Exp. 345 Hess Deep Plutonic Crust

Theme

Exploring the Plutonic Crust at a Fast-spreading Ridge: New drilling at Hess Deep

Proposal#551-Full>> Click HERE (Full version PDF)
Proposal#551-Add>> Click HERE (Addendum PDF)
Scientific Prospectus>> Coming soon
ODP Leg 147 Summary>> Click HERE (Related ODP cruise)

Schedule

Dec., 2012 – Feb., 2013

D/V

JOIDES Resolution

Drilling sites

Scientific objectives

Based on IODP Proposals 551-Full and 551-Add, this expedition aims to understand the nature of gabbroic rocks that formed at the fast-spreading East Pacific Rise (EPR) and test competing hypotheses of magmatic accretion and hydrothermal processes in the lower ocean crust. The scientific objectives will address (1) the architecture of the oceanic crust inferred from ophiolites and geophysical observations along modern fast-spreading ridges, and (2) the extent and nature of heat and mass fluxes between the asthenosphere, lithosphere, and hydrosphere reservoirs. This includes (1) how is the lower ocean crust accreted at fast-spreading ridges, and how does this relate to the differentiation of mid-ocean ridge basalts; (2) where, when, and at what temperature do hydrothermal fluids penetrate into the lower oceanic crust, and what effect do these have on the heat and chemical budgets near the ridge axis; and (3) how quickly does the lower oceanic crust cool, what is the thermal structure at the ridge axis, and how do the magmatic and hydrothermal systems interact to determine the thermal regime.

Co-chief scientist

TBD

 Shipboard scientists from J-DESC

TBD