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In these Lecture Slides, the Lecturer has put emphasis on following key points : Trace Elements, Spinel Lherzolite Field, Residual Phase, Garnet-Lherzolite Field, Plagiocalse, Lherzolite Field, Lithosphäre, Asthenosphäre, Depth, Generation
Typology: Slides
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Data from Data from
Schilling et al. Schilling et al.
(1983) (1983)
Origin of MORB in the
Spinel lherzolite field
is compatible with the REEs
HREE depletion expected if garnet was a residual phase in the garnet-lherzolite fieldEu-anomaly expected if plagioclase was residual in the shallow plagiocalse-lherzolite field
Spinell
Lithosphäre
MOR
Asthenosphäre
Alter
Ellam (1992)
Hohe Ce/Yb Verh.
SEE
0 km 60 120
SEE
Niedrige Ce/Yb Verh.
Spinell + GranatGranat
1200°
C
1200°
C
Trace element ratios and depth of melt generation Trace element ratios and depth of melt generation
E-MORBs (squares) enriched over N- MORBs (red triangles)
and T-MORBs (green dots) regardless of Mg#
Data from Schilling et al. (1983) Data from Schilling et al. (1983)
E-MORBs La/Sm > 1.8N-MORBs La/Sm < 0.7T-MORBs (transitional)intermediate values
The mantle beneath the ocean basins is not
homogeneous
ascent and/or in shallow chambers
Conclusions about MORBs, and the processes
beneath mid-ocean ridges
