Recent hydrovolcanic deposits with evidence of magmatic immiscibility on Deception Island, Antarctica
Outcrops of hydro-volcanic deposits on Deception Island are stratigraphically re-classified. The sequence was assigned to a pre-caldera phase, but it has very different compositional and consolidation characteristics, enabling it to be differentiated and redefined as a new unit. In this paper, it is...
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2004
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Online Access: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v59_n3_p495_Caselli https://hdl.handle.net/20.500.12110/paper_00044822_v59_n3_p495_Caselli |
Summary: | Outcrops of hydro-volcanic deposits on Deception Island are stratigraphically re-classified. The sequence was assigned to a pre-caldera phase, but it has very different compositional and consolidation characteristics, enabling it to be differentiated and redefined as a new unit. In this paper, it is stratigraphically relocated as a historical eruption, on the basis of its compositional similarity to ash-falls in Bransfield Basin. The studied deposits are bimodal (basaltic/rhyolitic) implying a relationship with magma immiscibility. The occurrence of more acidic periods would allow relatively more explosive vents with greater particle dispersion to take place. © 2004 Asociación Geológica Argentina. |
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