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合肥地区位于我国大陆中部,其内展布有多条活动断裂,包括著名的郯庐断裂带.由于该地区大部分断裂是隐伏的,其分布位置、活动特性及构造仍存在争议.本文利用PS-InSAR技术处理了合肥地区2017年10月至2019年8月共52景Sentinel-1A卫星升轨SAR数据,获取了该区域的平均形变速率图.我们发现池河—太湖断裂、桥头集—东关断裂和肥中断裂构成的三角形块体内存在与断层活动相关的地壳InSAR形变.利用贝叶斯方法,本文分别对三条断裂附近区域的形变进行了反演.结果 显示:池河—太湖断裂的走向为北北东,倾向南东,运动特性以右旋走滑为主兼具少许拉张分量;桥头集—东关断裂的走向为北西,倾向北东,活动特性以右旋走滑为主兼具部分逆冲分量;肥中断裂为一条走向近东西、倾向向南的左旋走滑兼具逆冲运动的断裂.综合三条断裂的运动特征,我们推断该三角形块体受到郯庐断裂的活动和北西方向挤压作用的综合影响,整体有轻微旋转趋势.这可能是该地区小震聚集的原因,应引起足够的重视. 相似文献
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石场－中楼盆地位于郯庐断裂带中段的沂河－沭河地区。郯庐断裂左旋切割了秦岭－大别－胶南造山带及前中生代地层,研究区内沂河－沭河断裂切割了年龄为１３６．２Ｍａ（４０Ａｒ／３９Ａｒ法）的胶南造山带北缘剪切带,并被时代为１１９Ｍａ（Ｋ－Ａｒ法）的青山群地层不整合覆盖,显示郯庐断裂在早白垩世曾发生了明显的走滑运动。石场－中楼盆地受沂河－沭河断裂的控制,整体为长６０ｋｍ、宽３０ｋｍ,长宽比近于２∶１的“菱型”构造盆地。盆地内早白垩世莱阳群的沉积厚度大于６２６３．７１ｍ,沉积速率大于０．４ｍｍ／ａ;沉积相特征反映盆地具有深而窄,沉积速度快、沉积相变剧烈的特点。盆地沉积中心的迁移方向与边界断裂的左旋走滑效应一致,“边走滑边沉积”的特征明显。根据构造背景、构造格架及沉积特征,确定石场－中楼盆地为郯庐断裂早白垩世左旋走滑过程中形成的拉分盆地 相似文献
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郯庐断裂带是贯穿我国东部北北东走向的一条深大断裂,其中南段及其邻区(115°E-121°E,29.5°N-35°N)穿过了大别造山带、苏鲁造山带、长江中下游成矿带及合肥盆地.为了研究该区域地壳速度结构及变形特征,我们使用安徽省和江苏省及其周边地区105个台站(固定台站98个,流动台站7个)的垂向连续波形数据,时间范围从2014年5月到2015年7月,共计14个月.利用背景噪声互相关方法,从垂直分量互相关函数中最终提取了2590条瑞利面波相速度频散曲线,反演得到周期范围为5~30s的瑞利波方位各向异性相速度分布图,再反演每个网格点瑞利面波相速度频散得到一维层状横波速度模型,然后拼合起来组成三维横波速度模型.根据本文反演结果并综合已有资料,我们得出如下结论:(1)在北大别、蚌埠隆起、长江中下游成矿带、合肥盆地北部大桥凹陷区域存在中地壳横波高速体,可能与岩石圈和下地壳拆沉以及中生代中国东部大范围岩浆活动有直接关系,更深层原因可能与古太平洋俯冲相关;(2)苏鲁造山带南缘,垂直于嘉山响水断裂,从南向北中上地壳低速体深度变浅,这个低速体可能是高压/超高压变质岩与扬子板块接触处的破碎带,是扬子板块与华北板块接触的边界;(3)郯庐断裂合肥-嘉山段两侧以及大别造山带东缘短周期瑞利面波相速度快轴方向与郯庐断裂带走向基本一致,可能是三叠纪碰撞期与白垩纪时期的大规模左旋走滑活动的结果;(4)合肥盆地南部15~20s周期的瑞利波相速度快轴方向为北西-南东向,反应该区域中下地壳快波方向为北西-南东向,推测是大别造山带折返的痕迹;(5)郯庐断裂带的结构和地震活动性存在明显的分段性,嘉山-郯城段郯庐断裂带现今地震活动性弱,但发生过较强的古地震,推断现今郯庐断裂带宿迁段可能处于闭锁状态,从长远来看要注意该地区发生大震的可能. 相似文献
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五河—合肥断裂是郯庐断裂带的西边界断裂,该断裂穿过合肥市城区,是1条规模较大、切割较深的隐伏活动断裂.为了研究该断裂的浅部结构特征、空间展布以及断裂活动性,我们利用2015年在合肥盆地完成的深地震反射剖面数据,采用初至波层析成像方法得到了郯庐断裂带合肥段的浅层P波速度结构和构造形态;考虑到仅根据速度结构剖面还难以确定断裂的准确位置、断层上断点埋深、断层的近地表构造组合样式等特征,研究中跨五河—合肥断裂还完成了2条高分辨率的浅层地震反射剖面.研究结果表明：郯庐断裂带合肥段是一个由多条主干断裂构成的复杂构造带,近地表速度结构表现为凹隆相间的构造特征,且沉积盖层厚度明显受到郯庐断裂带分支断裂的影响和控制.五河—合肥断裂在P波速度结构剖面表现为高速和低速区的分界,对断裂两侧的地层沉积具有重要的控制作用,该断裂向下错断了盆地基底,向上错断了埋深21~35 m的中更新统下部地层,其最新活动时代为中更新世早期.研究结果不仅为进一步认识五河—合肥断裂浅部构造形态提供了地震学依据,还可为该区断裂两侧的城镇规划和建设中避让活动断层提供基础资料. 相似文献
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郯城-庐江断裂带是中国东部最重要的一条断裂带,纵贯中国大陆东部,绵延2400km,总体呈北北东走向。郯庐断裂切穿整个地壳,向下延伸进入上地幔,它是中国乃至世界著名的切割深、延伸规模大、演化时间长的巨型断裂带。 相似文献
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1 研究背景
郯城—庐江断裂带(郯庐断裂带)是我国东部规模最大、延伸最长的深大断裂带,也是我国地震危险性最高的断裂构造之一.据史料记载,1668年郯城8?级地震(史称郯城大地震,位于郯城、临沂、临沭三县交界处)发生在该断裂潍坊—嘉山段郯城附近.近年来,郯庐断裂带第四纪活动地质证据被陆续发现,如郯庐断裂带江苏段全新世活动(曹筠等, 2018)以及郯庐断裂带北段(依兰—伊通断裂黑龙江通河段、吉林舒兰段,以往认为不具活动性)第四纪晚期活动证据(闵伟等,2013).此外,一些原有第四纪活动段,如新沂—五河段、乌云山—合肥段(郑颖平等,2014)等,也在近年被发现了活动证据. 相似文献
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渤海海域新生代盆地中的郯庐断裂带构造 总被引：14，自引：0，他引：14
郯庐断裂带从渤海海域新生代盆地东部边缘穿过,在盆地新生代盖层中主要表现为NNE向的右旋走滑断裂带,切割了控制古近纪盆地形成的NE-NNE向伸展断层.近年来的油气勘探成果表明,郯庐断裂带新生代构造活动对渤海海域的油气藏分布有直接或间接的影响.作为深断裂带的一部分,渤海海域新生代盆地中的郯庐断裂带的主要活动时期为渐新世以后,对渤海海域盆地渐新世以来的构造演化有明显的影响.然而郯庐深断裂带在晚中生代就已经存在,渤海海域古近纪裂陷盆地的形成利用了先存的郯庐断裂带中的构造要素. 相似文献
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郯庐断裂带南段淮河至女山湖段落已被证实具有晚第四纪活动性,为进一步追踪断裂带在女山湖以南的活动情况,选取明光至定远池河镇段落进行遥感解译、地质地貌调查、探槽开挖及年代样品测试等工作。研究发现,该段断裂在卫星影像上显示线性特征较差,发育断裂主要为池河-太湖断裂;断裂新活动主要表现为控制池河河谷的发育及沿明南土山村、池河石塘岳、池河周王等地展布的线性岗状地貌;在上述岗地边缘开挖探槽揭示断裂在该段最新活动方式具挤压逆冲性质,最新活动时代为中更新世,晚更新世以来不活动。上述结果初步表明,该段与其北侧相邻的淮河至女山湖段在第四纪活动性上存在差异,可能为郯庐断裂带在女山湖附近存在分段导致。 相似文献
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郯庐断裂带是中国东部规模最大的构造活动带,有着复杂的形成演化历史,对中国东部的区域构造、岩浆活动、矿产资源的形成和分布以及现代地震活动都有重要控制作用.2010年在郯庐断裂带中南段的江苏宿迁市附近,采用深地震反射探测方法对郯庐断裂带及其两侧地块的岩石圈结构进行了解剖.结果表明,该区莫霍面和岩石圈底界均向西倾,其中,地壳厚度约为31~36km,岩石圈厚度约为75~86km,且岩石圈厚度在郯庐断裂带下方出现突变.郯庐断裂带在剖面上表现为由多条主干断裂组成的花状构造,其内部发育有断陷盆地和挤压褶皱,具有伸展、挤压和走滑并存的构造形迹,暗示郯庐断裂带的形成和演化经历了多期复杂的构造活动.这一断裂带错断了近地表沉积层,向下切割莫霍面和岩石圈地幔,属岩石圈尺度的深大断裂构造系统.软流圈高温高压热物质沿断裂带的上涌、岩浆底侵或热侵蚀作用造成岩石圈出现拉张伸展和岩石圈减薄,并可能使岩石圈组构及其物质成分发生改变.本项研究结果不但可进一步加深对郯庐断裂带深、浅部结构的认识,而且还可为分析研究华北克拉通东部的深部过程和浅部构造响应提供资料约束. 相似文献
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阿尔金断裂带东段走滑速率沿断裂走向方向存在明显的流失现象,有关阿尔金断裂带的影响范围及走滑速率变化的机制需要有更多的深部结构证据来提供支撑.本文以阿尔金断裂带昌马段为窗口,获取了4条横穿阿尔金断裂带及相邻地区的大地电磁测深剖面.二维电性剖面显示在阿尔金断裂带北侧中上地壳以连续的高阻体为主,而南侧祁连山内部的深部电性结构在横向上有较为复杂的变化.这一点与区域构造背景相对应,即北侧的塔里木盆地东缘依然具有较好的整体性,南侧的祁连山是青藏高原北缘生长的最前端,变形强烈.在断裂带的结构特征上,阿尔金断裂带沿走向方向的切割深度在昌马盆地西侧发生了显著的降低,与阿尔金断裂带相对应的电性边界在这里向南偏移了约15 km,对应F18断裂,并与昌马盆地相接.祁连山北部的断裂带,包括昌马断裂、旱峡—大黄沟断裂总体呈现出低角度南倾的样式,切过高阻异常体的顶部.虽然昌马盆地可以起到连接断裂带的阶区的作用,将部分阿尔金断裂的走滑分量转移到盆地南侧的昌马断裂上,但是昌马断裂的走滑速率从西向东是增加的,东侧的走滑速率甚至大于阿尔金断裂沿走向方向的流失分量.我们认为在青藏高原北部主要断裂带的活动还是受印度—欧亚板块碰撞引起的远程挤压效应的影响,包括阿尔金断裂以及祁连山内部系列断层都处于斜向挤压应力环境.在这种基本构造模式下,阿尔金断裂、断裂F18、昌马盆地、昌马断裂构成了一个局部的走滑速率分解-转换-吸收体系,对局部应力状态产生影响. 相似文献
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合肥市位于合肥盆地东南缘,东侧紧邻郯庐断裂带,多条大型隐伏断裂穿过市区.为进一步认识合肥城市下方隐伏断裂的空间展布、性质,以及城市复杂的沉积环境,本文利用布设在合肥市区的58套三分量短周期地震仪组成的台阵,获得了37天的三分量连续波形数据,通过基于射线追踪的面波走时直接成像方法反演得到了合肥市地壳浅部0.6~3.6 km的三维剪切波速度结构,速度结构图像展现了地壳浅部的横向不均匀性和纵向成层性,揭示出NNE、NWW和近EW三组不同走向的隐伏断裂在城市地下浅部的构造特征.取得以下认识：（1）合肥市南、北方向在浅地表（2 km以内）存在显著速度差异,速度分界线位置与已知的近EW向的蜀山断裂一致,断裂南侧呈现低速凹陷,北侧则为高速隆起.低速中心深度达2~3 km,速度异常与该断裂在合肥盆地东部演化过程中的构造反转沉积了不同地层有关;（2）合肥市区存在明显的高速异常带,其走向、位置与穿过该区域的郯庐断裂带西支主干断裂相符,其中五河—合肥断裂在市区北部以东呈现低速凹陷特征,低速区范围与肥东凹陷晚白垩纪以来的沉积构造边界一致,认为肥东凹陷的最大沉积厚度可达2 km以上;（3）合肥市中心跨郯庐断裂带西支主干断裂之间呈现明显的凹、隆相间的复杂构造,推测其是在多组断裂的共同拉伸作用下形成的小型沉积盆地,沉积中心位于郯庐断裂带内部,最大厚度可达3~4 km.由于其展布方向在不同深度与该区域断裂的走向具有明显的相关性,推测不同深度的沉积形态与郯庐断裂带在不同时期的构造演化过程有关. 相似文献
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TRANSVERSE STRUCTURES FEATURES OF DIFFERENT DEPTHS DERIVED FROM BOUGUER GRAVITY ANOMALIES IN THE SOUTHERN SEGMENT OF TAN-LU FAULT ZONE 
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下载免费PDF全文 WANG Xin ZHANG Jing-fa JIANG Wen-liang JIANG Hong-bo TIAN Tian GAO Min FU Ping-jie 《地震地质》2016,38(2):370-385
To research the faults distribution and deep structures in the southern segment of Tan-Lu fault zone(TLFZ) and its adjacent area, this paper collects the Bouguer gravity data and makes separation by the multi-scale wavelet analysis method to analyze the crustal transverse structure of different depths. Meanwhile Moho interface is inversed by Parker variable density model. Research indicates that the southern segment of TLFZ behaves as a NNE-directed large-scale regional field gravity gradient zone, which separates the west North China-Dabie orogen block and the east Yangtze block, cutting the whole crust and lithosphere mantle. There are quite differences of density structures and tectonic features between both sides of this gradient belt. The sedimentary and upper crustal density structure is complex. The two east branches of TLFZ behave as linear gravity anomalous belt throughout the region, whereas the two west branches of TLFZ continue to extend after truncating the EW-trending gravity anomaly body. The lower crustal density structure is relatively simple. TLFZ behaves as a broad and gentle low abnormal belt, which reflects the Cretaceous-Paleogene extension environment caused graben structure. The two west branches of TLFZ, running through Hefei city, extend southward along the west margin of Feidong depression and pinch out in Shucheng area due to the high density trap occlusions in the south of Shucheng. The Feizhong Fault, Liu'an-Hefei Fault, and Feixi-Hanbaidu Fault intersect the two west branch faults of TLFZ without extending to the east. Recent epicenters are mainly located in conversion zones between the high-density and the low-density anomaly, especially in TLFZ and the junction of the faults, where earthquakes frequently occurred in the upper and middle crust. As strong earthquakes rarely occur in the southern segment of TLFZ, considering its deep feature of abrupt change of the Moho and intersections with many EW-trending faults, the hazard of strong earthquake cannot be ignored. 相似文献
14.
《中国科学D辑(英文版)》2008,(9)
The authors processed the seismic refraction Pg-wave travel time data with finite difference tomography method and revealed velocity structure of the upper crust on active block boundaries and deep features of the active faults in western Sichuan Province. The following are the results of our investigation. The upper crust of Yanyuan basin and the Houlong Mountains consists of the superficial low-velocity layer and the deep uniform high-velocity layer, and between the two layers, there is a distinct, and gently west-dipping structural plane. Between model coordinates 180-240 km, P-wave velocity distribution features steeply inclined strip-like structure with strongly non-uniform high and low velocities alternately. Xichang Mesozoic basin between 240 and 300 km consists of a thick low-velocity upper layer and a high-velocity lower layer, where lateral and vertical velocity variations are very strong and the interface between the two layers fluctuates a lot. The Daliang Mountains to the east of the 300 km coordinate is a non-uniform high-velocity zone, with a superficial velocity of approximately 5 km/s. From 130 to 150 km and from 280 to 310 km, there are extremely distinct deep anomalous high-velocity bodies, which are supposed to be related with Permian magmatic activity. The Yanyuan nappe structure is composed of the superficial low-velocity nappe, the gently west-dipping detachment surface and the deep high-velocity basement, with Jinhe-Qinghe fault zone as the nappe front. Mopanshan fault is a west-dipping low-velocity zone, which extends to the top surface of the basement. Anninghe fault and Zemuhe fault are east-dipping, tabular-like, and low-velocity zones, which extend deep into the base-ment. At a great depth, Daliangshan fault separates into two segments, which are represented by drastic variation of velocity structures in a narrow strip: the west segment dips westward and the east segment dips eastward, both stretching into the basement. The east margin fault of Xichang Mesozoic basin features a strong velocity gradient zone, dipping southwestward and stretching to the top surface of the basement. The west-dipping, tabular-like, and low-velocity zone at the easternmost segment of the profile is a branch of Mabian fault, but the reliability of the supposition still needs to be confirmed by further study. Anninghe, Zemuhe and Daliangshan faults are large active faults stretching deep into the basement, which dominate strong seismic activities of the area. 相似文献
15.
Velocity structure and active fault of Yanyuan-Mabian seismic zone—The result of high-resolution seismic refraction experiment 总被引：3，自引：0，他引：3
FuYun Wang YongHong Duan ZhuoXin Yang ChengKe Zhang JinRen Zhao JianShi Zhang XianKang Zhang QiYuan Liu AiLan Zhu XiWei Xu BaoFeng Liu 《中国科学D辑(英文版)》2008,51(9):1284-1296
The authors processed the seismic refraction Pg-wave travel time data with finite difference tomography method and revealed
velocity structure of the upper crust on active block boundaries and deep features of the active faults in western Sichuan
Province. The following are the results of our investigation. The upper crust of Yanyuan basin and the Houlong Mountains consists
of the superficial low-velocity layer and the deep uniform high-velocity layer, and between the two layers, there is a distinct,
and gently west-dipping structural plane. Between model coordinates 180–240 km, P-wave velocity distribution features steeply
inclined strip-like structure with strongly non-uniform high and low velocities alternately. Xichang Mesozoic basin between
240 and 300 km consists of a thick low-velocity upper layer and a high-velocity lower layer, where lateral and vertical velocity
variations are very strong and the interface between the two layers fluctuates a lot. The Daliang Mountains to the east of
the 300 km coordinate is a non-uniform high-velocity zone, with a superficial velocity of approximately 5 km/s. From 130 to
150 km and from 280 to 310 km, there are extremely distinct deep anomalous high-velocity bodies, which are supposed to be
related with Permian magmatic activity. The Yanyuan nappe structure is composed of the superficial low-velocity nappe, the
gently west-dipping detachment surface and the deep high-velocity basement, with Jinhe-Qinghe fault zone as the nappe front.
Mopanshan fault is a west-dipping low-velocity zone, which extends to the top surface of the basement. Anninghe fault and
Zemuhe fault are east-dipping, tabular-like, and low-velocity zones, which extend deep into the basement. At a great depth,
Daliangshan fault separates into two segments, which are represented by drastic variation of velocity structures in a narrow
strip: the west segment dips westward and the east segment dips eastward, both stretching into the basement. The east margin
fault of Xichang Mesozoic basin features a strong velocity gradient zone, dipping southwestward and stretching to the top
surface of the basement. The west-dipping, tabular-like, and low-velocity zone at the easternmost segment of the profile is
a branch of Mabian fault, but the reliability of the supposition still needs to be confirmed by further study. Anninghe, Zemuhe
and Daliangshan faults are large active faults stretching deep into the basement, which dominate strong seismic activities
of the area.
Supported by the National Basic Research Program of China (Grant No. 2004CB428400) 相似文献
16.
17.
18.
东昆仑活动断裂带及其强震活动 总被引：17，自引：0，他引：17
本文在简述东昆仑活动断裂带的构造背景与演化历史的基础上，重点叙述了该活动断裂带的展布，几何结构，第四纪运动和强震活动等特征，指出，这是一条具有长期演化历史，深部构造背景和第四纪乃至全新强烈活动的断裂带。因而在我国大地构造演化，尤其在青藏高原隆起形成，占有重要地位，同时，它还是我国西部地区一条主要的强震活动构造带，根据现代强震活动记录和在全带新发现的多期全新世古地震及其地表破裂带，分析了大震在断裂带 相似文献
19.
2017年4月12日浙江临安发生了4.2级地震,在震中附近范围(35～50 km)内,主要发育3条断裂,分别为马金—乌镇断裂、湖州—临安断裂和昌化—普陀断裂,通过对这3条断裂开展野外地质调查、断层泥年龄样品测试等手段得出:北东向的马金—乌镇断裂、湖州—临安断裂均被近东西向的昌化—普陀为界分南北为两段,其中,马金—乌镇断裂北段以正断为主,南段以逆断为主,两段活动时代均为中更新世早期;湖州—临安断裂南北两段均以逆断为主,北段活动时代为中更新世早期,南段活动时代为前第四纪。昌化—普陀断裂以走滑活动为主,自西向东分为西、中、东三段,活动时代自西向东逐渐减弱,东段为前第四纪断裂,中西段为中更新世断裂。 相似文献