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133 during the subduction of sedimentary materials of the same type as those that currently constitute the Serie Negra. The Nd model ages obtained in the mafic and siliciclastic rocks of the Montemolín Formation are there- fore significantly older than those obtained for the mafic rocks of the Mérida Ophiolite (Figure 8a). This important difference in TDM ages clearly indicates that the two groups of mafic rocks derive from partial melting of different mantle sections and experience different inten- sities of modification. The mantle section that generated Figure 6. Tectonic setting discrimination diagrams for the mafic rocks. a) Nb/Y-Th/Yb diagram (Shervais 1982; Pearce 2008, 2014). b) Ti-V diagram (Shervais 1982; Pearce 2014). c) La/Yb-Th/Nb diagram (Hollocher et al . 2012). d) N-MORB-normalized incompatible, immobile element patterns (normalizing N-MORB values after Sun and McDonough 1989). Symbols are as in Figure 3 INTERNATIONAL GEOLOGY REVIEW 13 Mérida Ophiolite (SW Iberia)