In Triassic, the NW-trending folds and NNW-trending reverse faults developed in Chengdao Region as a result of compressive stress, and the Chengbei 20 fault was a representative reverse fault.

• 研究表明：埕岛地区三叠纪以挤压变形为特征，变形的构造线方向为北西一北北西向，发育了北西向背斜和北北西向逆断层，埕北20断层在此时期是典型的逆冲断层；