Sauerstoffisotopenvariationen in ozeanischen magmatischen Gesteinsserien: Assimilation-fraktionierende Kristallisationsprozesse versus Variation der Mantelquelle

Drittmittelfinanzierte Einzelförderung

Details zum Projekt

Prof. Dr. Karsten Haase
Prof. Dr. Michael Joachimski
Dr. Stefan Krumm

Beteiligte FAU-Organisationseinheiten:
Lehrstuhl für Endogene Geodynamik
Lehrstuhl für Geologie (Exogene Dynamik)

Mittelgeber: Deutsche Forschungsgemeinschaft (DFG)
Projektstart: 01.01.2009
Projektende: 31.12.2010

Abstract (fachliche Beschreibung):

Oxygen isotopes are an important tool to study reactions between ascending mantle-derived magmas and material in the oceanic lithosphere that has been altered by surface processes like for example, sediments or hydrothermally altered rocks. Furthermore, crystal fractionation processes can also affect the O isotope composition especially of evolved magmas because different mineral phases fractionate O isotopes. Both assimilation and crystal fractionation thus impede the study of O isotope compositions of the magma sources in the mantle which could give important insights into recycling processes at subduction zones and in deep mantle plume-derived intraplate magmas. Here we suggest a study of the O isotope variation of five well-characterized lava series from different oceanic magmatic settings (mid-ocean ridge, oceanic intraplate, back-arc, and island arc settings) in order to define the variations between basaltic and silicic lavas and the processes affecting the O isotope ratios. Based on the understanding of lithospheric processes we will be able to distinguish the O isotope composition of the mantle sources of the magmas and draw conclusions on crustal recycling into the deep mantle and into the mantle wedge beneath subduction zones. 

Zuletzt aktualisiert 2018-22-11 um 18:20