The magmatic and geochemical evolution of oceanic intraplate volcanoes: constraints from the Louisville Seamounts (IODP Leg 330) and other Pacific hotspots

Third Party Funds Group - Sub project

Overall project details

Overall project: SPP 527: Bereich Infrastruktur - Integrated Ocean Drilling Program/Ocean Drilling Program

Project Details

Project leader:
PD Dr. Christoph Beier

Contributing FAU Organisations:
Lehrstuhl für Endogene Geodynamik

Funding source: DFG / Schwerpunktprogramm (SPP) (Deutsche Forschungsgemeinschaft)
Acronym: IODP/ODP
Start date: 01/10/2013

Abstract (technical / expert description):

The volcanoes of long-lived, age-progressive seamount chains are likely the result of mantle plumes rising from the upper and possibly even lower mantle underneath moving lithosphere plates. The volcanoes evolve through distinct stages from a shield-building to a post-shield or even post-erosional stages over a period of several millions of years. Typically, the major element compositions range from tholeiitic to SiO2-undersaturated magmas with decreasing age of the lava. The geochemical variability observed is influenced by changes of depth and degree of partial melting but may also be influenced by the mineralogical and geochemical composition of the mantle source. These parameters likely depend on the positioning of the mantle plume relative to the lithospheric plate. The impact of mantle plume temperature, dynamics and composition on these geochemical changes is only poorly understood. This project aims at analysing volcanic glasses and olivines from seamounts of the Louisville Seamount Chain (IODP Leg 330) and other Pacific Hotspots ((Macdonald, Society, Pitcairn, Juan Fernandez) to investigate the compositional variability of primitive melts erupted on old, fast moving lithosphere. The samples are readily available in Erlangen and Kiel. The composition of the glasses allows to better constrain the composition of the primary melt compared to whole rock analyses. In addition, the O isotope composition of glasses and olivines from different hotspots will be measured to determine the O isotope variability in mantle plumes. Combined with published ages and geochemical data this is the first systematic study on the variability of mantle melts in different hotspot settings and its relationship with the mantle plume positioning relative to the lithospheric plate.

External Partners

Bundesanstalt für Geowissenschaften und Rohstoffe (BGR)

Last updated on 2018-22-11 at 18:41

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