Mantle driven cretaceous flare-ups in Cordilleran arcs

Abstract

Abstract Continental arcs display episodic magmatism characterized by flare-ups and lulls. Models published to explain these patterns invoke (1) upper plate crustal processes driven by internal feedback; (2) episodic mantle melting processes, or (3) external lower plate tectonic events. This study addresses the role of mantle magmas during flare-ups in Mesozoic Cretaceous continental arcs using geochronological and geochemical data for three Cretaceous arc segments: the western Peninsular Ranges Batholith (wPRB), the Peruvian Coastal Batholith (PCB), and the Chilean Coastal Batholith (CCB). In all three arc segments, bedrock zircon age patterns defining a flare-up from ~125 to 90\u202fMa characterized by gabbro to granite units with Sri