GeoBremen2017: Biases in the geochemical record of oceanic magmatism

At the end of summer 2017, I gave a talk at the annual meeting of the Deutsche Mineralogische Gesellschaft (DMG) at GeoBremen2017. My talk focussed on the results of my 3-kbar experiments on primtive Icelandic basalts, and how they show that depleted mantle melts are much less likely to survive being processed during their ascent through the crust than enriched melts. In other words, enriched melts are more likely to erupt at the surface and depleted melts are more likely to freeze at depth, fundamentally biasing the record of oceanic magmatism we see at the surface. You can download my slides here.

Experimental liquid lines of descent (LLD) for melts from the depleted Háleyjabunga (Hál) and enriched Stapafell (Sta) eruptions. Grey dots show Icelandic compositions from the Western Volcanic Zone and Reykjanes Peninsula (Shorttle & Maclennan, 2011). The arrow shows where compositions were resynthesised to mimic fractional crystallisation.

IAVCEI: The effect of mantle-derived variability on the mineralogy of primitive basalts: Experimental constraints from Icelandic systems

In summer 2017, I presented a poster at the excellent IAVCEI Scientific Assembly in Portland. My contribution summarised the findings of my experimental work in Hannover so far. In particular, I focussed the effects of mantle-dervied heterogeneity on the phase equilibria of primitive Icelandic basalts in the 1–7 kbar range. You can download a copy of my poster here.

False-colour backscattered electron image of the run products of an experiment on the Háleyjabunga eruption, Iceland

Goldschmidt: Magma plumbing systems and plagioclase-hosted melt inclusions

In summer 2016, I presented two abstracts at Goldschmidt in Yokohama, Japan. In my invited contribution, I summarised how a range of petrological and geochemical observations can be combined to reconstruct magma plumbing system characteristics (slides). In my second contribution, I discussed the reliability of estimating magma volatile contents by measuring primitve plagioclase-hosted melt inclusions (slides).

Magma pluming systems in th EVZ.
Magma plumbing systems in the Eastern Volcanic Zone of Iceland.

 

AGU: Disentangling disequilibrium and tuning thermobarometers in Eastern Volcanic Zone of Iceland

At the end of 2015, I presented the following abstract at the AGU Fall Meeting in San Francisco. My contribution summarised the main findings of my work in Iceland so far and outlined my next research directions: calibrating new thermobarometric models optimised for mid-crustal pressures and performing new phase equilibria experiments on basalts in the 1–7 kbar pressure range. You can download a copy of my poster here.