I'm sure we have all wondered about helectites in caves, how about helectite icicles?

Great pictures, but only B- for helicticity, IMHO 

JasonC said:

only B- for helicticity

Click to expand...

  I'll get them to try harder next time.

I did wonder if there is any equivalence with their calcite cousins though, I'm guessing these would be a lot easier to research

Presumably on the timescale they're forming under, it must be draught-related? I can't think of another mechanism that would deflect them so quickly.

It's got to be a possibility but there are straight ones next to the bent ones and they are not all formed in the same direction. That said none were on the prevailing windward side.

I'm guessing these would be a lot easier to research

Click to expand...

Or maybe they'd just melt.

It was so cold that the water was probably freezing as soon as it touched the icicle, rather than getting to the lowest point.

Mendip had some good ice blobs:



Mike

I used to think that ice might be a useful way to study other mineral formations, but I'm not so sure any more. Forms that look almost identical often grow by very different mechanisms. One of the most interesting comparisons to me has been gypsum flowers with frost flowers. In some cases these are indistinauishable from one another. I think the frost ones are more precious in a way since they are the work of a single night and will be gone as soon as the sun is over the ridge an hour.

Kenilworth has a point but I must say I am intrigued as to how much relatively rapidly forming ice formations replicate speleothems.

mrodoc said:

Kenilworth has a point but I must say I am intrigued as to how much relatively rapidly forming ice formations replicate speleothems.

Click to expand...

In form or in formation?
Ice stalactites, stalagmites, flowstone, micro-gours, rafts, spattermites, helectites, crystals, crusts, and blossoms all resemble various calcite, gypsum, lava, and other mineral speleothems quite convincingly. I would assume that the formation of these ice features is quite well understood, or at least relatively easy to figure out. Some speleothems are still very poorly understood.
The biggest question is: how closely do the mechanisms of freezing resemble the mechanisms of deposition? I do not know the answer for sure, but if it is not very, I doubt there is much to be learned from the ice about cave formations.
It would be interesting in any case to catalogue photos of ice/mineral formations for comparison.

This is a crop from the only useful icicle photo I have, taken at Odin Mine during the last proper cold snap in December 2010. Interesting to note that some of these exhibit deflection near the tips, but not all. Also some of them are very densely 'ribbed' along their length, whilst others nearby are smooth. Presumably reflecting various levels of turbulence as the water drips? These icicles were about a metre long.

Stalactites start to form as straws, whilst icicles have the flow on the outside...

Mike