Weeks Lecture – STEVE SHIREY – Friday, October 18th 2013, 3:30 PM, Weeks Hall – Room AB20

Weeks Lecture

Shirey

STEVE SHIREY
Dept. or Terrestrial Magnetism

Carnegie Institution of Washington

Friday, October 18th 2013, 3:30 PM, Weeks Hall – Room AB20
Diamonds – Unique Recorders of Continental Evolution and Plate Tectonics

The exhumation of diamonds in erupted kimberlitic magmas passing through continents brings up the deepest, oldest, and most pristine mineral inclusions from the mantle that are known. Most of these amazing specimens come from the mantle keels of continents at depths greater than 150km. But some derive from greater depths including the mantle transition zone and the top of the lower mantle.

Diamonds and their inclusions present a remarkable chance to study deep mantle mineralogy and the migration of carbon-bearing fluids, leading to unique constraints on continent formation and mantle geodynamics.

Shirey et al. (2011) Start of the Wilson Cycle at 3 Ga shown by diamonds from subcontinental mantle. Science 333: 434-436.

Walter et al. (2011) Deep mantle cycling of oceanic crust: Evidence from diamonds and their mineral inclusions. Science 334: 54-57.

Shirey et al. (2013) Diamonds and the geology of mantle carbon. Reviews in Mineralogy and Geochemistry 75:355-421.