郯庐断裂带江苏段安丘-莒县断裂全新世活动及其构造意义
中国地震局地质研究所, 活动构造与火山重点实验室, 北京 100029
河北省地震局, 石家庄 050021
江苏省地震局, 南京 210014
宿迁市活动断层探测与地震危险性项目中国地震局地质研究所基本科研业务专项（IGCEA1602）和（SQZBTB20110162）共同资助
中图分类号:P541
Key Laboratory of Active Fault and Volcano, Institute of Geology, China Earthquake Administration, Beijing 100029, China
Earthquake Administration of Hebei Province, Shijiazhuang 050021, China
Earthquake Administration of Jiangsu Province, Nanjing 210014, China
郯庐断裂带是中国东部重要的活动断裂带和边界构造带，其鲁苏段全新世活动断层的空间展布和古地震序列是地学关注的焦点问题，也是准确评价区域地震危险性的重要参数.以往研究工作多集中在郯庐断裂带地表地貌现象明显且有强震记录的山东段，而江苏段则研究程度相对较低，有关郯庐断裂带江苏段全新世活动断层范围和古地震序列问题存在争议.本文利用野外地质地貌调查、浅层地震勘探、钻孔联合剖面以及古地震探槽等多层次综合方法，重点开展郯庐断裂带江苏段全新世活动断层的分布和古地震序列研究.结果显示全新世时期，安丘-莒县断裂是郯庐断裂带江苏段的主要活动断层，且江苏全段该断层都是全新世活动断层.通过对比宿迁闸-皂河镇断裂南北安丘-莒县断裂的断层地貌和断层最新活动时间，并结合宿迁闸-皂河镇断裂在第四纪没有活动过等证据，推测该断层在全新世时期并不是区域阻碍破裂的断层.探槽揭示郯庐断裂带江苏段全新世两次古地震事件，事件Ⅰ限定在（6.2±0.3）-（13.4±0.7）ka B.P.之间，而事件Ⅱ限定在（2.5±0.1）ka B.P.到现今，全新世两次古地震间隔较长.基于构造类比法，安丘-莒县断裂具有深部孕震的构造特点，是区域未来强震的潜在发震构造.
The Tanlu fault zone (TLFZ) is an important active structure which is a tectonic boundary in eastern China. The research on the distribution of the Holocene active faults and paleoearthquakes along the LFZ is important for seismic hazard assessment in this region, thus receiving much attention. Previous studies were primarily conducted on its Shandong segment that preserves obvious geological landforms and evidence of historical earthquakes. While the distribution of the Holocene active faults and paleoearthquakes along the Jiangsu segment remain controversial. In this paper, based on field geological and geomorphologic investigations, shallow seismic exploration, drilling and paleoseismic trenching, we reanalyze the distribution of the Holocene active faults and paleoearthquakes along the Jiangsu segment of the TLFZ.
The Anqiu-Juxian fault is the primary Holocene active fault along the Jiangsu segment of TLFZ evidenced by field geological investigations, shallow seismic exploration and drilling data. We suggest that this fault was active during the Holocene, while lacking reliable evidence before. Comparing the surface topography and timing of the latest activity of this fault located between the north and south of the Suqianzha-Zhaohezhen fault, as well as the evidence of fault activity in Quaternary, we consider that this Holocene active fault has not terminated to the north of the Suqianzha-Zhaohezhen fault. In other words, the Suqianzha-Zhaohezhen fault did not arrest the earthquake rupture propagation during the Holocene. Based on three paleoseismic trenches along the Anqiu-Juxian fault, we infer two events occurred in the Holocene. Event Ⅰ is constrained as(6.2±0.3)-(13.4±0.7)ka B.P., and the event Ⅱ is later than(3.8±0.3)ka B.P.. We suggest that large earthquakes along the Anqiu-Juxian during the Holocene might have a relatively long recurrence interval.
Considering the latest studies on deep crustal structure and impact of the 1668 Tancheng earthquake (M=8.5), seismic potential on the Jiangsu segment of the TLFZ should be highly concerned. Based on the structural analogue method, we suggest that the Anqiu-Juxian fault is one of most important potential seimogenic structures within the TLFZ.
图 1郯庐断裂带江苏段构造略图
郯庐断裂带江苏段构造略图
Figure 1.Tectonics map of Jiangsu segment of the Tan-Lu Fault Zone
Tectonics map of Jiangsu segment of the Tan-Lu Fault Zone
图 3郯庐断裂带江苏段安丘—莒县断裂典型露头和遥感影像
郯庐断裂带江苏段安丘—莒县断裂典型露头和遥感影像
Figure 3.Typical outcrop and remote-sensing image along the Anqiu-Juxian fault in the Jiangsu segment of the Tan-Lu Fault Zone
Typical outcrop and remote-sensing image along the Anqiu-Juxian fault in the Jiangsu segment of the Tan-Lu Fault Zone
图 5沿AQ3测线的钻孔剖面揭露断层
沿AQ3测线的钻孔剖面揭露断层
Figure 5.Fault revealed by drilling section along the AQ3 line
Fault revealed by drilling section along the AQ3 line
图 6平行于AQ5测线的钻孔联合剖面位置图
平行于AQ5测线的钻孔联合剖面位置图
Figure 6.Location of composite drilling profile paralleled AQ5 line
Location of composite drilling profile paralleled AQ5 line
图 7平行于AQ5测线的钻孔联合剖面(断层左侧红字代表对应层位的断距)
平行于AQ5测线的钻孔联合剖面(断层左侧红字代表对应层位的断距)
Figure 7.Composite drilling section paralleled AQ5 line(The scarlet letter on the left side of fault shows fault displacement corresponding horizon)
Composite drilling section paralleled AQ5 line(The scarlet letter on the left side of fault shows fault displacement corresponding horizon)
图 8新沂河探槽地理位置图(影像来源于Google earth)
Figure 8.Geographical location map of Xinyi trench(Image come from Google earth)
Geographical location map of Xinyi trench(Image come from Google earth)
图 9新沂河探槽(34°6′55.50″N，118°19′31.32″E)南壁剖面和解释图
新沂河探槽(34°6′55.50″N，118°19′31.32″E)南壁剖面和解释图
Figure 9.Map of southern wall of trench near Xinyi river and its interpretation
Map of southern wall of trench near Xinyi river and its interpretation
图 11合欢路探槽(34°0′51.32″N，118°18′23.08″E)剖面和解释图
合欢路探槽(34°0′51.32″N，118°18′23.08″E)剖面和解释图
Figure 11.Map of trench at Hehuan road and its interpretation ((A) is northern wall; (B) is southern wall)
Map of trench at Hehuan road and its interpretation ((A) is northern wall; (B) is southern wall)
图 12重岗山探槽(33°32′31.43″N，118°9′17.86″E)南壁剖面和解释图
重岗山探槽(33°32′31.43″N，118°9′17.86″E)南壁剖面和解释图
Figure 12.Map of southern wall of trench near Chonggang mountain and its interpretation
Map of southern wall of trench near Chonggang mountain and its interpretation
图 13综合限定郯庐断裂带江苏段古地震事件
综合限定郯庐断裂带江苏段古地震事件
Figure 13.Progessive constraining paleoearthquake events in the Jiangsu segment of the Tan-Lu Fault Zone
Progessive constraining paleoearthquake events in the Jiangsu segment of the Tan-Lu Fault Zone
表 1南京路钻孔联合剖面和重岗山14C样品测年结果
南京路钻孔联合剖面和重岗山14C样品测年结果
Table 1.Radiocarbon samples from composite drilling section near Nanjing road and profile of Chonggang mountain
Radiocarbon samples from composite drilling section near Nanjing road and profile of Chonggang mountain
表 2新沂河、合欢路、重岗山探槽光释光(OSL)测年结果
新沂河、合欢路、重岗山探槽光释光(OSL)测年结果
Table 2.OSL samples from trenching site in the Jiangsu segment of the Tan-Lu Fault Zone
OSL samples from trenching site in the Jiangsu segment of the Tan-Lu Fault Zone
Bureau of Geology and Mineral Resource of Jiangsu Province. 1984. Regional Geology of Jiangsu Province and Shanghai (in Chinese). Beijing:Geological Publishing House.
Cao J. 2015. Active characteristics in Quaternary on the segment of the Yishu Fault, The Tan-Lu Fault Zone (in Chinese). Beijing:China University of Geoscience (Beijing).
Cao J, Ran Y K, Xu H G, et al. 2018. Late Quaternary activity in the southem segment of the Anqiu-Juxian Fault of the Tan-Lu Fault Zone. Journal of Seismological Research (in Chinese), 41(2):280-292.
Deng Q D, Ran Y K, Yang X P, et al. 2007. Map of Active Tectonics in China (1:400 Million). Beijing:Seismological Press.
Department ofEarthquake Damage and Defense of China Earthquake Administration. 1999. Recent Earthquake Catalog of China (1912-1990, MS ≥ 4.7) (in Chinese). Beijing:Chinese Sciences and Technology Press.
Gao W M, Zheng L S, Li J L, et al. 1988. Seismogenic structure of the Earthquake (M=8.5) in 1668. Earthquake Research in China (in Chinese), 4(3):9-15.
Geological mapping team of Tan-Lu Active Fault Zone. 2013. Geological Map of Tan-Lu Active Fault Zone (in Chinese). Beijing:Seismological Press.
Institue of Geology State Earhquake Administration. 1987. The Tanlu Fault Zone (in Chinese). Beijing:Seismological Press.
Li J L, Chao H T, Cui Z W, et al. 1991. Research on active fault in Ducheng-Xinyi segment of the Tan-Lu Fault Zone. //Institute of Geology, Deng Q D eds. Research on Active Fault(1) (in Chinese). Beijing: Seismological Press, 164-173.
Li Q T. 1994. New evidence of Holocene active fault in Jiangsu segment of the Tan-Lu Fault Zone. //Editorial Board of "Active Fracture Research" Institute of Geology eds. Research on Active Fault(3) (in Chinese). Beijing: Seismological Press, 140-145.
Li X N. 2014. Late Quaternary kinematic characteristics and Paleoearthquakes along the western segment of the Xiangshan-Tianjingshan fault (in Chinese). Beijing:Institute of Geology, China Earthquake Administration.
Mao F Y, Zhang P Z. 1995. Progessive constraining method in paleoseismic study and paleoearthquakes along the major active faults in northern Xinjiang. //Editorial Board of "Active Fracture Research", Institute of Geology eds. Research on Active Fault(4) (in Chinese). Beijing: Seismological Press, 153-164.
Xie R Z, Zhu S J, Ding Z. 1991. Discussion of Holocene active fault in the Jiangsu segment of the Tan-Lu Fault Zone. Journal of Seismology (in Chinese), (4):15-18.
Zheng L S, Gao W M, Zheng C B. 1988. The segmentation of the Tan-Lu fault zone and activity in the Yishu fault zone. Earthquake Research in China (in Chinese), 4(3):129-135.
曹筠. 2015.郯庐断裂带沂沭段第四纪活动特征.北京:中国地质大学(北京).
曹筠, 许汉刚, 冉勇康等. 2017.郯庐断裂带沂水-汤头断裂南段晚第四纪活动新证及构造意义.地震地质, 39(2):287-303.
曹筠, 冉勇康, 许汉刚等. 2018.郯庐断裂带安丘-菖县断裂南段(郯城-淮河)晚第四纪活动特征.地震研究, 41(2):280-292.
邓起东, 冉勇康, 杨晓平等. 2007.中国活动构造图(1:400万).北京:地震出版社.
国家地震局地质研究所. 1987.郯庐断裂.北京:地震出版社.
国家地震局震害防御司. 1995.中国历史强震目录(公元前23世纪-公元1911年).北京:地震出版社.
江苏省地质矿产局. 1984.江苏省及上海市区域地质志.北京:地质出版社.
李家灵, 晁洪太, 崔昭文等. 1991. 郊庐断裂带都城~新沂段活断层研究. //《活动断裂研究》编委会, 邓起东编. 活动断裂研究(1). 北京: 地震出版社, 164-173.
李起彤. 1994. 郯庐断裂带江苏段全新世活动新证据. //《活动断裂研究》编委会, 国家地震局地质研究所. 活动断裂研究(3). 北京: 地震出版社, 140-145.
李新男. 2014.香山-天景山断裂带西段晚第四纪运动学特征与古地震研究.北京:中国地震局地质研究所.
毛凤英, 张培震. 1995. 古地震研究逐次限定方法与新疆北部主要断裂带的古地震研究. //《活动断裂研究》编委会, 国家地震局地质研究所编. 活动断裂研究(4). 北京: 地震出版社, 153-164.
郯庐活动断裂带地质填图课题组. 2013.郯庐活动断裂带地质图(1:50000).北京:地震出版社.
中国地震局震害防御司. 1999.中国近代地震目录(公元1912年-1990年, MS ≥ 4.7).北京:中国科学技术出版社.
图(13)
表(2)
返回顶部
Tectonics map of Jiangsu segment of the Tan-Lu Fault Zone
Typical outcrop and remote-sensing image along the Anqiu-Juxian fault in the Jiangsu segment of the Tan-Lu Fault Zone
Fault revealed by drilling section along the AQ3 line
Location of composite drilling profile paralleled AQ5 line
Composite drilling section paralleled AQ5 line(The scarlet letter on the left side of fault shows fault displacement corresponding horizon)
Geographical location map of Xinyi trench(Image come from Google earth)
Map of southern wall of trench near Xinyi river and its interpretation
Map of trench at Hehuan road and its interpretation ((A) is northern wall; (B) is southern wall)
Map of southern wall of trench near Chonggang mountain and its interpretation
Progessive constraining paleoearthquake events in the Jiangsu segment of the Tan-Lu Fault Zone