2.4 Data compilation
The Arctica islandica dataset was augmented with literature
∆47 values of aragonites with known calcification
temperatures (see S3 ). The dataset includes samples from
mollusks (Bernasconi et al., 2018; Caldarescu et al., 2021; this study),
foraminifera (Piasecki et al., 2019), travertines (Kele et al., 2015;
Bernasconi et al., 2018), cave deposits (Breitenbach et al., 2018),
lab-grown aragonites (Kluge et al., 2015) and heated aragonites (Müller
et al., 2017). Data from several older studies (e.g. Ghosh et al., 2006;
2007; Tripati et al., 2010; Wacker et al., 2013; 2014) was not included
because they were not corrected for the pressure baseline (He et al.,
2012; Bernasconi et al., 2013). Aragonite ∆47 data from
other studies (e.g. Zhang et al., 2018; Zhai et al., 2019; Dong et al.,
2021) were excluded because these lacked the standardization required to
bring ∆47 values into the I-CDES scale (Bernasconi et
al., 2021) or because the aragonite was precipitated out of equilibrium
(e.g. Kimball et al., 2015; Chen et al., 2019; S3 ). Clumped
isotope data from the literature was brought to the I-CDES reference
frame using the multi-linear correction proposed in Appendix A of
Bernasconi et al. (2021) using values of carbonate standards reported in
the studies (see S1 ). The full dataset including
∆47 values and temperatures with their uncertainties
used in this study is provided in S4 .
All data processing for this study is done in R (R Core Team, 2022) and
scripts are provided in S5 and published on Github
(https://github.com/nielsjdewinter/Aragonite_clumped). Details on
data processing are provided in S1 . We compare our data with
calibrations by Anderson et al., (2021) and Meinicke et al., (2020) as
well as with temperature dependencies of aragonite and calcite clumped
isotope compositions from ab initio modelling in Guo et al.
(2009) brought into the I-CDES reference frame (see S1 ).