Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (4) Citing Articles via Google Scholar Google Scholar Articles by BINDI, L. Articles by MENCHETTI, S. Search for Related Content GeoRef GeoRef Citation

Crystal chemistry of clinopyroxenes from Linosa Volcano, Sicily Channel, Italy: implications for modelling the magmatic plumbing system

¹ Dipartimento di Scienze della Terra, Università degli Studi di Firenze, Via La Pira, 4, I-50121, Firenze, Italy
² CNR – Istituto di Geoscienze e Georisorse, Via La Pira 4, I-50121 Firenze, Italy
³ Dipartimento di Scienze della Terra, Università degli Studi di Perugia, Piazza Università, I-06100, Perugia, Italy

^* E-mail: crystal{at}unifi.it

The Island of Linosa is a small part of the large submarine volcanic complex which is located at the SW edge of the Linosa Graben, Sicily Channel. The island was formed between 1.06±0.10 and 0.53±0.07 Ma, through three main stages of activity: Paleo-Linosa, Arena Bianca and Monte Bandiera. Major and trace element data show that the compositional variability of the three activity stages is limited, with most of the rocks showing basaltic to hawaiitic composition. Evolved benmoreites and trachytes are found as lithics in some pyroclastic units of Paleolinosa. The mafic rocks of the three stages show porphyritic texture, with phenocryst assemblages characterized by olivine, clinopyroxene and plagioclase. The volume ratio of olivine vs. clinopyroxene decreases from early to late stages of activity in mafic rocks with comparable major element composition. Clinopyroxene phenocrysts from mafic rocks of the three stages have poorly variable composition, clustering in the augite field. Phenocrysts from the first activity stage (Paleo-Linosa), show a slight increase in TiO₂, Al₂O₃ and CaO, and a decrease of Fe₂O₃ (total) with the increasing SiO₂ content of the host rocks. Crystals from the second and the third stage (Arena Bianca and Monte Bandiera) display a slightly more restricted range of FeO_tot, frequently with very high MgO, Al₂O₃ and TiO₂ contents. Crystal chemical investigation of clinopyroxenes from rocks of the three stages with comparable degrees of evolution, revealed significant variation of structural parameters, in particular V_M1 and V_cell. These show a consistent decrease, passing from clinopyroxenes of the early stage to crystals extracted from the mafic lavas of stages 2 and 3. Given the similar compositional ranges of the host rocks, structural variations of clinopyroxenes are interpreted to reveal modifications of crystallization pressure, which increased, passing from Paleo-Linosa to the Arena Bianca and Monte Bandiera stages. Given this information, the observed crystal-chemical variations provide information on the depth of magma reservoirs and on the evolution of the plumbing system of Linosa volcano.

KEYWORDS: crystal chemistry, clinopyroxene, volcanic plumbing system, magma chamber, Linosa island, Italy

This article has been cited by other articles:

				M. di Bella, S. Russo, M. Petrelli, and A. Peccerillo Origin and evolution of the Pleistocene magmatism of Linosa Island (Sicily Channel, Italy) European Journal of Mineralogy, August 1, 2008; 20(4): 587 - 601. [Abstract] [Full Text] [PDF]

				G. Corti, M. Cuffaro, C. Doglioni, F. Innocenti, and P. Manetti Coexisting geodynamic processes in the Sicily Channel Geological Society of America Special Papers, January 1, 2006; 409(0): 83 - 96. [Abstract] [Full Text] [PDF]