CAJ | 학술논문

北部湾盆地迈陈凹陷断裂系统十分复杂，为了明确其成因机制，在三维地震资料构造解析的基础上，应用砂箱模拟实验，对迈陈凹陷东部断裂系统形成进行分析。结果表明，迈陈凹陷东部可划分为上、下2套断裂系统，下部断裂系统是受长流-流沙港期NW-SE向区域拉张应力形成，上部断裂系统是受涠洲期NW-SE向区域拉张及右旋走滑应力形成。并且下部断裂体系受基底先存断裂影响较大，走向、倾向、断层组合都与其保持一致；上部断裂体系受基底断层影响较小，多为新生型断层或继承改造型断层。涠洲期走滑程度的强弱直接影响断裂发育的走向，弱走滑条件下实验结果与实际地质特征吻合度高，并且发育的次级小断层有利构造圈闭的形成，对三维地震构造精细解释有指导作用。
북부만분지매진요함단렬계통십분복잡，위료명학기성인궤제，재삼유지진자료구조해석적기출상，응용사상모의실험，대매진요함동부단렬계통형성진행분석。결과표명，매진요함동부가화분위상、하2투단렬계통，하부단렬계통시수장류-류사항기NW-SE향구역랍장응력형성，상부단렬계통시수위주기NW-SE향구역랍장급우선주활응력형성。병차하부단렬체계수기저선존단렬영향교대，주향、경향、단층조합도여기보지일치；상부단렬체계수기저단층영향교소，다위신생형단층혹계승개조형단층。위주기주활정도적강약직접영향단렬발육적주향，약주활조건하실험결과여실제지질특정문합도고，병차발육적차급소단층유리구조권폐적형성，대삼유지진구조정세해석유지도작용。
The fault system of the Maichen Sag in the Beibuwan Basin is very complex. In order to reveal its ge-netic mechanism, sandbox modelling technologies were applied in this paper to make a systemic analysis on the formation mechanism of the eastern fault system based on the structural analysis of 3D seismic data. The results show that the faults in the Maichen Sag can be divided into the upper and the lower fault systems. The lower fault system was formed by the NW-SE oriented regional tensile stress during the Changliu and Liushagang periods, and the upper fault system was formed by the NW-SE oriented regional tensile stress and right-lateral strike-slip stress during the Weizhou period. The lower fault system was greatly influenced by basement faults, and their di-rection, orientation and fault combination were consistent. The upper fault system was less affected by basement faults, which was mainly new faults or inherited transform faults. Fault direction was directly affected by strike-slip degree during the Weizhou period. The experimental results under the condition of weak strike-slip are con-sistent with the actual geological characteristics, and the development of secondary faults is conducive to the for-mation of structural traps, which play a guiding role in 3D seismic fine structure interpretation.