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High-MgO ultrapotassic rocks are found in four different areas of the Western Mediterranean basin associated in space and time with shoshonitic and calc-alkaline rocks. They represent different magmatic events at the active continental plate margin from Oligocene to Pleistocene. These rocks are found within the Western Alps (Northern Italy), in Corsica (France), in Murcia-Almeria (South-Eastern Spain), and in Southern Tuscany (Central Italy). Ultrapotassic terms are mostly lamprophyres, but olivine latitic lavas with a clear lamproitic affinity are also found. Lamproite-like rocks range from slightly silica under-saturated to silica over-saturated, and they are characterised by low Al 2 O 3 , CaO, and Na 2 O contents. They are plagioclase-free rocks, but K-feldspar is abundant beside other K-bearing phases. Shoshonitic and calc-alkaline rocks are invariably space associated to lamproites, and they either precede or follow them. High-Mg ultrapotassic rocks are characterised by strong enrichment of incompatible elements, which prevent further enrichment due to shallow level crustal contamination. K 2 O and incompatible element contents decrease passing from high-Mg ultrapotassic to high-Mg shoshonitic and calc-alkaline rocks suggesting that K and incompatible trace elements enrichments are a primary characteristic. Ultrapotassic to calc-alkaline rocks from Western Mediterranean regions, in spite of their different age of emplacement, are characterised by similar incompatible trace elements distribution. Depletion of High Field Strength elements with respect to Large Ion Lithophile elements is observed. Positive spikes at Th, U, and Pb, with negative spikes at Ba, Nb, Ta, Sr, P, and Ti, are common characteristics of ultrapotassic (lamproitic) to high-K calc-alkaline rocks. Ultrapotassic rocks are extremely enriched in radiogenic Sr and unradiogenic Nd with respect to the associated shoshonitic and calc-alkaline rocks. Different isotopic values are distinctive of the different magmatic provinces irrespective of magmatic affinities. 87 Sr/ 86 Sr i ranges between 0.71645 and 0.71759 for Western Alps lamproites, between 0.71226 and 0.71230 for Corsica lamproite, between 0.71642 and 0.72259 for Murcia-Almeria lamproites, and between 0.71578 and 0.71672 for Tuscany lamproites. Radiogenic Sr decreases along with K 2 O through shoshonitic to calc-alkaline rocks. Conversely 143 Nd/ 144 Nd i values increase with decreasing K 2 O, with the highest value of 0.51243 found for the one samples from Murcia-Almeria. Contrasting trends are observed among initial values of lead isotopes, but all falling well within the field of upper crustal rocks. Different trends of 207 Pb/ 204 Pb i and 208 Pb/ 204 Pb i vs. 206 Pb/ 204 Pb i for samples from the different provinces are observed. Several evidences indicate that most of the magmas of the different provinces have been generated in a depleted upper mantle (i.e., lithospheric) modified by metasomatism, but an asthenospheric component is also recognised in Corsica. At least two different s...

The dacite of El Joyazo contains abundant metapelitic xenoliths. These can be divided into two main types: garnet-biotite-sillimanite and spinel-cordierite xenoliths. In the xenoliths the widespread occurrence of rhyolitic glass as interstitial films, foliation-parallel layers and primary melt inclusions in all mineral phases indicates that these assemblages developed in the presence of a melt phase, i.e. during anatexis. The composition of the interstitial glass is comparable to that of the melt inclusions, suggesting that melt was locally produced. Phase equilibria indicate that anatexis occurred at P-T conditions of 5–7 kbar and 850±50°C.Several microstructural lines of evidence show that melt extraction was assisted by deformation during foliation development, and that on the scale of the xenoliths (up to 50 cm) melt escaped mainly by flow along foliation planes. The development of a syn-anatectic foliation also suggests that metapelitic rocks were involved in high-grade metamorphism and partial melting prior to fragmentation and dispersion in the host dacite.Mass balance calculations, based on the chemical composition of interstitial glass and melt inclusions in minerals, the bulk xenoliths and representative samples of potential pelitic sources support a model wherein the xenoliths represent restites after the extraction of 30 to 55 wt.% melt from graphitic metapelite protoliths similar to the rocks constituting the surrounding Alpujarride metamorphic complex.

The salt waters from the Emilia-Romagna sector of the Northern Apennine Foredeep have been investigated using major and trace element and stable isotope (d 2 H, d 18 O, d 37 Cl, d 81 Br and 87 Sr/ 86 Sr ratio). Ca, Mg, Na, K, Sr, Li, B, I, Br and SO 4 vs. Cl diagrams suggest the subaerial evaporation of seawater beyond gypsum and before halite precipitation as primary process to explain the brine's salinity, whereas saline to brackish waters were formed by mixing of evaporated seawater and water of meteoric origin. A diagenetic end-member may be a third component for mud volcanoes and some brackish waters. Salinization by dissolution of (Triassic) evaporites has been detected only in samples from the Tuscan side of the Apennines and/or interacting with the Tuscan Nappe. In comparison with the seawater evaporation path, Ca-Sr enrichment and Na-K-Mg depletion of the foredeep waters reveal the presence of secondary processes such as dolomitization-chloritization, zeolitization-albitization and illitization. Sulfate concentration, formerly buffered by gypsum-anhydrite deposition, is heavily lowered by bacterial and locally by thermochemical reduction during burial diagenesis. From an isotopic point of view, data of the water molecule confirm mixing between seawater and meteoric endmembers. Local 18 O-shift up to ?11% at Salsomaggiore is related to water-rock interaction at high temperature (&150°C) as confirmed by chemical (Mg, Li, Ca distribution) and isotopic (SO 4 -H 2 O) geothermometers. 37 Cl/ 35 Cl and 81 Br/ 79 Br ratios corroborate the Electronic supplementary material The online version of this article (marine origin of the brines and evidence the diffusion of halogens from the deepest and most saline aquifers toward the surface. The 87 Sr/ 86 Sr ratio suggests a Miocene origin of Sr and rule out the hypothesis of a Triassic provenance of the dissolved components for the analyzed waters issuing from the Emilia-Romagna sector of the foredeep. Waters issuing from the Tuscan side of the Apennines and from the Marche sector of the foredeep show higher 87 Sr/ 86 Sr ratios because of the interaction with siliciclastic rocks.

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