## 3 Results
### The Sines Massif
#### 3.1.3 Petrography, Mineral Chemistry, and Geochemistry
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline \multirow{3}{*}{**at \%**} & \multicolumn{8}{c}{**Cumulate Gabbro**} \\ \cline{2-11}  & \multicolumn{2}{c}{**Olivine**} & \multicolumn{2}{c}{**Pyroxene**} & \multicolumn{2}{c}{**Amphibole**} & \multicolumn{2}{c}{**Plagioclase**} & \multicolumn{2}{c}{**Imemite**} \\  & \multicolumn{2}{c}{\(n=5\)} & \multicolumn{2}{c}{\(n=3\)} & \multicolumn{2}{c}{\(n=4\)} & \multicolumn{2}{c}{\(n=4\)} & \multicolumn{2}{c}{\(n=2\)} \\  & **Min** & **Max** & **Min** & **Max** & **Min** & **Max** & **Min** & **Max** & **Min** & **Max** \\ \hline
**O** & 61.567 & 63.646 & 60.440 & 61.007 & 59.764 & 60.797 & 62.562 & 65.073 & 61.711 & 61.529 \\
**Si** & 10.764 & 11.855 & 15.941 & 16.566 & 12.313 & 12.986 & 13.904 & 14.814 & 0.804 & 0.600 \\
**Ti** & n.d. & n.d. & 0.350 & 0.439 & 1.637 & 1.771 & n.d. & n.d. & 15.833 & 16.344 \\
**Al** & 0.100 & 0.618 & 1.744 & 1.974 & 5.204 & 5.540 & 12.922 & 14.320 & 0.534 & 0.840 \\
**Mg** & 12.844 & 17.564 & 8.382 & 8.833 & 7.560 & 7.860 & n.d. & n.d. & 1.321 & 2.518 \\
**Fe** & 8.741 & 11.914 & 2.565 & 2.849 & 3.726 & 3.938 & n.d. & n.d. & 19.115 & 17.567 \\
**Ca** & 0.207 & 0.366 & 7.920 & 8.869 & 5.190 & 5.470 & 5.161 & 6.562 & 0.275 & 0.215 \\
**Mn** & 0.000 & 0.222 & 0.000 & 0.133 & 0.000 & 0.129 & n.d. & n.d. & 1.321 & 0.383 \\
**Na** & n.d. & n.d. & 1.056 & 1.122 & 2.124 & 2.390 & 1.661 & 2.558 & n.d. & n.d. \\ K & n.d. & n.d. & n.d. & n.d. & 0.524 & 0.584 & 0.000 & 0.295 & n.d. & n.d. \\ \hline
**Ca/(Ca + Na)** & & & & & & & 0.67 & 0.79 & & \\
**Mg/(Mg + Fe)** & 0.52 & 0.67 & & & & & & & & \\ \hline \multicolumn{10}{c}{**Gabbro-Diorite**} \\ \cline{2-11}  & \multicolumn{2}{c}{**Olivine**} & \multicolumn{2}{c}{**Pyroxene**} & \multicolumn{2}{c}{**Biotite**} & \multicolumn{2}{c}{**Plagioclase**} & \multicolumn{2}{c}{**Ilmenite**} \\  & \multicolumn{2}{c}{\(n=3\)} & \multicolumn{2}{c}{\(n=4\)} & \multicolumn{2}{c}{\(n=3\)} & \multicolumn{2}{c}{\(n=4\)} & \multicolumn{2}{c}{\(n=2\)} \\  & **Min** & **Max** & **Min** & **Max** & **Min** & **Max** & **Min** & **Max** \\ \hline
**O** & 57.796 & 58.844 & 58.346 & 58.900 & 55.762 & 58.686 & 59.420 & 61.240 & 58.265 & 60.052 \\
**Si** & 11.846 & 12.429 & 16.456 & 17.472 & 12.624 & 14.348 & 18.240 & 19.420 & 2.412 & 1.765 \\
**Ti** & n.d. & n.d. & 0.450 & 0.571 & 1.801 & 2.563 & n.d. & n.d. & 8.199 & 16.736 \\
**Al** & 0.416 & 1.429 & 1.614 & 2.020 & 6.975 & 7.953 & 11.050 & 12.140 & 1.611 & 0.656 \\
**Mg** & 11.298 & 12.612 & 8.771 & 9.051 & 6.689 & 8.348 & n.d. & n.d. & 2.007 & 1.685 \\
**Fe** & 14.933 & 16.937 & 3.237 & 3.617 & 5.626 & 6.764 & n.d. & n.d. & 26.594 & 18.319 \\
**Ca** & 0.213 & 0.426 & 8.111 & 9.361 & n.d. & n.d. & 3.960 & 5.220 & 0.598 & 0.272 \\
**Mn** & 0.375 & 0.446 & 0.130 & 0.160 & n.d. & n.d. & n.d. & 0.314 & 0.514 \\
**Na** & n.d. & n.d. & 0.982 & 1.132 & 1.005 & 1.639 & 1.633 & 2.530 & n.d. & n.d. \\
**K** & n.d. & n.d. & n.d. & n.d. & 4.523 & 4.547 & 0.270 & 0.390 & n.d. & n.d. \\ \hline
**Ca/(Ca + Na)** & & & & & & & & 0.61 & 0.72 & & \\
**Mg/(Mg + Fe)** & 0.40 & 0.46 & & & & & & & & \\ \hline \hline \end{tabular} \(n\)—number of analyses; n.d.—not determined.  
\end{table} 
Table 4: Mineral chemistry by scanning electron microscopy with energy-dispersive spectroscopy (SEM–EDS) in atomic percent (at %). Figure 8: Microphotographs of (**a**) cumulate gabbro and (**b**) gabbro-diorite under polarized light microscope. ol—olivine, cpx—clinopyroxene, plg—plagioclase, bt—biotite. The gabbro-diorite sample exhibited a hypidiomorphic texture and was found to be composed of plagioclase (50-60%) and clinopyroxene (20-25%), and, to a lesser extent, olivine (5-10%), biotite (10-15%), and ilmenite (5-10%). The sample was heterogeneous, with plagioclase-enriched layers  
Figure 9: XRD diffractograms of (**a**) cumulate gabbro and (**b**) gabbro-diorite.