分层伸展叠加变形二维离散元模拟
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摘要
分层伸展叠加变形是裂陷盆地演化过程中普遍存在的一种复杂的构造地质现象,是裂陷盆地构造地质研究和油气成藏研究的热点。目前有关分层伸展叠加变形的研究仍处于几何学描述阶段,缺乏对其动力学演化过程的解析。本文采用构造地质研究领域中新兴的模拟方法——离散元,通过构建离散元模型模拟研究分层伸展叠加变形的断裂发育过程。结果表明:(1)上下两套伸展断裂系统之间是否存在韧性滑脱层(泥岩层或膏岩层)是分层叠加变形的主控物质因素;(2)中间韧性地层隔断了下部断层向上的继承性发育,从而形成上下两套断裂系统分层伸展,垂向上叠加的变形特征;(3)受韧性地层侧向牵引作用影响,上部断裂系统的横向展布明显扩大;(4)在相同岩性条件下,降低伸展速度会显著降低两侧断层发育的差异性,但不会改变垂向上分层伸展的变形特征。研究解析了分层伸展叠加变形的动力学演化过程,有助于进一步认识分层伸展叠加变形机制及其对油气运聚成藏的控制作用。
Superimposed extensional deformation of different layers is a complex tectonic deformation in the evolution of rift basins. Many researches have been carried out on superimposed extensional deformation, most of which are focused on geometry description. Few investigations have been carried out on the dynamic evolution of superimposed extensional deformation. The main objective of this study is to simulate the evolution of the fault system in superimposed extensional deformation of different layers using discrete element modeling. Modelling results showed that the presence of ductile strata embedded in the middle part of the model has a significant influence on superimposed extensional deformation of different layers. Moreover, the results also demonstrate that the ductile strata embedded in the model, separating the upper and lower brittle strata, resulted in two fault systems. The upper fault system is far wider than the lower fault system, due to lateral extension of the middle ductile strata. Decreasing extensional velocity decreases the difference of development of fault system between the upper and the lower brittle strata, but does not affect superimposed extensional deformation. Our numerical models are consistent with seismic profiles of the Nanpu Sag. This study provides basic insight into the dynamic evolution of the superimposed extensional deformation of different layers.
Superimposed extensional deformation of different layers is a complex tectonic deformation in the evolution of rift basins. Many researches have been carried out on superimposed extensional deformation, most of which are focused on geometry description. Few investigations have been carried out on the dynamic evolution of superimposed extensional deformation. The main objective of this study is to simulate the evolution of the fault system in superimposed extensional deformation of different layers using discrete element modeling. Modelling results showed that the presence of ductile strata embedded in the middle part of the model has a significant influence on superimposed extensional deformation of different layers. Moreover, the results also demonstrate that the ductile strata embedded in the model, separating the upper and lower brittle strata, resulted in two fault systems. The upper fault system is far wider than the lower fault system, due to lateral extension of the middle ductile strata. Decreasing extensional velocity decreases the difference of development of fault system between the upper and the lower brittle strata, but does not affect superimposed extensional deformation. Our numerical models are consistent with seismic profiles of the Nanpu Sag. This study provides basic insight into the dynamic evolution of the superimposed extensional deformation of different layers.
引文
李新坡,何思明.2010.节理岩质边坡破坏过程的PFC2D数值模拟分析.四川大学学报(工程科学版),42(S1):70-76.
刘刚,赵坚.2007.节理分布对岩体破坏影响的模拟研究.中国矿业大学学报,36(1):17-23.
刘顺桂,刘海宁,王思敬,胡波,张晓平.2008.断续节理直剪试验与PFC2D数值模拟分析.岩石力学与工程学报,27(9):1828-1837.
孟令森,尹宏伟,张洁,徐士进.2007.岩石强度和应变速率对水平挤压变形影响的离散元模拟.岩石学报,23(11):2918-2926.
石崇,徐卫亚.2015.颗粒流数值模拟技巧与实践.北京:中国建筑工业出版社:1-7.
张洁,尹宏伟,徐士进.2008.用离散元方法讨论岩石强度对主动底辟盐构造断层分布模式的影响.南京大学学报(自然科学版),44(6):642-652.
Bahroudi A,Koyi H A and Talbot C J.2003.Effect of ductile and frictional décollements on style of extension.Journal of Structural Geology,25(9):1401-1423.
Botter C,Cardozo N,Hardy S,Lecomtec I,Paton G and Escalona A.2016.Seismic characterisation of fault damage in 3D using mechanical and seismic modelling.Marine and Petroleum Geology,77:973-990.
Carmona A,Gratacós O,Clavera-Gispert R,Mu?oz J A and Hardy S.2016.Numerical modelling of syntectonic subaqueous sedimentation:The effect of normal faulting and a relay ramp on sediment dispersal.Tectonophysics,684:100-118.
Cundall P A.1971.A computer model for simulating progressive large scale movements in blocky rock systems.International Proceedings Symposium on Rock Fracture,12:128-132.
Cundall P A and Strack O D L.1979.A discrete numerical model for granular assemblies.Geotechnique,29(1):47-65.
Egholm D L.2007.A new strategy for discrete element numerical models:1.Theory.Journal of Geophysical Research,112:B05203.
Egholm D L,Sandiford M,Clausen O R and Nielsen S B.2007.A new strategy for discrete element numerical models:2.Sandbox applications.Journal of Geophysical Research,112:B05204.
Finch E,Hardy S and Gawthorpe R.2003.Discrete element modeling of contractional fault propagation folding above rid basement fault block.Journal of Structural Geology,25(4):515-528.
Gary G G,Morgan J K and Sanz P F.2014.Overview of continuum and particle dynamics methods for mechanical modeling of contractional geologic structures.Journal of Structural Geology,59:19-36.
González G,Gerbault M,Martinod J,Cembrano J,Carrizo D,Allmendinger R and Espina J.2008.Crack formation on top of propagating reverse faults of the Chuculay Fault System,northern Chile:Insights from field data and numerical modelling.Journal of Structural Geology,30(6):791-808.
Gross M R,Gutiérrez-Alonso G,Bai T,Wacker M A,Collinsworth K B and Behl R J.1997.Influence of mechanical stratigraphy and kinematics on fault scaling relations.Journal of Structural Geology,19:171-183.
Hardy S.2015.The Devil truly is in the detail.A cautionary note on computational determinism:Implications for structural geology numerical codes and interpretation of their results.Interpretation,3(4):29-35.
Hardy S and Finch E.2005.Discrete element modeling of detachment folding.Basin Research,17(4):507-520.
Imbera J,Tuckwell G W,Childsa C,Walsh J J,Manzocchi T,Heath A E,Bonson C G and Strand J.2004.Threedimensional distinct element modeling of relay growth and breaching along normal faults.Journal of Structural Geology,26(10):1897-1911.
Iwashita K and Oda M.2000.Micro-deformation mechanism of shear banding process based on modified distinct element method.Powder Technology,109(1-3):192-205.
Jarrige J J.1992.Variation in extensional fault geometry related to heterogeneities within basement and sedimentary sequences.Tectonophysics,215:161-166.
Keep M and McClay K R.1997.Analogue modelling of multiphase rift systems.Tectonophysics,273:239-270.
Liu Z and Koyi H A.2013.The impact of a weak horizon on kinematics and internal deformation of a failure mass using discrete element method.Tectonophysics,586:95-111.
McClay K R and White M J.1995.Analogue modelling of orthogonal and oblique rifting.Marine and Petroleum Geology,12(2):137-151.
Morley C K,Gabdi S and Seusutthiya K.2007.Fault super imposition and linkage resulting from stress changes during rifting:Examples from 3D seismic data,Phitsanulok Basin,Thailand.Journal of Structural Geology,29:646-663.
Nicol A,Watterson J,Walsh J J and Childs C.1996.The shapes,major axis orientations and displacement patterns of fault surfaces.Journal of Structural Geology,18(2):235-248.
Potyondy D O and Cundall P A.2004.A bonded-particle model for rock.International Journal of Rock Mechanics&Mining Sciences,41(8):1329-1364.
Ren X H,Wang H J and Zhang J X.2012.Numerical study of AE and DRA methods in sandstone and granite in orthogonal loading directions.Water Science and Engineering,5(1):93-104.
Roche V,Homberg C and Rocher M.2012.Architecture and growth of normal fault zones in multilayer systems:A3D field analysis in the South-Eastern Basin,France.Journal of Structural Geology,37:19-35.
Sch?pfer M P J,Arslan A,Walsh J J and Childs C.2011.Reconciliation of contrasting theories for fracture spacing in layered rocks.Journal of Structural Geology,33(4):551-565.
Sch?pfer M P J,Childs C and Walsh J J.2006.Localisation of normal faults in multilayer sequences.Journal of Structural Geology,28(5):816-833.
Soliva R and Benedicto A.2005.Geometry,scaling relations and spacing of vertically restricted normal faults.Journal of Structural Geology,27(2):317-325.
Steffen A,Gent H V and Urai J L.2011.DEM simulation of normal faults in cohesive materials.Tectonophysics,512(1):12-21.
Strayer L M,Erickson S G and Suppe J.2004.Influence of growth strata on the evolution of fault-related folds:Distinct element models//McClay K R.Thrust Tectonics and Hydrocarbon System.AAPG Memoir,82:413-437.
Strayer L M and Suppe J.2002.Out-of-plane motion of a thrust sheet during along-strike propagation of a thrust ramp:A distinct element approach.Journal of Structural Geology,24(4):637-650.
Tron V and Brun J.1991.Experiments on oblique rifting in brittle-ductile systems.Tectonophysics,188(1):71-84.
Wilkins S J and Gross M R.2002.Normal fault growth in layered rocks at Split Mountain,Utah:Influence of mechanical stratigraphy on dip linkage,fault restriction and fault scaling.Journal of Structural Geology,24(9):1413-1429.
Yin H W,Zhang J,Meng L S,Liu Y P and Xu S J.2009.Discrete element modeling of the faulting in the sedimentary cover above an active salt diapir.Journal of Structural Geology,31(9):989-995.
Zhang J,Morgan J K,Gary G G,Harkins N W,Sanz P F and Chikichev I.2013.Comparative FEM and DEM modeling of basement-involved thrust structures,with application to Sheep Mountain,Greybull area,Wyoming.Tectonophysics,608:408-417.
Zhao C B,Hobbs B E,Ord A,Robert P A,Hornby P and Peng S L.2007.Phenomenological modeling of crack generation in brittle crustal rocks using the particle simulation method.Journal of Structural Geology,29(6):1034-1048.
刘刚,赵坚.2007.节理分布对岩体破坏影响的模拟研究.中国矿业大学学报,36(1):17-23.
刘顺桂,刘海宁,王思敬,胡波,张晓平.2008.断续节理直剪试验与PFC2D数值模拟分析.岩石力学与工程学报,27(9):1828-1837.
孟令森,尹宏伟,张洁,徐士进.2007.岩石强度和应变速率对水平挤压变形影响的离散元模拟.岩石学报,23(11):2918-2926.
石崇,徐卫亚.2015.颗粒流数值模拟技巧与实践.北京:中国建筑工业出版社:1-7.
张洁,尹宏伟,徐士进.2008.用离散元方法讨论岩石强度对主动底辟盐构造断层分布模式的影响.南京大学学报(自然科学版),44(6):642-652.
Bahroudi A,Koyi H A and Talbot C J.2003.Effect of ductile and frictional décollements on style of extension.Journal of Structural Geology,25(9):1401-1423.
Botter C,Cardozo N,Hardy S,Lecomtec I,Paton G and Escalona A.2016.Seismic characterisation of fault damage in 3D using mechanical and seismic modelling.Marine and Petroleum Geology,77:973-990.
Carmona A,Gratacós O,Clavera-Gispert R,Mu?oz J A and Hardy S.2016.Numerical modelling of syntectonic subaqueous sedimentation:The effect of normal faulting and a relay ramp on sediment dispersal.Tectonophysics,684:100-118.
Cundall P A.1971.A computer model for simulating progressive large scale movements in blocky rock systems.International Proceedings Symposium on Rock Fracture,12:128-132.
Cundall P A and Strack O D L.1979.A discrete numerical model for granular assemblies.Geotechnique,29(1):47-65.
Egholm D L.2007.A new strategy for discrete element numerical models:1.Theory.Journal of Geophysical Research,112:B05203.
Egholm D L,Sandiford M,Clausen O R and Nielsen S B.2007.A new strategy for discrete element numerical models:2.Sandbox applications.Journal of Geophysical Research,112:B05204.
Finch E,Hardy S and Gawthorpe R.2003.Discrete element modeling of contractional fault propagation folding above rid basement fault block.Journal of Structural Geology,25(4):515-528.
Gary G G,Morgan J K and Sanz P F.2014.Overview of continuum and particle dynamics methods for mechanical modeling of contractional geologic structures.Journal of Structural Geology,59:19-36.
González G,Gerbault M,Martinod J,Cembrano J,Carrizo D,Allmendinger R and Espina J.2008.Crack formation on top of propagating reverse faults of the Chuculay Fault System,northern Chile:Insights from field data and numerical modelling.Journal of Structural Geology,30(6):791-808.
Gross M R,Gutiérrez-Alonso G,Bai T,Wacker M A,Collinsworth K B and Behl R J.1997.Influence of mechanical stratigraphy and kinematics on fault scaling relations.Journal of Structural Geology,19:171-183.
Hardy S.2015.The Devil truly is in the detail.A cautionary note on computational determinism:Implications for structural geology numerical codes and interpretation of their results.Interpretation,3(4):29-35.
Hardy S and Finch E.2005.Discrete element modeling of detachment folding.Basin Research,17(4):507-520.
Imbera J,Tuckwell G W,Childsa C,Walsh J J,Manzocchi T,Heath A E,Bonson C G and Strand J.2004.Threedimensional distinct element modeling of relay growth and breaching along normal faults.Journal of Structural Geology,26(10):1897-1911.
Iwashita K and Oda M.2000.Micro-deformation mechanism of shear banding process based on modified distinct element method.Powder Technology,109(1-3):192-205.
Jarrige J J.1992.Variation in extensional fault geometry related to heterogeneities within basement and sedimentary sequences.Tectonophysics,215:161-166.
Keep M and McClay K R.1997.Analogue modelling of multiphase rift systems.Tectonophysics,273:239-270.
Liu Z and Koyi H A.2013.The impact of a weak horizon on kinematics and internal deformation of a failure mass using discrete element method.Tectonophysics,586:95-111.
McClay K R and White M J.1995.Analogue modelling of orthogonal and oblique rifting.Marine and Petroleum Geology,12(2):137-151.
Morley C K,Gabdi S and Seusutthiya K.2007.Fault super imposition and linkage resulting from stress changes during rifting:Examples from 3D seismic data,Phitsanulok Basin,Thailand.Journal of Structural Geology,29:646-663.
Nicol A,Watterson J,Walsh J J and Childs C.1996.The shapes,major axis orientations and displacement patterns of fault surfaces.Journal of Structural Geology,18(2):235-248.
Potyondy D O and Cundall P A.2004.A bonded-particle model for rock.International Journal of Rock Mechanics&Mining Sciences,41(8):1329-1364.
Ren X H,Wang H J and Zhang J X.2012.Numerical study of AE and DRA methods in sandstone and granite in orthogonal loading directions.Water Science and Engineering,5(1):93-104.
Roche V,Homberg C and Rocher M.2012.Architecture and growth of normal fault zones in multilayer systems:A3D field analysis in the South-Eastern Basin,France.Journal of Structural Geology,37:19-35.
Sch?pfer M P J,Arslan A,Walsh J J and Childs C.2011.Reconciliation of contrasting theories for fracture spacing in layered rocks.Journal of Structural Geology,33(4):551-565.
Sch?pfer M P J,Childs C and Walsh J J.2006.Localisation of normal faults in multilayer sequences.Journal of Structural Geology,28(5):816-833.
Soliva R and Benedicto A.2005.Geometry,scaling relations and spacing of vertically restricted normal faults.Journal of Structural Geology,27(2):317-325.
Steffen A,Gent H V and Urai J L.2011.DEM simulation of normal faults in cohesive materials.Tectonophysics,512(1):12-21.
Strayer L M,Erickson S G and Suppe J.2004.Influence of growth strata on the evolution of fault-related folds:Distinct element models//McClay K R.Thrust Tectonics and Hydrocarbon System.AAPG Memoir,82:413-437.
Strayer L M and Suppe J.2002.Out-of-plane motion of a thrust sheet during along-strike propagation of a thrust ramp:A distinct element approach.Journal of Structural Geology,24(4):637-650.
Tron V and Brun J.1991.Experiments on oblique rifting in brittle-ductile systems.Tectonophysics,188(1):71-84.
Wilkins S J and Gross M R.2002.Normal fault growth in layered rocks at Split Mountain,Utah:Influence of mechanical stratigraphy on dip linkage,fault restriction and fault scaling.Journal of Structural Geology,24(9):1413-1429.
Yin H W,Zhang J,Meng L S,Liu Y P and Xu S J.2009.Discrete element modeling of the faulting in the sedimentary cover above an active salt diapir.Journal of Structural Geology,31(9):989-995.
Zhang J,Morgan J K,Gary G G,Harkins N W,Sanz P F and Chikichev I.2013.Comparative FEM and DEM modeling of basement-involved thrust structures,with application to Sheep Mountain,Greybull area,Wyoming.Tectonophysics,608:408-417.
Zhao C B,Hobbs B E,Ord A,Robert P A,Hornby P and Peng S L.2007.Phenomenological modeling of crack generation in brittle crustal rocks using the particle simulation method.Journal of Structural Geology,29(6):1034-1048.