As these things happen, recently we’ve managed to get two of our papers out quasi simultaneously on completely different topics. The first in Geochimica Cosmochimica Acta (GCA) and the second in Scientific Reports.

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For our GCA paper:

“Oxygen isotope fractionation during amorphous to crystalline calcium carbonate transformation at varying relative humidity and temperature”

We took amorphous calcium carbonate and allowed it transform into calcium carbonates at various humidities in the presence and absence of CO2, while measuring the d18O and d13C of the transforming ACC and CaCO3. It turns out that the end-product calcium carbonate does not always reflect its formation conditions but moreso those during transformation – a problem, since there is often no indication that it has transformed! Also, removing CO2 from the equation really makes the transformation process even more complex.

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For our Scientific Reports paper:

“Fossil biocalcite remains open to isotopic exchange with seawater for tens of millions of years“

We used isotopic labelling and NanoSIMS to show the difference between how modern, and fossilized foraminifera “react” with diagenetic fluids, or their ambient seawater. Although fossilized forams are much more resistant to any isotope exchange, they remain open even after millions of years of burial.