The South Kunsong area is a negative tectonic unit in the western part of the Wan’an Basin, in which the N−S trending faults run through the north and the south. The unique tectonic characteristics make it a window for studying the tectonic evolution and regional fault strike-slip activities in the western part of the Wan’an Basin. The sedimentary strata in the study area are divided into three sets of structural layers, the structure-sedimentary filling section in the South Kunsong area is drawn by the back stripping method, and the tectonic subsidence and tectonic subsidence rate in the South Kunsong area are calculated. Settlement process and controlling factors. The research results show that the fault combination styles in the lower and middle structural layers are mainly core-type faults, "Y"-type faults, stepped faults and high-angle flower-shaped structures. W−E trending and NE−SW trending; the upper tectonic layer is not developed with faults and is stable deposition; under the control of regional strike-slip faults and the South China Sea spreading movement, the tectonic evolution of the South Kunsong area has experienced four stages since the Eocene: the initial stage. During the rifting period, extensional fault-deflection period, strike-slip reformation period and thermal subsidence period, the stratigraphic structure properties of the Cenozoic also showed a three-stage transformation of extension and strike-slip, control of strike-slip faults, and thermal subsidence.
| 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 |