Textural and Mineralogical Analysis of Volcanic Rocks by µ-XRF Mapping. (10th May 2016)

• Record Type: Journal Article
• Authors: Germinario, Luigi; Cossio, Roberto; Maritan, Lara; Borghi, Alessandro; Mazzoli, Claudio
• Is Part Of: Microscopy and microanalysis. Volume 22:Number 3(2016:Jun.)
• Page Start: 690
• Page End: 697
• Publication Date: 2016-05-10
• Subjects: micro-XRF imaging, -- X-ray maps, -- quantitative texture analysis, -- modal composition, -- Euganean trachyte; Microscopy -- Periodicals; Microchemistry -- Periodicals; 502.82
• DOI: 10.1017/S1431927616000714
• Languages: English
• ISSNs: 1431-9276

Abstract

Abstract: In this study, µ -XRF was applied as a novel surface technique for quick acquisition of elemental X-ray maps of rocks, image analysis of which provides quantitative information on texture and rock-forming minerals. Bench-top µ -XRF is cost-effective, fast, and non-destructive, can be applied to both large (up to a few tens of cm) and fragile samples, and yields major and trace element analysis with good sensitivity. Here, X-ray mapping was performed with a resolution of 103.5 µ m and spot size of 30 µ m over sample areas of about 5×4 cm of Euganean trachyte, a volcanic porphyritic rock from the Euganean Hills (NE Italy) traditionally used in cultural heritage. The relative abundance of phenocrysts and groundmass, as well as the size and shape of the various mineral phases, were obtained from image analysis of the elemental maps. The quantified petrographic features allowed identification of various extraction sites, revealing an objective method for archaeometric provenance studies exploiting µ -XRF imaging.