Storage and evolution of mafic and intermediate alkaline magmas beneath ross Island, Antarctica ...

• Main Authors: Iacovino, K, Oppenheimer, C, Scaillet, B, Kyle, P
• Format: Article in Journal/Newspaper
• Language: English
• Published: Oxford University Press 2016
• Subjects: alkaline volcanism; basanite; CO₂; phase equilibria; phonotephrite; Ross Island; Hut Point; Hut Point Peninsula; Antarc*; Antarctica
• Online Access: https://dx.doi.org/10.17863/cam.6946; https://www.repository.cam.ac.uk/handle/1810/261735

We present the results of phase equilibrium experiments carried out on basanite and phonotephrite lavas from Ross Island, Antarctica. Experiments were designed to reproduce the P-T-X-fO₂ conditions of deep and intermediate magma storage and to place constraints on the differentiation of each of the two predominant lava suites on the island, which are thought to be derived from a common parent melt. The Erebus Lineage (EL) consists of lava erupted from the Erebus summit and the Dry Valley Drilling Project (DVDP) lineage is represented by lavas sampled by drill core on Hut Point Peninsula. Experiments were performed in internally heated pressure vessels over a range of temperatures (1000-1150°C) and pressures (200-400 MPa), under oxidized conditions (NNO to NNO+3, where NNO is the nickel-nickel oxide buffer), with X_Η2O of the H₂O-CO₂ mixture added to the experimental capsule varying between zero and unity. The overall mineralogy and mineral compositions of the natural lavas were reproduced, suggesting ...