Sorry to bother you ALL, but I found an abstract this morning and I have
tried to find whether the same results were published in an article, but
so far with little luck. The abstract is:

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Title   Aragonite to calcite transformation: The use of oxygen isotope
        fractionation to investigate the Sr distribution coefficient.

Authors DELANEY, M.L. & KASTNER, M.

Source  Eos, Transactions AGU, 65(45):948
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In fact, any articles other people know of which deals with the topic
of aragonite-calcite transformation and oxygen-isotope ratios would be
greatly appreciated.

Thanking you in advance

        Darren

University of Oxford