Geochemical evidence for subduction erosion in the Trans-mexican Volcanic Belt
A seminar presented by Susanne Straub (Lamont-Doherty Earth Observatory, Columbia University).
Abstract
Recycling of upper plate crust in subduction zones, or “subduction erosion”, is a major mechanism of crustal destruction at convergent margins, yet assessing the impact of eroded crust on arc magmas is difficult owing to the compositional similarity between the eroded crust, trench sediment and arc crustal basement that may all contribute to arc magma formation. In this talk, I discuss how we unravelled the respective crustal signatures of forearc eroded crust, trench sediment and arc crustal basement in the high-Mg# arc magmas of the Trans-Mexican Volcanic Belt by comprehensive Sr-Nd-Pb-Hf-He-O isotope studies and how these results may pertain to the Hikurangi margin.
