*********************************** From: Valentin R. Troll <trollv@xxxxxxxxxxx> *********************************** Dear Colleagues, We would like to draw your attention to our symposium "Magmatic differentiation in subduction zones" (Theme 7, Symposium S46) at the 2007 Goldschmidt meeting in Cologne in August. It looks to be a very promising session and we hope to see you all there. S46 Magmatic differentiation in subduction zones Conveners: John Gamble (J.Gamble@xxxxxx) Ralf Gertisser (r.gertisser@xxxxxxxxxxxxxxxx) Valentin Troll (trollv@xxxxxxxxxxx) Magmas provide one of the most important probes of the interior of the Earth. Chemical information locked in plutonic or volcanic rocks can, in principle, be used to ascertain the compositions of the source from which the magma was originally formed and to unravel the physical conditions of melt generation. However, in all but a few cases, the compositions of magmas change as they ascend through the lithosphere in response to differentiation processes such as fractional crystallisation, decompression, crustal contamination and mixing and mingling with other magmas. Recognising that the melt phase and crystalline cargo in volcanic rocks (eg phenocryst assemblage in andesites) represent an aggregate of these multistage differentiation events, we can apply, modern in- situ trace element and isotopic analytical techniques to unravel the differentiation history of plutons and volcanoes. This not only gives us a means of accounting for the effects of differentiation and constraining the nature of the original magma source(s), but also gives us a way of quantifying these processes and associated elemental fluxes in subduction systems. This session seeks to bring together researchers that aim to unravel differentiation processes in subduction settings by applying methodologies such as crystal isotope stratigraphy, classical and experimental petrology, geochronology and geochemistry to quantify contributions from the slab, the mantle wedge and from magma-crust interaction during final ascent and shallow-level magma storage. ============================================================== To unsubscribe from the volcano list, send the message: signoff volcano to: listserv@xxxxxxx, or write to: volcano-request@xxxxxxxx To contribute to the volcano list, send your message to: volcano@xxxxxxxx Please do not send attachments. ==============================================================
