Weakening Mechanisms in a Basalt-Hosted Subduction Megathrust Fault Segment, Southern Alaska.

ABSTRACT: Basaltic and gabbroic rocks that define the seafloor have been suggested to act as sources of rheological heterogeneity during subduction, with the capacity to enhance or dampen seismicity. Despite this, relatively little is known from the rock record regarding the progression and conditions of mafic oceanic crust deformation during subduction, particularly in the shallow megathrust region of the seismogenic zone. We describe subduction-related deformation structures and characterize deformation conditions from an exhumed, basalt-hosted megathrust in the Chugach accretionary complex of south-central Alaska. Rocks in the Chugach preserve a record of seafloor mineralogical changes from pre-subduction, hydrothermal circulation that produced sheet silicates with a lower frictional strength tha

SUBMITTER: Braden Z 

PROVIDER: S-EPMC9285822 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature