Crystal chemistry of clinopyroxene from alkaline undersaturated rocks of the Monte Vulture Volcano, Italy

Bindi, Luca; Cellai, Daniela; Melluso, Leone; Conticelli, Sandro; Morra, Vincenzo Brescia; Menchetti, Silvio

doi:10.1016/s0024-4937(98)00069-3

Cited by 45 publications

(17 citation statements)

References 36 publications

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“…In both the complexes, the clinopyroxenes have compositional spectrum ranging from 'Q' (diopside-augite) to 'J' (aegirine, aegirine-augite type (Morimoto et al 1989). The trends of clinopyroxene variation is as per with almost similar variations noted in other ultramafic-maficalkaline-carbonatite complexes of the other parts the world (Bindi et al 1999).…”

Section: Pyroxene Thermometrysupporting

confidence: 56%

Evaluation of phase chemistry and petrochemical aspects of Samchampi-Samteran differentiated alkaline complex of Mikir Hills, northeastern India

et al. 2010

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The Samchampi-Samteran alkaline complex occurs as a plug-like pluton within the Precambrian granite gneisses of Mikir Hills, Assam, northeastern India and it is genetically related to Sylhet Traps. The intrusive complex is marked by dominant development of syenite within which ijolitemelteigite suite of rocks is emplaced with an arcuate outcrop pattern. Inliers of alkali pyroxenite and alkali gabbro occur within this ijolite-melteigite suite of rocks. The pluton is also traversed by younger intrusives of nepheline syenite and carbonatite. Development of sporadic, lumpy magnetite ore bodies is also recorded within the pluton. Petrographic details of the constituent lithomembers of the pluton have been presented following standard nomenclatorial rules. Overall pyroxene compositions range from diopside to aegirine augite while alkali feldspars are typically orthoclase and plagioclase in syenite corresponds to oligoclase species. Phase chemistry of nepheline is suggestive of Na-rich alkaline character of the complex. Biotite compositions are typically restricted to a uniform compositional range and they belong to 'biotite' field in the relevant classification scheme. Garnets (developed in syenite and melteigite) typically tend to be Ti-rich andradite, which on a closer scan can be further designated as melanites. Opaque minerals mostly correspond to magnetite. Use of Lindsley's pyroxene thermometric method suggests an equilibration temperature from ∼ 450 • -600 • C for melteigite/alkali gabbro and ∼ 400 • C for syenite. Critical assessment of other thermometric methods reveals a temperature of equilibration of ∼ 700 • -1350 • C for ijolite-melteigite suite of rocks in contrast to a relatively lower equilibration temperature of ∼ 600 • C for syenite. Geobarometric data based on pyroxene chemistry yield an equilibration pressure of 5.32-7.72 kb for ijolite, melteigite, alkali pyroxenite, alkali gabbro and nepheline syenite. The dominant syenite member of the intrusive plug records a much higher (∼ 11 kb) equilibration pressure indicating a deeper level of intrusion. Major oxide variations of constituent lithomembers with respect to differentiation index (D.I.) corroborate a normal magmatic differentiation. A prominent role of liquid immiscibility is envisaged from field geological, petrographic and petrochemical evidences. Tectonic discrimination diagrams involving clinopyroxene chemistry strongly suggest within plate alkaline affinity for the parental magma which is in conformity with the regional plume tectonics.

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Section: Pyroxene Thermometrysupporting

confidence: 56%

Evaluation of phase chemistry and petrochemical aspects of Samchampi-Samteran differentiated alkaline complex of Mikir Hills, northeastern India

et al. 2010

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“…Fig. 4 Fino et al, 1982Fino et al, , 1986Melluso et al, 1996;Bindi et al, 1999;Beccaluva et al, 2002, De Astis et al, 2006 intercalations of pyroclastic products (rich in alkali, feldspathoids, feldspars, pyroxenes, plagioclases etc.). These volcanic deposits are confined by impermeable layers, and could entrap saline groundwaters (Spilotro et al, 2005) derived from the leaching of weathering products of feldspathoids belonging to the sodalite group.…”

Section: +mentioning

confidence: 99%

Groundwaters of Mt. Vulture volcano, southern Italy: Chemistry and sulfur isotope composition of dissolved sulfate

et al. 2010

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We report the chemical composition of groundwaters-including the first data on the sulfur isotopic composition of dissolved sulfate-from the volcanic aquifers of Mt. Vulture, one of the most important hydrological basins of southern Italy. A total of 27 water samples taken at different altitudes among drilled wells and springs were collected. The majority of groundwaters have a bicarbonate alkaline and bicarbonate alkaline-earth composition. High-salinity waters are sulfatebicarbonate alkaline in composition. The water-rock interaction process is mainly affected from uprising of CO 2 -rich gases which cause an increase of the water acidity promoting basalt weathering with an enrichment in certain chemical species (i.e., Na + , Ca 2+ , SO 4 2-) and a high total carbon content. The δ 34 S values of dissolved sulfate ranging from +4‰ to +8.6‰ can be explained by leaching of volcanites. Higher δ 34 S values (from 9.6‰ to 10.4‰) detected in a few water springs can be ascribed either to the interaction with the pyroclastic layer rich in feldspathoids, such as haüyna, that have sulfur isotopic compositions up to +10.6‰ or animal manure contamination inducing localized bacterial sulfate reduction with an increase in the δ 34 S of sulfate. Taking into account that Upper Triassic evaporite deposits have higher δ 34 S values (from +13.5‰ to +17.4‰,) than those measured in all water samples the dissolution of these deposits could be excluded.

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“…The rock sample, collected at the Monte Vulture Volcano, the easternmost volcanic district of the Roman Comagmatic Province, was found to be mainly constituted of clinopyroxene grains. [21] Ag hydrosols were prepared by reduction of AgNO 3 (99.9999% purity, Aldrich) with excess NaBH 4 (99.9% purity, Aldrich) in extrapure distilled water, according to the Creighton's procedure. [22] NaCl (Aldrich, purity 99.999%) was added in small amounts (∼10 −3 M) under prolonged stirring in order to increase SERS enhancement and stability of the colloidal suspensions.…”

Section: Methodsmentioning

confidence: 99%

Surface‐enhanced Raman micro‐spectroscopy of DNA/RNA bases adsorbed on pyroxene rocks as a test ofin situsearch for life traces on Mars

Muniz‐Miranda

Gellini

Salvi

et al. 2009

J Raman Spectroscopy

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SERS spectroscopy with 785-nm laser excitation minimizing fluorescence emission is exploited for remote analysis of life traces in an extraterrestrial environment. Adenine and guanine, nucleobases present in both DNA and RNA strands, and microRNA containing adenine and guanine have been used as testing ligands for identifying traces of nucleic acids in Martian rocks and sediments. SERS spectra of these nucleobase samples adsorbed on pyroxene substrates have been investigated with micro-Raman apparatus in the absence of sample manipulation and inducing the signal enhancement by deposition of silver colloidal nanoparticles over the pyroxene/nucleobase substrates. An order-of-magnitude estimate of the sample amount responsible for the SERS spectra is given.

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Crystal chemistry of clinopyroxene from alkaline undersaturated rocks of the Monte Vulture Volcano, Italy

Cited by 45 publications

References 36 publications

Evaluation of phase chemistry and petrochemical aspects of Samchampi-Samteran differentiated alkaline complex of Mikir Hills, northeastern India

Evaluation of phase chemistry and petrochemical aspects of Samchampi-Samteran differentiated alkaline complex of Mikir Hills, northeastern India

Groundwaters of Mt. Vulture volcano, southern Italy: Chemistry and sulfur isotope composition of dissolved sulfate

Surface‐enhanced Raman micro‐spectroscopy of DNA/RNA bases adsorbed on pyroxene rocks as a test ofin situsearch for life traces on Mars

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