Crime Scene Investigation, Mid-Atlantic Ridge: Deciphering the Role of Changes of Magmatic Injection Rate in the Death of Ocean Core Complexes
Additional Funding Sources
The project described was supported by a student grant from the UI Office of Undergraduate Research.
Abstract
The ocean floor makes up more than two-thirds of Earth’s surface and hosts the planet’s largest continuous plate boundary, the mid-ocean ridge (MOR). The MOR marks the location where tectonic plates spread apart and new crust is formed, but the manner in which this crust forms is poorly known. Few constraints exist on the interplay between crustal faulting and magmatism, which is believed to exert a first order control on MOR evolution. We examine how the rate of change of magmatic activity may alter the style of faulting along a mid-ocean ridge using data collected in 2016 along the ~13°N Marathon Fracture Zone of the Mid-Atlantic Ridge and numerical models. We use a marker-in-cell, finite-difference code to simulate the oceanic crust and lithosphere as an elastic-plastic material spreading above a viscous asthenosphere. We impose a horizontal divergence equal to a fraction of the plate separation rate to simulate magma injection within the upper ~6 km of the crust, . Models were run with different rates of change in axial magma supply to test the hypothesis that the rate of change in magma supply along a MOR axis is an important controlling parameter on the style and lifetime of faults.
Crime Scene Investigation, Mid-Atlantic Ridge: Deciphering the Role of Changes of Magmatic Injection Rate in the Death of Ocean Core Complexes
The ocean floor makes up more than two-thirds of Earth’s surface and hosts the planet’s largest continuous plate boundary, the mid-ocean ridge (MOR). The MOR marks the location where tectonic plates spread apart and new crust is formed, but the manner in which this crust forms is poorly known. Few constraints exist on the interplay between crustal faulting and magmatism, which is believed to exert a first order control on MOR evolution. We examine how the rate of change of magmatic activity may alter the style of faulting along a mid-ocean ridge using data collected in 2016 along the ~13°N Marathon Fracture Zone of the Mid-Atlantic Ridge and numerical models. We use a marker-in-cell, finite-difference code to simulate the oceanic crust and lithosphere as an elastic-plastic material spreading above a viscous asthenosphere. We impose a horizontal divergence equal to a fraction of the plate separation rate to simulate magma injection within the upper ~6 km of the crust, . Models were run with different rates of change in axial magma supply to test the hypothesis that the rate of change in magma supply along a MOR axis is an important controlling parameter on the style and lifetime of faults.
Comments
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