Late Triassic tholeiitic magmatism in Western Sicily: A possible extension of the Central Atlantic Magmatic Province (CAMP) in the Central Mediterranean area?

Late Triassic basaltic rocks crop out in the Lercara area in Western Sicily. Major and trace element composition, as well as Sr-Nd isotopic ratios (Sr-87/Sr-86(i) = 0.7074-0.7076; epsilon Nd-i = from -0.69 to -1.09) of the Lercara rocks shows many similarities with Large Ion Lithophile Elements (LILE)- and Light Rare Earth Elements (LREE)-rich tholeiitic basalts of the Central Atlantic Magmatic Province (CAMP), that erupted during the Mesozoic fragmentation of the Pangea supercontinent and subsequent opening of the Central Atlantic Ocean. The geochemical features of the Lercara igneous rocks, together with the spatial distribution of the similar to 200 Ma old CAMP rocks are unlikely to be associated with the arrival of a thermal anomaly in the form of a mantle plume and are more compatible with adiabatic melting of passively upwelling sub-lithospheric mantle. The original melts variably interacted with lower crustal rocks before reaching the surface. AFC modeling suggests two distinct differentiation paths including either simple mixing or assimilation-fractional crystallization processes involving lower crustal rocks. These interactions with continental crust indicate that an ocean basement most probably had not yet formed. (C) 2013 Elsevier B.V. All rights reserved.