Study of ancient dolomitic mortars of the church of Santa Marı́a de Zamarce in Navarra (Spain): comparison with simulated standards

Dolomitic lime: thermal decomposition of nesquehonite

“…As reported in the introduction, this exothermic phenomenon does not occur in the works by Botha and Strydom [4,5] or Brousse and Guering [10], nor has any explanation been given for this peak [2,8]. The occurrence of a similar exothermic peak for the HY has been discussed in our previous work [11]. The explanation we provided, together with the discussion in the paper by Sawada et al [7] is as follows: MgCO 3 crystallizes suddenly from the amorphous phase with a sharp exothermic peak and a rapid evolution of carbon dioxide takes place simultaneously, which justifies the sharp weight loss.…”

“…As reported in our previous work [11], a selfgenerated atmosphere contributes to the detection of this peak. The holed lids used, the heating rate, the atmosphere and a packed sample are critical to observe the phenomenon.…”

“…The influence of procedural variables in the occurrence of the exothermic phenomenon has been mentioned before [11,13]. As reported in our previous work [11], a selfgenerated atmosphere contributes to the detection of this peak.…”

Caracterización de morteros mudéjares de la iglesia de San Gil Abad (Zaragoza, España): Investigación de la tecnología de fabricación de morteros históricos de yeso

“…In several mortars, the double signal at 672 ºC and 694 ºC ( Figure 5A) attributed to the loss of CO 2 , could be due to different carbonates (primary and secondary) or the presence of an amorphous one (22). Figura 5.…”

“…En algunos morteros la pérdida de CO 2 puede producirse en dos pasos, a 672 ºC y 694 ºC respectivamente (Figura 5A), lo que justificaría la presencia de carbonatos con un origen diferente (primario y secundario) o de carbonatos amorfos sin cristalinidad (22 In the majority of the samples, carbonates decomposition in the DTA curves seems to occur in a continuous form, without thermal steps; so the endothermic peaks of the different carbonates (calcite and dolomite) appear overlapped, making the identification of dolomite difficult. This circumstance, together with no evidence of dolomite in the paste under the OM study, has allowed the dolomite assignation as a minority component of the aggregates.…”