SGTSG

Stagnant slabs in the transition zone linked to widespread volcanism in Eastern Australia and Zealandia Dr. Ben Mather , Prof. Dietmar Muller, Dr. Maria Seton, Dr. Nick Mortimer, Saskia Ruttor Regional context Interested in the last 100 million years of tectonic evolution when Australia separated from Antarctica. The region now known as “Zealandia” is most likely a fragment of continental crust that was rafted off mainland Australia. Mortimer et al. (2017), GSA today ← Muller et al. (2016), EPSL Volcanic activity 3 major hotspot chains: Tasmantid seamount chain Lord Howe seamount chain Cosgrove track These chains are made up of central volcanoes with leucitite-bearing eruptions. However, there smaller lava field volcanoes that exhibit no time dependence. Lava shield volcanoes outnumber eruptions from central volcanoes. Hotspot chains What drives non-age progressive eruptions in Eastern Australia and Zealandia? Previous geodynamic studies Convective eddy that forms at the trailing edge of sharp discontinuities in lithospheric thickness Davies et al. 2014, Farrington et al 2010, Demidjuk et al. 2007 Shear-driven upwellings in the mantle that induce partial melting at the base of the lithosphere Conrad et al. 2011 Edge-driven convection Asthenopheric shear

Oct 18, 2019 9:00 AM — 10:00 AM