Abrupt tectonics and rapid slab detachment with grain damage

Area of Science:

• Geophysics
• Tectonics
• Material Science

Background:

• Subducting slabs are key to plate tectonics.
• Understanding slab detachment is crucial for explaining geological phenomena.

Purpose of the Study:

• To develop a model for subducting slab necking and detachment.
• To investigate the role of rheology and grain-size evolution in slab detachment.

Main Methods:

• A simple numerical model was developed.
• The model incorporates grain-sensitive rheology and grain-size evolution with damage.

Main Results:

• Necking and detachment are triggered by thickened buoyant crust.
• Grain damage accelerates necking, allowing rapid slab detachment (within 1 million years).
• Thick continental crustal plugs cause faster necking than smaller ocean plateau plugs.

Conclusions:

• The model explains rapid slab loss and associated geological events.
• It provides insights into abrupt continental rebound and plate motion changes.