## 5 Discussion  
### Bulk Rock  
Regarding the composition of the main oxides present in the granite waste at the quarry, the analytical results have highlighted a certain compositional homogeneity, which was quite predictable considering the limited area under investigation. From a compositional standpoint, the analyzed granite samples in this study were consistent with previous research conducted in the area [36; 46; 47], thus reflecting the characteristics of the U2 magmatic suite within the Corsica-Sardinia batholith [48]. Specifically, the analyzed granites exhibited a SiO\({}_{2}\) content (74.36 \(\pm\) 2.15 wt.%) falling within the wide range of SiO\({}_{2}\) values characterizing the U2 suite of the Corsica-Sardinia batholith, ranging from 53.56 to 77.14 wt.% [49]. The analyzed granites resulted in calc-alkaline, in accordance with the characteristics of the U2 magmatic suite [49]. The results presented in this paper, regarding \begin{table}
\begin{tabular}{c c} \hline \hline
**wt.\%** & **Mean \(\pm\) std. dev.** \\ \hline Crushing powder & 21.6 \(\pm\) 7.7 \\ Light diamagnetic & 66.4 \(\pm\) 6.5 \\ Intermediate diamagnetic & 1.5 \(\pm\) 0.5 \\ Heavy diamagnetic & 2.1 \(\pm\) 1.0 \\ Total & 91.6 \(\pm\) 1.7 \\ Total diamagnetic & 70.0 \(\pm\) 6.8 \\ \hline \hline \end{tabular}
\end{table} 
Table 10: Percentage yields of the different fractions obtained through the working process (9 processed samples). \begin{table}
\begin{tabular}{c c c c} \hline \hline
**ppm** & **Light** & **Intermediate** & **Heavy** \\ \hline La & 6.1 \(\pm\) 0.1 & 7.4 \(\pm\) 1.2 & 8.1 \(\pm\) 1.6 \\ Ce & 12 \(\pm\) 0 & 15 \(\pm\) 2 & 16 \(\pm\) 3 \\ Pr & 1.3 \(\pm\) 0.0 & 1.7 \(\pm\) 0.2 & 1.9 \(\pm\) 0.3 \\ Nd & 4.9 \(\pm\) 0.0 & 6.3 \(\pm\) 1.0 & 7.2 \(\pm\) 0.7 \\ Sm & 0.93 \(\pm\) 0.05 & 1.3 \(\pm\) 0.0 & 1.7 \(\pm\) 0.1 \\ Eu & 0.68 \(\pm\) 0.05 & 0.63 \(\pm\) 0.04 & 0.62 \(\pm\) 0.07 \\ Gd & 0.81 \(\pm\) 0.4 & 1.1 \(\pm\) 0.1 & 1.5 \(\pm\) 0.2 \\ Tb & 0.11 \(\pm\) 0.01 & 0.16 \(\pm\) 0.03 & 0.23 \(\pm\) 0.03 \\ Dy & 0.62 \(\pm\) 0.07 & 0.94 \(\pm\) 0.17 & 1.3 \(\pm\) 0.2 \\ Ho & 0.12 \(\pm\) 0.01 & 0.18 \(\pm\) 0.04 & 0.28 \(\pm\) 0.07 \\ Er & 0.34 \(\pm\) 0.05 & 0.45 \(\pm\) 0.07 & 0.76 \(\pm\) 0.15 \\ Tm & 0.05 \(\pm\) 0.01 & 0.07 \(\pm\) 0.02 & 0.13 \(\pm\) 0.04 \\ Yb & 0.36 \(\pm\) 0.05 & 0.50 \(\pm\) 0.08 & 0.89 \(\pm\) 0.20 \\ Lu & 0.07 \(\pm\) 0.01 & 0.09 \(\pm\) 0.02 & 0.16 \(\pm\) 0.04 \\ \(\Sigma\)REE & 29 \(\pm\) 0 & 36 \(\pm\) 5 & 41 \(\pm\) 7 \\ Th & 2.2 \(\pm\) 0.3 & 3.6 \(\pm\) 1.2 & 6.2 \(\pm\) 2.2 \\ U & 1.1 \(\pm\) 0.6 & 1.0 \(\pm\) 0.3 & 1.8 \(\pm\) 0.7 \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Mean (\(\pm\)std. dev.) REEs, thorium, and uranium composition in diamagnetic sub-samples (3 analyzed sub-samples per fraction). the metalluminous character, align with those of [PERSON] et al. [50], who stated that the high-K calc-alkaline association includes both metalluminous and weakly peraluminous felsic rocks. This may seem to contrast with the findings of [PERSON] et al. [23], who reported that the rocks from the three units of the Budduso pluton exhibit a slightly peraluminous character. This discrepancy can be explained by considering that this study analyzed samples from a very limited area of the entire Budduso pluton, specifically an area predominantly within the Middle Unit of the pluton. Regarding the REEs composition, the analyzed granites exhibited REE distribution patterns consistent with the characteristics of the U2 suite, characterized by moderate enrichment in LREEs, a slight negative europium anomaly, and a relatively flat trend of HREEs [49]. The Th/U ratio in the analyzed granite waste is \(\sim\)8, about double the chondritic Th/U ratio (=4) and is preserved during partial melting processes. Generally, fractional crystallization preferentially depletes Th and other REEs relative to U due to the early crystallization of Th-containing phases [51].