Back-thrusting response of continental collision: Early Cretaceous NW-directed thrusting in the Changle-Nan’ao belt (Southeast China)

摘要: The SE coastal area of the South China Block (SCB) is generally interpreted as a Cretaceous active continental margin due to subduction Paleo-Pacific plate beneath Eurasian plate. There, NE-SW striking Changle-Nan’ao belt was previously considered a major strike-slip fault zone with large displacement accommodating northward Our new field and laboratory investigations document NW-directed ductile thrust that placed gneiss upon Early Cretaceous foliated volcanic rocks. Structural analyses and Anisotropy Magnetic Susceptibility results indicate fabrics in both units are represented by foliation and NW-SE stretching lineation with top-to-the-NW shear sense. This deformation occurred at ca. 130-105 Ma, before the deposition undeformed (ca. 104 Ma) rocks, intrusion 90 Ma isotropic plutons. continent-ward structure tentatively a back-thrust resulting collision West Philippines microcontinent the SCB rather than an effect simple oceanic subduction.