智利北部从三叠纪到第四纪活跃的 Mejillones 断层的岩性控制

IF 2.7 3区 地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS
Kellen Azúa , Francisco Pastén-Araya , José González-Alfaro , José Salomón , Sergio Ruiz , César Pastén , Pablo Salazar
{"title":"智利北部从三叠纪到第四纪活跃的 Mejillones 断层的岩性控制","authors":"Kellen Azúa ,&nbsp;Francisco Pastén-Araya ,&nbsp;José González-Alfaro ,&nbsp;José Salomón ,&nbsp;Sergio Ruiz ,&nbsp;César Pastén ,&nbsp;Pablo Salazar","doi":"10.1016/j.tecto.2024.230395","DOIUrl":null,"url":null,"abstract":"<div><p>Understanding the lithological control of crustal faults near cities is important for assessing the seismic hazard and characterising complex fault systems. We studied the Mejillones Fault (MF), located near one of the strategic ports in northern Chile. The MF is an active geological fault that extends 40 km in the N-S direction and is part of an extensive complex system of structures known as the Atacama Fault System (AFS). We built an S-wave tomography model using seismic ambient noise data that was recorded continuously in a dense network of stations from 2013 to 2015. The tomographic maps exhibited velocity anomalies that correlate with surface geology. We found lower velocities in the western part of the MF than in the eastern zone, with a shear wave velocity (Vs) of about 2.4 km/s, associated to fractured metamorphic rocks (Triassic) and marine sediments (Neogene-Quaternary). Higher velocities (Vs &gt; 3.0 km/s) in the eastern part of the fault are related to igneous rocks from the Upper Jurassic. The difference in velocities between the western and eastern zones of the MF remained persistent in depth. The potential depth of the MF could be &gt;5 km and delimits the boundary between 2 different geological zones. Intermediate Vs (∼2.8 km/s) at −23.25°, observed up to 4 km depth, can be associated with andesitic rocks deposited in an intra-arc basin (Upper Triassic) and accommodated by the MF over the last ∼200 Myr, evidencing the activity of this fault from Triassic to Quaternary.</p></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":null,"pages":null},"PeriodicalIF":2.7000,"publicationDate":"2024-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Lithological control of the active Mejillones fault from Triassic to Quaternary, northern Chile\",\"authors\":\"Kellen Azúa ,&nbsp;Francisco Pastén-Araya ,&nbsp;José González-Alfaro ,&nbsp;José Salomón ,&nbsp;Sergio Ruiz ,&nbsp;César Pastén ,&nbsp;Pablo Salazar\",\"doi\":\"10.1016/j.tecto.2024.230395\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Understanding the lithological control of crustal faults near cities is important for assessing the seismic hazard and characterising complex fault systems. We studied the Mejillones Fault (MF), located near one of the strategic ports in northern Chile. The MF is an active geological fault that extends 40 km in the N-S direction and is part of an extensive complex system of structures known as the Atacama Fault System (AFS). We built an S-wave tomography model using seismic ambient noise data that was recorded continuously in a dense network of stations from 2013 to 2015. The tomographic maps exhibited velocity anomalies that correlate with surface geology. We found lower velocities in the western part of the MF than in the eastern zone, with a shear wave velocity (Vs) of about 2.4 km/s, associated to fractured metamorphic rocks (Triassic) and marine sediments (Neogene-Quaternary). Higher velocities (Vs &gt; 3.0 km/s) in the eastern part of the fault are related to igneous rocks from the Upper Jurassic. The difference in velocities between the western and eastern zones of the MF remained persistent in depth. The potential depth of the MF could be &gt;5 km and delimits the boundary between 2 different geological zones. Intermediate Vs (∼2.8 km/s) at −23.25°, observed up to 4 km depth, can be associated with andesitic rocks deposited in an intra-arc basin (Upper Triassic) and accommodated by the MF over the last ∼200 Myr, evidencing the activity of this fault from Triassic to Quaternary.</p></div>\",\"PeriodicalId\":22257,\"journal\":{\"name\":\"Tectonophysics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.7000,\"publicationDate\":\"2024-06-15\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Tectonophysics\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0040195124001975\",\"RegionNum\":3,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"GEOCHEMISTRY & GEOPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Tectonophysics","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0040195124001975","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
引用次数: 0

摘要

了解城市附近地壳断层的岩性控制对于评估地震危害和描述复杂的断层系统非常重要。我们研究了位于智利北部战略港口附近的梅希洛内斯断层(MF)。该断层是一条活跃的地质断层,在南北方向延伸 40 公里,是被称为阿塔卡马断层系统(AFS)的广泛复杂结构系统的一部分。我们利用 2013 年至 2015 年在密集台站网络中连续记录的地震环境噪声数据建立了 S 波层析成像模型。层析成像图显示了与地表地质相关的速度异常。我们发现,与东部地区相比,飞行区西部的速度较低,剪切波速度(Vs)约为 2.4 km/s,与断裂变质岩(三叠纪)和海洋沉积物(新元古代-第四纪)有关。断层东部较高的速度(Vs > 3.0 km/s)与上侏罗纪的火成岩有关。中断裂西段和东段的速度差异在深度上仍然存在。该断层的潜在深度可达 5 千米,并划定了两个不同地质带的边界。在-23.25°处观测到的中等Vs(2.8 km/s)可达4 km深,这可能与弧内盆地(上三叠统)沉积的安山岩有关,在过去的200 Myr期间被MF所容纳,证明了该断层从三叠纪到第四纪的活动。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
Lithological control of the active Mejillones fault from Triassic to Quaternary, northern Chile

Understanding the lithological control of crustal faults near cities is important for assessing the seismic hazard and characterising complex fault systems. We studied the Mejillones Fault (MF), located near one of the strategic ports in northern Chile. The MF is an active geological fault that extends 40 km in the N-S direction and is part of an extensive complex system of structures known as the Atacama Fault System (AFS). We built an S-wave tomography model using seismic ambient noise data that was recorded continuously in a dense network of stations from 2013 to 2015. The tomographic maps exhibited velocity anomalies that correlate with surface geology. We found lower velocities in the western part of the MF than in the eastern zone, with a shear wave velocity (Vs) of about 2.4 km/s, associated to fractured metamorphic rocks (Triassic) and marine sediments (Neogene-Quaternary). Higher velocities (Vs > 3.0 km/s) in the eastern part of the fault are related to igneous rocks from the Upper Jurassic. The difference in velocities between the western and eastern zones of the MF remained persistent in depth. The potential depth of the MF could be >5 km and delimits the boundary between 2 different geological zones. Intermediate Vs (∼2.8 km/s) at −23.25°, observed up to 4 km depth, can be associated with andesitic rocks deposited in an intra-arc basin (Upper Triassic) and accommodated by the MF over the last ∼200 Myr, evidencing the activity of this fault from Triassic to Quaternary.

求助全文
通过发布文献求助,成功后即可免费获取论文全文。 去求助
来源期刊
Tectonophysics
Tectonophysics 地学-地球化学与地球物理
CiteScore
4.90
自引率
6.90%
发文量
300
审稿时长
6 months
期刊介绍: The prime focus of Tectonophysics will be high-impact original research and reviews in the fields of kinematics, structure, composition, and dynamics of the solid arth at all scales. Tectonophysics particularly encourages submission of papers based on the integration of a multitude of geophysical, geological, geochemical, geodynamic, and geotectonic methods
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信