Van Keken, 2003

‘cold nose’

Limits of SZ

Mantle wedge processes

Van Keken, EPSL, 2003

Basaltic crust

Harzburgitic mantle

Peridotitic mantle

45 km

7 km

Compositional stratification

Abbott et al., JGR, 1994Tpot=200-250 K higher

Compositional stabilization of oceanic lithosphere

Vlaar et al., EPSL, 1994

Vlaar et al., EPSL, 1994

Pre-plate tectonic cooling mechanism (?)

Sufficient to cool to near-present dayTpot within 1 Byr

Courtesy of R. Blewett

Zegers and Van Keken, Geology, 2001

Zegers and Van Keken, Geology, 2001

Zegers and Van Keken, Geology, 2001

Zegers and Van Keken, Geology, 2001