## 3 Results
### Colour Analysis  
Tables S3 and S4 (Supplementary Materials) shows the results of the chromatic analysis carried out on the Sierra del Cuchillo samples (global samples) and dolomite clasts (all sections), respectively.  
The results of the colourimetric study reveal the great chromatic variety of the samples studied. Dolostone clasts colour range in lightness (L*) from pale to dark (reddish) brown. As expected, the studied total samples have a light colour and less colour variability because of the quantities of matrix and calcite cements, with L* values between 36.9 and 51.3 (Table S3, Supplementary Materials). Lightness of dolomite clasts varies from 20.4 to 80.7 (Table S4, Supplementary Materials). With the classification of the samples according to the Munsell system, it has been possible to analyse the colour of the dolomitic clasts,  
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Element and** **Form**} & \multirow{2}{*}{**Unit**} & \multicolumn{3}{c}{**Concentration**} & \multicolumn{3}{c}{**Element and**} & \multicolumn{3}{c}{**Concentration**} \\ \cline{3-10}  & & **Mean** & **SD** & **Max** & **Min** & **Form** & & **Mean** & **SD** & **Max** & **Min** \\ \hline SiO\({}_{2}\) & wt\% & 0.31 & 0.17 & 0.74 & 0.04 & Sr & ppm & 197.19 & 24.82 & 267.20 & 132.00 \\ Al\({}_{2}\)O\({}_{3}\) & wt\% & 0.14 & 0.09 & 0.37 & 0.01 & Ni & ppm & 2.97 & 1.07 & 5.00 & 0.50 \\ Fe\({}_{2}\)O\({}_{3}\) & wt\% & 0.15 & 0.10 & 0.42 & 0.05 & Co & ppm & 4.95 & 2.01 & 7.00 & <0.20 \\ MnO & wt\% & 0.01 & 0.00 & 0.01 & \textless{}0.01 & Ce & ppm & 1.52 & 1.03 & 5.00 & 0.40 \\ MgO & wt\% & 16.17 & 1.84 & 19.43 & 11.70 & Ba & ppm & 17.87 & 9.63 & 40.00 & 2.00 \\ CaO & wt\% & 35.81 & 2.51 & 41.28 & 29.56 & Cr & ppm & 4.39 & 3.02 & 12.00 & 1.00 \\ Na\({}_{2}\)O & wt\% & 0.22 & 0.08 & 0.42 & 0.07 & V & ppm & 5.20 & 3.55 & 17.00 & 1.00 \\ K\({}_{2}\)O & wt\% & 0.03 & 0.02 & 0.09 & \textless{}0.01 & Th & ppm & 4.92 & 3.83 & 13.00 & \textless{}0.20 \\ TiO\({}_{2}\) & wt\% & 0.01 & 0.00 & 0.02 & \textless{}0.01 & Nb & ppm & 2.23 & 1.83 & 6.00 & <0.10 \\ P\({}_{2}\)O\({}_{5}\) & wt\% & 0.07 & 0.12 & 0.82 & \textless{}0.01 & La & ppm & 3.46 & 2.94 & 11.00 & 0.50 \\ LOI & wt\% & 47.04 & 2.62 & 58.21 & 40.97 & Cs & ppm & 3.97 & 2.92 & 11.00 & <0.10 \\ Zr & ppm & 8.63 & 4.36 & 16.00 & 1.00 & Pb & ppm & 1.00 & 0.57 & 2.00 & 0.30 \\ Y & ppm & 0.97 & 0.49 & 2.00 & 0.30 & Mo & ppm & 1.91 & 1.34 & 5.00 & <0.10 \\ Rb & ppm & 2.80 & 1.21 & 5.00 & 0.60 & & & & & \\ \hline \hline \end{tabular}
\end{table}
Table 4: Chemical composition of dolostones (n: 48). Statistical parameters. (SD: standard deviation).  
avoiding the high luminosity effect of the white venules. Figure 9 shows the correlation of the two systems used by converting the Munsell categories to the L* a* b* scale, as well as with \(\Delta\)E (Chromatic or total colour difference), based on the CIElab system analysed with a colourimeter.  
Analysing only the dolomitic clasts (different shades of brown), the spectrum of Munsell colour categories, and their equivalents in the L* b* a* scale is much larger. For example, within the browns there are darker terms (5 YR3/2; 5 YR2/2; 10 YR2/2) that correspond to a numerically lower colour quality (chromatic difference). From the point of view of the textural types, it is observed that these darker browns correspond to mesocrystalline dolostones (Figure 9). Regarding the breccia type, no chromatic discrimination is observed. Regarding the mineralogical composition (ordering and stoichiometry) of the dolomites, there is no obvious correlation with colour (Figure 10).  
Figure 8: Mg/Ca vs. Fe\({}_{2}\)O\({}_{3}\) and Sr plots from the dolostones of the main breccia microfacies corresponding to all the studied sections.