The Sichuan Basin, situated in the heart of China, is renowned for its abundant oil and gas reserves within a geologically intricate sedimentary basin. A multitude of strike-slip faults, characterized by their extensive reach, substantial scale, and modest displacement, are particularly prominent in the basin’s central region. In order to elucidate the influence of these faults on the formation of oil and gas reservoirs, high-precision seismic data analysis and numerical simulation techniques were used to investigate the strike-slip fault system in the central Sichuan area. The results show that the primary strike-slip faults in the central Sichuan region bifurcate into two distinct orientations: nearly EW(east-west) and NE(northeast-southwest). These first-order faults are inclined to emerge along the peripheries of secondary tectonic units. The near EW-oriented faults were predominantly active prior to the Permian era, coinciding with the Hercynian phase, whereas the NE-oriented faults were shaped later, during the transition from the Late Hercynian to the Indosinian period. The evolution of these strike-slip faults is intricately tied to a series of overlapping tectonic events. The culmination of the ancient uplift in central Sichuan predating the Permian era precipitated the genesis of the near EW-oriented faults. Subsequently, a pivotal tectonic regime shift during the Late Hercynian epoch, coupled with the subsequent Indosinian period’s fore-arc structural modifications near the Longmen Mountains, catalyzed the emergence of the NE-oriented faults. Moreover, the Deyang Anyue fault trough is identified as a pivotal factor in dictating the regional stress distribution, effectively hindering the east-west faults from traversing beyond the fault trough boundary, thereby stifling their further development.
| 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 |