Coexisting calc-alkaline and ultrapotassic magmatism at Monti Ernici,Mid Latina Valley (Latium, central Italy)

摘要: New major and trace element data, Sr-Nd-Pb-O isotopic ratios for volcanic mafic rocks outcropping at Monti Ernici in the Mid Latina Valley (southern Latium) are reported, with aim of investigating nature evolution Plio-Quaternary K-rich volcanism Central Italy. Petrographical geochemical studies allow us to identify ranging from ultrapotassic (HKS) shoshonitic (SHO), calc-alkaline (CA), these last ones being identified first time. The CA exhibit most primitive signatures Sr, Nd, Pb isotopes ( 87 Sr/ 86 Sr =0.706326–0.706654; 143 Nd/ 144 Nd = 0.512388–0.512361; 206 Pb/ 204 18.944–18.940). δ 18 O values variable (δ cpx +5.75 +7.08 ‰; ol +5.50 +6.23 ‰), suggesting interaction carbonate wall rocks. Radiogenic isotope incompatible elements distribution have several characteristic common equivalent Pontine Islands (Ventotene), Campania Aeolian arc volcanoes. Conversely, HKS closely resemble Roman Province 0.709679–0.711102; +6.27 ‰). high LILE (Large Ion Lithophile Elements: Rb, Cs, Th, U, K, LREE) HFSE (High Field Strength Ta, Nb, Zr, Hf, Ti), radiogenic compositions indicate that all suites contain subduction-related components, suggest a N-MORB-type mantle source variably contaminated by hydrous fluids and/or melts released undergoing slabs, possibly during two distinct stages metasomatism. coexistence ultra-alkaline sub-alkaline orogenic magmatism, combined tectonic, geophysical geological evidence, support possibility beneath central-southern Italy (Ernici-Roccamonfina Province) was vertically zoned produced different magma