Polyphase rifting of greater Pearl River Delta region (South China): Evidence for possible rapid changes in regional stress configuration

The greater Pearl River Delta (PRD) Region, consisting of several late Mesozoic–Cenozoic basins, has preserved information on the tectonic history of the coastal region of South China. An integrated morphological and structural study of the basins has revealed several phases of extension subsequent to the collapse of the Mesozoic arc magmatism. A N–S extension associated with the exhumation of the magmatic arc during the late Mesozoic–early Cenozoic was followed by an ENE–WSW extension producing NW-striking normal faults in the region. Paleo-stress analysis of fault slips measured at seven localities reveals stress configurations consistent with the field observation. The basin development during the Cenozoic was strongly controlled by relative motion of neighboring plates as well as pre-existing structures. The results suggest that stress configuration can change relatively rapidly in a continental margin undergoing a transition from an active-margin to passive-margin.