|
|||||
|
|
| 松辽盆地中部深部断层影响浅部次级断层发育的数值研究 | |
| 引用本文： | 龚发雄,单业华,李自安,刘士林.松辽盆地中部深部断层影响浅部次级断层发育的数值研究[J].大地构造与成矿学,2009,33(3). |
| 作者姓名： | 龚发雄 单业华 李自安 刘士林 |
| 作者单位： | 1. 中国石油冀东油田分公司勘探开发研究院,河北,唐山,063004;中国科学院广州地球化学研究所,广东,广州,510640;中国科学院研究生院,北京,100049 2. 中国科学院广州地球化学研究所,广东,广州,510640 3. 中国科学院广州地球化学研究所,广东,广州,510640;中国科学院研究生院,北京,100049 |
| 基金项目： | 中国科学院"百人计划"启动项目，国家自然科学基金面上项目 |
| 摘 要： | 利用Poly3D模拟了松辽盆地长垣隆起中部后裂谷期应力场,由此预测浅部次级断层的产状和密度。计算结果表明,深部断层的存在会扰乱浅部应力场,距离深部断层越近,扰动程度越明显,从而导致了浅层次级断层的走向变化和不均匀的密度分布;浅部次级断层的走向和分布与深部断层的形态和空间位置相关,它们在断层的端部、转折段及其附近变化较大。同样地,在施加远场的不同方向水平拉伸、相同应变量下,可计算出相应的浅部次级断层走向和密度的计算值。在不同反射层模拟得到的最佳伸展方向与区域分析基本相同,但此时预测断层走向和密度与实际情况仍有较大差别。考虑到模型中深部断层面的拖曳力分量均设置为零,即不存在独立的断层活动,这一差别暗示出浅部次级断层的发育不仅受远场构造作用影响,而且还受深部断层独立活动的制约。 |
| 关 键 词： | 深部断层 Poly3D 应力场扰动 断层密度 断层走向 松辽盆地 |
The Impact of Pre-existing Faults on the Formation of Above Smaller Faults in Middle Songliao Basin, Northeastern China: A Numerical Study |
|
| GONG Faxiong,SHAN Yehua,LI Zi'an,LIU Shilin.The Impact of Pre-existing Faults on the Formation of Above Smaller Faults in Middle Songliao Basin, Northeastern China: A Numerical Study[J].Geotectonica et Metallogenia,2009,33(3). | |
| Authors: | GONG Faxiong SHAN Yehua LI Zi'an LIU Shilin |
| Abstract: | The post-rift stress field in the middle Changyuan uplift,the Songliao basin is simulated using a Poly3D software,based upon which secondary faults are predicted. The modeling results show that the pre-existing faults may perturb the stress fields in above seismic layers. The perturbation aggravates towards the pre-existing faults,and produces the variability of fault orientations and irregular distribution of fault densities in the above layers,where computed fault strikes and density distribution are substantially influenced by the geometries and locations of the pre-existing faults,at their bends and edges,for instance. By assigning different remote directions extension to the model,we compared observed and predicted fault strikes and densities in the three above layers,and then looked for the best extension direction among them. In T3 layer,the best extensional direction is N80°E,in accordance with the result obtained by the regional structural analysis,or N85°E. But the difference between the computed fault strikes and densities and observed ones is also obvious. In view of the tractions on the deep faults set as 0,namely,there are not initiative fault activities,and this contradiction of the direction of extension obtained from computed data and the regional structural analysis implies that the development of secondary faults is not only affected by the remote tectonic setting,but also constrained by the initiative activity of pre-existing faults. |
| Keywords: | Poly3D |
| 本文献已被 万方数据 等数据库收录！ | |