Lamprophyre as the Source of Zircon in the Veneto Region, Italy

Minerals

Daria Zaccaria¹  Maria Grazia Perna¹  Gianluigi Rosatelli¹  Noemi Vicentini¹  Francesco Stoppa¹  Emma Humphreys-Williams²  Will Brownscombe²  Victor V. Sharygin³ 

[1] DiSPUTer, University “G. d’Annunzio” Chieti-Pescara, 66100 Chieti, Italy;The Natural History Museum,London SW7 5BD, UK;VS Sobolev Institute of Geology and Mineralogy, Siberian Branch of the RAS, 630090 Novosibirsk, Russia;

关键词: zircon;    lamprophyres;    U–Pb dating;    zircon geochemistry;    Veneto region;    Italy;   

DOI  :  10.3390/min11101081

来源: DOAJ

【 摘 要 】

Discrete zircons, up to 9 mm in length, occur in alluvial deposits from the Veneto area. They are likely derived from the disaggregation of lamprophyric rocks belonging to a regional, pervasive dyke-swarm. Zircon and REE phases occur in both alkaline lamprophyres and connate calcite-bearing felsic lithics and their debris in lamprophyre breccia. We present 36 new complete U–Pb and trace element analyses of zircons and associated inclusions. We used a statistical approach on a larger dataset using new and literature data to evaluate the confidence figure to give an estimation of age of zircons. Inclusions suggest a genetic link with an S–CO₂–ZrO–BaO–SrO–CaO-rich fluid/melt possibly associated with carbonate-rich alkaline parental magma and a metasomatised mantle source. This paper confirms the importance of calcite–syenite and lamprophyre genetic link and zircon magmatic origin, in contrast with hydrothermal and metamorphic zircons. U–Pb dating by LA-ICP-MS provides time constrains (40.5–48.4 Ma, Lutetian), consistent with the age of the alkaline magmatic event. Trace element data indicate a link to anorogenic magmatism associated with mantle upwelling. Complex zoning is highlighted by cathodoluminescence images. The Veneto zircons are helpful for regional geological information and may have commercial potential as a critical resource for green technologies.

【 授权许可】

Unknown