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辽宁省主要活动断层与地震活动特征分析 总被引:6,自引:1,他引:5
本文结合编制 1:100 万辽宁省地震构造图,分析了辽宁省近 20 年来地震构造环境相关研究成果,确定辽宁地区共有第四纪以来活动断裂 29 条:全新世断裂 1 条;晚更新世断裂 5 条;早、中更新世断裂 23 条。其中北东向晚更新世活动断裂和北西向全新世活动断裂为辽宁地区的主要控震、发震构造。北东向晚更新世活动断裂与北西向断裂交汇部位、海城河隐伏断裂的端点部位和鸭绿江断裂南西端黄海海域是未来发生中强地震的主要部位。本研究可为深入研究辽宁地区地震构造条件、编制第五代全国地震区划图提供基础资料。 相似文献
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龙门山北部3条不同走向的断裂带所围限的三角地区是我国陕甘川交界地区研究地震活动的重要场所.通过对区内秦岭南缘断裂、 平武—青川断裂、 岷江断裂及虎牙断裂活动特征研究和活动时代分析认为: 秦岭南缘断裂, 包括迭部—舟曲断裂、 武都—康县—略阳断裂及茶店—勉县断裂在晚更新世曾有过活动, 在全新世活动不明显; 龙门山断裂带东北段平武—青川断裂最后一次活动发生在晚更新世, 表现为右旋走滑的逆断裂, 全新世活动不明显; 岷江断裂和虎牙断裂不但在晚更新世活动强烈, 而且在全新世继续活动; 龙门山北部这个三角地区依然是未来地震活动关注的重点地区. 相似文献
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着重对库尔勒附近分布的多条活动断裂中的霍拉山前、北轮台、博东与兴地等断裂活动新形迹进行了分析研究。研究结果表明 ,自晚更新世晚期至全新世断裂发生过多次显著新活动 ,有的断裂具有发生中等以上地震的构造条件 ,未来有发生中等地震的可能。 相似文献
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托斯台逆断裂-褶皱带晚第四纪活动特征 总被引:1,自引:0,他引:1
托斯台逆断裂-褶皱带位于乌鲁木齐山前坳陷的西部,为近东西向展布的新生代逆断裂.背斜带。它主要由北单斜带、中部背斜带和南单斜带3个构造带组成,在各构造带均发育逆活动断裂。地震勘探资料显示,南单斜带与中部背斜带为滑脱体,逆断裂在深部沿滑脱面与清水河子深断裂相汇。研究表明,北单斜带与中部背斜带逆断裂断错了晚更新世堆积物,在晚更新世有显著的活动;南单斜带逆断裂断错了全新世堆积物,在全新世时期有最新活动。中部背斜带逆断裂晚更新世以来水平缩短速率为0.6~1.3mm/a;南单斜逆断裂全新世水平缩短速率为0.2~0.6mm/a。 相似文献
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1975年海城MS7.3地震是中国第1次成功预报的7级以上破坏型地震,避免了大量人员和财产损失。但在地震后的调查中并没有发现较为连续的地表破裂带,只在零星地点发现了一些地表裂缝和喷砂冒水现象。该地震的等震线表现出较为明显的共轭特征,因此研究者对于海城地震的发震断层一直存在一定争议。文中对与海城河断裂共轭相交的金州断裂盖州北—鞍山段进行了遥感影像解译、微地貌测量和古地震探槽开挖等工作,发现金州断裂自大石桥市沿NE向至鞍山市南,在盆山过渡带的晚更新世和全新世地貌面上存在较为明显的沿NE向展布的断层陡坎。由于人类活动,断层陡坎展布不连续。断层陡坎的高度多为1~2m,最大可达3m;在海城市南葫芦峪村开挖的古地震探槽揭露出盖州北—鞍山段具有宽约20m的基岩破碎带,晚更新世晚期—全新世以来(距今(37.6±2.2) ka)至少发生过2次古地震事件。较新的一次地震发生于全新世(距今(11.7±0.8) ka以后,很可能为距今400~500a)。由于全新世地层太薄所限,无法识别出更多全新世古地震,但可以判断金州断裂盖州北—鞍山段为晚更新世晚期—全新世活动断裂。 相似文献
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在广泛搜集以往研究资料的基础上,运用野外地震地质考察、典型地质剖面和探槽剖面分析、系统取样等方法,研究了苍山-尼山断裂的活动性质、最新活动时代和古地震事件。研究表明:苍山-尼山断裂以左旋走滑运动为主兼有逆冲运动分量;其第四纪晚期以来的活动具有分段性,以甘霖为界,北西段为晚更新世晚期至全新世早期,南东段为晚更新世晚期;有确凿证据的古地震事件有2次,其发生时间分别是距今6.4万年左右(E1)和距今1.4万年左右(E2);另据考证,公元前179年"齐楚地震"也发生在该断裂上。根据历史地震和现代地震的研究成果,分析认为该断裂未来具有发生6.5级左右地震的潜在危险。 相似文献
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喀什河断裂中更新世以来的活动速率研究 总被引:1,自引:0,他引:1
利用地貌和新近系位错测量的方法,结合遥感、地貌、变形测量与新近纪测年等手段,重点研究了伊犁盆地喀什河断裂中更新世以来的垂直活动速率。喀什河断裂在中更新世以来的新活动主要表现在河流阶地和地层的位错,综合研究了这些位错数据,分析了断裂各段在中更新世以来的活动速率,讨论了1812年尼勒克地震的平均位错反映的断裂现今最新的活动速率,提供了喀什河断裂中更新世以来不同时期活动的定量数据,填补了天山内部新近纪晚期研究的部分空白,对现今地壳运动与地球动力学研究及减轻地质灾害有重要意义。 相似文献
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PRELIMINARY STUDY OF PALEOEARTHQUAKES ON THE MIDDLE-EASTERN SEGMENT OF JINTA NANSHAN FAULT
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Hexi Corridor is located at the northeastern margin of the Tibetan plateau. Series of late Quaternary active faults are developed in this area. Numerous strong earthquakes occurred in history and nowadays. Jinta Nanshan fault is one of the boundary faults between the Qinghai-Tibet block and the Alxa block. The fault starts from the northwest of Wutongdun in the west, passes through Changshan, Yuanyangchi reservoir, Dakouzi, and ends in the east of Hongdun.
Because the Jinta Nanshan fault is a new active fault in this region, it is important to ascertain its paleoearthquakes since late Pleistocene for the earthquake risk study. Previous studies were carried out on the western part, such as field geomorphic investigation and trench excavation, which shows strong activity in Holocene on the western segment of Jinta Nanshan fault. On the basis of the above research, in this paper, we carried out satellite image interpretation, detailed investigation of faulted landforms and differential GPS survey for the whole fault. Focusing on the middle-eastern part, we studied paleoearthquakes through trench exploration on the Holocene alluvial fan and optical luminescence dating.
The main results are as follows:Early Pleistocene to late Pleistocene alluvial strata are widely developed along the fault and Holocene sediment is only about tens of centimeters thick. The Jinta Nanshan fault shows long-lasting activity since late Quaternary and reveals tens of centimeters of the lowest scarp which illustrates new strong activity on the middle-east segment of this fault. Since late Pleistocene, 4 paleoearthquakes happened respectively before(15.16±1.29) ka, before(9.9±0.5) ka, about 6ka and after(3.5±0.4) ka, revealed by 4 trenches, of which 2 are laid on relatively thicker Holocene alluvial fan. Two events occurred since middle Holocene, and both ruptured the whole fault. 相似文献
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珠江三角洲断裂构造最新活动性研究 总被引:11,自引:6,他引:11
根据在珠江三角洲及其周围地区测得的热释光年龄和第四系沉积物的分布等资料,分析讨论了断裂的最新活动性。自晚更新世以来,陈三角洲外围几条主要的北东向断裂的局部地段以外,基本上处于比较稳定的状态。晚更新世一全新世早期有过明显活动的断裂有狮子洋东西两侧的北西向断裂,近南北向的崖门断裂和北东向的古劳-广州断裂。近东西向的瘦狗岭断裂新世亦有过活动。 相似文献
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在野外地质调查的基础上,通过研究秦皇岛市F1、F2、F3断裂断层泥中石英颗粒表面的SEM特征,认为F1断裂最末一次活动时间在早更新世至中更新世;F2断裂最末一次活动时间在晚更新世中晚期;F3断裂最末一次活动时间在晚更新世末或全新世初。 相似文献
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郯庐断裂带莱州湾段的构造特征 总被引:5,自引:1,他引:5
本文利用海上浅层地震勘探剖面分析了郯庐断裂带莱州湾段的上更新统、全新统和活动构造的某些特征。晚更新世末期发生的构造运动使上更新统产生断裂与褶皱,沿郯庐断裂带东主干断裂发育了狭长的背斜构造,在西主干断裂两侧次级横向(东西向)断裂十分发育,这些横向断裂是一些高角度的张性正断层。 相似文献
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The Riyue Mt. Fault is a secondary fault controlled by the major regional boundary faults (East Kunlun Fault and Qilian-Haiyuan Fault). It lies in the interior of Qaidam-Qilianshan block and between the major regional boundary faults. The Riyue Mt. fault zone locates in the special tectonic setting which can provide some evidences for recent activity of outward extension of NE Tibetan plateau, so it is of significance to determine the activity of Riyue Mt. Fault since late Pleistocene to Holocene. In this paper, we have obtained some findings along the Dezhou segment of Riyue Mt. Fault by interpreting the piedmont alluvial fans, measuring fault scarps, and excavating trenches across the fault scarp. The findings are as follows:(1) Since the late Pleistocene, there are an alluvial fan fp and three river terraces T1-T3 formed on the Dezhou segment. The abandonment age of fp is approximately (21.2±0.6) ka, and that of the river terrace T2 is (12.4±0.11) ka. (2) Since the late Pleistocene, the dextral strike-slip rate of the Riyue Mt. Fault is (2.41±0.25) mm/a. In the Holocene, the dextral strike-slip rate of the fault is (2.18±0.40) mm/a, and its vertical displacement rate is (0.24±0.16) mm/a. This result indicates that the dextral strike-slip rate of the Riyue Mt. Fault has not changed since the late Pleistocene. It is believed that, as one of the dextral strikeslip faults, sandwiched between the the regional big left-lateral strike-slip faults, the Riyue Mt. Fault didn't cut the boundary zone of the large block. What's more, the dextral strike-slip faults play an important role in the coordination of deformation between the sub-blocks during the long term growth and expansion of the northeast Tibetan plateau. 相似文献
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Huang Qingtuan 《中国地震研究》2005,19(2):214-223
INTRODUCTION TheLonghai ZhangpucoastalareaofFujianProvinceliesonthesouthernsideoftheoutletofthe JiulongjiangRiver.Tectonically,itislocatedonthesouthernsegmentoftheChangle Zhao’anfault zone.Previously,alotofseismogeologicresearchworkhasbeencarriedoutinthi… 相似文献
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A NEW DISCOVERY OF ACTIVITY OF FUSHAN SECTION OF THE TAN-LU FAULT ZONE IN THE LATE QUATERNARY
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ZHAO Peng YAO Da-quan YANG Yuan-yuan ZHENG Hai-gang WANG Xing-zhou XU Hong-tai FANG Zhen 《地震地质》2017,39(5):889-903
The east branch fault of Tan-Lu fault zone extends from Fengshan Town of Sihong County on the north shore of the Huaihe River in Jiangsu Province, into Fushan Town of Mingguang City on the south shore of Huaihe River in Anhui Province. The landform changes from Subei plain on the north of Huaihe River to Zhangbaling uplift area on the south of Huaihe River. The terrain rises gradually with larger relief amplitude. The Fushan section of the Tan-Lu fault zone is located in Ziyang to Fushan area of Mingguang City. The fault is shown in the satellite image as a clear linear image, and the fault extends along the east side of a NNE-trending hillock. In this section the Quaternary strata are unevenly distributed, which causes some difficulties in the study of recent fault activity.In recent years, the author has found that the fault of the Fushan section of the Tan-Lu fault zone on the south of the Huaihe River still has a certain control effect on the landform and the Quaternary strata. Based on satellite imagery and geological data, we select the appropriate location in the Fushan section to excavate the Santang trench Tc1 and Fushannan trench Tc2, and clean up the Fushannan profile Pm, which reveals rich phenomena of recent fault activity. Santang trench reveals three faults, and the faulting phenomenon is obvious. One of the faults shows the characteristic of right-lateral strike-slip normal faulting; Fushannan profile reveals one fault, with the same faulting behavior of right-lateral strike-slip normal fault. Comprehensive stratigraphic sample dating results indicate that the fault dislocated the middle Pleistocene strata, late Quaternary strata and early Holocene strata. All our work shows that the fault of Fushan section has intensive activity since late Pleistocene, and the latest active age can reach early Holocene. The latest earthquake occurred at(10.6±0.8)~(7.6±0.5)ka BP. The faults exposed by trenches and profiles show the characteristics of right-lateral strike-slip normal faulting, which reflects the complexity of the tectonic stress field in the area where the fault locates. 相似文献