CGB participates in Hess Deep Plutonic Crust Drilling Expedition

On December 9th, 2012, CGB post-doc geochemist Romain Meyer sets out for the equatorial Pacific to participate in a two-month long research cruise exploring the deep oceanic crust.

The cruise project is called the “Hess Deep Plutonic Crust” expedition, named for the rift valley on the East Pacific Rise (EPR) where sampling will take place. This ambitious project aims to answer many questions about the formation and evolution of the lower oceanic crust. Despite all we know about our planet’s history and evolution, we have yet to understand fundamental questions of how magma rises from the mantle through the crust, how the melt fractionates and crystallizes, and even how heat is transported within the lower-crustal body. The way scientists are able to study these processes is to take core samples from a “tectonic window” into the lower oceanic crust.

The Hess Deep rift valley has unique features that provide access to fault-exposed plutonic lower oceanic crust. Opposing hypotheses about the magmatic and hydrothermal processes within the lower oceanic crust at the EPR will be tested using the recovered cores.

Onboard the JOIDES Resolution, an Integrated Ocean Drilling Program (IODP) vessel outfitted for scientific drilling operations, Romain will take samples of residual mantle after melting and crystallized magmatic material for geochemical analyses to discriminate how magma moved and crystallized in the lower oceanic crust. As part of this multi-disciplinary project, Romain will also sample rock showing seawater-altered fracture networks and serpentines for CGB microbiologist and collaborator Steffen Leth Jørgensen’s biological signature investigations. This project will add to the UiB’s long history of research in oceanic crustal properties both with ancient terrestrial exposures in Norway and modern oceanic drilling initiatives.