CONTRIBUTIONS OF FOLD-ACCOMMODATION FAULTS IN FOLD SCARPS TO THE CALCULATION OF SHORTENING INCREMENT: A CASE STUDY FROM QIULITAGE ANTICLINE (SOUTHERN TIAN SHAN, CHINA)

doi:10.3969/j.issn.0253-4967.2015.03.003

Abstract

Abstract:

Fold-accommodation faults, secondary faults subordinated to the principal fold, are of much significance to accommodate strain variation in different parts of the rock during the evolution of folding. They are generally found in groups. And each of them has limited displacement and does not connect with the main detachment. After the geological survey in the East Qiulitage anticline zone, we find that the secondary faults accompanying fold scarps in this area are out-of-syncline thrusts and also give an instance of secondary faults occurring later than the folding. The fact that the secondary faults in fold scarps force the hanging wall to move upward relative to the footwall not only makes the terrace tilting and increases the slope of fold scarps, but also affects the authenticity in calculating regional shortening increment. The theoretical results show that if we do not consider the increased fold scarps height influenced by the secondary faults, the shortening increment is 51.42m. Otherwise, the value will be 45.23m and the difference between them is 6.19m. Because the deviation is 13.7% of the total shortening increment, the contributions of fold-accommodation faults to the calculation should not be ignored. The fold scarps in the northern and southern flanks of the East Qiultiage anticline depend on same bedrock type and formation mechanism. But three levels of fold scarps were found in the cross section of less than 300 meters in horizontal distance. This fact indicates that the active kink band of northern part is more closed because of higher compressive stress and faster lifting, which produce a large number of secondary faults in the fold scarps only in the northern flank. Therefore, the study of secondary faults is of significance in understanding of regional tectonic evolution and interaction between folds and faults. But there still exist many problems: 1)Limited by the observing scope, discontinuous distribution of secondary faults and variations of displacement along fault, we may underestimate the influence of secondary faults and the theoretical result should be the minimum. 2)What is the quantitative relationship among the increased height of fold scarps, the transfer slip and the dip of secondary faults?3)If secondary faults only grow in active kink band, how will they affect fold scarp?More examples of fold-accommodation faults are needed for further research.

Key words: fold-accommodation fault, fold scarp, shortening, East Qilitage anticline

摘要：

通过对东秋里塔格背斜地区内与褶皱陡坎伴生的次级断层进行的地质调查, 确定了该次级断层属于伸出向斜的逆冲断层, 也给出了次级断层的发生时间晚于褶皱作用起始时间的1个变形实例.褶皱陡坎中发育的次级断层使得陡坎上盘地层沿断层面整体向上迁移, 不仅次级断层使得阶地面发生掀斜并增大褶皱陡坎的坡度, 而且直接影响了区域缩短增量计算的真实性.计算结果显示, 当不考虑次级断层对褶皱陡坎高度的影响时, 计算所得缩短增量为51.42m, 考虑次级断层对褶皱陡坎高度的影响时, 计算得到的地壳缩短量为45.23m.二者相差6.19m, 偏差占总缩短增量的13.7%, 是一个不可忽视的量值.东秋里塔格背斜北翼和南翼的褶皱陡坎发育于相同岩性的基岩中而且具有相同的形成机制.但是背斜北翼在水平距离不足300m的范围内发育了3级褶皱陡坎, 这表明北翼相对于南翼, 其活动枢纽带更为紧闭.这是由于北翼存在更加强烈的挤压应力及更加快速的隆升作用.因此, 次级断层的研究对于正确认识区域构造演化、了解褶皱与断层相互作用关系具有重要意义.但是仍存在很多问题: 1)受观察剖面范围有限、次级断层分布不连续和断距沿延伸方向不断增大等因素的制约, 次级断层对缩短增量造成的影响可能被低估, 计算结果应为缩短量的最小值. 2)次级断层增加的陡坎高度与断层的断距、倾角具有怎样的定量关系? 3)若次级断层只发育于活动枢纽带内, 又会产生怎样的影响?这些问题还需更多的研究实例来进行更加深入的研究.

关键词: 褶皱相关断层, 褶皱陡坎, 地壳缩短, 东秋里塔格背斜

CLC Number:

P315.2

ZHANG Ling, YANG Xiao-ping, HUANG Wei-liang, LI Sheng-qiang. CONTRIBUTIONS OF FOLD-ACCOMMODATION FAULTS IN FOLD SCARPS TO THE CALCULATION OF SHORTENING INCREMENT: A CASE STUDY FROM QIULITAGE ANTICLINE (SOUTHERN TIAN SHAN, CHINA)[J]. SEISMOLOGY AND GEOLOGY, 2015, 37(3): 697-708.

张玲, 杨晓平, 黄伟亮, 李胜强. 褶皱陡坎中相关断层在缩短量计算中的作用——以东秋里塔格背斜为例[J]. 地震地质, 2015, 37(3): 697-708.

References

陈杰, Scharer K M, Burbank D W, 等. 2005. 利用河流阶地限定活动褶皱的类型和生长机制: 运动学模型［J］. 地震地质, 27(4): 513—529.
CHEN Jie, Scharer K M, Burbank D W, et al. 2005. Kinematic models of fluvial terraces over active folds: Constraints on the growth mechanism and kinematics of the fault-related folds［J］. Seismology and Geology, 27(4): 513—529(in Chinese).
邓洪菱, 张长厚, 李海龙, 等. 2009. 褶皱相关断裂构造及其地质意义［J］. 自然科学进展, 19(3): 285—296.
DENG Hong-ling, ZHANG Chang-hou, LI Hai-long, et al. 2009. Fold-accommodation faults and their geological significance［J］. Progress in Natural Science, 19(3): 285—296(in Chinese).
邓起东. 2002. 中国活动构造研究的进展与展望［J］. 地质评论, 48(2): 168—177.
DENG Qi-dong. 2002. Advances and overview on researches of active tectonics in China［J］. Geological Review, 48(2): 168—177(in Chinese).
邓起东, 陈立春, 冉勇康. 2004. 活动构造定量研究与应用［J］. 地学前缘, 11(14): 383—392.
DENG Qi-dong, CHEN Li-chun, RAN Yong-kang. 2004. Quantitative studies and applications of active tectonics［J］. Earth Science Frontiers, 11(4): 383—392(in Chinese).
邓起东, 冯先岳, 张培震, 等. 2000. 天山活动构造［M］. 北京: 地震出版社.
DENG Qi-dong, FENG Xian-yue, ZHANG Pei-zhen, et al. 2000. Active Tectonics in Tian Shan［M］. Seismological Press, Beijing(in Chinese).
管树巍, 陈宁华, 徐峰, 等. 2003. 库车凹陷秋里塔格褶皱带几何学和运动学特征与油气圈闭［J］. 石油学报, 24(6): 30—34.
GUAN Shu-wei, CHEN Ning-hua, XU Feng, et al. 2003. Properties of geometry and kinematics related to hydrocarbon traps in Qiulitag anticline zone of Kuqa Depression［J］. Acta Perolei Sinica, 24(6): 30—34(in Chinese).
李涛, 陈杰. 2014. 利用河流阶地限定活动逆断层相关褶皱晚第四纪变形机制和速率: 方法与认识［J］. 地震地质, 36(2):478—488. doi: 10.3969/j.issn.0253-4967.2014.02.016.
LI Tao, CHEN Jie. 2014. Using deformation fluvial terraces to constrain mechanism and rates of thrust related fold: methods and recognition［J］. Seismology and Geology, 36(2):478—488(in Chinese).
卢华复, 王胜利, 贾东, 等. 2002. 天山中段南麓的第四纪褶皱作用［J］. 科学通报, 47(21): 1675—1679.
LU Hua-fu, WANG Sheng-li, JIA Dong, et al. 2002. Quaternary folding in the south piedmont of central segment of Tian Shan Mountains［J］. Chinese Science Bulletin, 47(21): 1675—1679(in Chinese).
沈军, 赵瑞斌, 李军, 等. 2001. 塔里木盆地西北缘河流阶地变形测量与地壳缩短速率［J］. 科学通报, 46(4)334—338.
SHEN Jun, ZHAO Rui-bin, LI Jun, et al. 2001. Deformation observation of the stream terraces and shortening rate of crust in the northwestern margins of the Tarim Basin［J］. Chinese Science Bull, 46(4): 334—338(in Chinese).
汪新, 贾承造, 杨树锋, 等. 2002. 南天山库车冲断褶皱带构造变形时间: 以库车河为例［J］. 地质学报, 76(1): 55—63.
WANG Xin, JIA Cheng-zao, YANG Shu-feng, et al. 2002. The timing of deformation on the Kuche fold and thrust belt in the central part of the southern Tianshan: Based on the Kuche river area［J］. Acta Geologica Sinica, 76(1): 55—63(in Chinese).
吴传勇, 沈军, 陈建波, 等. 2006. 新疆南天山库车凹陷晚第四纪以来地壳缩短速率的初步研究［J］. 地震地质, 28(2): 279—288.
WU Chuan-yong, SHEN Jun, CHEN Jian-bo, et al. 2006. Preliminary study of late Quaternary crustal shortening rate along Kuqa depression in south Tianshan, Xinjiang［J］. Seismology and Geology, 28(2): 279—288(in Chinese).
杨晓平, 周本刚, 李军, 等. 2001. 新疆南天山亚肯背斜晚更新世以来的隆起和缩短［J］. 地震地质, 23(4): 581—587.
YANG Xiao-ping, ZHOU Ben-gang, LI Jun, et al. 2001. Shortening and uplift of the active Yaken anticline in southern Tianshan, China since late Pleistocene［J］. Seismology and Geology, 23(4): 581—587(in Chinese).
中国地震局震害防御司. 1999. 中国近代地震目录(公元1912年—1900年(M_S≥4.7))［M］. 北京: 中国科学技术出版社.
Earthquake Disaster Prevention Department of China Earthquake Administration. 1999. Catalogue of Chinese Earthquakes(1912-1990, M_S≥4.7)［M］. China Science and Technology Press, Beijing (in Chinese).
Chen Y G, Lai K Y, Lee Y H, et al. 2007. Coseismic fold scarps and their kinematic behavior in the 1999 Chi-Chi earthquake, Taiwan［J］. Journal of Geophysical Research: Solid Earth(1978—2012), 112(B3).
Hubert-Ferrari A, Suppe J, Gonzalez-Mieres R, et al. 2007. Mechanisms of active folding of the landscape(southern Tian Shan, China)［J］. Journal of Geophysical Research: Solid Earth(1978—2012), 112(B3).
Jamison W R. 1987. Geomrtric analysis of fold development in overthrust terranes［J］. Journal of Structural Geology, 9(2): 207—219.
Lave J, Avouac J P. 2000. Active folding of fluvial terraces across the Siwaliks Hills, Himalayas of central Nepal［J］. Journal of Geophysical Research, 105(3): 5735—5770.
Li T, Chen J, Thompson J A, et al. 2013. Quantification of three-dimensional folding using fluvial terraces: A case study from the Mushi anticline, northern margin of the Chinese Pamir［J］. Journal of Geophysical Research: Solid Earth, 118: 4628—4647.
Mitra S. 1990. Fault-propogation fold: Geometry, kinematic evolution, and hydrocarbon traps(1)［J］. AAPG Bulletin, 74(6): 921—945.
Mitra S. 2002. Fold-accommodation faults［J］. AAPG Bulletin, 86(4): 671—694.
Molnar P, Brown E T, Burchfiel B C, et al. 1994. Quaternary climate change and the formation of river terraces across growing anticlines on the north flank of the Tien Shan, China［J］. The Journal of Geology, 102(5): 583—602.
Scharer K M, Burbank D W, Chen J, et al. 2006. Kinematic models of fluvial terraces over active detachment fold: Constraints on the growth mechanism of the Kashi-Atushi fold system, Chinese Tian Shan［J］. Geological Society of American Bullutin, 118: 1006—1021.
Suppe J. 1983. Geometry and kinematics of fault-bend folding［J］. American Journal of Science, 283: 684—721.
Suppe J, Chou G T, Hook S C. 1992. Rate of folding and faulting determined from growth strata［A］. In: Thrust Tectonics. Springer Netherlands. 105—112.
Suppe J, Medwedeff D A. 1990. Geometry and kinematics of fault propagation folding［J］. Eclogae Geologicae Helvetiae, 83(3): 409—454.
Thompson S C, Weldon R J, Rubin C M, et al. 2002. Late Quaternary slip rates across the central Tien Shan, Kyrgyzstan, Central Asia［J］. Journal of Geophysical Research: Solid Earth(1978—2012), 107(B9): ETG -7.
Wrede V. 2005. Thrusting in a fold regime: Fold accommodation faults in the Ruhr Basin, Germany［J］. Journal of Structural Geology, 27(5): 789—803.

[1]	ZHANG Wei-heng, CHEN Jie, LI Tao, DI Ning, YAO Yuan. LATE QUATERNARY SHORTENING RATE OF THE SANSUCHANG ANTICLINE, SOUTHERN LONGMEN SHAN FORELAND THRUST BELT [J]. SEISMOLOGY AND GEOLOGY, 2022, 44(6): 1351-1364.
[2]	WANG Zhen-nan, LU Ren-qi, XU Xi-wei, HE Deng-fa, CAI Ming-gang, LI Ying-qiang, LUO Jia-hong. THREE-DIMENSIONAL STRUCTURAL FEATURES OF THE PENGXIAN ACTIVE BLIND FAULT IN THE CENTRAL LONGMEN SHAN FRONT BELT [J]. SEISMOLOGY AND GEOLOGY, 2019, 41(4): 944-959.
[3]	LI Wei, ZHANG Shi-min, JIANG Da-wei, GAO Yu. THRUST OF THE SOUTHERN LONGMENSHAN FAULT IN THE LATE QUATERNARY REVEALED BY RIVER LANDFORMS [J]. SEISMOLOGY AND GEOLOGY, 2017, 39(6): 1213-1236.
[4]	LI Sheng-qiang, ZHANG Ling, YANG Xiao-ping, HUANG Wei-liang, HUANG Xiong-nan, YANG Hai-bo. ACTIVE FAULTS AND THEIR FORMATION MECHANISM IN THE EAST SEGMENT OF QIULITAGE ANTICLINE BELT, KUQA DEPRESSION [J]. SEISMOLOGY AND GEOLOGY, 2016, 38(2): 223-239.
[5]	LI Tao, CHEN Jie, XIAO Wei-peng. DEFORMATION CHARACTERISTICS AND KINEMATICS OF ACTIVE DETACHMENT FOLD SCARP：A CASE STUDY FROM THE MINGYAOLE ANTICLINE, PAMIR-SOUTHERN TIANSHAN FORELAND [J]. SEISMOLOGY AND GEOLOGY, 2014, 36(3): 677-691.
[6]	LI Tao, CHEN Jie. USING DEFORMED FLUVIAL TERRACES TO CONSTRAIN GROWTH MECHANISM AND RATES OF THRUST RELATED FOLD：METHODS AND RECOGNITION [J]. SEISMOLOGY AND GEOLOGY, 2014, 36(2): 478-488.
[7]	LI Kang, XU Xi-wei, TAN Xi-bin. USING DEFORMATION TERRACES TO CONFINE THE SHORTENING AND UPLIFT OF THE LONGQUAN ANTICLINE [J]. SEISMOLOGY AND GEOLOGY, 2013, 35(1): 22-36.
[8]	LI An, YANG Xiao-ping, HUANG Wei-liang, Yiliyaer. QUATERNARY DEFORMATION OF THE HEJING THRUST-FOLD BELT ON NORTHERN MARGIN OF THE YANQI BASIN, SOUTHERN TIANSHAN [J]. SEISMOLOGY AND GEOLOGY, 2012, (2): 240-253.
[9]	WANG Hu, RAN Yong-kang, CHEN Li-chun, SHI Xiang. THE DISCUSSION ON THE CALCULATION METHOD OF SURFACE SHORTENING AMOUNT DUE TO REVERSE-FAULTING SURFACE RUPTURE:WITH THE EXAMPLE OF SURFACE DEFORMATION OF THE M_S 8.0 WENCHUAN EARTHQUAKE [J]. SEISMOLOGY AND GEOLOGY, 2008, 30(4): 1033-1045.
[10]	CHEN Chang-Yun, HE Hong-Lin. CRUST SHORTENING OF DALIANGSHAN TECTONIC ZONE IN CENOZOIC ERA AND ITS IMPLICATION [J]. SEISMOLOGY AND GEOLOGY, 2008, 30(2): 443-453.
[11]	YANG Xiao-ping, DENG Qi-dong, ZHANG Pei-zhen, XU Xi-wei. CRUSTAL SHORTENING OF MAJOR NAPPE STRUCTURES ON THE FRONT MARGINS OF THE TIANSHAN [J]. SEISMOLOGY AND GEOLOGY, 2008, 30(1): 111-131.
[12]	SONG Fang-min, MIN Wei, HAN Zhu-jun, XU Xi-wei. ACTIVITIES AND SLIP RATE OF THE FRONTAL FAULTS OF THE KALPINTAG NAPPE,TIANSHAN MOUNTAINS,CHINA [J]. SEISMOLOGY AND GEOLOGY, 2007, 29(2): 272-281.
[13]	WU Chuan-yong, SHEN Jun, CHEN Jian-bo, LI Jun, XIANG Zhi-yong, XIE Tian, SONG Zheng-na, WANG Cui. PRELIMINARY STUDY OF LATE QUATERNARY CRUSTAL SHORTENING RATE ALONG KUQA DEPRESSION IN SOUTH TIANSHAN, XINJIANG [J]. SEISMOLOGY AND GEOLOGY, 2006, 28(2): 279-288.
[14]	YANG Xiao-ping, RAN Yong-kang, SONG Fang-min, XU Xi-wei, CHENG Jian-wu, MIN Wei, HAN Zhu-jun, CHEN Li-chun. THE ANALYSIS FOR CRUST SHORTENING OF KALPIN THRUST TECTONIC ZONE, SOUTH-WESTERN TIANSHAN, XINJIANG, CHINA [J]. SEISMOLOGY AND GEOLOGY, 2006, 28(2): 194-204.
[15]	RAN Yong-kang, YANG Xiao-ping, XU Xi-wei, CHENG Jian-wu, CHEN Li-chun. DEFORMATION PATTERN AND SHORTENING RATES IN THE EAST PART OF KALPIN THRUST SYSTEM IN SOUTHWEST TIANSHAN DURING LATE QUATERNARY [J]. SEISMOLOGY AND GEOLOGY, 2006, 28(2): 179-193.