Preferential Formation of Chlorite Over Talc During Si‐Metasomatism of Ultramafic Rocks in Subduction Zones

Talc formation via silica-metasomatism of ultramafic rocks is believed to play key roles in subduction zone processes. Yet, the conditions talc remain poorly constrained. We used thermodynamic reaction-path models assess at slab-mantle interface and show that it restricted a limited set pressure–temperature conditions, protolith, fluid compositions. In contrast, our predict chlorite ubiquitous relevant zones. The scarcity abundance evident rock record exhumed terranes. during Si-metasomatism may thus more role volatile cycling, strain localization, controlling decoupling-coupling transition plate interface. Conversely, observed predicted ubiquity corroborates its prominent processes previous studies attributed talc.