Kimberlite eruptions driven by slab flux and subduction angle

Area of Science:

• Geology
• Geophysics
• Petrology

Background:

• Kimberlites, primary sources of diamonds, erupt from mantle upwellings.
• Previous eruption timing models (plate velocity, mantle plumes) do not fully explain subduction signatures in Cretaceous kimberlites.

Purpose of the Study:

• To investigate a unified subduction process that explains the timing of kimberlite eruptions.
• To develop a novel formulation for calculating subduction angle and its connection to kimberlite emplacement.

Main Methods:

• Formulation of subduction angle calculation using trench migration, convergence rate, slab thickness, and density.
• Correlation of calculated subduction angles and slab flux peaks with kimberlite eruption pulses.

Main Results:

• Subduction angles combined with slab flux peaks accurately predict kimberlite eruption pulses.
• High subduction rates stimulate mantle return flow, activating fertile reservoirs.
• Slab-influenced melt is transported to the surface, with eruption location linked to subduction angle.

Conclusions:

• Subduction dynamics provide a unifying mechanism for understanding kimberlite eruption timing.
• The deep-time slab dip formulation has implications for modeling deep Earth cycles and mineral deposit formation.