What drove continued continent-continent convergence after ocean closure? Insights from high-resolution seismic-reflection profiling across the Daba Shan in central China

Abstract

We conducted deep seismic-reflection surveying across the Jurassic Daba Shan thrust belt of central China to investigate how and why the continued convergence between north and south China lasted ∼50 m.y. after the Triassic closure of their intervening oceans. Our study, together with surface geology, gravity surveying, and magnetic observations, indicates widespread occurrence of mafic plutons below the Daba Shan thrust belt. We propose that subduction of dominantly eclogitized mafic crust of northern south China provided the driving force for continued convergence between north and south China after ocean closure.