|本期目录/Table of Contents|

[1]张波,郑龙,何文贵,等.阿拉善地块西部鼎新断裂的发现及其构造意义[J].地震研究,2022,45(04):543-551.[doi:10.20015/j.cnki.ISSN1000-0666.2022.0054]
　ZHANG Bo,ZHENG Long,HE Wengui,et al.Discovery of the Dingxin Active Fault in the Western Alxa Block and Its Tectonic Significance[J].Journal of Seismological Research,2022,45(04):543-551.[doi:10.20015/j.cnki.ISSN1000-0666.2022.0054]
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阿拉善地块西部鼎新断裂的发现及其构造意义(PDF/HTML)

《地震研究》[ISSN:1000-0666/CN:53-1062/P]

卷:
45
期数:
2022年04期
页码:
543-551
栏目:
出版日期:
2022-08-20

文章信息/Info

Title:
Discovery of the Dingxin Active Fault in the Western Alxa Block and Its Tectonic Significance
作者:
张波; 郑龙; 何文贵; 朱俊文; 蔡艺萌
(甘肃兰州地球物理国家野外科学观测研究站,甘肃 兰州 730000)
Author(s):
ZHANG Bo; ZHENG Long; HE Wengui; ZHU Junwen; CAI Yimeng
(Gansu Lanzhou Geophysics National Observation and Research Station,Lanzhou 730000,Gansu,China)
关键词:
鼎新断裂;  活动断裂;  阿拉善地块;  青藏高原
Keywords:
the Dingxin fault;  active fault;  the Alxa Block;  the Tibetan Plateau
分类号:
P315.24
DOI:
10.20015/j.cnki.ISSN1000-0666.2022.0054
摘要:
在阿拉善地块西部新发现一条活动断裂——鼎新断裂,该断裂位于金塔县鼎新镇以东,长约30 km,走向100°～130°,几何形态略向NE凸出。通过差分GPS实测鼎新断裂的15条断层陡坎,发现陡坎高度为(0.4±0.1)～(23.8±1.0)m,陡坎高度中间大、向东西两侧减小,说明断裂具有长期的倾滑活动。在断裂东端开挖2个探槽,探槽显示陡倾的逆断层,光释光测年结果显示被断错的最新地层的沉积年龄分别为(23.38±1.99)ka和(31.25±2.66)ka,说明断裂的最新活动时代至少为晚更新世晚期。鼎新断裂、俄博庙断裂等一系列活动断裂的发现,提高了区域大震危险性,两条断裂截然不同的几何学和运动学特征体现了阿拉善内部构造变形的复杂性,其动力学特征需要进一步深入研究。
Abstract:
This paper reports a newly discovered active fault,the Dingxin fault in the western part of the Alxa Block.This fault is located to the east of Dingxin Town of Jinta County,and is about 30 km long and 100°-130° in strike,and its geometric pattern slightly curves toward northest.Fifteen fault scarp profiles are measured by differential GPS,and the scarp heights ranged between(0.4±0.1)-(23.8±1.0)m,which decrease from the center of the fault to the east and the west.This indicates that the fault has long-term,dip-slip activities.Two trenches excavated at the eastern end of the fault show steep and reverse fault planes.Results from the optically stimulated luminescence(OSL)dating show that the deposition ages of the latest faulted strata are(23.38±1.99)ka and(31.25±2.66)ka respectively.This indicates that the Dingxin fault is a Late-Pleistocene fault.The discovery of the Dingxin fault,the Ebomiao fault etc.implies that the risk of large earthquakes in the Alxa Block is increasing.The distinct kinematic difference between the Dingxin fault and the Ebomiao fault reflects the complexity of inner deformation in the western Alxa Block,and its geodynamic characteristic needs to be further studied.

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备注/Memo

备注/Memo:
收稿日期:2021-12-14
基金项目:甘肃省地震局地震科技发展基金(2016Q03)、中国地震局地震预测研究所基本科研业务费专项(2020IESLZ02,2021IESLZ06)和甘肃省地震局创新团队项目(2019TD0101)联合资助.

更新日期/Last Update: 2022-08-01