Empirical calibration of the clumped isotope paleothermometer using calcites of various origins

Calibration of the dolomite clumped isotope thermometer from 25 to 350 °C, and implications for a universal calibration for all (Ca, Mg, Fe)CO3 carbonates

“…When only carbonates digested at high temperatures (T ≥ 70°C) are considered, most of the suites of carbonate minerals of various origins (inorganic or biogenic calcites, aragonites, siderites from Henkes et al, 2013, Wacker et al, 2014, Defliese et al, 2015, Kele et al, 2015 are remarkably similar to our (proto)dolomite dataset -with the exception of the calcite data from Kluge et al, (2015) S3). This observation about experimental data from seven laboratories supports the hypothesis made above that calcites and dolomites (and possibly aragonites and siderites) have similar kinetic fractionation ∆* over acid digestion, at least for high digestion temperatures (with apparently no influence of the cation identity or mineral structure).…”

“…Until now, the carbonate clumped isotope thermometer has 5 been experimentally calibrated for synthetic inorganic calcite Dennis and Schrag, 2010;Zaarur et al, 2013;Tang et al, 2014;Defliese et al, 2015;Kluge et al, 2015), siderite ) and a variety of biogenic carbonates: aragonitic otholith (Ghosh et al, 2007), foraminifera (Tripati et al, 2010;Grauel et al, 2013), deep-sea corals (Thiagarajan et al, 2011), calcitic and aragonitic mollusks and brachiopods (Eagle et al, 2013;Henkes et al, 2013, Came et al, 2014, bio-apatite (Eagle et al, 2010) or empirically on a variety of biogenic calcites (Wacker et al, 2014) (Figure 1). All materials used in these studies had growth temperatures below 70°C, except for the recent studies of Kele et al, (2015) and Kluge et al, (2015), which include samples having growth temperatures up to 95 and 250°C, repectively.…”

“…However, since 2013, the emergence of additional calibration studies on various materials resulted in increasing differences among published ∆ 47 -T calibration lines, illustrated by the large dispersion of published ∆ 47 calibration data in Figure 1 (see also examples of compilations of the published slopes and intercepts on calculated ∆ 47 -T linear regressions in Wacker et al, 2014or Defliese et al, 2015, that appear to reduce both the precision and accuracy of the temperature estimates made on the basis of ∆ 47 data (even if only similar digestion temperatures are considered).…”

Modeling the effects of diagenesis on carbonate clumped-isotope values in deep- and shallow-water settings

“…Specifically, the abundance of carbonate groups with more than one rare (generally heavy) isotope (a 'clumped' isotopologue), such as 13 , relative to a random distribution of isotopes amongst all isotopologues is a unique function of temperature for an isotopically equilibrated system. This temperature dependence has been demonstrated for carbonates using theory , experiments (e.g., Ghosh et al, 2006;Dennis and Schrag, 2010;Zaarur et al, 2013;Kluge et al, 2015;Kelson et al, 2017), and observations of natural and biological materials formed at known temperatures (e.g., Ghosh et al, 2007;Tripati et al, 2010;Thiagarajan et al, 2011;Henkes et al, 2013;Grauel et al, 2013;Came et al, 2014;Wacker et al, 2014;Douglas et al, 2014;Eagle et al, 2015;Kele et al, 2015;Katz et al, 2017 . Excesses of mass 47 CO 2 molecules relative to a random distribution of isotopes is expressed by the symbol  47 (footnote 2)…”

Reconstructing Holocene temperature and salinity variations in the western Baltic Sea region: a multi-proxy comparison from the Little Belt (IODP Expedition 347, Site M0059)

“…A proxy, which appears to be only dependent on temperature and may therefore be ideal for the Baltic Sea, is clumped isotopes on molluscs (Henkes et al, 2013;Wacker et al, 2014). This proxy has not yet been applied to samples from the Baltic Sea.…”