The PIs will test the hypothesis of simple shear of extension and the "upper plate paradox" through a mass-balance analysis exercise across two conjugate margins. South China Sea has well-defined conjugate margins with well known spreading history and a network of seismic data and wells. They will analyze the South China Sea margin and describe the deformation on matching across-margin profiles of the conjugate Palawan margin. They will study the sediment-loaded subsidence rate of the pre-rift basement from well-log data and the degree of crustal extension from MCS sections across the margins. Forward modeling of basin formation will identify whether the observed amounts of subsidence are compatible with uniform extension models.
