Some fluid mechanical constraints on crystallization and recharge within sills

Area of Science:

• Geology
• Geochemistry
• Fluid Mechanics

Background:

• Magma injection into crustal sills causes heating and melting.
• Injected magma cools, crystallizes, and forms cumulate layers.
• Crystal sedimentation and melt trapping influence layer properties.

Purpose of the Study:

• To model controls on cumulate layer thickness and density stratification.
• To investigate the balance between homogeneous layer formation and stratification.
• To understand variability in cumulate layers within magma chambers.

Main Methods:

• Utilized an idealized model based on fluid mechanics and thermodynamics.
• Simulated magma replenishment in sill-like magma chambers.
• Analyzed the impact of cooling and sedimentation timescales.

Main Results:

• Cumulate layer formation depends on the ratio of cooling to sedimentation timescales.
• Density stratification of trapped melt is a key outcome.
• Crystal size and roof melt properties influence layer composition and stratification.

Conclusions:

• Magma chamber replenishment leads to potentially variable cumulate layer composition and stratification.
• The interplay between cooling, sedimentation, and crystal properties governs cumulate layer evolution.
• This research provides insights into magma reservoir architecture and dynamics.