UKC

We went for a walk near Buxton, and not far from the Health and Safety Laboratories we saw a large pool with a stream running from it. The edges of the stream were encrusted in limestone, and the water beautifully clear.

Does anyone know anything about it? Is it natural, or part of some industrial process?

In reply to Submit to Gravity:

Was the stream running out from underground? There's a lot of old lime manufacturing waste in the area - this can generate a high pH groundwater underground with Ca and OH ions in solution. Once the water is in contact with CO2 in the air the Ca precipitates out as CaCO3. Could have been that or it could be something else entirely...

In reply to Pagan:

This pond:

https://www.flickr.com/photos/30701804@N03/13915320302/in/photostream/

led into this stream:

https://www.flickr.com/photos/30701804@N03/13915304012/

In reply to Submit to Gravity:

Is that just off the A515 near Harpur Hill?

In reply to Clarence:

It's near Harpur Hill, yes. Not sure which road.

In reply to Submit to Gravity:

Just got it on Google Earth, just off Grinlow Road. That whole area has been quarried and used for making cement. It is not far from the infamous Blue Lagoon which has a ph level of 11.4 which would be unpleasant to swim in apparently. Almost certainly the legacy of previous industrial processing.

In reply to Submit to Gravity:

Definitely looks like the situation I described above - the water looks to be running from beneath the waste heaps at the back (and sides) of your first photo into the pond before flowing out. It's hard to tell exactly but there look to be tufa deposits in the pond too - you'd expect that.

In reply to Clarence:

My bloody dog was drinking it! She should have strong bones now...

In reply to Pagan:

Thanks - I wondered if it was a deliberate way of precipitating out the lime. It's certainly effective. I've never seen anything like it before.

In reply to Submit to Gravity:

You see that type of calcite deposit all the time in caves around the Peak, which is a naturally ocurring process.

In reply to Submit to Gravity:

A nice pic of the lime kilns being used over a century ago at the top of this page

http://www.brocross.com/industrial%20history/derbyshire%20limekilns/derbysh...

In reply to Submit to Gravity:

Definitely not deliberate; these sorts of deposits are bad news for local ecosystems - the reason the water was so clear is probably because just about everything in it is dead! The precipitated calcite smothers the ecosystem and the high pH of the water means that some metals can be transported in solution more easily - so not good for anything that might drink from the stream.

It's a similar process to the one which produces stalactites in caves but because quicklime is much more unstable than limestone, it dissociates in water much more readily - you get much more calcium in solution. The tufa deposits in your photos would have taken hundreds of thousands of years to form from rainwater in limestone.