A combined study of noble gases, trace elements, and Sr-Nd isotopes for alkaline and tholeiitic lava from the Hyblean Plateau (Italy)

Although the samples show the same He isotope signatures as mantle harzburgite xenoliths from Hyblean Miocenic diatremes, the distribution of some trace element pairs argues against a close geochemical parentage between the Pliocenic-Pleistocenic volcanic rocks and mantle xenoliths. This can be reconciled if the xenoliths come from mantle portions whose trace element distribution was modified by carbonatitic metasomatic melts responsible for the enrichment of incompatible trace elements but not able to carry significant He amounts.