DISCUSSION ON DEVELOPMENT MODELS OF THE SHEARING FRACTURES IN FAULT BEND FOLDS
-
摘要: 围绕库车前陆盆地内某典型断层转折褶皱剖面，实测统计该剖面不同构造部位的剪切裂缝，分析断层转折褶皱中剪切裂缝的发育规律，进而建立断层转折褶皱剪切裂缝的发育模式。统计结果表明，研究区剪切裂缝有2种类型，一类是与岩层面高角度相交的高角度缝，广泛发育在构造各个部位；另一类是与层面近于平行的顺层裂缝，主要发育在断层面附近，并随岩层的变形，产状发生改变。远离断层面，剪切裂缝发育程度整体上呈减小趋势，下盘裂缝发育强度的减小大于上盘，上盘裂缝发育强度整体大于下盘。褶皱内层剪切裂缝较外层发育，褶皱两翼裂缝发育强度大于褶皱枢纽。断层产状的改变，会引起上盘运动状态的改变，使得在上盘活动轴面附近出现应力集中，局部剪切裂缝发育强度出现增大现象。断层转折褶皱剪切裂缝的发育模式可以分为3个阶段，断层形成前主要发育与层面高角度相交的区域性剪切裂缝；断层形成初期，断层面附近两盘牵引变形不明显，上盘穿过断坡下部破折点处活动轴面的部分会产生新的剪切裂缝，即与岩层高角度相交剪切缝和与断层面低角度相交剪切缝；牵引构造明显时，断层面附近两盘弯曲部位会产生顺层剪切裂缝，两翼的裂缝发育强度大于枢纽。Abstract: This paper focuses on a typical section of fault-bend fold in Kuqa foreland basin, by use of the shear fractures data measured in different structural position of the outcrop, and the fractures development laws are analyzed and then development models of the shearing fractures in fault-bend fold in Kuqa foreland basin are established. Statistical result shows that the shear fractures in the outcrop can be divided into two types: shear fractures at a high angle to layers extensively develops in each position in the outcrop, and bed-parallel fractures presenting near the fault, mainly develops near the fault with attitudes changing with the deformation of the layers. The intensity of shear fractures development decreases with the distance away from the fault as a whole. The gradient of shear fractures development in the footwall has a greater descending rate than that in the hanging wall. The density of shear fractures in the hanging wall is greater than that in the footwall. The density of shear fractures in the hinge of the fold is less than that in the forelimb and backlimb, besides higher density appears in the internal surface with respect to that in the external surface. The change of the dip angle in the fault bendfold causing the alteration of the movement for the hanging wall makes the stresses concentrating on the axial faces. So the phenomenon of the increase of intensity of shear fractures near this position can be appeared. The development model of shear fractures in the fault-bend fold shall be separated into 3 stages: regional fractures are mainly developed before the generation of fault; after the formation of the fault with dragging deformations near not obvious, new shear fractures will be formed in the position where the axial surface pinned at the lower ramp inflection point passes through, one at a high angle to the layer and the other at a low angle to the fault; the bed-parallel fractures will be presented in the curved sections and the intensity of fractures development near fold hinge is higher than that in two limbs, when the dragging deformations are obvious. The study on the model of shearing fractures development has a guiding significance for exploring the law of fractures development and prospecting the fractured reservoir in the foreland basin, especially in the deep layers with complex tectonic style.
-
Key words:
- fault-bend fold /
- shear fractures /
- distribution law /
- development model
-
图 2 断层转折褶皱野外露头剖面图
(a, b, c为照相区域, AA'为断层面的位置)
Figure 2. A profile map of outcrop of fault-bend fold in Kuqa, Xinjiang
图 3 剖面上与岩层面高角度相交的剪切裂缝
Figure 3. Shear fractures with high angle crossing to the layer in the section
图 4 裂缝发育强度与距断层距离关系散点图
(断层面位于图 2中AA'处)
Figure 4. Scatter diagram showing relationship between fracture development intensity and distance to the fault
图 6 褶皱上三处测点的位置图
(黄色部分表示测量区域)
Figure 6. Locations of the three measurement sites in the fold
图 7 断层转折褶皱剪切裂缝发育模式图
Figure 7. Development models of shearing fractures in fault bend fold
表 1 裂缝发育强度与距断层距离关系统计
Table 1. Statistics of relationship between fracture development intensity and distance to the fault
点号 密度(条/m) 位置 1 33.3 下盘紧靠断层面 2 11.1 下盘距层面1.5 m 3 5.0 下盘距层面3.5 m 4 3.7 下盘距断面6.2 m 5 23.0 上盘距断面1.0 m 6 33.3 上盘距断面1.7 m 7 19.7 上盘距断面3.5 m 8 14.1 上盘距断面4.2 m 9 15.6 上盘距断面6.0 m 10 8.2 上盘距断面9.6 m 11 6.3 上盘距断层面12.0 m 
下载: 导出CSV
表 2 卡普沙良河剖面上断层相关褶皱不同部位的裂缝密度
Table 2. Fracture densities in different positions of fault-related fold in Kapushaliang River
构造部位 前翼(a处) 枢纽(b处) 后翼(c处) 裂缝密度/(条·m-1) 33.3 25 58.5 25 20 33.3 20 12.72 25 9.1 10 16.7 注:每列数据自上而下反映的是从褶皱核部至外部的裂缝发育情况
下载: 导出CSV
-
[1] 杨明慧, 刘池洋.中国中西部类前陆盆地特征及含油气性[J].石油与天然气地质, 2000, 21(1):46~49. doi: 10.11743/ogg20000111YANG Ming-hui, LIU Chi-yang. Characters of quasi-foreland basins in western-central China and their oil and gas potential[J]. Oil & Gas Geology, 2000, 21(1): 46~49. doi: 10.11743/ogg20000111 [2] 甘克文.漫谈前陆逆掩断层带油气勘探的经验教训[J].石油与天然气地质, 2004, 25(2):149~155. doi: 10.11743/ogg20040206GAN Ke-wen. An informal discussion on experiences and lessons of petroleum exploration in foreland over-thrust zone[J]. Oil & Gas Geology, 2004, 25(2): 149~155. doi: 10.11743/ogg20040206 [3] 刘和甫, 汪泽成, 熊保贤, 等.中国中西部中、新生代前陆盆地与挤压造山带耦合分析[J].地学前缘, 2000, 7(3):55~72. http://www.cnki.com.cn/Article/CJFDTOTAL-DXQY200003007.htmLIU He-fu, WANG Ze-cheng, XIONG Bao-xian, et al. Coupling analysis of Mesozoic Cenozoic foreland basin and mountain system in central and western china[J]. Earth Science Frontiers, 2000, 7(3): 55~72. http://www.cnki.com.cn/Article/CJFDTOTAL-DXQY200003007.htm [4] 王瑞飞.特低渗透砂岩油藏储层微观特征[M].北京:石油工业出版社, 2008.WANG Rui-fei. Microscopic characteristics of ultra-low permeability sandstone reservoirs[M]. Beijing: Petroleum Industry Press, 2008. [5] Zeng Lianbo. Microfracturing in the Upper Triassic Sichuan Basin tight-gas sandstones: Tectonic, overpressure, and diagenetic origins[J]. AAPG Bulletin, 2010, 94(12): 1811~1825. doi: 10.1306/06301009191 [6] Suppe J. Geometry and kinematics of fault-bend folding[J]. American Journal of Sciences, 1983, 283: 684~721. http://citeseerx.ist.psu.edu/showciting?cid=377272 [7] Kim Y S, Peacock D C P, Sanderson D J. Fault damage zones[J]. Journal of Structural Geology, 2004, 26(3): 503~517. doi: 10.1016/j.jsg.2003.08.002 [8] Blenkinsop T G. Relationship between faults, extension fractures and veins, and stress[J]. Journal of Structural Geology, 2008, 30(5): 622~632. doi: 10.1016/j.jsg.2008.01.008 [9] Atilla A. Fracture, fault, and hydrocarbon entrapment, migration and flow[J]. Marine and Petroleum Geology, 2000, 17(7): 797~814. doi: 10.1016/S0264-8172(00)00020-9 [10] 曾联波.低渗透砂岩储层裂缝的形成与分布[M].北京:科学出版社, 2008.ZENG Lian-bo. Formation and distribution of fractures in low permeability sandstone reservoirs[M]. Beijing: Science Press, 2008. [11] Withjack M O, Olson J, Peterson Eric. Experimental models of extensional forced folds[J]. AAPG Bulletin, 1990, 74(7): 1038~1054. http://aapgbull.geoscienceworld.org/content/74/7/1038 [12] Jin G H, Groshong Jr R H. Trishear kinematic modeling of extensional fault-propagation folding[J]. Journal of Structural Geology, 2006, 28: 170~183. doi: 10.1016/j.jsg.2005.09.003 [13] James F M, Shankar M. Deformation and secondary faulting associated with basement-involved compressional and extensional structures[J]. AAPG Bulletin, 2011, 95(4): 675~689. doi: 10.1306/09131010007 [14] Chester J S, Logan J M, Spang J H. Influence of layering and boundary conditions on fault-bend and fault-propagation folding[J]. Geological Society of America Bulletin, 1991, 103: 1059~1072. doi: 10.1130/0016-7606(1991)103<1059:IOLABC>2.3.CO;2 [15] Lin M L, Chung C F, Jeng F S. Deformation of overburden soil induced by thrust fault slip[J]. Engineering Geology, 2006, 88: 70~89. doi: 10.1016/j.enggeo.2006.08.004 [16] Erslev E A. Trishear fault-propagation folding[J]. Geology, 1991, 19(6): 617~620. doi: 10.1130/0091-7613(1991)019<0617:TFPF>2.3.CO;2 [17] Allmendinger R W. Inverse and forward numerical modeling of trishear fault-propagation folds[J]. Tectonics, 1998, 17(4): 640~656. doi: 10.1029/98TC01907 [18] Cristallini E O, Allmendinger R W. Backlimb trishear: A kinematic model for curved folds developed over angular fault bends[J]. Journal of Structural Geology, 2002, 24(2): 289~295. doi: 10.1016/S0191-8141(01)00063-3 [19] Salvini F, Storti F. The distribution of deformation in parallel fault-related folds with migrating axial surfaces: comparison between fault-propagation and fault-bend folding[J]. Journal of Structural Geology, 2001, 23: 25~32. doi: 10.1016/S0191-8141(00)00081-X [20] Lin X B, Chen H L, Cheng X G, et al. Conceptual models for fracturing in fault related folds[J]. Mining Science and Technology, 2010, 20(1): 103~108. http://www.wenkuxiazai.com/doc/a0d428c250e2524de5187ee6.html [21] Cardozo N, Allmendinger R W, Morgan J K. Influence of mechanical stratigraphy and initial stress state on the formation of two fault propagation folds[J]. Journal of Structural Geology, 2005, 27: 1954~1972. doi: 10.1016/j.jsg.2005.06.003 [22] 贾东, 陈竹新, 罗良, 等.断层相关褶皱的磁组构与有限应变:川西岷江冲断构造的实例分析[J].自然科学进展, 2007, 17(1):31~39. http://www.cnki.com.cn/Article/CJFDTOTAL-ZKJZ200702007.htmJIA Dong, CHEN Zhu-xin, LUO Liang, et al. Magnetic fabrics in fault-related fold and its relation with finite strain:an example from Ming jiang thrust structures in Western Sichuan[J]. Progress in Natural Science, 2007, 17(1): 31~39. http://www.cnki.com.cn/Article/CJFDTOTAL-ZKJZ200702007.htm [23] 李军, 尹宏伟, 张洁, 等.三角剪切模型及其在川东大池干构造解译中的应用[J].石油学报, 2007, 28(4):68~72. doi: 10.7623/syxb200704013LI Jun, YIN Hong-wei, ZHANG Jie, et al. Trishear model and its application to interpretation of Dachigan structure in the eastern Sichuan Province[J]. Acta Petrolei Sinica, 2007, 28(4): 68~72. doi: 10.7623/syxb200704013 [24] 沈海超, 程远方, 王京印, 等.断层对地应力场影响的有限元研究[J].大庆石油地质与开发, 2007, 26(2):34~37. http://www.cnki.com.cn/Article/CJFDTOTAL-DQSK200702009.htmSHEN Hai-chao, Cheng Yuan-fang, Wang Jing-yin, et al. Study of finite element on effects of faults on ground stress field[J]. Petroleum Geology & Oilfield Development in Daqing, 2007, 26(2): 34~37. http://www.cnki.com.cn/Article/CJFDTOTAL-DQSK200702009.htm [25] 孙礼建, 朱元清, 杨光亮, 等.断层端部及附近地应力场的数值模拟[J].大地测量与地球动力学, 2009, 29(2):7~12. http://www.cnki.com.cn/Article/CJFDTOTAL-DKXB200902005.htmSUN Li-jian, ZHU Yuan-qing, YANG Guang-liang, et al. Numerical simulation of ground stress field at ends and vicinity of a fault[J]. Journal of Geodesy and Geodynamics, 2009, 29(2): 7~12. http://www.cnki.com.cn/Article/CJFDTOTAL-DKXB200902005.htm [26] 曾联波, 漆家福, 王永秀.低渗透储层构造裂缝的成因类型及其形成地质条件[J].石油学报, 2007, 28(4):52~56. doi: 10.7623/syxb200704010ZENG Lian-bo, QI Jia-fu, WANG Yong-xiu. Origin type of tectonic fractures and geological conditions in low-permeability reservoirs[J]. Acta Petrolei Sinica, 2007, 28(4): 52~56. doi: 10.7623/syxb200704010 [27] 曾联波, 王正国, 肖淑容, 等.中国西部盆地挤压逆冲构造带低角度裂缝的成因及意义[J].石油学报, 2009, 30(1):56~60. doi: 10.7623/syxb200901011ZENG Lian-bo, WANG Zheng-guo, XIAO Shu-rong, et al. The origin and geological significance of low dip-angle fractures in the thrust zones of western basins of China[J]. Acta Petrolei Sinica, 2009, 30(1): 56~60. doi: 10.7623/syxb200901011 [28] Hardy S. A method for quantifying the kinematics of fault-bend folding[J]. Journal of Structural Geology, 1995, 17(12): 1785~1788. doi: 10.1016/0191-8141(95)00077-Q [29] Masini M, Bulnes M, Poblet J. Cross-section restoration: A tool to simulate deformation. Application to a fault-propagation fold from the Cantabrian fold and thrust belt, NW Iberian Peninsula[J]. Journal of Structural Geology, 2010, 32(6): 172~183. http://adsabs.harvard.edu/abs/2010JSG....32..172M [30] González G, Gerbault M, Martinod J, et al. Crack formation on top of propagating reverse faults of Chuculay Fault System, northern Chile: Insights from field data and numerical modeling[J]. Journal of Structural Geology, 2008, 30: 791~808. doi: 10.1016/j.jsg.2008.02.008 [31] 曾佐勋, 樊光明.构造地质学[M].武汉:中国地质大学出版社, 2010.ZENG Zuo-xun, FAN Guang-ming. Structural Geology[M]. Wuhan: China University of Geoscience Press, 2010. -
下载:
图(7) / 表(2)
计量
- 文章访问数: 325
- HTML全文浏览量: 165
- PDF下载量: 23
- 被引次数: 0
