Abstract Deciphering how the widespread late Cenozoic conglomerates were formed across the Tibetan Plateau is crucial for understanding the competition between tectonics and climate. Here we target the mid‐Pleistocene conglomerate cap along the northern Saishiteng range (SR), North Tibet. 26Al/10Be burial dating constrains the onset accumulation of the conglomerate cap to 828 +116/−105 to 679 +55.0/−51.1 kyr ago. Newly‐discovered seismites and localized unconformities indicate the mid‐Pleistocene growth of the SR, leading to accumulation of the conglomerate cap. Integrating our new observation with previous studies on other gravel beds across the Tibetan Plateau, we reveal diachronous depositional ages of these gravel beds ranging from 1.37 to 0.56 Myr. Given the spatial and temporal distribution patterns of gravel beds, we infer that tectonic uplift primarily governed the accumulation of the low‐elevation (<2,400 m) gravel beds, whereas the interplay between tectonics and climate change shaped most high‐elevation (>2,400 m) gravel beds across the plateau.

The Quaternary chronostratigraphic framework serves as a fundamental basis for evaluating the active parameters of Neotectonic movements and fault activity. However, the scarcity of the continuous stratigraphic sections and the lack of absolute age calibration have led to diverse interpretations regarding the Quaternary stratigraphic divisions in the Beijing Plain, particularly concerning the classification of the thick gravel layer at depth. These discrepancies significantly affect the delineation of boundaries between the Upper Pliocene and Lower Pleistocene, as well as the determination of the timing of the latest Quaternary tectonic event. Consequently, the development of reliable seismo-tectonic models and the quantitative assessment of seismic hazards in the North China Plain remain constrained. In this study, we analyzed a 603-m-long continuous stratigraphic core obtained from borehole XD04, drilled in the Dachang Sag located in the eastern Beijing Plain. By conducting systematic paleomagnetic analyses and dating key stratigraphic horizons using optically stimulated luminescence (OSL) and cosmogenic nuclide techniques, we established a detailed Quaternary chronostratigraphic framework for the Dachang Sag. The base of the Holocene Yanjiao Formation () is Qyj h identified at a depth of 4.8 m, while the base of the Upper Pleistocene Junying Formation () occurs at 76.4 Q3jY p m. The lower boundary of the Middle Pleistocene Zhaili Formation () corresponds to the Brunhes-Q2zl p Matuyama (B/M) magnetostratigraphic boundary or a parallel unconformity with its underlying strata at a depth of 229.9 m. Furthermore, the base of the Lower Pleistocene Xiadian Formation () aligns with the Q1xd p Matuyama-Gauss (M/G) magnetostratigraphic boundary at a depth of 412.8 m. Strata below the M/G boundary are assigned to the Pliocene Shunyi Formation (). Notably, the fine-grained sediments between depths of Nsy 2 39.14 m and 229.85 m represent lacustrine deposits filled within the Dachang paleo-lake during the Middle to early Late Pleistocene. OSL dating results indicate that the paleo-lake disappeared between 41.5 +/- 1.7 ka and 58.4 +/- 2.6 ka ago, likely due to the interplay between the eastward extrusion of the Qinghai-Tibetan Plateau and the westward subduction of the Pacific Plate during the Late Quaternary. Additionally, the parallel unconformity between the Middle Pleistocene Zhaili Formation () and the Lower Pleistocene Xiadian Formation () Q2zlQ1xd pp provides geological evidence for Neotectonic activity. Finally, a thick gravel layer occurring between depths of 512.6 and 591.4 m is attributed to the Pliocene Shunyi Formation (), representing the sedimentary deposits Nsy 2 associated with the differential uplift and formation of the Tangxian paleo-planation surface. This uplift was driven by the intense extrusion of the Qinghai-Tibetan Plateau during the mid-to-late Pliocene. Therefore, the presence of this deep gravel layer reflects the far-field tectonic effects of the eastward movement of the Plateau.

The Banquan Basin is a pull-apart basin with the largest scale and the most prominent structure due to dextral slip of the Tanlu Fault Zone (TLFZ) in late Cenozoic. The depositional history of the basin records the start time and evolution of the right-lateral strike-slip movement of the TLFZ. This paper studies the sedimentary and tectonic evolution of the Banquan Basin by seismic reflection exploration, borehole detection and cosmogenic nuclide chronology. We analyze the coupling relationship between the pull-apart basin and the strike-slip fault and discuss the start time and tectonic significance of the right-lateral strike-slip of the TLFZ. Our study indicates that the Banquan Basin has undergone three evolutionary stages: weak rifting during the pre-pull-apart period, strong extension during the syn-pull-apart period and subsidence during the post-pull-apart period. This implies that the TLFZ, which controls the evolution of the basin, experienced an evolutionary process of weak activity, intensified activity and migration of activity toward the central basin. The sedimentary filling of the basin has strong response to the episodic pull-apart and extension of the basin. Lying upon the basement of the basin, a thin layer of Miocene mudstone slowly accumulated due to local rifting before the strong pull-apart event. Along with the dextral slipping and pull-apart process, the basin was filled with alluvial fan facies, fluvial facies and floodplain facies strata from bottom to top. The latest tectonic movement of the TLFZ in the North China Block in late Cenozoic was dominated by episodic dextral strike-slip motion, and this deformation pattern started at 4.01±1.27 Ma. The latest tectonic deformation in North China since late Cenozoic was governed by eastward extrusion and tectonic orogenesis of the eastern margin of the Qinghai-Xizang Plateau since late Miocene. The eastward thrusting of the Liupanshan fault zone and sinistral shearing of the Qinling fault zone led to the anticlockwise rotation and pushing of secondary blocks in North China, resulting in a planar bookshelf faulting and rotation pattern. This unique deformation pattern transferred eastwards to the North China Plain at ∼ Ma and the process continues to the present time. This planar bookshelf rotation, accompanied with regional sinistral strike-slip movement of the ∼EW-trending boundary fault zones to the north and south of the North China Block and dextral strike-slip motion of the NNE-trending boundary faults between secondary blocks, is likely to be the long-range effect of the strong extrusion of the eastern margin of the Qinghai-Xizang Plateau.

In order to solve the vibration problem of low-damping flexible mechanism in motion, a cascade vibration suppression (CVS) trajectory planning method combining the advantages of the optimal double S-curve trajectory planning method and the input shaping method is proposed. The CVS method can effectively suppress the vibration in the period of uniform motion. The correctness of this method is proved by theoretical analysis and digital simulation. Finally, the application results of the proposed method in the FAST feed support system show that it can effectively improve the motion accuracy of the parallel cable mechanism, especially when the motion speed is constant, improving the position tracking accuracy by over 20%.

The Five-hundred-meter Aperture Spherical radio Telescope is the world’s largest single-dish radio telescope and is located in the southwest of China. The cable-driven parallel robot and A-B rotator of the feed support system in Five-hundred-meter Aperture Spherical radio Telescope are designed to realize the theoretical position and attitude of the receiver. The feed support system is a pose-redundant and rigid–flexible coupling system; thus, the method of pose distribution between the A-B rotator and the cable-driven parallel robot impacts on the cable tension distribution and stiffness of the feed support system, which are crucial to the feed support system stability. The main purpose of this study is to examine the pose optimal distribution method for the feed support system. First, a mechanical model of the feed support system, which considers the time-varying barycenter of the feed cabin and the back-illuminated strategy of the receiver, is established. Then, a pose distribution method that ensures the position and attitude accuracy of the receiver is proposed for the feed support system. Considering the performance indices of the variance of cable tensions and the stiffness of the cable-driven parallel robot, an optimization of the rotation angles of the A-B rotator with multiple objectives is implemented using a genetic algorithm. Finally, simulations are conducted to demonstrate the effectiveness of the proposed method compared with others. Results show that the proposed approach not only ensures the attitude accuracy of the receiver but also maintains the lower variance of cable tensions and higher stiffness of the feed support system.

The Five-hundred-meter Aperture Spherical Radio Telescope (FAST) requires high accuracy of positioning and attitude adjusting. Due to its flexible structure, the cable-cabin system can be excited to vibrate, which affects the performance. To alleviate the vibration during the slewing task, taking advantage of s-curve planning and input shaping, a cascade motion planning method is proposed. Considering the main vibration mode, a simplified cable-cabin model is built for simulation according to the parameters of FAST. Simulation experiments are conducted to prove that the cascade method is effective in vibration suppression and robust to the change of natural frequency.

Unlike other large rivers flowing out of Tibet, the Yellow River escapes from the plateau towards the NE crossing no less than five NW-SE striking, actively growing ranges and intervening basins. Thick Plio-Quaternary deposits and fluvial terraces testify to a phase of aggradation and sediment infill up to the average surface elevation (3200-3250 ma.s.l.) of the Gonghe, Guide and Qinghai Lake basins. A set of seven main terraces across the Gonghe Basin suggests progressive down-cutting of the Yellow River carving the 500 m deep Longyang gorge at the basin exit. Be-10 and Al-26 concentrations in quartz of surface and sub-surface samples of four terraces constrain the timing of incision by determining the burial age of the deposit and the exposure age of its surface. Modelling the depth dependence of the Be-10 concentration and the Al-26/Be-10 ratio allows us to constrain the onset of the ongoing phase of incision to 120-250 ka. These ages suggest long-term incision rates between 2-6 mm a(-1). Together with the present morphology of the Yellow River terraces across the Gonghe basin and the Longyang gorge, our results imply rapid river catchment evolution and interaction between river dynamics, tectonic and climate in northeastern Tibet.

The Kunlun Fault, an active fault on the border between the Bayan Har and Kunlun-Qaidam blocks, is one of the major left lateral strike-slip faults in the Tibetan Plateau. Previous research has not reached a consensus on agreeable slip rates along much of its length and the slip rate gradient along the eastern part, both of which play critical roles in a range of models for the eastward extrusion and thickened crust of the Tibetan Plateau. New slip rates have been determined at sites along the eastern part of the Kunlun Fault by dating deposits and measuring atop displaced fluvial terrace risers. Field investigations and interpretation of satellite images reveal geometrical features of the fault and the late Quaternary offset, new earthquake ruptures and surface-rupturing segmentation, from which long-term slip rates and earthquake recurrence intervals on the fault are estimated. The tectonic geomorphology method has determined that the long-term horizontal slip rates on the Tuosuohu, Maqin and Maqu segments from west to east are 11.2±1, 9.3±2, and 4.9±1.3 mm/a while their vertical slip rates are 1.2±0.2, 0.7±0.1, and 0.3 mm/a in the late Quaternary. Results indicate that the slip rates regularly decrease along the eastern ∼300 km of the fault from >10 to <5 mm/a. This is consistent with the decrease in the gradient such that at the slip rate break point is at the triple point intersection with the transverse fault, which in turn is transformed to the Awancang Fault. The vector decomposition for this tectonic transformation shows that the western and eastern branches of the Awancang Fault fit the slip-partitioning mode. The slip rate of the southwestern wall is 4.6 mm/a relative to the northeastern wall and the slip direction is 112.1°. The mid-eastern part of the Kunlun Fault can be divided into three independent segments by the A’nyêmaqên double restraining bend and the Xigongzhou intersection zone, which compose the surface rupture segmentation indicators for themselves as well as the ending point of the 1937 M7.5 Tuosuohu earthquake. The average recurrence interval of the characteristic earthquakes are estimated to be 500–1000 a, respectively. The latest earthquake ruptures occurred in AD 1937 on the western Tuosuohu segment, as compared to ∼514–534 a BP on the Maqin segment, and ∼1055 to 1524 a BP on the Maqu segment. This may indicate a unidirectional migration for surface rupturing earthquakes along the mid-eastern Kunlun Fault related to stress triggered between these segments. Meanwhile, the long-term slip rate is obtained through the single event offset and the recurrence interval, which turn out to be the same results as those determined by the offset tectonic geomorphology method, i.e., the decreasing gradient corresponds to the geometrical bending and the fault’s intersection with the transverse fault. Therefore, the falling slip rate gradient of the mid-eastern Kunlun Fault is mainly caused by eastward extension of the fault and its intersection with the transverse fault.

Based on the interpretation of satellite image,field investigation and geomorphic survey and sample dating of surface,the strath terrace and fill terrace at the outlet of Moleqiehe River on the western segment of Altyn Tagh Fault zone(ATF)are used to study the tectonic uplift rate,uplift model and aggradation rate,and cooperated with data of the regional climate,the response to climate evolution of development of terrace are discussed.The previous studies of the terraces related with the Altyn Tagh Fault zone are mainly focused on the horizontal offset in order to obtain sinistral-slip rate,but few studies involve the uplift using terraces.As a structural zone with strike-thrust characteristic,the ATF is a boundary structure of the northern fringe of Qinghai-Tibet Plateau,and its thrusting and uplifting movement is of significance for controlling the uplift of the northern fringe of the Plateau.Therefore,the study of uplift of the ATF will be helpful for understanding the uplift model and mechanism and promoting the kinematic study of the northern fringe of the Plateau.The formation of strath terrace is closely related with tectogenetic movement,the landform age of the terrace represents the starting time of uplift.Based on the height and strath and landform age,the uplift rate can be calculated.The fill terrace is formed by climate forcing,the surface age represents the end time of one aggradation event.If the starting time of aggradation is obtained,the aggration rate can be calculated.There are four stream terraces at the outlet of Moleqiehe River(T4,T3,T2,and T1).T4 and T3 are strath terraces,T2 is fill terrace,and T1 are fill-cut terraces.The landform ages of T3,T2,and T1 are 18.98±1.42kaBP,13.08±1.01kaBP,and 5.72±0.43kaBP,respectively.The existence of T3 reveals the uplift rate of 6.66±0.50mm/a since 18.98±1.42kaBP.The existence of T3 and T2 reveals the time of fast uplift movement and aggradation events between 18.98±1.42kaBP to 13.08±1.01kaBP,the uplift rate is bigger than 20mm/a and the aggradation rate bigger than 10mm/a.The model of tectonic uplift shows tilted uplift from south toward north across the ATF,and this model is one of the types of the Qinghai-Tibet Plateau extending toward north.The aggradations,that constructed the T2,are the result of the coactions of fast uplift and deglaciation climate between 15kaBP to 12kaBP.

基于卫星影像解译和野外考察测量, 本文对东昆仑断裂带中东部的3条次级断裂(托索湖断裂、玛沁断裂和玛曲断裂)的滑动速率以及全新世以来的古地震活动特征进行了分析研究.

地貌年代是新构造特别是活动构造定量研究的瓶颈问题.通过对川滇块体北东边界构造带所在的区域气候变化过程和地貌研究成果的综合分析.利用众多的年代学数据,从区域尺度对地貌的年代、形态和物质组成等特征对比分析,探讨了该区冰川地貌、河流阶地和冲洪积扇的演化特征,揭示了区域气候变化与区域性地貌演化存在的内在对应关系.气候变化产生的气温、湿度、降水量等变化控制了该区冰川地貌和流水地貌的演化.区域内冰川地貌主要是末次冰期的产物,对应于末次冰期两个冰阶,河流作用在7～10ka和1～5ka两个阶段改造末次冰期堆积地貌形成相应的侵蚀地貌.主要河流阶地发育对应于降水量剧烈变化的气候过程,其中形成三级阶地而的流水下切作用最强,随后堆积的深厚物质是二级阶地的主体,并一直没有被后期流水下切作用蚀穿,与气候变化的强度等特点对应.区内冲洪积扇主要有3个堆积时期,即3～5ka,7～10ka和20～25ka,主要发育在气候变化最剧烈的时期,大量的碎屑物形成并短距离搬运堆积.将区域分析综合的结果应运到康定南团结乡附近的地貌分析,可以很好的理解该区的地貌演化,用侵蚀改造的地貌演化结论否认了以前的堆积地貌认识,理清了地貌发育的年龄序列.综合分析与应用的结果表明,区域气候-地貌-构造系统研究对于活动构造年代学具有非常重要的意义.

Cosmogenic dating(in situ cosmogenic nuclides)has been widely used in geologic and geographic domain along with the application of accelerator mass spectrometry(AMS)and highly sensitive conventional noble-gas mass spectrometry in the early 1980s,since Raymond Davis and Oliver Schaffer proposed that cosmogenic nuclides produced within minerals at the surface of the earth could be applied to geological problems.At present,this dating method is used to study glacier,desert and relief evolution,volcano development and active structure movement etc.There are a lot of materials which can be used in cosmogenic dating method.Because of its tight crystal structure,quartz can minimize possible contamination by meteoric10 Be,and also for its low 27Al content,it becomes an ideal material for cosmogenic dating method.During the process of the isolation of 10Be and 26Al from quartz sample,quartz isolation and purification are one of the key steps.HCl/H2O2 and HF/HNO3 leaching is a safe method used to isolate and purify the quartz samples widely.However,there is defect about the method.It takes more time for sample preparation and curtails the life of instrument.Based on the above method,three experiments were designed to compare with the primary one.The results of experiment reveal that the purification efficiency can be enhanced by increasing the leaching solution concentration and the amount of sample,and ultrasonic cleaner can be replaced by hotplate /magnetic stirrer.

The paper carries out geometric segmentation of the eastern segment of East Kunlun Active Fault(Maqin-Maqu segment)based on the interpretation of ETM and QuickBird satellite images and using segmental signs of strike-slip fault,such as geometric and tectonic discontinuities in combination of geomorphic features and fault zone materials. In this study,we divide the Kunlun Active Fault(Maqin-Maqu segment)into eight segments,geometrically,namely,Dongqinggou,Dawutan,Kendingna,Xikehe,Tangdi,Maqu,Moxi and Luocha. Faults in the former seven segments are developed en echelon,of which,that in the Tangdi and Maqu segments are of right-stepping en echelon,and the rest are of left-stepping. The space between steps is small and well-connected. Beside the stepover,the segmentation indicators also include the bend of fault strike and the intersection of fault with others. Luocha segment is divided mainly by the strike bend. The east Kunlun Fault intersects with the Awancang Fault and Xikehe-Maqu Fault at the south side of Mohatang,which is taken as an indicator of segmentation of the Xikehe segment. The extensive landform and evidence of paleo-seismic rupture indicate that the Maqin-Maqu segment has experienced numerous movements. The fault splays out from northwest to southeast,which has good correlation with the slip rate gradients along the Eastern Kunlun Fault.

The Wenchuan earthquake(MS=8.0)of May 12,2008 in Sichuan Province,China produced surface ruptures along the seismogenic reverse faults.It is very important to analyze the co-seismic surface ruptures quantitatively for the comprehension of tectonic behavior of the great earthquake.We discuss several issues about the quantitative analysis of co-seismic surface ruptures produced by reverse faults with some examples from Wenchuan earthquake.With the geometric relations between the parameters of deformation and survey data from planar and linear geomorphologic benchmark,solution methods for those parameters are provided.The vertical slip,horizontal dip-slip and dip angles on survey profiles were measured to calculate the actual deformation of the fault.The relationship between the apparent deformation and the real value was provided quantitatively for oblique profiles and linear benchmarks.We also made some discussions on the application of the survey data to the analysis of regional structural geometry and kinematics.

A 240km-long co-seismic surface rupture was produced along the Beichuan-Yingxiu Fault during the 2008 Wenchuan earthquake.We made a detailed survey at representative sites along the surface rupture and analyzed the data based on the geometry between the benchmark and deformation.The co-seismic vertical slip,horizontal dip-slip shortening,strike slip and moving direction of the hanging-wall were calculated based on the survey data of these sites.Results show that the spatial distribution of the co-seismic deformation of the fault varies a lot along the fault.The maximal horizontal slip,as we got till now,is located in the Shenxigou site of Hongkou with a value of 4.98m,and the maximal strike slip is also located in the same site with a value of 4.5m.The maximal vertical displacement is located to the northeast of Shenxigou with a value of 5.7～6.7m.The average horizontal slip for the NE trending fault is 1～2m,and the average vertical slip is 3m.But horizontal and vertical slip for the NW-trending branch from Xiaoyudong to Caoba is only 0.5～1.5m.The data from Leigu town show that the gravity deformation resulting from the fault-related landslide was perhaps superimposed on the tectonic one.The dip angles of the fault at the surveyed sites calculated from the horizontal shortening and vertical displacement indicate that the Beichuan-Yingxiu Fault is a steep dipping reverse fault with some strike-slip.From the comparison between field results and geophysical inversion,we believe that the spatial distribution of co-seismic fault-slip is related to the barriers and rupture process along the fault plane.

Shallow seismic surveying is a common method applied to the research of blind fault activity at the Quaternary stratum region,especially in urban area.The bifurcating,uniting,bending,intermitting and ending off of reflection waves on stacked time section are important signs which are often used to judge the existence of blind fault.At the northern area of Songhuajiang River in Harbin City,we finished two seismic reflection profiles.On the shallow seismic reflection profiles of Lugangtun and Jubaotun,the T0 wave group corresponding to the interface between Cretaceous sand-mud stone and lower Pleistocene gravel is clear.T0-1 reflecting wave group corresponding to the contact surface between gravel and clay,or fine sand and gravel,is also clear.Based on the stacking seismic profiles and borehole data,we conclude that the Ashihe fault offset the bottom stratum of lower Pleistocene,and Binzhou fault cut off the bottom stratum of upper Pleistocene.By building high quality composite drilling geological profiles,dating the samples from bores,and contrasting stratum from one bore to the other,we consider that the Ashihe fault does not offset the Quaternary formation,the fault may only exist in Cretaceous sand-mud stone.The Binzhou fault is only an early Pleistocene fault;it doesn't offset the late Pleistocene formation.Finally,we think that the bifurcating,bending,intermitting and ending off of seismic reflection wave group on Luegangtun and Jubaotun seismic profiles are not the result of fault activity,but the phase change of Quaternary formation.

In order to efficiently obtain high-quality quantitative parameters in active tectonics research, it is necessary to introduce digital aerophotogrammetry as a surveying and mapping tool. Testing research was performed along the Xianshuihe fault zone, which is located in the mountain area of western Sichuan Province. Using spatially enhanced, orthorectified images, large scale topography and ground surface profiles, we obtained a series of data of the active Xianshuihe fault zone near Tuanjie in the south of Kangding county. Left lateral horizontal deformation of the fault is about 43m and vertical deformation is about 5.8m since the T1 proluvial fan was formed. Digital aerophotogrammetry provides high precision when measuring quantitative parameters in the study of active tectonics such as accumulative horizontal and vertical deformations and fault length, detailed geometric structure resolution and geomorphological mapping, thus greatly improving field work efficiency.

Based on detailed logging of fourteen drill holes, combined with the results of other researchers, the preliminary summarization on sedimentary characteristics of the late Pleistocene of the Fuzhou basin is done. The deposition of Fuzhou basin began from about 56.5ka BP and the sediments are composed of gravel, sand, clay and silt, which show a depositional sequence with granularity becoming smaller from the lower to the upper and a big lateral variation of lithology. There are three silt layers in late Quaternary strata of Fuzhou basin. The first and second layers were developed during the middle and late Holocene, the deposition time is about 7.86ka BP to 1.44ka BP and they are the results of ”Changle Transgression”. The third was developed during the late of late Pleistocene and the deposition time is from 44ka BP to 20ka BP and it is the result of ”Fuzhou Transgression”. The buried late Quaternary sediments in Fuzhou basin can be divided into upper Pleistocene series and Holocene series, which include four formations from old to new. They are the Longhai formation (Q(superscript 3 subscript p)l), Dongshan formation (Qhd), Changle formation (Qhc) and Jiangtian formation (Qhj), respectively. The Longhai formation can be divided into three members and belongs to the Pleistocene series, other three formations belong to the Holocene series.

Among the Altun Tectonic system, there are thrust faults and thrusting components in the Altun strike-slip fault zone. Being similar to the Altun strike-slip fault zone, the thrust fault can be divided into three segments. They are the western segment, middle segment and eastern segment. The western segment is from Ayinaike to the debouchment of the Cheerchenhe River. There is thrusting component on the southern marginal fault of Altun and there are small thrust faults in piedmont in the western segment and evidences are discovered that show the latest terraces and alluvial fan being affected by thrust activity. The middle segment is from the debouchment of Cheerchenhe River to Lapeiquan. There are large-scale thrust faults in the northern margin of Altun Mountains, and there is evidence to show the younger surface of landform displaced by the thrust activity of the middle segment. The eastern segment is from Lapeiquan to Kuantanshan. There is thrusting component on the northern marginal fault of Altun, and thrust faults are developed on the northern margin of Altun Mountains and pediment alluvial fan. From the middle and late Pleistocene to present, the thrust rate on the middle and eastern segments of thrust fault is less than 2mm/a. Since 16ka BP, the thrust rate in Jianggalasayi on the west of the middle segment is 0.33mm/ a, the thrust rate in Milanqiao on the middle part of fault is 1.42mm/a since 32ka BP. The thrust rate of the middle part is bigger than that of the western part. The biggest thrust rate of the eastern segment is at Tuanjiexiang near to the middle part, being 1.81mm/a. From the middle part to the eastern or western part, the thrust rate becomes smaller. At Liuchengzi of the western part, the thrust rate is 0.57mm/a since 72.36ka BP. While at Hongliugou of the eastern part, the thrust rate is only 0.05mm/a since 8.99ka BP.

大量震例研究表明,活动断层产生的直下型地震对城市的破坏非常严重,应用先进有效的地质与地球物理探测技术,准确地探明城市之下及附近活动断层分布,确定直下型地震的震源和危害性是我国城市减灾工作面临的一个非常急近的实际问题.<福州市活断层探测与地震危险性评价>项目作为中国地震局全国城市活动断层探测的试点与示范项目于2001年初开始实施,2004年8月通过中国地震局的验收.项目围绕解决城市范围内的断裂定位、定年、定性、深部背景、地震危险性和危害性及防震减肥灾对策等一系列科学问题,通过"初查与目标区主要活断层鉴定"、"深部地震构造环境探测"、"地震活断层鉴定与危险性评价"、"地震活断层的详细探测"、"地震活断层危害性评价"和"活断层地理信息系统建设"等阶段的探测和评价工作,同时在福州市城、郊区全面开展壤中气汞、土壤汞、气氡、地质雷达、多道直流电法、瞬变电磁法、浅层地震折射法、浅层地震反身法、浅层地震反射法、勘探震源效果对比、用于建立福州盆地埋藏第四系(标准)部面的钻探等多种手段的试验探测,总结各种试验探测的技术指标和实践经验,在活断层的综合试验探测、定位定年、地震危险性和危害性评价等方面取得了下列成果与结论:(1)福州市活断层综合试验探测成果表明,在充分收集、整理与分析相关地质、地球物理、钻孔等资料的基础上,以地球化学探测为先导"侦察机",确定了活断层的可能们置;以浅层地震勘探为主要探测方法,辅以电磁勘探作为补充,并利用钻探建立的第四系(标准)剖面或地层层序及测进获得的各种地球物理参数进行必要的校正和验证,结合裸露骨地表断层或埋深较浅断层的槽探及古地震调查或隐伏断层两侧钻孔岩芯岩性、层序、绝对年龄或孢粉等相对年龄的测定与对比等,是进行城市活断层探测(定位)与地震危险性、危害性评价(定年、定性)的最佳组合方法.(2)福州盆地位于具有发生中等强度地震的区域地震构造环境中,"台湾动力触角"对影响相对较弱.(3)福州分地主要断裂的活动性较弱,经鉴定的6条目标断裂都不是全新世断裂.其中,八一水库-尚干断裂和闽侯-南屿断裂至少为晚更新世中期以来的不活动断裂,其它为晚更新世以来不活动断裂.(4)福建盆地深部不存在发生直下型强烈破坏性地震的构造环境,其邻近的长乐-诏安断裂带是未来可能会发生对福州市有影响的地震震源区.(5)福州盆地主要断裂存在发生中等-中强地震的危险性,但发震概率较小.(6)福州盆地地震危害性较弱,地面发生地震地表破裂带的可能性不大.(7)开发建立了全国第一个活断层地理信息系统,具备信息查询显示、数据管理、数据的分析处理和咨询服务等功能.