Trans-crustal structural control of CO<sub>2</sub>-rich extensional magmatic systems revealed at Mount Erebus Antarctica.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 35637190.
- Also identified by DOI 10.1038/s41467-022-30627-7 and PMC identifier 9151792.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Erebus volcano, Antarctica, with its persistent phonolite lava lake, is a classic example of an evolved, CO<sub>2</sub>-rich rift volcano. Seismic studies provide limited images of the magmatic system. Here we show using magnetotelluric data that a steep, melt-related conduit of low electrical resistivity originating in the upper mantle undergoes pronounced lateral re-orientation in the deep crust before reaching shallower magmatic storage and the summit lava lake. The lateral turn represents a structural fault-valve controlling episodic flow of magma and CO<sub>2</sub> vapour, which replenish and heat the high level phonolite differentiation zone. This magmatic valve lies within an inferred, east-west structural trend forming part of an accommodation zone across the southern termination of the Terror Rift, providing a dilatant magma pathway. Unlike H<sub>2</sub>O-rich subduction arc volcanoes, CO<sub>2</sub>-dominated Erebus geophysically shows continuous magmatic structure to shallow crustal depths of < 1 km, as the melt does not experience decompression-related volatile supersaturation and viscous stalling.