珠江口盆地珠一坳陷裂后期断裂作用:迁移、转换及其动力学

发布时间：2018-05-28 06:30

本文选题：珠一坳陷 + 裂后期　；参考：《地球科学》2017年01期

【摘要】：珠江口盆地裂后期断裂作用对新近系油气成藏具有重要影响,但人们对其发育特征及动力学演化规律的认识一直不够.利用钻井约束的高精度三维及二维地震资料对珠一坳陷裂后期断裂的几何学与运动学特征进行了分析,结果表明珠一坳陷裂后期存在南海期和东沙期两期断裂作用,从南海期断裂作用到东沙期断裂作用,断裂的几何学、运动学特征以及动力学机制均发生了转换.南海期断裂作用具有从南向北迁移的特征;而东沙期断裂具有由东向西迁移的特征.两期断裂都以伸展为主,其中东沙期断裂具有微弱扭性特征.南海期断裂区域伸展方向为NNE10°~15°,东沙期为NNE20°~25°,区域伸展方向发生了5°~10°的顺时针偏转.南海期断裂作用发生于南海同扩张期,可能与南海扩张期间北部陆缘残留的伸展作用有关.东沙期断裂作用形成于南海后扩张期的东沙运动,该时期区域主应力轴σ_2方向与吕宋岛弧和欧亚大陆的挤压碰撞方向一致.东沙期断裂特征进一步证实了东沙运动是中中新世以来吕宋岛弧与欧亚大陆碰撞的结果.研究结果对整个南海地区裂后期南海运动与东沙运动的进一步认识具有重要意义.
[Abstract]:The late faulting in the Pearl River mouth basin has an important influence on the formation of Neogene oil and gas reservoirs, but the characteristics of its development and the law of its dynamic evolution have not been well understood. The geometric and kinematic characteristics of the late fault in the Zhu-1 depression are analyzed by using the high-precision 3-D and two-dimensional seismic data constrained by drilling. The results show that there are two stages of faults in the late period of the Zhu-depression: the South China Sea period and the Dongsha period. From the South China Sea fault to the Dongsha fault, the geometry, kinematics and dynamic mechanism of the fault have been transformed. The fault in the South China Sea has the characteristics of migration from south to north, while the fault in Dongsha period has the characteristics of migration from east to west. The two faults are mainly extensional, and the Middle East Sand faults have weak torsional characteristics. The extension direction of the South China Sea fault zone is NNE10 掳15 掳, and the east sand stage is NNE20 掳25 掳. The regional extension direction has a clockwise deflection of 5 掳~ 10 掳. The fault in the South China Sea occurred in the South China Sea and the extension of the northern continental margin during the extension of the South China Sea. The fault in the Dongsha period was formed in the east sand movement in the post-spreading period of the South China Sea. The 蟽 _ 2 direction of the principal stress axis in this period is consistent with the direction of compressional collision between the Luzon Island arc and the Eurasian continent. The characteristics of the Dongsha fault further confirm that the Dongsha movement is the result of the collision between the Luzon Island Arc and the Eurasian continent since the Miocene. The results are of great significance to the further understanding of the South China Sea movement and the Dongsha movement in the late period of the South China Sea.
【作者单位】：中国地质大学构造与油气资源教育部重点实验室;中海石油有限公司深圳分公司研究院;
【基金】：国家科技重大专项(No.2011ZX05023-001-015)
【分类号】：P618.13

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