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Federico Lucci, Università Roma Tre (Italy)
Valentina Runci, Università Roma Tre (Italy)
Domenico Cozzupoli, Università Roma Tre (Italy)
Guido Giordano, Università Roma Tre (Italy)
David Phillps, Melbourne University (Australia)
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The Ross Sea Region, at the northeast edge of the Antarctic Plate, is characterised by the widespread occurrence of Cenozoic post-rift alkaline volcanism. Volcanism is dominantly monogenetic and it is characterised by the scatter occurrence of small scoria cones and lava flows. Monogenetic centres are generally associated to the occurrence of the major right-lateral strike-slip fault systems (NW-SE direction), which cut through the Transantartic Mountains across North Victoria Land. Where the fault systems change to extensional (with N-S direction), also the volcanism changes from monogenetic to shield volcanoes and stratovolcanoes.
The Mt. Melbourne is a quiescent, N-S trending quaternary stratovolcano, located between the Campbell and the Tinker glaciers, at the transition from the NNE-trending Southern Cross Mountains and the Ross Sea. Here, we present preliminary data from the volcanic rocks of the Mt. Melbourne volcanic complex. The study presents new stratigraphic data, the petrography and the geochemistry (major, minor and trace elements) of the main volcanic units, and their Ar-Ar age determinations. The identification of very high-Fe Olivine (Fa>90%) and Anorthoclase in different recent K-Trachytic products suggests a more complex evolution history than the classic one proposed for K-alkaline series. We interpret this evidence as one of the key-constraint to propose an evolutionary model of the recent volcanic activities of the Mt. Melbourne Volcano.
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