Walter D. Mooney, Ph.D. US Geological Survey Menlo Park, California USA [email protected] Lecture #7: Challenges and Opportunities in Studies of Lithospheric Evolution CAGS/SinoProbe Short Course: Lithospheric Evolution through Time April 8-12, 2011
Jan 04, 2016
Walter D. Mooney, Ph.D.US Geological SurveyMenlo Park, California [email protected]
Lecture #7:Challenges and Opportunitiesin Studies of Lithospheric Evolution
CAGS/SinoProbe Short Course: Lithospheric Evolution through Time April 8-12, 2011
Dehydration reactions in subduction zone
Ranero et al., 2004
How much H2O within subducting plate?
[Rüpke et al., 2006]
Faults and Fluid flow
Tveranger et al., 2005
First continental crust
Density differences allow subduction of mafic rocks. Further partial melting and fractionation makes higher silica melt that won’t subduct
Water outKomatiite partially melts, Basalt getsto surface, piles up. The stack sinks, partially melts when pressure high enough. Fractionation makes increasingly silica-rich magmas
First Then:
Generation of Continental Crust through TimeA based on Nd isotopes in shales44 B based on Pb isotopes77 C from Taylor & McLennan (1995)
Hawkesworth & Kemp (2006)
Mantle Structure
Source: Forte and Mitrovica (2001)
Tomographic Model
Van Heijst, Ritsema, and Woodhouse, 1999
Li et al. (in preparation)
Mantle Structure
Modified from: Meibaum and Anderson (2003)
Homogeneous Heterogeneous
Density model of the crust and upper mantle based on joint inversion of the new satellite gravity and seismic data.
M. Kaban, M. Rothacher
Tomographic Model
Van Heijst, Ritsema, and Woodhouse, 1999
Li et al. (in preparation)
Mantle Structure
Modified from: Meibaum and Anderson (2003)
Homogeneous Heterogeneous
Density model of the crust and upper mantle based on joint inversion of the new satellite gravity and seismic data.
M. Kaban, M. Rothacher