It is not favorable area to find gas field in the area, which the natural asphalt commonly occurs and oil and gas seepage and extensional fracture are developed.

• 但在广泛古生界地层裸露区，特别是碳酸岩发育的地带，普遍见天然沥青、油气苗及张性断裂，是找油气的不利区域。