The hydrous component in leucite from Somma-Vesuvius and Roccamonfina volcanoes (southern Italy) - a FTIR spectroscopic investigation

Autor(en): Giuseppina Balassone, Anton Beran, Giuseppe Fameli, Carmine Amalfitano, Carmela Petti
Abstrakt: FTIR microspectroscopic data on the hydrous species occurring in leucites from different host rocks of Somma-Vesuvius and Roccamonfina volcanoes (southern Italy) are reported. All leucite samples contain significant amounts of structurally incorpored H2O molecules, confirmed by the H2O combination band at 5226cm-1. Three main types of infrared spectra can be discerned. Type 1, with a single band maximum at 3600cm-1 represents the typical spectrum of the Somma-Vesuvius samples, whereas type 2, revealing two additional band maxima at 3654 and 3506cm-1, characterises the Roccamonfina crystals. Type 3, showing a broad absorption band with a band maximum around 3390cm-1 was encountered only in two Vesuvian samples. Due to the presence of three discernible band maxima and of four to five deconvoluted component bands, the presence of at least two different H2O molecules can be derived. Estimates of the water content give values between 40 and 2777 wt.ppm for the Somma-Vesuvius samples; a zoning of the water content is inherent to the Vesuvian leucite crystals. Roccamonfina leucites show significantly higher and very homogeneous water contents in the range of 4602 to 5700 wt.ppm, suggesting the influence of an environmental factor on the growth of the crystals. Œ by E. Schweizerbart'sche Verlagsbuchhandlung 2006.
Organisation(en): Institut für Mineralogie und Kristallographie
Journal: Neues Jahrbuch für Mineralogie. Abhandlungen
Band: 182
Seiten: 149-156
Anzahl der Seiten: 8
ISSN: 0077-7757
Publikationsdatum: 2005
Peer-reviewed: Ja
ÖFOS 2012: 1051 Geologie, Mineralogie
Link zum Portal: https://ucrisportal.univie.ac.at/de/publications/abd96117-b92c-4ee8-b4e6-42eb2a227680

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