Coring calcite

[Smithers]

Hi all,

I need some advice as to the type of coring drill bits to use for drilling through calcite.  This isn't actually for digging, but rather for sample collection for scientific purposes.  Don't worry I do have permission to collect samples for my PhD, so I'm not just going in and randomly breaking off bits of stal.

One of the specimens I'm interested in sampling is a broken stalagmite ~0.4m in diameter and >1m in length.  I would like to take a core section from the top and bottom of the stalagmite along the centre of the growth axis.  Due to the length of the sample I'm only going to be able to constrain growth for the top ~10cm and bottom ~10cm (depends on the spec of the coring drill bit).

I have access to Makita SDS drills (although I'm not sure of the exact model), can you guys give me some advice as to what I would need to have in terms of drill bits and adapters to be able to take a core from the calcite.  Basically I need advice on brands, whether I should go for tungsten carbide or diamond cutting blade, whether I need a pilot drill bit to go down the centre of the coring bit etc.

Cheers,

Chris

 

[graham]

Chris

The department does have a coring drill, although we damaged it a bit a few years back, when Arch & Anth borrowed it. But PLS should be able to advise you on this.

 

[Pitlamp]

Don't geologists who are needing cores from lava beds for palaeomagnetism work  use core drills? If you have a geology department at your uni they may have one (or know someone who has one) that you might borrow. If It's capable of drilling basalt it'll chew through stalagmites with no difficulty.

 

[Cave_Troll]

Gina does this sort of thing for a living. I'd suggest asking her if she can help

 

[cfmwh]

We use DK Holdings for our coring bits.
If they don't have the right diameter / length, they can make to your requirements.
Very helpful company and reasonably priced.

http://www.dk-holdings.co.uk/stone/drillint.html

 

[SamT]

I've never done owt like this - but I'm guessing you wouldn't want to engage the SDS hammer action whilst whilst core drilling stal, or maybe I'm wrong. 

Just a thought

 

[Gina]

I suggest getting in touch with Marc Luetscher (Uni. Innsbruck).  He has much experience of this and I will soon be asking him about the same thing.

 

[hrock]

sam you right if you were using a nice diamond bit with no hammer action you would get a lovely core to take home.

have you considered cutting a slice out of it calcite is great with a good hand saw.