Glasses in mantle xenoliths: A tool for understanding mantle processes

A new perspective in the evolution of mantle material was developed along with the concept of metasomatism, that is peridotitic mantle could not only be depleted through melting process, but it could also get enriched by migration and reaction with fluids coming from deeper mantle portions. Anydrous mantle parageneses alone are not able to generate the wide magma spectrum which characterise, for example, alkaline intraplate magmatism and the presence of hydrous minerals, such as amphibole and phlogopite, has to be invoked. However, not every magmatic event occurring in the astenospheric or even lithospheric mantle reach the surface and, hence, may be detected. Most very-low degree partial melts, such as Iamproites, Iamprophyres or carbonatites, rarely, if ever, reach the surface, but, nevertheless, they may deeply modify the overlying mantle portions. In this context mantle glasses represent a powerful tool for investigating these basic petrogenetic problems. Their study may contribute...