The formation and evolution of the South China Sea is well recorded in the northern continental margin. But the discrepancies of the tectonic and sedimentary evolution between the west and east of the northern margin are still enigmatic. Several drilling and simulation wells with analogous geological setting are chosen from the deep water areas of the Zhujiang River Estuary Basin and the Qiongdongnan Basin. Based on backstripping and previous studies, high resolution sedimentation rates and subsidence rates are constructed. Results show that both two basins are characterized by analogous sedimentation rates and subsidence rates in the syn-rift stage, but significant discrepancies are revealed in the post-rift stage. Episodic sedimentary and tectonic evolution characteristics are revealed in the Zhujiang River Estuary Basin, sedimentation rates are characterized by “two rapid sedimentation periods and three slow sedimentation periods” and subsidence rates are characterized by “two rapid subsidence periods and one slow subsidence period”. But the sedimentation rates are characterized by “graben” style evolution, and the subsidence rates are characterized by “step-up” style evolution in the Qiongdongnan Basin. The “step-up” subsidence rates in the Qiongdongnan Basin might be controlled by activities of the Hainan mantle plume which moved northwestward derived from the dextral strike-slip of the Red River Fault. And it coincided with the magmatism and the subsidence rate in the northwest margin of the South China Sea. The distribution of the rapid deposition and accelerated subsidence in the Qiongdongnan Basin after 1.8 Ma BP could be mainly controlled by the meanwhile dextral strike-slip of the Red River Fault.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |