QUATERNARY DETACHMENT FOLDING AND PROPAGATION OF NORTH LIMB FAULT OF MUSHI ANTICLINE,NORTHERN MARGIN OF THE PAMIR

doi:10.3969/j.issn.0253-4967.2011.02.004

Abstract

Abstract:

The Mushi anticline locates at the frontier Pamir arcuate nappe tectonics belt(PFT),which is a detachment fold with a gentle south limb and steep north limb,and its earth crust minimum shortening is ～0.7km with uplift up to 1.5km.The north limb fault of Mushi anticline is composed of a series of obsequent slope fault scarps,and the distribution of vertical displacements among different fault scarps presents a pattern of one increasing and the other decreasing.No matter of the entire western segment of the northern limb faults or a single fault,the displacement distribution is asymmetric,that is,high in the east and low in the west,and the same to displacement gradient.This may reflect the late Quaternary folding of Mushi anticline as being intensive in the east and feeble in the west.The fault may be a shallow,rootless secondary fault formed during the growth process of the anticline in order to accommodate the constantly decreased space of anticline nucleus as the fold tightened gradually.The late Quaternary shortening rate of the fault is 0.8mm/a,absorbing only one fifth of the nowadays crustal shortening rate of the region.The growth of Mushi anticline and the north limb fault of Mushi anticline both are in accordance with global fault dataset scaling relationship,that is,fault length is over 100m.The power-law regression scaling exponent of west segment of the northern limb fault of Mushi anticline is n=1.37(R²=0.88),and its specific value(k)of maximum fault displacement and fault length is far less than that of the Mushi anticline,which is ～4.3％,but 1～2 orders of magnitude larger than that of global fault dataset(10^-4～10^-5). This may show that the northern limb fault of Mushi anticline is the offshoot of several moderate strong earthquakes,and it is still in initial stages.

Key words: Pamir, Mushi anticline, fold-related thrust fault, fault scarp, displacement-length scaling relationship

摘要：

发育在帕米尔弧形推覆构造带最前缘的木什活动背斜是一南缓北陡的第四纪滑脱褶皱,背斜的最小地壳缩短量为0.7km,构造隆升幅度可达1.5km。木什背斜北翼逆断层由一系列坡向北的反向断层陡坎组成,不同断坎间垂直位移分布呈现此消彼长的特征,不论是整个北翼逆断层西段还是单条断坎,其垂直位移均呈东高西低的不对称分布,位移梯度东高西低,这可能反映了背斜西段晚第四纪褶皱作用的东强西弱。该断层可能是背斜生长过程中为了调节褶皱逐渐紧闭时不断减小的核部空间形成的浅部、无根的前翼次级剪切逆冲断层,本身不会产生中强地震。该断层晚第四纪平均水平缩短速率为0.8mm/a,仅吸收了该区现今GPS地壳缩短速率的1/5。木什背斜和背斜北翼逆断层的生长均遵从根据全球断层数据获得的断层长度＞100m的标度律。木什背斜北翼逆断层西段陡坎的幂律回归标度指数n=1.37(R²=0.88),其断层最大位移(D_max)与断层长度(L)的比值(k)远小于木什背斜的约4.3％,但比全球地震地表破裂带的k值(10^-4～10^-5)要大1～2个数量级,这表明木什背斜北翼断裂陡坎可能是数个中强震的派生产物,但尚处于断层发育的早期。

关键词: 帕米尔, 木什背斜, 褶皱相关逆断层, 断层陡坎, 断层位移-长度标度律

CLC Number:

P315.2

XIAO Wei-peng, CHEN Jie, LI Tao, LI Wen-qiao, Thompson J. QUATERNARY DETACHMENT FOLDING AND PROPAGATION OF NORTH LIMB FAULT OF MUSHI ANTICLINE,NORTHERN MARGIN OF THE PAMIR[J]. SEISMOLOGY AND GEOLOGY, 2011, 33(2): 289-307.

肖伟鹏, 陈杰, 李涛, 李文巧, Thompson J. 帕米尔北缘木什背斜第四纪滑脱褶皱作用与北翼逆断裂的生长[J]. 地震地质, 2011, 33(2): 289-307.

References

陈汉林,张芬芬,程晓敢,等.2010.帕米尔东北缘地区构造变形特征与盆山构造［J］.地质科学,45(1): 102-112.
CHEN Han-lin,ZHANG Fen-fen,CHENG Xiao-gan,et al.2010.The deformation features and basin-range coupling structure in the northeastern Pamir tectonic belt ［J］.Chinese Journal of Geology,45(1): 102-112(in Chinese).
陈杰,李涛,李文巧,等.2011. 帕米尔构造结及邻区的晚新生代构造与现今变形［J］.地震地质,33(2):241-259.
CHEN Jie, LI Tao, LI Wen-qiao,et al.2011. Late Cenozoic and present tectonic deformation in the Pamirs salient, northwestern China ［J］.Seismology and Geology, 33(2):241-259(in Chinese).
陈杰,曲国胜,胡军,等.1997.帕米尔北缘弧形推覆构造带东段的基本特征与现代地震活动［J］.地震地质,19(4): 301-312.
CHEN Jie,QU Guo-sheng,HU Jun,et al.1997.Arcuate thrust tectonics and its contemporary seismicity in the eastern section of the external zone of the Pamir ［J］.Seismology and Geology,19(4): 301-312(in Chinese).
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).
陈杰,Heermance R V,Burbank D W,等.2007.中国西南天山西域砾岩的磁性地层年代与地质意义［J］.第四纪研究,27(4): 576-587.
CHEN Jie,Hermance R V,Burbank D W,et al.2007.Magneto-chronology and its implication of the Xiyu conglomerate in the southwestern Chinese Tian Shan foreland ［J］.Quaternary Sciences,27(4): 576-587(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-related faults and geological significance ［J］.Progress in Natural Science,19(3): 285-296(in Chinese).
冯先岳.1994.新疆乌恰地震破裂带 .见: 国家地震局地质研究所编.活动断裂研究(3). 北京: 地震出版社.45-55.
FENG Xian-yue.1994.Surface rupture associated with the 1985 Wuqia earthquake in Xinjiang .In: Institute of Geology,SSB(ed).Research on Active Fault(3). Seismological Press,Beijing.45-55(in Chinese).
冯先岳,栾超群,李军,等.1987.卡兹克阿尔特断裂古地震研究［J］.内陆地震,1(3):231-239.
FENG Xian-yue,LUAN Chao-qun,LI Jun,et al.1987.Study on the paleoearthquake along the Kazikearte fault ［J］. Inland Earthquake,1(3): 231-239(in Chinese).
何登发,John Suppe,贾承造.2005.断层相关褶皱理论与应用研究新进展［J］.地学前缘,12(4): 353-364.
HE Deng-fa,John Suppe,JIA Cheng-zao.2005.New advances in theory and application of fault-related folding ［J］.Earth Science Frontiers,12(4): 353-364(in Chinese).
刘胜,邱斌,尹宏,等.2005.西昆仑山前乌泊尔逆冲推覆带构造特征［J］.石油学报,26(6): 16-19.
LIU Sheng,QIU Bin,YIN Hong,et al.2005.Structural characteristics of Wuboer thrust belts in the foreland of West Kunlun Mountains ［J］.Acta Petrolei Sinica,26(6): 16-19(in Chinese).
李涛,陈杰,肖伟鹏,等.2011.利用变形河流阶地限定帕米尔北缘木什背斜的缩短、隆升和侧向扩展［J］.地震地质,33(2):308-322.
LI Tao,CHEN Jie,XIAO Wei-peng,et al.2011.Using deformation terraces to confine the shortening,uplift and lateral propagation of the Mushi anticline,northern margin of the Pamir ［J］.Seismology and Geology,33(2): 308-322(in Chinese).
钱俊锋,肖安成,程晓敢,等.2008.喀什北缘南天山冲断带构造变形分析［J］.中国矿业大学学报,37(4): 538-544.
QIAN Jun-feng,XIAO An-cheng,CHENG Xiao-gan,et al.2008.Structural deformation of fold-thrust belt in the north margin of Kashi,southern Tien Shan ［J］.Journal of China University of Mining & Technology,37(4): 538-544(in Chinese).
肖安成,贾承造,杨树锋,等.2000. 中国南天山西部冲断褶皱系前缘区的运动学特征［J］.沉积学报,18(3): 439-444.
XIAO An-cheng,JIA Cheng-zao,YANG Shu-feng,et al.2000.The kinematics characters of the thrust-fold belts western front regions in southern Tianshan China ［J］.Acta Sedimentologica Sinica,18(3): 439-444(in Chinese).
尹金辉,陈杰,郑勇刚,等.2001.卡兹克阿尔特断裂带活动特征［J］.中国地震,17: 221-230.
YIN Jin-hui,CHEN Jie,ZHENG Yong-gang,et al.2001.Active characteristics of Kazkeaerte Fault zone ［J］.Earthquake Research in China,17: 221-230(in Chinese).
Amos C B,Burbank D W,Read S A L.2010.Along-strike growth of the Ostler Fault,New Zealand: Consequences for drainage deflection above active thrusts ［J］.Tectonics,29: TC4021.doi: 10.1029/2009TC002613.
Armstrong F C,Oriel S S.1965.Tectonic development of Idaho-Wyoming thrust belt .American Association of Petroleum Geologists Bulletin,49: 1847-1866.
Burtman V S,Molnar P.1993.Geological and geophysical evidence for deep subduction of continental crust beneath the Pamir ［J］.Geological Society of America Special Paper,281: 76.
Cartwright J A,Trudgill B D,Mansfield C S.1995.Fault growth by segment linkage; An explanation for scatter in maximum displacement and trace length data from the Canyonlands Grabens of SE Utah ［J］.Journal of Structural Geology,17: 1319-1326.
Chen J, Heermance R, Burbank D W, et al. 2007. Quantification of growth and lateral propagation of the Kashi anticline, southwest Chinese Tianshan ［J］.Journal of Geophysical Research,112: B03S16. doi: 10.1029/2006JB004345.
Cowie P A,Scholz C.1992.Displacement-length scaling relationship for faults: Data synthesis and discussion ［J］.Journal of Structural Geology,14: 1149-1156.
Davis K,Burbank D W,Fisher D,et al.2005.Thrust-fault growth and segment linkage in the active Ostler Fault zone,New Zealand ［J］.J Struct Geol,27(8):1528-1546.doi: 10.1016/j.jsg.04.011.
Dawers N H,Anders M H.1995.Displacement-length scaling and fault linkage ［J］.J Struct Geol,17: 607-614.
Elliott D.1976.The energy balance and deformation mechanisms of thrust sheets ［J］.Philosophical Transactions of the Royal Society of London,283: 289-312.
Heermance R V,Chen J,Burbank D W,et al.2008.Temporal constraints and pulsed Late Cenozoic deformation during the structural disruption of the active Kashi foreland,northwest China ［J］.Tectonics,27: TC6012.doi: 10.1029/2007TC002226.
Manighetti Ⅰ,King G C P,Gaudemer Y,et al.2001.Slip accumulation and lateral propagation of active normal faults in Afar ［J］.Journal of Geophysical Research,106: 13667-13696.
McClay KR.2004.Thrust tectonics and hydrocarbon systems: Introduction .In: McClay K R(ed).Thrust Tectonics and Hydrocarbon Systems.AAPG Memoir,82: ix-xx.
Medwedeff D A.1992.Geometry and kinematics of an active,laterally propagating wedge thrust,Wheeler Ridge,California .In: Mitra S,Fisher G W(eds).Structural Geology of Fold and Thrust Belts.Johns Hopkins University Press,Baltimore,MD.3-28.
Mitra S.2002.Fold-accommodation faults ［J］.AAPG Bulletin,86: 671-693.
Nicol A,Walsh J J,Watterson J,et al.1996.Fault size distributions: Are they really power-law？［J］. Journal of Structural Geology,18: 191-197.
Scharer K M,Burbank D W,Chen J,et al.2004.Detachment folding in the southwestern Tian Shan: Tarim foreland,China: Shortening estimates and rates ［J］.Journal of Structural Geology,26: 2119-2137.doi: 10.1016/j.jsg.2004.02.016.
Schlische R W,Young S S,Ackermann R V,et al.1996.Geometry and scaling relations of a population of very small rift-related normal faults ［J］.Geology,24: 683-686.
Scholz C H.1982.Scaling laws for large earthquakes: Consequences for physical models ［J］.Bulletin of the Seismological Society of America,72: 1-14.
Scholz C H.1990.The Mechanics of Earthquakes and Faulting ［M］.Cambridge University Press,Cambridge,UK.
Scholz C H,Dawers N H,Yu J Z,et al.1993.Fault growth and fault scaling laws: Preliminary results .In: Schubert G(ed).Special Section on Physical Processes in Geodynamics 98.American Geophysical Union,Washington. 21951-21961.
Sobel E R,Dumitru T A.1997.Thrusting and exhumation around the margins of the western Tarim Basin during the India-Asia collision ［J］.Journal of Geophysical Research,102: 5043-5063.doi: 10.1029/96JB03267.
Sobel E,Chen J,Heermance R V.2006.Late Oligocene-early Miocene initiation of shortening in the southwestern Chinese Tian Shan: Implications for Neogene shortening rate variation ［J］.Earth and Planetary Science Letters,247: 70-81.doi: 10.1016/j.epsl.2006.03.048.
Thomas A C,Huang F,Strub P T,et al.1994.Comparison of the seasonal and interannual variability of phytoplankton pigment concentrations in the Peru and California Current systems ［J］.J Geophys Res,99: 7355-7370.
Thompson S C,R J Weldon,C M Rubin,et al.2002.Late Quaternary slip rates across the central Tien Shan,Kyrgyzstan,central Asia ［J］.J Geophys Res,107(B9): 2203.doi: 10.1029/2001JB000596.
Walsh J J,Childs C,Imber J,et al.2003.Strain localization and population changes during fault system growth within the Inner Moray Firth,Northern North Sea ［J］.Journal of Structural Geology,25: 307-315.
Wells D L, Coppersmith K J. 1994. New emprirical relationships among magnitude, rupture length, rupture width, rupture area, and surface displacement ［J］. Bulletin of the Seismological Society of America, 84:974-1002.
Willemse E J M.1997.Segmented normal faults: Correspondence between three dimensional mechanical models and field data ［J］.J Geophys.Res,102: 675-692.
Yang S F,Li J,Wang Q.2008.The deformation pattern and fault rate in the Tianshan Mountains inferred from GPS observation ［J］.Science in China (Ser D),51(8): 1064-1080.
Yin A,Rumelhart P E,Butler R,et al.2002.Tectonic history of the Altyn Tagh Fault system in northern Tibet inferred from Cenozoic sedimentation ［J］.Geological Society of America Bulletin,114: 1257-1295.doi: 10.1130/0016-7606(2002)114<1257: THO TAT>2.0.CO; 2.
Zubovich A V,Wang X Q,Scherba Y G,et al.2010.GPS velocity field of the Tien Shan and surrouding regions ［J］.Tectonics,29: TC6014.doi: 10.1029/2010TC002772.

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