Mai is known for inferred PreCambrian rocks, there's even a map.

But most of it's gobbledegook to me.

http://www.dmr.go.th/ewtadmin/ewt/dmr_web/images/English/Precambrian.jpg

Edited September 6, 2015 by Chicog

[cooked]

Richard, have you been in the cave? Does your explanation explain the smooth surfaces? I understand limestone will tend to be smooth, but also the shape, it makes it look like there was a big bubble in there or something....

No, I've not been in the Cave - hence my explanation was more general.

If the surfaces are more rounded, you also mentioned a 'big bubble' shape to the cave its likely that the cave held water for many many years.

I am ready to be shot down in flames but rounded cavities in limestone are often (I thought always) formed by boulders that get transported down stream and get trapped, so just whirl around and around forming a nice round shape. Only happens during floods of course. Gas bubble? That was a joke question, right?

[LarryBird]

Richard, have you been in the cave? Does your explanation explain the smooth surfaces? I understand limestone will tend to be smooth, but also the shape, it makes it look like there was a big bubble in there or something....

No, I've not been in the Cave - hence my explanation was more general.

If the surfaces are more rounded, you also mentioned a 'big bubble' shape to the cave its likely that the cave held water for many many years.

I am ready to be shot down in flames but rounded cavities in limestone are often (I thought always) formed by boulders that get transported down stream and get trapped, so just whirl around and around forming a nice round shape. Only happens during floods of course. Gas bubble? That was a joke question, right?

Why would it be a joke?

And for further explanation this "cave" is actually more like a hollow mountain. It starts well above ground, and I am doubting there was ever much water at certain levels of it.

[richard_smith237]

Richard, have you been in the cave? Does your explanation explain the smooth surfaces? I understand limestone will tend to be smooth, but also the shape, it makes it look like there was a big bubble in there or something....

No, I've not been in the Cave - hence my explanation was more general.

If the surfaces are more rounded, you also mentioned a 'big bubble' shape to the cave its likely that the cave held water for many many years.

I am ready to be shot down in flames but rounded cavities in limestone are often (I thought always) formed by boulders that get transported down stream and get trapped, so just whirl around and around forming a nice round shape. Only happens during floods of course. Gas bubble? That was a joke question, right?

Both are possible - it would depend on the energy of the environment (i.e. volumes and speed of water flow).

Its likely that the Karstifed geometry originates from dissolution of rock minerals - perhaps once the caves have opened sufficiently 'storm' events generate a higher energy erosion.

Either way, both mineral dissolution and boulder transport would generate smooth sides - it could be argued that pretty much any type of erosion will create a smooth geometry.

[cooked]

Richard, have you been in the cave? Does your explanation explain the smooth surfaces? I understand limestone will tend to be smooth, but also the shape, it makes it look like there was a big bubble in there or something....

No, I've not been in the Cave - hence my explanation was more general.

If the surfaces are more rounded, you also mentioned a 'big bubble' shape to the cave its likely that the cave held water for many many years.

I am ready to be shot down in flames but rounded cavities in limestone are often (I thought always) formed by boulders that get transported down stream and get trapped, so just whirl around and around forming a nice round shape. Only happens during floods of course. Gas bubble? That was a joke question, right?

Why would it be a joke?

And for further explanation this "cave" is actually more like a hollow mountain. It starts well above ground, and I am doubting there was ever much water at certain levels of it.

So you envisage a bubble forming inside solid limestone? Or maybe in liquid limestone? I must have missed something, mind you I haven't touched a geology book since 1970.

[LarryBird]

Cooked, have you been to the cave?

[MESmith]

Richard, have you been in the cave? Does your explanation explain the smooth surfaces? I understand limestone will tend to be smooth, but also the shape, it makes it look like there was a big bubble in there or something....

No, I've not been in the Cave - hence my explanation was more general.

If the surfaces are more rounded, you also mentioned a 'big bubble' shape to the cave its likely that the cave held water for many many years.

I am ready to be shot down in flames but rounded cavities in limestone are often (I thought always) formed by boulders that get transported down stream and get trapped, so just whirl around and around forming a nice round shape. Only happens during floods of course. Gas bubble? That was a joke question, right?

Why would it be a joke?

And for further explanation this "cave" is actually more like a hollow mountain. It starts well above ground, and I am doubting there was ever much water at certain levels of it.

Do you really think the cave was always above ground level? Always a mountain? We're talking geology, not real estate developments

btw the first reply was spot on, very funny

Edited September 6, 2015 by MESmith