Awesome photo

[bubba]

Check out this pic that Cumbrian Neil has just uploaded to the gallery - calcified miners tools in Bonne Terre Mine, Missouri, USA.

 

[SamT]

Wow - cool.

 

[Fred]

Excellent,

I remember being well impressed when seeing a calcified wooden ladder in cave in the Czech Republic - "Rudicke Propani" or something like that I think.

 

[Fred]

<Note to self>

Remember Google can be quite a useful search tool

</Note to self>

The cave was Rudicke Propadani - found a picture on a Moravian Karst site

Rudicke Propadani

IIRC this ladder is in a passage which bypasses a sumped section of the cave - the sump was also unique in my experience - never seen so many plastic bottles down a cave, the last 40m to the actual sump was carpeted in them.

 

[SamT]

thats amazing,

I remember being told (and indeed told other people in my role as a guide) in treak cliff cavern that the stal take 1600 years to grow one inch.

Now looking at those pictures I think it might be a little quicker

but of course I realise that it will vary with flow rates of water, solubility of the limestone etc etc.

 

[Cumbrian Neil]

The mine's name, Bonne Terre, means Good Earth... but my French sucks so correct me if I am wrong. The site was bought by a diving club from St Louis and has been developed into a tourist attraction. I was surprised at how quickly the calcification had occured as it was still mined in the 1900s. The owners have no respect for the huge flowstone and gour pools that exist... they actually allow tourists to touch many of the formations.

The website for the mine is - Bonne Terre Mine

CN.

 

[Dave H]

Now looking at those pictures I think it might be a little quicker

Come on! How many of you have seen stals hanging from concrete bridges and roofs?

In the 1980's I worked in an ex-secret service bunker (The Carpet Baggers HQ - then used as a potato store - now refurbished) built around 1940. The stals hadn't started to form until the bitumen on the roof had cracked (circa 1950's when the site was abandoned) In 30 years the lonest straws were between 8 and 9 inches long. Some of the stals on UK motorway bridges are long enough to easily see whilst driving.

 

[Stu]

thats amazing,

I remember being told (and indeed told other people in my role as a guide) in treak cliff cavern that the stal take 1600 years to grow one inch.

Now looking at those pictures I think it might be a little quicker

but of course I realise that it will vary with flow rates of water, solubility of the limestone etc etc.

It will depend, you're correct.

Classic case is Giant's. A lot of the rubble from the blast was placed further down the passages especially around Base Camp. This occurred during the '60's. It's firmly calcited in now.

 

[cap n chris]

Conservation tape gets "stalled" and stuck to certain surfaces in caves on Mendip in as little as three weeks.

It all depends on numerous factors, I suppose.

 

[SamT]

thinking about it - the ones in treak cliff - famous stalk and that - dont really drip very much. So could be right about varying times.

 

[Stu]

Water (I know obvious) and oxygen levels are what count. Opening up passage ways usually blocked can lead to increase rate of growth.

 

[Dave H]

Water (I know obvious) and oxygen levels are what count. Opening up passage ways usually blocked can lead to increase rate of growth.

So would be the concentration of calcium in the water, the availability of carbon dioxide, the evaporation co-efficient (hence your opened passage observation), and quite a few other variables.

For instance, take a cave under a limestone pavement, or very thin soils, like Swinstow or Simpsons in Yorkshire. Very little soils above = less nitrogen absorbed into the water (which now becomes very weak nitric acid) = less chemical erosion of the limestone = less calcium to come out of solution = less stall formation.
Or take St. Cuthberts or GB in the Mendips, where glaciation did not remove the soil and you get more profuse stal formation.
Or go to Jamaica under the tropical forests, where you will be lucky to see the roof for stal in many caves!

It's a very complex subject realy, but I will ask one question to the forum.
On flowstone and sometimes on stals you get micro-gours forming, and despite the angle of the slope they are forming on, the vertical period of the gours is predominantly 1cm. Why?

 

[Cumbrian Neil]

It is was strange in Bonne Terre because it was a lead mine... not a limestone cave.

CN.

 

[Dave H]

I thought that lead was what T'owd Man was looking for in so many caves?

 

[cap n chris]

Dave H asked:

On flowstone and sometimes on stals you get micro-gours forming, and despite the angle of the slope they are forming on, the vertical period of the gours is predominantly 1cm. Why?

Apart from the traditional explanation for gour growth, in 1993 Finlayson & Li claimed they were not necessarily initiated by roughness/irregularities but that surface tension at a water level caused calcite to crystallise at the water/air/rock interface. Therefore, they said, gours could develop on either rough or smooth surfaces and at all slope angles from horizontal (rimstone dams) to vertical, to even overhanging!

I can find no mention of periodicity and find your observation very interesting - obviously there are going to be exceptions that test your observation but nonetheless the only thing I can think of which may relate (with regard to microgours) is that the period is proportional to water droplet size/surface tension breakpoint in some regard. I shall look more closely next time I'm near some good examples.

 

[Mole]

It is was strange in Bonne Terre because it was a lead mine... not a limestone cave.

CN.

It means there's CaCO3 around there somewhere,either in the country rock,or as a gangue mineral in the vein,or in a crosscourse.

 

[mudmonkey]

Aren't most lead mines in limestone? Certainly there's lots on Mendip, Dales, Derbyshire etc.....

 

[Mole]

Lead mineralisation occurs in many types of rock,not just Limestone.
Non Limestone areas that spring to mind are Central Wales,parts of North Wales,the Lake District,Devon and Cornwall.

If there is Calcite present,and the conditions are right,stals can occur.
After all,a mine and a cave are just holes in the ground,but the cave is a lot older.

 

[Cumbrian Neil]

I'd never seen so much stal growth in any other mine I have been in. In fact, I can't recall ever seeing stal in the mines I explored in Cumbria. But there again, the only lead mine that comes to mind is the Plumbago Mine in Borrowdale.

As a side note - Bonne Terre used a Room and Pillar method of mining... one of the "pillars" was wrapped with cable because they used a wee bit too much bang. The ceilings are 60-70 feet high and the miners worked the ceiling by peeling huge chunks of rock/ore off it from catwalks they hung from the ceiling. Many of the miners quit working when they changed from carbide "stinkies" to Oldham style lamps because they could see how high up they were!

CN.

 

[Dave H]

Many of the miners quit working when they changed from carbide "stinkies" to Oldham style lamps because they could see how high up they were!