The fate of marine magnetic anomaly in subduction zones: A global appraisal

Seafloor spreading magnetic anomalies of oceanic plates progressively decay and disappear when approaching entering subduction. Previous studies focused on the Japan Trench showed that before subduction, flexure lithosphere opens normal faults rejuvenates hydrothermal circulation which results in alteration minerals. After thermal demagnetization affects minerals crust increasing temperature subducting slab passes their Curie temperature. No other subduction zone was investigated so far. Here we study evolution five zones. The major observed differences are controlled by age related physical properties. Before old show a significant (20-30%) to whereas those young at Cascadia displays no such as consequence negligible Juan de Fuca plate. plate rapid reflecting extrusive basalt, amounting for 30-40% more than 70% Cascadia. Beyond complete about 40% magnetization remains less 30%