Ultramafic xenoliths from the Veneto Volcanic Province (Italy): Petrological and geochemical evidence for multiple metasomatism of the SE Alps mantle lithosphere

Gasperini, Daniela; Bosch, Delphine; Braga, Roberto; Bondi, Mirella; Macera, Patrizia; Morten, Lauro

doi:10.2343/geochemj.40.377

Cited by 23 publications

(10 citation statements)

References 102 publications

(132 reference statements)

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“…Future investigations will be focused on other heterogeneous xenoliths suites sampled close to collisional boundaries such as those of the Veneto Volcanic Province in the Southern Alps to highlight possible analogies and differences at regional scale Gasperini et al, 2006;Morten, 1979). Table 4 Least-squares mass balance calculations to explain the petrogenesis of orogenic magmas such as the Betic lamproites (Turner et al, 1999).…”

Section: Discussionmentioning

confidence: 99%

Metasedimentary and igneous xenoliths from Tallante (Betic Cordillera, Spain): Inferences on crust–mantle interactions and clues for post-collisional volcanism magma sources

Bianchini

Braga

Langone

et al. 2015

Lithos

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Section: Discussionmentioning

confidence: 99%

Metasedimentary and igneous xenoliths from Tallante (Betic Cordillera, Spain): Inferences on crust–mantle interactions and clues for post-collisional volcanism magma sources

Bianchini

Braga

Langone

et al. 2015

Lithos

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“…They contain 50-80% olivine, pyroxene, and minor spinel, usually unaltered, which allows their classification as spinel lherzolites. These are key pieces of the Almadén geologic history because given that the upper mantle cannot be investigated by direct sampling, it follows that peridotite xenoliths hosted in basaltic rocks provide a powerful insight to define its main petrological features (e.g., Gasperini et al, 2006).…”

Section: Rock Typesmentioning

confidence: 99%

Intraplate mafic magmatism, degasification, and deposition of mercury: The giant Almadén mercury deposit (Spain) revisited

Higueras

Oyarzún

Lillo

et al. 2013

Ore Geology Reviews

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The giant Almadén mercury deposit (Spain) is hosted by the Lower Silurian Criadero Quartzite; in turn this ore-bearing rock unit is cross-cut by the so-called Frailesca unit, a diatreme body of basaltic composition. The geochemical characteristics of the Silurian to Devonian Almadén District volcanic units indicate that these rocks originated from an enriched, evolving mantle source that ultimately yielded basanites-nephelinites to rhyolites, through olivine-basalts, pyroxene-basalts, trachybasalts, trachytes, very scarce rhyolites, and quartzdiabases. The Silurian intraplate alkaline volcanism developed in submarine conditions which triggered widespread hydrothermal activity resulting in Hg ore formation and pervasive alteration to carbonates. The δ 18 O, δ 13 C, and δ 34 S isotopic signatures for carbonates and pyrite suggest different sources for carbon and sulfur, including magmatic and organic for the former and magmatic and sea water for the latter. The most important and efficient natural source of mercury on Earth is by far the volcanic activity, which liberates mercury via quiescent degassing and catastrophic (Plinian) events when eruptions can overwhelm the atmospheric budget of Hg. Thus, we suggest that CO 2 degasification and coeval distillation of mercury from the volcanic rocks fed the huge hydrothermal system that led to massive deposition of mercury at Almadén. Build up of Hg 0 gas in magmatic chambers during waning rifting in the Late Ordovician, followed by renewed volcanism in the Early Silurian, would have resulted in massive degasification of the accumulated mercury. Part of this mercury went into the Criadero Quartzite leading to formation of the huge Almadén deposit and others (e.g., El Entredicho) along the same stratigraphic level. Progressive depletion of the deep seated magmatic Hg stock would have resulted in a drastic reduction in ore deposit size after the Lower Silurian when smaller deposits formed (e.g., Las Cuevas).

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“…12) around an average composition of Hf/Zr ratio of 0.023 and Ta/Nb ratio of 0.061, comprising 193 anorogenic Mediterranean samples which classify consistently as basanite [32]. Genuine basanites are rare in Italy and restricted to the Veneto Province [33] and Hyblean plateau [34]. In addition, there are some samples from the Roman Region [35].…”

Section: Petrogenesismentioning

confidence: 99%

Magma evolution inside the 1631 Vesuvius magma chamber and eruption triggering

et al. 2017

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Vesuvius is a high-risk volcano and the 1631 Plinian eruption is a reference event for the next episode of explosive unrest. A complete stratigraphic and petrographic description of 1631 pyroclastics is given in this study. During the 1631 eruption a phonolite was firstly erupted followed by a tephritic phonolite and finally a phonolitic tephrite, indicating a layered magma chamber. We suggest that phonolitic basanite is a good candidate to be the primitive parental-melt of the 1631 eruption. Composition of apatite from the 1631 pyroclastics is different from those of CO 2 -rich melts indicating negligible CO 2 content during magma evolution. Cross checking calculations, using PETROGRAPH and PELE software, accounts for multistage evolution up to phonolite starting from a phonolitic basanite melt similar to the Vesuvius medieval lavas. The model implies crystal settling of clinopyroxene and olivine at 6 kbar and 1220 ∘ C, clinopyroxene plus leucite at a pressure ranging from 2.5 to 0.5 kbar and temperature ranging from 1140 to 940 ∘ C. Inside the phonolitic magma chamber K-feldspar and leucite would coexist at a temperature ranging from from 940 to 840 ∘ C and at a pressure ranging from 2.5 to 0.5 kbar. Thus crystal fractionation is certainly a necessary and probably a sufficient condition to evolve the melt from phono tephritic to phonolitic in the 1631 magma chamber. We speculate that phonolitic tephrite magma refilling from deeper levels destabilised the chamber and triggered the eruption, as testified by the seismic precursor phenomena before 1631 unrest.

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Ultramafic xenoliths from the Veneto Volcanic Province (Italy): Petrological and geochemical evidence for multiple metasomatism of the SE Alps mantle lithosphere

Cited by 23 publications

References 102 publications

Metasedimentary and igneous xenoliths from Tallante (Betic Cordillera, Spain): Inferences on crust–mantle interactions and clues for post-collisional volcanism magma sources

Metasedimentary and igneous xenoliths from Tallante (Betic Cordillera, Spain): Inferences on crust–mantle interactions and clues for post-collisional volcanism magma sources

Intraplate mafic magmatism, degasification, and deposition of mercury: The giant Almadén mercury deposit (Spain) revisited

Magma evolution inside the 1631 Vesuvius magma chamber and eruption triggering

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