Re: conodont removal

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Dear Adam,

removal of conodonts from well indurated organic rich shales can be a 
bit of a nightmare.

Try......

1. soaking in about 10% Sodium Hypochlorite (strong bleach) with 
about 100g of NaOH pellets to start the reaction (for periods of one 
week) THIS IS PROBABLY THE BEST METHOD

2. 5% Hydrogen peroxide added to hot water, it fizzes a lot so don't 
fill the container too full.

3. Dehydrate the shale in a low temperature oven (overnight) then soak 
for a few hours in Petroleum ether (cover to prevent evaporation) 
pour off the Pet. ether (filtering it back into the bottle) and then 
add hot water

4. try the above but substitute kerosene.

5. Alternations of the above, especially 2+3 is usually quite 
successful.

6. if all else fails and you just want an age for the sample, smash it 
up with a hammer and try 5.

It will be worth geeting hold of Austin, R. L. 1987. 
'Conodonts; Investigative techniques and applications' British 
Micropalaeontological Society Series, Ellis Horwood Ltd., Chichester.
This details many of the above techniques for breaking down rock plus 
others.

If you have any trouble or queries don't hesitate to ask for help.

best wishes,

Phil Donoghue,
Dept. of Geology,
University of Leicester,
University Road,
Leicester LE1 7RH.