从伪水杨酸微观结构看地震动力学

IF 4.8 1区 地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS
Silvia Aldrighetti , Giorgio Pennacchioni , Giulio Di Toro
{"title":"从伪水杨酸微观结构看地震动力学","authors":"Silvia Aldrighetti ,&nbsp;Giorgio Pennacchioni ,&nbsp;Giulio Di Toro","doi":"10.1016/j.epsl.2025.119424","DOIUrl":null,"url":null,"abstract":"<div><div>During an earthquake, most of the dissipation of the stored elastic strain energy occurs by fracturing processes and frictional heat along and adjacent to the seismic fault. Information on earthquake energy partitioning and dynamics can be retrieved from the analysis of exhumed faults containing pseudotachylytes (solidified frictional melts produced during seismic faulting). Here, microstructural analysis is carried out on an east-west striking pseudotachylyte-bearing fault of the dextral strike-slip Gole Larghe Fault Zone within the Adamello granitoid pluton (Italian Alps), exhumed from 8–11 km depth. FESEM cathodoluminescence analysis reveals a strong fragmentation of the wall rocks, invisible with other techniques, which decays in the first centimetres from the pseudotachylyte fault-parallel vein. In the northern block the microfracture density is on average low (7448 mm<sup>-2</sup>) and the microfractures strike preferentially E-W. In contrast, in the southern block microfracture density is on average high (12,120 mm<sup>-2</sup>), and the microfractures strike preferentially N-S. This asymmetric wall rock damage provides evidence that the microfractures developed as result of the dynamic stress field associated with earthquake rupture propagation. The measured surface area associated with wall rock fracturing and the volume of the pseudotachylyte allow the estimate of the energy dissipated in fracturing processes <em>U</em><sub>S</sub> (0.015–1.88 MJ m<sup>-2</sup>) and frictional heat <em>Q</em> (32 MJ m<sup>-2</sup>), respectively. The comparison between <em>U</em><sub>S</sub> and <em>Q</em> implies that frictional heat is the major energy sink during rupture propagation in these intracontinental earthquakes.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"663 ","pages":"Article 119424"},"PeriodicalIF":4.8000,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Earthquake dynamics from pseudotachylyte microstructure\",\"authors\":\"Silvia Aldrighetti ,&nbsp;Giorgio Pennacchioni ,&nbsp;Giulio Di Toro\",\"doi\":\"10.1016/j.epsl.2025.119424\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>During an earthquake, most of the dissipation of the stored elastic strain energy occurs by fracturing processes and frictional heat along and adjacent to the seismic fault. Information on earthquake energy partitioning and dynamics can be retrieved from the analysis of exhumed faults containing pseudotachylytes (solidified frictional melts produced during seismic faulting). Here, microstructural analysis is carried out on an east-west striking pseudotachylyte-bearing fault of the dextral strike-slip Gole Larghe Fault Zone within the Adamello granitoid pluton (Italian Alps), exhumed from 8–11 km depth. FESEM cathodoluminescence analysis reveals a strong fragmentation of the wall rocks, invisible with other techniques, which decays in the first centimetres from the pseudotachylyte fault-parallel vein. In the northern block the microfracture density is on average low (7448 mm<sup>-2</sup>) and the microfractures strike preferentially E-W. In contrast, in the southern block microfracture density is on average high (12,120 mm<sup>-2</sup>), and the microfractures strike preferentially N-S. This asymmetric wall rock damage provides evidence that the microfractures developed as result of the dynamic stress field associated with earthquake rupture propagation. The measured surface area associated with wall rock fracturing and the volume of the pseudotachylyte allow the estimate of the energy dissipated in fracturing processes <em>U</em><sub>S</sub> (0.015–1.88 MJ m<sup>-2</sup>) and frictional heat <em>Q</em> (32 MJ m<sup>-2</sup>), respectively. The comparison between <em>U</em><sub>S</sub> and <em>Q</em> implies that frictional heat is the major energy sink during rupture propagation in these intracontinental earthquakes.</div></div>\",\"PeriodicalId\":11481,\"journal\":{\"name\":\"Earth and Planetary Science Letters\",\"volume\":\"663 \",\"pages\":\"Article 119424\"},\"PeriodicalIF\":4.8000,\"publicationDate\":\"2025-05-09\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Earth and Planetary Science Letters\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0012821X25002237\",\"RegionNum\":1,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"GEOCHEMISTRY & GEOPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Earth and Planetary Science Letters","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0012821X25002237","RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
引用次数: 0

摘要

在地震中,储存的弹性应变能的大部分耗散是通过沿地震断层及其附近的破裂过程和摩擦热发生的。地震能量分配和动力学信息可以从含有假断层液(地震断裂过程中产生的凝固摩擦熔体)的出土断层分析中获取。本文对意大利阿尔卑斯山脉阿达梅洛花岗质岩体内一条东西向走滑的Gole Larghe断裂带内一条东西向含伪石质断裂进行了显微构造分析。FESEM阴极发光分析显示,在伪石质断层平行脉的最初厘米处,围岩有很强的碎裂,用其他技术是看不见的。北部块体微裂缝密度平均较低(7448 mm-2),微裂缝以东西向为主。南侧块体微裂缝密度平均较高(12120 mm-2),且微裂缝以北向南方向为主。这种不对称围岩损伤为微裂缝的形成提供了与地震破裂传播相关的动应力场的证据。通过测量与围岩压裂相关的表面积和伪水酸盐的体积,可以分别估算出压裂过程中耗散的能量US (0.015-1.88 MJ m-2)和摩擦热Q (32 MJ m-2)。US和Q的比较表明,摩擦热是这些大陆内地震破裂传播过程中的主要能量汇。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
Earthquake dynamics from pseudotachylyte microstructure
During an earthquake, most of the dissipation of the stored elastic strain energy occurs by fracturing processes and frictional heat along and adjacent to the seismic fault. Information on earthquake energy partitioning and dynamics can be retrieved from the analysis of exhumed faults containing pseudotachylytes (solidified frictional melts produced during seismic faulting). Here, microstructural analysis is carried out on an east-west striking pseudotachylyte-bearing fault of the dextral strike-slip Gole Larghe Fault Zone within the Adamello granitoid pluton (Italian Alps), exhumed from 8–11 km depth. FESEM cathodoluminescence analysis reveals a strong fragmentation of the wall rocks, invisible with other techniques, which decays in the first centimetres from the pseudotachylyte fault-parallel vein. In the northern block the microfracture density is on average low (7448 mm-2) and the microfractures strike preferentially E-W. In contrast, in the southern block microfracture density is on average high (12,120 mm-2), and the microfractures strike preferentially N-S. This asymmetric wall rock damage provides evidence that the microfractures developed as result of the dynamic stress field associated with earthquake rupture propagation. The measured surface area associated with wall rock fracturing and the volume of the pseudotachylyte allow the estimate of the energy dissipated in fracturing processes US (0.015–1.88 MJ m-2) and frictional heat Q (32 MJ m-2), respectively. The comparison between US and Q implies that frictional heat is the major energy sink during rupture propagation in these intracontinental earthquakes.
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
Earth and Planetary Science Letters
Earth and Planetary Science Letters 地学-地球化学与地球物理
CiteScore
10.30
自引率
5.70%
发文量
475
审稿时长
2.8 months
期刊介绍: Earth and Planetary Science Letters (EPSL) is a leading journal for researchers across the entire Earth and planetary sciences community. It publishes concise, exciting, high-impact articles ("Letters") of broad interest. Its focus is on physical and chemical processes, the evolution and general properties of the Earth and planets - from their deep interiors to their atmospheres. EPSL also includes a Frontiers section, featuring invited high-profile synthesis articles by leading experts on timely topics to bring cutting-edge research to the wider community.
×
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