Abstract
An extensive set of samples representative of the evolution of Etna since the beginning of its activity in the Quaternary has been analyzed for trace element contents by neutron activation on whole rock samples. Major element data were taken fromTanguy (1980).
Several petrogenetic processes have played a role in the observed chemical variations:
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binary trace element plots form linear arrays extrapolating to the origin for most second row and higher transition elements and the rare alkali metals thus indicating their hygromagmaphile (HYG) character;
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3d transition elements show two types of behavior when plotted against an HYG element. Concentrations remain relatively constant for the less evolved rocks in the range from tholeiite through transitional basalts to alkali basalts. On the contrary, concentrations drop rapidly in the series evolving from alkali basalts to trachytes;
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in addition to the latter two general trends, geochemical regularities specific to Etnean lavas are born out. Rare alkali metals, as well as potassium, for instance, show a trend of abnormal enrichment in the most recent historical eruptions.
The recurrence in time of rather primary magmas indicates that the petrogenetic evolution of the lavas cannot be explained by the differentiation of a single batch of mantle derived magma.
However, the chemical composition of the mantle source has remained relatively homogeneous with a nature very near the chondritic one. Mineralogically, the source must differ from that for oceanic basalts to account for Th/Ta differences. Early tholeiitic primary magma evolving into later alkali basalts is adequately modeled by variations of the degree of partial melting of a closed system source.
Highly evolved products have episodically been emitted as a result of extensive crystal fractionation, during which no basalts are erupted. These episodes are abruptly interrupted by the eruption of basalts presumably indicating recharge of the magma plumbing system by pristine mantle derived material.
Selective contamination in alkali elements from the sedimentary basement is also indicated by the data. The presence of partially digested sedimentary xenoliths is an additional argument for this process.
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Bibliographie
Barberi F., Bizouard H., Capaldi G., Ferrara G., Gasparini P., Innocenti F., Joron J-L., Lambert B., Treuil M., Allegre J-C., 1978,Age and Nature of Basalts from the Thyrrhenian Plain. DSDP leg 42 A site 373 A. Initial Report of the Deep Sea Drilling Project,XVII, I, p. 509.
Chayla B., Jaffrezic H, Joron J-L., 1973,Analyse par activation dans les neutrons épithermiques. C.R. Acad. Sci. Paris,277, D, p. 273–275.
Carter S-R. andCivetta L., 1977,Genetic Implications of the Isotope and Trace Element Variations in the Eastern Sicilian Volcanics. Earth Planet. Sci. Letters.,36, p.168–180.
Clocchiatti R., Joron J.-L. etTreuil M., 1986,Interaction entre le magma de l'Etna et son soubassement sédimentaire: arguments en faveur de la contamination sélective en alcalins des laves récentes. Bull. PIRPSEV (in press).
--,Metrich N., 1984,La cristallisation des pyroclastes des éruptions etnéennes de 1669 (Mt. Rossi) et de 1982 Mt. Silvestri). Témoignages et contamination. Bull. PIRPSEV,92.
Condomines M., Tanguy J.-C., Kieffer G., Allegre C.-J., 1982,Magmatic Evolution of a Volcano Studied by 230 Th-238 U Disequilibrium and Trace Elements Systematics: The Etna Case. Geochim. Cosmochim. Acta.,46, p. 1397–1416.
Cristofolini R., Ghiara M-R., Stanzione D. andTranchina A., 1984,Petrologic and Geochemical Features of Rocks from Recent Eruptions at Mt. Etna. Neues Jahrbuch Mineral. Abh.,149, 3, p. 267–282.
Hamelin B., Lambert B., Joron J-L., Treuil M. andAllegre J-C., 1979,Geochemistry of Basalts from the Thyrrenian Sea. Nature,278, 5707, p. 832.
Jaffrezic H., Joron J-L., Treuil M., Wood D-A., 1980,A Study of the Precision Attained by Neutron Activation Analysis Using International Standard Rocks GSN and BCR 1 as Examples. Jour of Radioanal. Chem.,55, 2, p. 417.
Joron J-L., Bougault H., Wood D-A., Treuil M., 1978,Application de la géochimie des éléments en traces à l'étude des propriétés et des processus de genèse de la croûte océanique et du manteau supérieur. Bull. Soc. géol. Fr.,XX, 4, p. 521.
—— etTreuil M., 1977,Utilisation des propriétés des éléments fortement hygromagmaphiles pour l'étude de la composition chimique et de l'hétérogénéité du manteau. Bull. Soc. géol. Fr., no spécial Géochimie,XIX, 6, p. 1197.
—— ——,Jaffrezic H., Villemant B., 1980,Etude géochimique des éléments en trace dans les séries de roches volcaniques du rift d'Asal. Identification et analyse des processus d'accrétion. Bull. Soc. géol. Fr.,XXII, 6, p. 851–861.
—— —— —— ——,Richard O., 1980,Géochimie des éléments en traces du magmatisme de l'Afar et de la mégastructure de la Mer Rouge. Afar — Golfe d'Aden. Implications pétrogenétiques et géodynamiques. Bull. Soc. géol. Fr.,XXII, 6, p. 945–957.
Kieffer G., Tanguy J-C., 1976,Présence de tholéiites porphyriques à la base de l'Etna primordial: leur importance magmatologique, volcanologique et morphostructurale. C.R. Acad. Sci. Paris,283, D, p. 1703–1706.
Romano R., 1982,Succession of the Volcanic Activity in the Etnean Area. Mem. Soc. Geol. It.,23, p. 27–48.
Tanguy J-C., 1966,Les laves récentes de l'Etna. Bull. Soc. géol. Fr.,8, VIII, p. 201–217.
——, 1978,Tholeitic Basalt Magmatism of Mount Etnea and Its Relations with the Alkaline Series. Contrib. Mineral. Petrol.,66, p. 51–67.
--, 1980,L'Etna. Etude pétrologique et paléomagnétique: implications volcanologiques. Thèse Doctorat ès Sciences. Paris VI.
-- etClocchiatti R., 1985,The Etnean Lavas, 1977–83. Petrology and Mineralogy, Bull. PIRPSEV,97.
—— etKieffer G., 1976,The 1974 Eruption of Mount Etna. Bull. Volcanol.,40-4, p. 239–252.
Treuil M. etJoron J-L., 1975,Utilisation des éléments hygromagmaphiles pour la simplification de la modélisation quantitative des processus magmatiques. Soc. Ital. Miner. Petrol.,XXXI, p. 125–174.
—— etVaret J., 1973,Critères volcanologiques pétrologiques et géochimiques de la genèse et de la différenciation des magmas basaltiques: exemple de l'Afar. Bull. Soc. géol. Fr.,XV, p. 506–540.
——, 1982,Géochimie du manteau: distribution des éléments en traces dans les magmas basaltiques. 2:proposition d'une méthode d'identification des effets de sources et de distinction de ceux de la fusion partielle et de la différenciation des magmas. Exemple des domaines d'expansion océanique. Jour Radioanal. Chem.,71, 1.2, p. 347–363.
—— —— ——,Villemant B., etCalas G., 1979,Géochimie des éléments hygromagmaphiles, coefficients de partage minéraux/liquide et propriétés structurales de ces éléments dans les liquides magmatiques. Bull. Soc. Fr. Minér. Cristal.,102, 402–409.
Villemant B., Treuil M., 1983,Comportement des éléments en traces et majeurs dans la série alcaline du Velay: comparaison avec la Chaîne des Puys (Massif Central, France). Bull. Minéral.,106, p. 465–486.
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Joron, J.L., Treuil, M. Étude géochimique et pétrogenèse des laves de l'Etna, Sicile, Italie. Bull Volcanol 47, 1125–1144 (1984). https://doi.org/10.1007/BF01952368
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DOI: https://doi.org/10.1007/BF01952368