A study of faulting patterns in the Pearl River Mouth Basin through analogue modeling

The Pearl River Mouth Basin is one of the most favorable areas for gas exploration on the northern slope of the South China Sea. Differences of fault patterns between shelf and slope are obvious. In order to investigate the tectonic evolution, five series of analogue modeling experiments were compared. The aim of this study is to investigate how crustal thickness influences fault structures, and compare this to the observed present-day fault structures in the Pearl River Mouth Basin. The initial lithospheric rheological structure can be derived from the best fit between the modeled and observed faults. The results indicate. (1) Different initial crustal rheological structures can produce different rift structures in the Pearl River Mouth Basin. (2) We also model that the Baiyun Sag in the southern Pearl River Mouth Basin may have had a thinned crust before rifting compared to the rest of the basin. (3) The thickness ratio of brittle to ductile crust in southern Pearl River Mouth Basin is less than normal crust, suggesting an initially hot and weak lithosphere. (4) Slightly south of the divergent boundary magma may have taken part in the rifting process during the active rift stage.