Calibration of the oxygen and clumped isotope thermometers for (proto-)dolomite based on synthetic and natural carbonates

May combine two claims.

A recalculation of Kele et al. (2015) by Bernasconi et al. (2018) showed that while the slope remained constant, the intercept decreased by 0.038 ‰.

“A recalculation of the Kele et al. (2015) by Bernasconi et al. (2018), however, showed that while the slope remained constant, the intercept decreased by 0.038 ‰.”

• cites Kele et al., 2015 sourceCould not verify

  The accepted manuscript describes Kele et al.’s isotope corrections and discusses calibration slopes, but it does not address a recalculation by Bernasconi et al. (2018). Searches for the claimed unchanged slope and 0.038‰ intercept decrease found no passage reporting that result. (LLM, conf=0.76)

  Experimental — accuracy not yet measured
• cites Bernasconi et al., 2018 sourceSupported

Classified as probably not a substantial claim.

General estimates for calcite or dolomite Δ47 blocking temperatures during cooling range between 200 and 300 °C, respectively (e.g. Bonifacie et al., 2017; Ryb et al., 2017).

“General estimates for calcite or dolomite Δ 47 blocking temperatures during cooling range between 200 and 300 °C, respectively (e.g.Bonifacie et al., 2017;Ryb et al., 2017).”

• cites Bonifacie et al., 2017 sourceNot checked — no full text of the source
• cites Ryb et al., 2017 sourceSupported

Probably not a substantial claim: may not pass S3 (load-bearing).

The effect on recalculated temperatures in older publications is difficult to predict without a full recalculation that includes all heated and equilibrated gases measured with the samples.

“The effect on the recalculated temperatures in older publications is difficult to predict without a full recalculation that includes all heated and equilibrated gases measured with the samples (Petersen et al., 2019).”

• cites Petersen et al., 2019 sourceSupported

May combine two claims.

The slope of the new dolomite calibration (0.0428 ± 0.0020) is slightly shallower than the calcite calibration of Kele et al. (2015) recalculated in Bernasconi et al. (2018) (0.0449 ± 0.0019), but within uncertainties.

“Comparison with the calcite calibration of Kele et al. (2015) recalculated in Bernasconi et al. (2018) shows a slightly shallower slope within the uncertainties of each other (0.0428 ± 0.0020 vs. 0.0449 ± 0.0019).”

• cites Kele et al., 2015 sourceSupported
• cites Bernasconi et al., 2018 sourcePartly supported

  The ‘Calculation of Δ47 and the Effect of the 17O Correction’ section reports a recalculated Kele et al. calibration slope of 0.0449, supporting the comparison’s cited value. It gives the uncertainty as ±0.001, however, not ±0.0019. The new dolomite slope is the citing paper’s own result, not a result attributed to Bernasconi et al. (LLM, conf=0.90)

  Experimental — accuracy not yet measured

Classified as probably not a substantial claim. May combine two claims.

In this study the results are firmly anchored to the absolute reference frame using a calcite-based correction scheme using the widely distributed ETH Standards, which allows other laboratories to better compare the data to ours (Bernasconi et al., 2018).

“In addition, in this study we firmly anchor the results to the absolute reference frame using a calcite-based correction scheme using the widely distributed ETH Standards, which allows other laboratories to better compare the data to ours (Bernasconi et al., 2018).”

• cites Bernasconi et al., 2018 sourceSupported

May combine two claims.

Comparison of calibrations established in different laboratories remains challenging due to lack of carbonate standards, pre-2016 data not calculated with Brand parameters, and different phosphoric acid fractionation factors.

“The comparison of calibrations established in different laboratories, however, remains challenging, because of many factors: the lack of carbonate standards to compare across laboratories, the fact that clumped isotope data pre-2016 are not calculated using the”

• cites Bernasconi et al., 2018 sourceSupported
• cites Petersen et al., 2019 sourcePartly supported

  The Introduction (p. 4) says interlaboratory discrepancies remain, and Data Selection (p. 7) describes difficulties comparing early calibrations processed with older parameters. But the paper describes carbonate standards available across laboratories (p. 9), rather than a lack of them, and says differences in acid-digestion fractionation and correction parameters were eliminated as causes of the remaining disagreement (p. 19). It does not establish a pre-2016 cutoff for data calculated without Brand parameters. (LLM, conf=0.87)

  Experimental — accuracy not yet measured

Probably not a substantial claim: may not pass S3 (load-bearing).

Ordered crystalline dolomite forms from an initial amorphous calcium-magnesium carbonate phase that first crystallizes to a non-stoichiometric proto-dolomite, and then transforms over hours to weeks, depending on the temperature, to fully ordered stoichiometric dolomite (Rodriguez-Blanco et al., 2015).

“Ordered crystalline dolomite forms from an initial amorphous calcium-magnesium carbonate phase that first crystallizes to a non-stoichiometric proto-dolomite, and that then transforms over hours to weeks, depending on the temperature, to fully ordered stoichiometric dolomite (Rodriguez-Blanco et al., 2015).”

• cites Rodriguez-Blanco et al., 2015 sourceSupported

May combine two claims.

The observed offset of the Daëron et al. (2019) calibration to the new (proto-)dolomite Δ47 temperature calibration is 0.04‰, very similar to the offset between absolute Δ47 acid fractionations of calcite and dolomite re-evaluated with IUPAC parameters.

“The observed offset of their calibration to our new (proto-)dolomite Δ 47 temperature calibration is with 0.04 ‰ very similar to the offset between the absolute Δ 47 acid fractionations of calcite and dolomite of Müller et al. (2017a) re-evaluated with the new IUPAC parameters in our study (see Table 4).”

• cites Daëron et al., 2019 sourcePartly supported

  Split into 2 atoms — 1 confirmed, 0 partially supported, 0 disputed, 0 misattributed, 1 unverifiable. Expand the claim to see per-atom verdicts.

  Experimental — accuracy not yet measured
• cites Müller et al., 2017aNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing).

Another approach to overcome the difficulty of precipitating low temperature dolomites was the theoretical modelling of the dolomite-water oxygen isotope fractionation of Zheng (1999).

“Another approach to overcome the difficulty of precipitating low temperature dolomites was the theoretical modelling of the dolomite water oxygen isotope fractionation of Zheng (1999).”

• cites Zheng (1999) sourceSupported

May combine two claims.

The Winkelstern et al. (2016) dataset reevaluated in Petersen et al. (2019) for 75°C acid digestion is significantly different in slope (p = 0.0395) and intercept from the re-evaluated ETH calcite calibration dataset.

“the statistical evaluation of the Winkelstern et al. (2016) dataset reevaluated in Petersen et al. (2019) for 75 °C acid digestion is significantly different in slope (p value of 0.0395) and intercept to the re-evaluated ETH calcite calibration dataset.”

• cites Winkelstern et al., 2016Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Petersen et al., 2019 sourcePartly supported

  Section 3.4 (p. 15) confirms that Petersen et al. reprocessed Winkelstern data, and Section 3.7 (p. 18) reports tests of slope and intercept differences between calibration studies. Our copy does not report the claimed comparison with a re-evaluated ETH calcite calibration dataset or the slope p value of 0.0395; its mentions of ETH concern carbonate standards (p. 9). (LLM, conf=0.86)

  Experimental — accuracy not yet measured

Classified as probably not a substantial claim.

Based on Fernandez et al. (2017), more samples covering a wider temperature range lead to more robust calibrations.

“Based on observations from the statistical evaluation of Fernandez et al. (2017) of existing Δ 47 -T calibrations that more samples covering a wider temperature range lead to more robust calibrations”

• cites Fernandez et al., 2017 sourceSupported

Probably not a substantial claim: may not pass S2 (checkable).

Regular analysis of dolomite standards would drastically reduce uncertainties arising from mineral-specific acid fractionation correction and from small differences in sample purification and data processing across laboratories.

“The regular analysis of dolomite standards would drastically reduce the uncertainties arising from mineral specific acid fractionation correction and uncertainties arising from small differences in sample purification procedures and data processing across laboratories (see also Bernasconi et al., 2018).”

• cites Bernasconi et al., 2018 sourcePartly supported

  The Outlook (page unavailable) says repeated carbonate-standard measurements can improve interlaboratory comparability across different acid-reaction and gas-purification systems, and recommends developing standards with different mineralogies, including dolomite. The data-correction section says carbonate normalization could eliminate uncertainty from temperature-dependent acid fractionation; Case III reports close agreement for one dolomite but a remaining difference for another. The paper does not establish that regular analysis of dolomite standards would *drastically* reduce mineral-specific fractionation and data-processing uncertainties across laboratories. (LLM, conf=0.85)

  Experimental — accuracy not yet measured

May combine two claims.

The XRD patterns of the samples synthesized at 220 °C clearly display all three dolomite ordering reflections and all of the analyzed samples are stoichiometric.

“Finally, the XRD patterns of the samples synthesized at 220 °C clearly display all three dolomite ordering reflections and all of the analyzed samples are stoichiometric.”

May combine two claims.

The Δ47 value of sample Leeds 34 matches well the other 220°C samples and shows no sign of dis-equilibrium.

“(the Δ 47 value of sample Leeds 34 matches well the other 220 °C samples and shows no sign of dis-equilibrium)”

May combine two claims.

Although the protodolomite samples synthesized at 70 °C show no 015 ordering reflection and their Mg content varied between 42 and 48%, their dissolution rate when exposed to 10% HCl or 104% phosphoric acid was much slower than that observed for a typical calcite or high Mg-calcite (15 mol% Mg).

“Although the protodolomite samples synthesized at 70 °C show no 015 ordering reflection and their Mg content varied between 42 and 48 %, their dissolution rate when exposed to 10% HCl or 104% phosphoric acid was much slower than what we observe for a typical calcite or high Mg-calcite (15 mol % Mg)”

• cites Dolomieu, 1791Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Lumsden and Chimahusky, 1980 sourceNot checked — no full text of the source

May combine two claims.

The linear regression is well constrained, based on 289 individual measurements of 20 different samples formed at 5 different temperatures.

“The narrow 95% confidence interval envelope shows the well constrained linear regression that is based on 289 individual measurements of 20 different samples formed at 5 different temperatures.”

May combine two claims.

The poorly ordered lacustrine Rodolo dolomite has δ13C VPDB of -3.71 ± 0.06‰ and δ18O VPDB of 2.77 ± 0.12‰.

“The poorly ordered lacustrine Rodolo dolomite has a δ 13 C VPDB of -3.71 ± 0.06 ‰ and a relatively high δ 18 O VPDB of 2.77 ± 0.12 ‰”

May combine two claims.

The natural sample from Qatar has a Mg content of 49.5%, all ordering peaks besides the 101 reflection are clearly visible, and the (015)/(110) ratio is 0.29.

“The natural sample from Qatar has a Mg content of 49.5 %, all ordering peaks, besides the 101 reflection, are clearly visible and the (015)/(110) ratio is with 0.29 slightly better expressed than the other two natural samples from Brazil”

May combine two claims.

The δ13C of Sansa and NIST SRM 88b are similar (1.45 ± 0.09‰ and 2.12 ± 0.10‰), but their oxygen isotope compositions differ (-3.56 ± 0.18‰ for Sansa and -7.09 ± 0.13‰ for NIST SRM 88b).

“Whereas their δ 13 C are similar (1.45 ± 0.09 ‰ and 2.12 ± 0.10 ‰), their oxygen isotope composition is different with -3.56 ± 0.18 ‰ for Sansa and -7.09 ± 0.13 ‰ for NIST SRM 88b.”

May combine two claims.

The two diagenetic dolomites are more difficult to react with phosphoric acid compared to Rodolo, causing worse reproducibility among individual replicates, but their Δ47 values reproduce extremely well.

“The two diagenetic dolomites are more difficult to react with phosphoric acid compared to the Rodolo, which is the cause of the worse reproducibility amongst all individual replicates measured during one year (Table S2), however, the Δ 47 values reproduce extremely well.”

May combine two claims.

The intercept of the calcite calibration is significantly lower, so the two calibrations do not overlap at their 95% confidence intervals.

“However, the intercept of the calcite calibration is significantly lower so that the two calibrations do not overlap at their 95% Cl's (Fig. 6).”

May combine two claims.

Samples crystallized at 140 °C exhibited the ordering reflections 015 and 021, but still lacked the 101 reflection, pointing to poorly ordered dolomite with (015)/(110) ratios between 0.14 and 0.21 and Mg content close to stoichiometric dolomite of 47.3 to 49.2%.

“Samples crystallized at 140 °C exhibited in their XRD pattern the ordering reflections of dolomite 015 and 021, but still lacked the 101 reflection pointing to poorly ordered dolomite with (015)/(110) ratios between 0.14 and 0.21 and Mg content close to stoichiometric dolomite of 47.3 to 49.2 %.”

May combine two claims.

The Rodolo dolomite is stoichiometric, but the ordering reflections are moderately well expressed with (015)/(110) of 0.35.

“The Rodolo dolomite is stoichiometric, but the ordering reflections are moderately well expressed with (015)/ (110) of 0.35.”

May combine two claims.

The two cold natural dolomite samples have similar oxygen isotope composition but distinct carbon isotope compositions (-8.32‰ for LV 15 cm and -10.21‰ for LV 71 cm).

“both samples have similar oxygen isotope composition, but their carbon isotope compositions are more distinct with -8.32 ‰ for the more shallow sample and -10.21‰ for the deeper one.”

May combine two claims.

The 015 ordering reflection is much more expressed than for samples synthesized at lower temperatures, and the degree of ordering increases from 0.28 for the 2.1 week experiment (Leeds 34) up to around 0.4 for the 12 weeks experiments (Leeds 84-86).

“The 015 ordering reflection is much more expressed than for the samples synthesized at lower temperatures and the degree of ordering is increasing from 0.28 for the 2.1 week experiment (Leeds 34) up to around 0.4 for the 12 weeks experiments (Leeds 84-86 in Table 1).”

May combine two claims.

The average Δ47 CDES 70°C values of the two cold natural dolomite calibration samples are 0.637‰ for LV 15 cm and 0.619‰ for LV 71 cm.

“The average Δ 47 CDES 70°C values of the two”

Probably not a substantial claim: may not pass S3 (load-bearing).

The δ13C VPDB and δ18O VPDB of the synthetic samples are quite similar to each other.

“The δ 13 C VPDB and δ 18 O VPDB of the synthetic samples are quite similar to each other”

May combine two claims.

In both Lagoa Vermelha samples the ordering reflection 015 is clearly smaller than the 110 reflection, with an ordering ratio (015)/(110) of 0.15 and 0.22 for LV 15 cm and LV 71 cm, respectively.

“In both samples the ordering reflection 015 is clearly smaller than the 110 reflection, with an ordering ratio (015)/(110) of 0.15 and 0.22 for LV 15 cm and LV 71 cm, respectively.”

May combine two claims.

The dolomites NIST SRM 88b and Sansa are well-ordered and stoichiometric dolomites.

“The dolomites NIST SRM 88b and Sansa are well-ordered and stoichiometric dolomites (see Table 3).”

May combine two claims.

Our 70°C samples match well the temperature-dependent (proto-)dolomite water oxygen isotope fractionation of Horita (2014), whereas our samples at 140 and 220°C show more scatter.

“Whereas our 70 °C samples match well their temperature dependent (proto-)dolomite water oxygen isotope fractionation, our samples at 140 and 220 °C show more scatter.”

• cites Horita (2014) sourceNot checked — no full text of the source

May combine two claims. The quote only partly states this claim.

The AC effectively needed to put the calibrations on the same level is approximately 0.030‰, between the values of Defliese et al. (2015) and Murray et al. (2016), corresponding to the observed offset between lagoonal proto-dolomite concretions.

“The AC effectively needed to put the calibrations on the same level is an AC of approximately 0.030 ‰, which is somewhere in between the values of Defliese et al. (2015), and that of Murray et al. (2016), and corresponds to the observed offset between our lagoonal proto-dolomite concretions and the ones of Bonifacie et al. (2017).”

• cites Defliese et al., 2015 sourceNot checked — no full text of the source
• cites Murray et al., 2016 sourceNot checked — no full text of the source
• cites Bonifacie et al., 2017 sourceNot checked — no full text of the source

May combine two claims.

For Lagoa Vermelha, the upper sample (LV 15 cm) has Δ47 CDES 70°C of 0.637 ± 0.022‰ (16 replicates), while Bonifacie et al. (2017) obtained Δ47 CDES 90°C of 0.591 ± 0.022‰ (4 replicates) for their surface sample, an offset of 0.046‰.

“For a direct comparison between the two studies we can compare the natural samples of Lagoa Vermelha where we obtained a Δ 47 CDES 70°C of 0.637 ± 0.022 ‰ for the upper one (LV 15 cm, 16 replicates) and Bonifacie et al. (2017) obtained a Δ 47 CDES 90°C of 0.591 ± 0.022 ‰ (4 replicates) for their surface sample, an offset of 0.046 ‰.”

• cites Bonifacie et al., 2017 sourceNot checked — no full text of the source

May combine two claims.

From Fig. 9, the new experimental data overlap with those of Vasconcelos et al. (2005) and Horita (2014), whereas the Matthews and Katz (1977) calibration is slightly below the data compilation over the entire temperature range.

“From Fig. 9 it appears that our new experimental data overlap with those of Vasconcelos et al. (2005) and Horita (2014), whereas the Matthews and Katz (1977) calibration is slightly below the data compilation over the entire temperature range.”

• cites Vasconcelos et al., 2005 sourceNot checked — no full text of the source
• cites Horita, 2014 sourceNot checked — no full text of the source
• cites Matthews and Katz (1977) sourceNot checked — no full text of the source

May combine two claims.

In case of the 140°C samples, only the shortest experiment, protodolomite Leeds 21, matches Horita's data, whereas the others show larger fractionations.

“In case of the samples synthesized at 140 °C suspiciously only the one sample of the shortest experiment, the protodolomite Leeds 21 matches that data of Horita, whereas the others show larger fractionations.”

• cites HoritaNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

The quote only partly states this claim.

Sansa is a well-ordered stoichiometric dolomite with a Δ47 CDES 70°C value of 0.526 ± 0.014 ‰.

“the warmer well-ordered stoichiometric dolomite”

The quote only partly states this claim.

There is a discrepancy in the intercept of the new dolomite calibration relative to the calibration of Bonifacie et al. (2017).

“However, there is a discrepancy in the intercept of the calibration”

• cites Bonifacie et al. (2017) sourceNot checked — no full text of the source

• AssumptionRests on an assumption: The (proto-)dolomite samples used for calibration formed in isotopic equilibrium with their precipitation solutions.

May combine two claims.

Three possible reference materials are proposed that have a range of compositions and are available in large amounts for distribution.

“We propose three possible reference materials (XRD patterns displayed in Fig. 3 and Table 3) that have a range of compositions and are available in large amounts for distribution.”

May combine two claims.

The new dolomite calibration has an identical slope but an offset of about 30 ppm relative to the calibration of Bonifacie et al. (2017) for 90°C acid digestion.

“This new dolomite calibration has identical slope but an offset of about 30 ppm to the one of Bonifacie et al. (2017) for 90 °C digestion.”

• cites Bonifacie et al. (2017) sourceNot checked — no full text of the source

• AssumptionRests on an assumption: The (proto-)dolomite samples used for calibration formed in isotopic equilibrium with their precipitation solutions.

The quote only partly states this claim.

Combination of the datasets from this study, Horita (2014) and Vasconcelos et al. (2005) resulted in a linear relationship covering a temperature range from 25 to 350°C.

“Combination of these three datasets resulted in the black dashed line giving the displayed linear relationship and covers a temperature range from 25 to 350 °C.”

• cites Horita (2014) sourceNot checked — no full text of the source
• cites Vasconcelos et al. (2005) sourceNot checked — no full text of the source

• AssumptionRests on an assumption: The oxygen isotope fractionation data from this study, Vasconcelos et al. (2005) and Horita (2014) are directly comparable and can be combined into a single temperature relationship.

May combine two claims. The quote only partly states this claim.

Rodolo is a stoichiometric but poorly ordered dolomite with a Δ47 CDES 70°C value of 0.632 ± 0.006 ‰.

“the lacustrine low temperature dolomite”

May combine two claims.

Müller et al. (2017a) also determined the acid fractionation for dolomite at 100 °C and observed that at this temperature it is smaller than that of calcite.

“In this study, Müller et al. (2017a) also determined the acid fractionation for dolomite at 100 °C and observed that at this temperature it is smaller than that of calcite supporting the findings of Murray et al. (2016).”

• cites Müller et al., 2017aNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Murray et al., 2016 sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

Müller et al. (2017a) observed a significantly smaller acid fractionation for aragonite (0.172 ‰), compared to calcite (0.197 ‰) and dolomite (0.226 ‰) at 70 °C acid digestion temperature.

“In a study on the absolute Δ 47 acid fractionation at 70 °C acid digestion temperature, Müller et al. (2017a) moreover, observed a significantly smaller acid fractionation for aragonite (0.172 ‰), compared to calcite (0.197 ‰) and dolomite (0.226‰).”

• cites Müller et al., 2017aNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Classified as probably not a substantial claim.

Some recent studies observed a different phosphoric acid fractionation for Δ47 during acid digestion of dolomite compared to calcite.

“some recent studies observed a different phosphoric acid fractionation for Δ 47 during acid digestion of dolomite compared to calcite.”

• cites Defliese et al., 2015 sourceNot checked — no full text of the source
• cites Murray et al., 2016 sourceNot checked — no full text of the source
• cites Müller et al., 2017aNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

It remains unclear how dolomite forms at Earth surface conditions and why it is so abundant during certain time intervals in the geological past.

“In spite of all the efforts it remains unclear how this mineral forms at Earth surface conditions and why it is so abundant during certain time intervals in the geological past”

• cites Land, 1985 sourceNot checked — no full text of the source
• cites Given and Wilkinson, 1987 sourceNot checked — no full text of the source
• cites Spencer and Hardie, 1990Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• AssumptionRests on an assumption: Dolomite is a very common carbonate mineral in ancient sediments, but is rarely found in modern environments.
• AssumptionRests on an assumption: The controls on dolomite formation are still debated after more than two centuries of research.

Probably not a substantial claim: may not pass S2 (checkable).

Simultaneous analyses of dolomite reference material will enable a much better comparison of published dolomite clumped and oxygen isotope data amongst different laboratories.

“In addition, the simultaneous analyses of dolomite reference material will enable a much better comparison of published dolomite clumped and oxygen isotope data amongst different laboratories.”

Classified as probably not a substantial claim.

Recently two dolomite-specific Δ47-T calibrations were published (Winkelstern et al., 2016; Bonifacie et al., 2017) with the aim of eliminating additional uncertainties in the interpretation of dolomite clumped isotope temperatures.

“Recently two dolomite-specific Δ 47 -T calibrations were published (Winkelstern et al., 2016;Bonifacie et al., 2017) with the aim of eliminating additional uncertainties in the interpretation of dolomite clumped isotope temperatures.”

• cites Winkelstern et al., 2016Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Bonifacie et al., 2017 sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

Bonifacie et al. (2017) for 90 °C acid digestion revealed that the temperature relationship of dolomite is within error of the one of calcite based on a compilation of many different published laboratories carried out in the same study.

“On the other hand, Bonifacie et al. (2017) for 90 °C acid digestion revealed that the temperature relationship of dolomite is within error of the one of calcite based on a compilation of many different published laboratories carried out in the same study.”

• cites Bonifacie et al., 2017 sourceNot checked — no full text of the source

Classified as probably not a substantial claim.

For dolomite, the temperature dependence of the acid fractionation correction factor (AFF) is still debated.

“For dolomite, however, the temperature dependence of the AFF is still debated.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Defliese et al. (2015) observed similar temperature sensitivities for the AFF of dolomite and calcite.

“Whereas Defliese et al. (2015) observed similar temperature sensitivities for the AFF of dolomite and calcite”

• cites Defliese et al., 2015 sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

In modern environments only few places of active (proto-)dolomite formation at the surface are known, and in most of these cases microorganisms have been shown to play an active or passive role.

“In modern environments only few places of active (proto-)dolomite formation at the surface are known and in most of these cases microorganisms have been shown to play an active or passive role”

• cites Vasconcelos and McKenzie, 1997 sourceNot checked — no full text of the source
• cites Wright, 1999 sourceNot checked — no full text of the source
• cites Bontognali et al., 2010 sourceNot checked — no full text of the source

• AssumptionRests on an assumption: Dolomite is a very common carbonate mineral in ancient sediments, but is rarely found in modern environments.

Probably not a substantial claim: may not pass S3 (load-bearing).

The results of Müller et al. (2017a) indicate that the Δ47 acid fractionations of dolomite and calcite seem to be identical at about 90 °C acid digestion temperature.

“Interestingly, the results of Müller et al. (2017a) indicate that the Δ 47 acid fractionations of dolomite and calcite seems to be identical at about 90 °C acid digestion temperature”

• cites Müller et al., 2017aNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

May combine two claims.

This study demonstrates the necessity to apply (proto-)dolomite specific Δ47-T relationships for accurate temperature estimates of dolomite formation, ideally done at identical acid digestion temperatures to avoid additional uncertainties introduced by acid digestion temperature corrections.

“This study demonstrates the necessity to apply (proto-)dolomite specific Δ 47 -T relationships for accurate temperature estimates of dolomite formation, ideally done at identical acid digestion temperatures to avoid additional uncertainties introduced by acid digestion temperature corrections.”

• AssumptionRests on an assumption: Clumped isotope thermometry is solely temperature dependent.

Classified as probably not a substantial claim.

Murray et al. (2016) observed a much steeper temperature sensitivity for the AFF of dolomite relative to calcite.

“Murray et al. (2016) observed a much steeper temperature sensitivity for the AFF of dolomite relative to calcite.”

• cites Murray et al., 2016 sourceNot checked — no full text of the source

May combine two claims.

There is no trend over the course of the experiments, and the rest of the samples record the designated temperatures.

“There is no trend over the course of the experiments to observe and it seems the rest of the samples records the designated temperatures.”

Classified as probably not a substantial claim.

For the measurement sequences of this dolomite study, the ETH calcite standards were treated identically to the unknown (proto-)dolomite samples with 1200 s reaction time.

“For the measurement sequences of this dolomite study, the ETH calcite standards were treated identically to the unknown (proto-)dolomite samples with 1200 s reaction time.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

All uncertainties are reported at the 95% confidence level and range between 0.02 and 0.14 ‰ for δ13C VPDB, 0.04-0.54 ‰ for δ18O VPDB, 0.05-0.77 ‰ for δ47, and 0.010-0.054 ‰ for Δ47 CDES 70°C.

“All uncertainties are reported at the 95% Cl and range between 0.02 and 0.14 ‰ for δ 13 C VPDB , 0.04-0.54‰ for δ 18 O VPDB , 0.05-0.77‰ for δ 47 and 0.010-0.054‰ for Δ 47 CDES 70°C .”

May combine two claims.

Defliese et al. (2015) determined that the temperature dependence of the acid fractionation factor for dolomite between 25 and 90°C is identical to that of calcite, whereas Murray et al. (2016) observed a significantly steeper temperature dependence for dolomite.

“For instance, Defliese et al. (2015) determined that temperature dependence of the acid fractionation factor for dolomite between 25 and 90 °C is identical to the one of calcite whereas Murray et al. (2016) observed a temperature dependence significantly steeper for dolomite.”

• cites Defliese et al., 2015 sourceNot checked — no full text of the source
• cites Murray et al., 2016 sourceNot checked — no full text of the source

Classified as probably not a substantial claim.

The dolomite from Qatar was interpreted to be a primary precipitate from the pore fluids and not a replacement of calcite or aragonite (Brauchli et al., 2016).

“This dolomite was interpreted to be a primary precipitate from the pore fluids and not a replacement of calcite or aragonite (Brauchli et al., 2016).”

• cites Brauchli et al., 2016 sourceNot checked — no full text of the source

May combine two claims.

Original data in all publications before 2017 were not processed using the IUPAC parameters, which can lead to significant changes in calculated compositions.

“the original data in all publications before 2017 were not processed using the IUPAC parameters, which also can lead to significant changes in calculated compositions (Daëron et al., 2016).”

• cites Daëron et al., 2016 sourceNot checked — no full text of the source

May combine two claims.

The annual mean water temperature of Lagoa Vermelha is approximately 25 °C, and the recorded temperature in 20 cm sediment depth was 25.5 ± 5.7 °C from November 2011 till May 2015 (Do Nascimento, 2018).

“The annual mean water temperature of Lagoa Vermelha is approximately 25 °C, and the recorded temperature in 20 cm sediment depth was 25.5 ± 5.7 °C from November 2011 till May 2015 (Do Nascimento, 2018)”

• cites Do Nascimento, 2018 sourceNot checked — no full text of the source

May combine two claims.

The cultures of Vasconcelos et al. (2005) produced a mixture of calcite and proto-dolomite; dissolving calcite with EDTA left an Mg-rich phase with the main d(104) XRD peak in the dolomite position, more resistant to dissolution than carbonate phases with lower Mg concentration.

“The cultures of Vasconcelos et al. (2005) produced a mixture of calcite and proto-dolomite and before measurement they dissolved the calcite with EDTA, thus the Mg rich phase that has the main d(104) XRD peak in the position of a dolomite, was more resistant to dissolution than all carbonate phases with lower Mg concentration.”

• cites Vasconcelos et al., 2005 sourceNot checked — no full text of the source

May combine two claims.

The study of Horita (2014) covers 80-350°C, whereas Vasconcelos et al. (2005) covers 25-45°C with a slightly more shallow temperature relationship.

“The study of Horita (2014) contains samples that cover a temperature range from 80 to 350 °C, whereas the study of Vasconcelos et al. (2005) covers a temperature range of 25 to 45 °C with a slightly more shallow temperature relationship.”

• cites Horita (2014) sourceNot checked — no full text of the source
• cites Vasconcelos et al. (2005) sourceNot checked — no full text of the source

The quote only partly states this claim.

An additional uncertainty in the comparison is that Bonifacie et al. (2017) was not corrected for IUPAC parameters, so the exact difference remains unclear until their data are recalculated.

“An additional uncertainty in this comparison is the fact that the Bonifacie et al. (2017) was not corrected for the”

• cites Bonifacie et al., 2017 sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

In case of the 220°C samples, the two samples with larger oxygen isotope fractionation could be explained by inheritance of a more poorly ordered dolomite formed at lower temperature, or by the degree of ordering affecting oxygen isotope equilibrium with water.

“In case of the 220 °C the two samples with larger oxygen isotope fractionation could be explained by in two ways, first it could be that they inherited the isotope composition of a more poorly ordered dolomite (like sample Leeds 34, which we did exclude here) that formed at lower temperature during the heating stage of the experiment or that the degree of ordering affects the oxygen isotope”

May combine two claims.

However, these two calibrations give very comparable results to the Matthews and Katz (1977) calibration, suggesting that proto- or poorly ordered dolomites have a very similar oxygen isotope fractionation to ordered dolomites.

“However, these two calibrations give very comparable results to the Matthews and Katz (1977) calibration, suggesting that the proto-or poorly ordered dolomites have a very similar oxygen isotope fractionation to ordered dolomites.”

• cites Matthews and Katz (1977) sourceNot checked — no full text of the source

May combine two claims.

Combining the results of the three studies (this study, Vasconcelos et al., 2005, Horita, 2014) derives a more accurate temperature dependence of the water-(proto-)dolomite oxygen isotope fractionation because it is based on more data points and covers 25-350°C.

“In spite of the possible limitations discussed above, we propose to combine the results of the three studies to derive a more accurate temperature dependence of the water-(proto-)dolomite oxygen isotope fractionation because it is based on more data points and covers a wide temperature range of 25 to 350 °C (see Fig. 9).”

• cites Vasconcelos et al., 2005 sourceNot checked — no full text of the source
• cites Horita, 2014 sourceNot checked — no full text of the source

May combine two claims.

The offset of about 30 ppm between calcite and dolomite, and between siderite and calcite for siderites reacted at 70°C, shows the necessity to treat different minerals digested at 70°C differently than calcites.

“The offset of about 30 ppm between calcite and dolomite as well as the offset observed between siderite and calcite for the siderites reacted at 70 °C (van Dijk et al., 2019), however, shows the necessity to treat different minerals digested at 70 °C differently than calcites.”

• cites van Dijk et al., 2019 sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The XRD pattern of the (proto-)dolomites used in Horita (2014) are very similar to ours, although they used various carbonate seeds to synthesize the dolomites.

“The XRD pattern of the (proto-)dolomites used in Horita (2014) are very similar to ours, although they used various carbonate seeds to synthesize the dolomites.”

• cites Horita (2014) sourceNot checked — no full text of the source

May combine two claims.

Applying an acid fractionation correction for Δ47 analyses on dolomite can result in large uncertainties and produce erroneous temperature estimates.

“The above discussion shows that applying an acid fractionation correction for Δ 47 analyses on dolomite can result in large uncertainties and produce erroneous temperature estimates.”

Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

Additional measurement of various dolomite and calcite standards would enable a better and more direct data comparison to solve this discrepancy.

“Additional measurement of various dolomite and calcite standards would enable a better and more direct data comparison to solve this discrepancy.”

Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

Regular analysis of dolomite standards would help correct for offsets between laboratories digesting carbonates at different reaction temperatures, allowing laboratories without their own temperature calibration to apply dolomite-specific Δ47-T calibrations with more confidence.

“Once more the regular analysis of dolomite standards would help to correct for offsets between laboratories digesting the carbonates at different reaction temperatures allowing laboratories without own temperature calibration the application of dolomite specific Δ 47 -T calibrations with more confidence.”

May combine two claims.

For a dolomite formed at 25°C, using the calcite calibration would give 6°C colder temperatures; for one formed at 80°C, 12°C colder temperatures, impacting calculated δ18O of the fluid source.

“For example for a dolomite formed at 25 °C we would obtain 6 °C colder temperatures if calculated as a calcite and for one formed at 80 °C we would obtain 12 °C colder temperatures, which further impacts the calculated δ 18 O of the fluid source.”

May combine two claims.

All of these studies faced the challenge that in the laboratory at temperatures below 100°C it becomes difficult to synthesize dolomite, although naturally occurring dolomite samples in most cases formed at lower temperatures.

“Unfortunately all of these studies faced the challenge that in laboratory at temperatures below 100 °C it becomes difficult to synthesize dolomite, although naturally occurring dolomite samples in most cases formed at lower temperatures (e.g. via mixing of fluids, as diagenetic replacement phase or biologically mediated primary precipitate, see Warren (2000) for a review).”

• cites Warren (2000) sourceNot checked — no full text of the source

May combine two claims.

The (proto-)dolomite specific Δ47-temperature calibration of Bonifacie et al. (2017) is based on 12 samples formed at 25-350°C with 67 individual measurements and includes one sample from Lagoa Vermelha and one from Brejo do Espinho.

“The (proto-)dolomite specific Δ 47 -temperature calibration of Bonifacie et al. (2017) is based on 12 different samples formed at temperatures between 25 and 350 °C with a total of 67 individual measurements and contains one sample from Lagoa Vermelha and another one of a neighbouring lagoon (Brejo do Espinho) that formed under similar conditions as the ones we used in this study.”

• cites Bonifacie et al., 2017 sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The observation that the 70°C acid digestion calibration (without AFF) lies on the theoretical line for 25°C acid digestion might be because they underestimate the dolomite-specific Δ47 acid fractionation or could be coincidence.

“On the other hand, the observation that our calibration for 70 °C acid digestion temperature (without AFF) lies on their theoretical line for 25 °C acid digestion might be due that they underestimate the dolomite specific Δ 47 acid fractionation or could be just coincidence.”

Classified as probably not a substantial claim.

The only way to remove these uncertainties for dolomite measurements is the use of dolomite reference materials in addition to calcite standards used to transfer data to CDES.

“The only way to remove these uncertainties for dolomite measurements is the use of dolomite reference materials in addition to the calcite standards that are used to transfer the data to the CDES.”

May combine two claims.

Therefore, there is no difference in the temperature dependence of Δ47 between ordered stoichiometric dolomites and proto-dolomite, or if such differences exist, they are well below current analytical uncertainty.

“Therefore, we conclude that there is no difference in the temperature dependence of Δ 47 between ordered stoichiometric dolomites and so-called proto-dolomite, or, if such differences exist, they are well below the current analytical uncertainty.”

May combine two claims.

We consider this a good indication that these phases, although not well ordered, are not very high magnesium calcites, but poorly ordered dolomites.

“We consider this a good indication that these phases, although not well ordered, are not very high magnesium calcites (Kaczmarek and Thornton, 2017), but poorly ordered dolomites.”

• cites Kaczmarek and Thornton, 2017 sourceNot checked — no full text of the source

Classified as probably not a substantial claim.

Murray and Swart (2017) showed that for dolomite formed at 25°C, the calculated δ18O of the fluid source can vary by up to 3.6‰ depending on which calibration is used.

“In Fig. 1 they show that for dolomite formed at 25 °C the calculated δ 18 O of the fluid source can vary by up to 3.6 ‰ depending on which calibration is used.”

• cites Murray and Swart (2017) sourceNot checked — no full text of the source

May combine two claims.

An offset between the Δ47-T relationship of dolomite and calcite was predicted by theoretical calculations of Guo et al. (2009), but the offset was of opposite sign to what is observed experimentally.

“An offset between the Δ 47 -T relationship of dolomite and calcite was also predicted by theoretical calculations of Guo et al. (2009), however, the offset was of opposite sign of what we observe experimentally.”

• cites Guo et al., 2009 sourceNot checked — no full text of the source

Probably not a substantial claim: may not pass S3 (load-bearing).

A third explanation for the 220°C samples is that some solution leaked/evaporated, slightly enriching the remaining solution in 18O.

“A third explanation could be that some of the solution leaked/evaporated out of the experiment container slightly enriching the remaining solution in the heavier 18 O (these would be then the two samples matching Horita's data Leeds 84 and 85).”

Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing). May combine two claims.

This would be valuable not only for clumped isotopes but also for oxygen isotopes, as there are also uncertainties in oxygen isotope fractionation with different preparation systems.

“This would be valuable not only for clumped isotopes but also for oxygen isotopes as well, as there are also uncertainties in oxygen isotope fractionation with different preparation systems.”

May combine two claims.

While proto-dolomites are not well ordered, they show properties that distinguish them from calcite.

“While these proto-dolomites are not well ordered, they show properties that distinguish them from calcite.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

Further uncertainties might originate from the oxygen isotope analyses of the water when comparing studies published during almost half a century.

“Further uncertainties might originate from the oxygen isotope analyses of the water when comparing studies published during almost half a century.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Sansa is the product of diagenetic alteration of a primary early Triassic marine carbonate.

“which is the product of diagenetic alteration of a primary early Triassic marine carbonate (Table 3).”

Probably not a substantial claim: may not pass S2 (checkable).

Other unknown factors in sample preparation and/or data standardization are the cause for the discrepancy with Winkelstern et al. (2016).

“This points to other unknown factors in the sample preparation and/or data standardization as cause for the discrepancy.”