The subducted ocean crust is identified in the source of Cenozoic CIM basalts.
Mantle source low-F melt metasomatism is required for the enriched CIM basalts.
The mantle source metasomatism is recent or current.
The Cenozoic CIM basalts are a special consequence of plate tectonics.
The study of CIM basalts has implications for OIB and E-MORB petrogenesis.