Late Tertiary-Quaternary volcanism around Calatrava, within the Hercynian massif of central Spain, is alkaline mafic-ultramafic, with ∼250 centres, mainly monogenetic cones and vents, with melilitite the most abundant eruptive. Carbonatite may be expected in association with melilitite and a clear example of magmatic carbonate emerged from a brief field reconnaissance. It is a vent filled with a mixed eruption of glassy melilitite lapilli in a carbonate matrix. Levels and profiles of trace elements are inseparable from recognized carbonatite, and totally unlike those in local sedimentary limestone and caliche. C and O isotopes are the same as those reported for carbonatite ashes in other provinces. Carbonate is present as globules in the melilitite glass, and as inclusions within large clinopyroxene and olivine grains, which are largely xenocrystic. Euhedral spinels in melilitite and carbonate matrix are chromite mantled with titano-magnetite, reported previously only from high-temperature kimberlite. Wehrlite fragments indicate direct eruption from the mantle. Phlogopite and chromian spinel are found only as inclusions in the olivine, pointing to a phlogopite-carbonate mantle source region of the type favoured for carbonatite and melilitite melt generation. Calatrava represents the most southerly and westerly expression in mainland Europe of intra-continental carbonatite-melilitite volcanism. Follow-up field visits have shown that carbonate volcanism is extensive and voluminous throughout the province, requiring a long-term research programme.

A group of carbonate-rich tuffs are described from the Murumuli crater, Katwe-Kikorongo volcanic field, SW Uganda which contain abundant carbonatite pelletal lapilli, together with melilitite lapilli and a range of xenocrysts and lithic fragments including clinopyroxenites considered to be of mantle origin. The carbonatite lapilli consist essentially of Sr-bearing calcite and Mg-calcite which form quench-textured laths. The lapilli contain microphenocrysts of Ti-magnetite, perovskite, apatite, clinopyroxene, sanidine and altered prisms of melilite. A 7 cm long dolomite carbonatite bomb is described which displays a form typically assumed by lava clots erupted in a molten state. Chemical analyses of a tuff, the bomb and a range of minerals are presented. Carbonatite clearly played an important role in the Katwe-Kikorongo magmatism and it is suggested that carbonatite magma evolved from carbonate-bearing melilitite.

We present petrographic and mineralogical data for 21 mantle xenoliths (12 lherzolites, 8 wehrlites and 1 composite) selected from a suite of more than 70 samples collected from the Monticchio Formation, Mt. Vulture volcano, southern Italy. The xenoliths are rounded, coarse- to porphyroclastic-textured, and very fresh, with the following equilibrated mineral assemblages; olivine (Fo90–92), orthopyroxene (∼En89, Wo2.0), clinopyroxene (Mg90–92, 3–6% Al2O3, 1–1.5% Cr2O3), and chrome-spinel (14–20% MgO, ∼30–40% Cr2O3). Many xenoliths contain partial melt glasses and accessory sulphide (pentlandite) Some contain primary mica (phlogopite with ∼4% FeO, 1.8% Cr2O3, 1.4–2.8% TiO2) with slightly zoned rims (Fe-, Ti-, Al-enriched). One contains relics of garnet (pyrope; Mg84). Secondary veins in several xenoliths contain carbonate with significant Sr levels (∼0.5–1.0% SrO), occasional apatite and scarce melanite, all typical of carbonatites and presumably related to the host magma (melilitite/carbonatite). Although amphibole is a common megacryst in the same volcanic units, no primary amphibole was found in the xenoliths themselves. Calculated pressures and temperatures using a range of geothermometers/barometers give values of 14–22 kbar and 1050–1150°C. In particular, the En-Sp and Di-Sp thermo/barometers (Mercier, 1980) show a good positive correlation between P and T. The Monticchio xenoliths lie on the high-T side of an ‘oceanic’ geotherm. The xenolith geotherm is hotter than general heat flow values in this region at the current day (50 mWm−2) but it compares well with the high-pressure end of a typical alkaline continental rift.

Italian carbonatites form part of a suite with melilitites, normally an association characteristic of continental interiors; the perfect analogue of the Italian suite being the kamafugites (from the type area in SW Uganda, where the western branch of the East African Rift Zone cuts across the craton). The latter are commonly attributed to plume generation, whereas the Italian carbonatites, strung along the Appennine front, are usually linked to subduction. Evidently these two mechanisms are not essential, since neither can apply in both provinces. This conclusion is re-inforced by the related magmatism registered in both provinces in the Cretaceous. Phlogopite is ubiquitous in the mantle debris, and compositions from the two provinces overlap. Xenolithic phlogopites are distinct from cognate micas in the lavas, and from the carrier melt compositions, with similar distribution patterns in both suites. Kamafugitic magmas must be products of exceptional conditions, and added to the many near-identical magmatic features, the Italian and Ugandan volcanoes have sampled similar mantle conditions. Although the large scale geodynamic regimes are in total contrast, as are the deep mantle tomographic structures, the crucial common factor at the igneous province level is extensional tectonics. Extension, promoting release of volatiles (esp. CO2), is the vital trigger for this small volume, primary magmatism.