Keywords: Gabbroic rocks Crustal recycling Variscan orogeny Uthospheric mantle Spanish Central SystemThe gabbroic intrusions that crop out along the Spanish Central System (SCS) are geochemically heterogeneous, including primitive and evolved rocks. Differentiation is mainly related to fractionation of Cr-spinel and olivine, but mixing with coeval granitic magmas or crustal assimilation may have also played a role in the evolution of the most differentiated rocks. The most primitive uncontaminated gabbros show arc like trace element chondrite and primitive-mantle normalised patterns, characterised by large ion Iithophile elements (ULE)-Iigh t rare earth elements (tREE) enrichment, Sr and Pb positive and Nb-Ta-Ti negative anomalies. However, paleogeographic constraints suggest that the SCS was located far from subduction zones, so these geochemical signatures could be better explained by a recycling of continental crustal components within the mantle. The most primitive SCS gabbros expand the Sr-Nd isotopic compositional range of the Variscan basic magmatism in the Central Iberian Zone to more depleted values. This reflects a heterogeneous sub-continental Iithospheric mantle under central Spain ranging from a depleted mantle (ENd = +3.1. 87Sr/86Sr= 0.704) towards an isotopically enriched component (ENd = -1.6, 87Sr/ 86Sr = 0.706). Geochemical modelling suggests that mantle enrichment could be explained by minor lower crustal metapelitic granulite contamination (-2%). Additionally. the Sr-Nd-Pb isotopic ratios of the most primitive gabbros match the composition of the European subcontinental lithospheric mantle recorded in ultramafic xenoliths from western and central Europe.

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Should abandoned mine sites be eligible for some offi cial protection Wlder the umbrella of geoconser vation? Providing they have enough educational and scientifi c value, the answer is affmnative, and we suggest that they should be granted protection at the level of We analyze the advantages and disadvantages of abandoned mines and districts as geologic observational sites, through the analysis of two mining districts from SE Spain:Mazarron and Cartagena-La Union. We propose that if an abandoned mine site or district has enough geological value, not only the mining site but also the whole geologic block hosting the ore deposits should also be protected. In this respect, the Sierr a de Cartagena, hosting the Cartagena La Union district, is a valuable geological asset where an important chapter of the Alpine and late Alpine geologic history of SE Spain is written.

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