| 假玄武玻璃的岩石磁学研究进展 |
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| 引用本文：张蕾,李海兵,孙知明,曹勇.2026.假玄武玻璃的岩石磁学研究进展[J].地球学报,47(1):17-30. |
| DOI：10.3975/cagsb.2025.111721 |
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| 基金项目:由国家自然科学基金项目(编号: 42230312; 42172262; 42372266)、地球深部探测与矿产资源勘查国家科技重大专项(编号: 2024ZD1000500)和中国地质调查局地质调查项目(编号: DD20240041)联合资助。 |
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| 中文摘要:与断层相关的假玄武玻璃记录了地震发生过程的重要信息, 其岩石磁学研究可以揭示地震断裂作用的物理-化学性质和地震机制。本文在综合假玄武玻璃岩石磁学研究最新文献的基础上, 结合笔者所在研究团队在龙门山断裂带获得的相关研究成果, 综述了假玄武玻璃的岩石磁学进展。假玄武玻璃的磁性物质转换过程为: 在400~1 300 ℃的摩擦热作用下, 断裂带中的顺磁性矿物转换成了假玄武玻璃中的磁铁矿和磁赤铁矿等铁磁性矿物; 在≥1 300 ℃的高温强还原性的摩擦熔融作用下, 铁的氧化物和硫化物发生热解生成单质铁; 单质铁和单质硫在≥1 500 ℃的高温强还原性的摩擦熔融作用下生成单斜磁黄铁矿。假玄武玻璃中的新生单质铁、单斜磁黄铁矿、磁铁矿和磁赤铁矿等磁性物质引起了假玄武玻璃高磁异常特征。假玄武玻璃的磁组构研究可以获得古地震发生机制、古应力场方向和古应变特征。结合假玄武玻璃及其围岩的岩石磁学、数值模拟、地球化学和显微结构特征可以确定同震摩擦熔融温度、孕震深度、氧化还原和流体作用等环境。综合岩石磁学、微米-纳米尺度的超显微学和微区地球化学研究、高温-超高温加热实验和快速剪切摩擦实验等多种研究方法可以更加准确地揭示假玄武玻璃的磁学特征, 有助于获得地震断裂带最直接的物理-化学和力学信息。 |
| 中文关键词:假玄武玻璃 岩石磁学 磁组构 地震断裂作用 |
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| A Review of Rock Magnetism of Pseudotachylyte |
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| Abstract:Fault-related pseudotachylytes are critical for understanding seismic processes, as rock magnetic studies can elucidate the physicochemical properties and earthquake mechanisms of seismic faults. Building on recent advances in the rock magnetism of pseudotachylytes and incorporating findings from the Longmen Shan fault zone obtained by the author and their team, this study synthesizes recent advances in the rock magnetism of pseudotachylytes. The formation of magnetic materials in pseudotachylyte involves the transformation of paramagnetic minerals into ferromagnetic minerals (e.g., magnetite and maghemite) under frictional heating at temperatures ranging from 400 °C to 1 300 °C. Under high temperature (≥1 300 °C) and strongly reducing conditions, iron oxides and sulfides decompose to form metallic iron. At ultrahigh temperatures (≥1 500 °C), metallic iron further reacts with sulfur to produce monoclinic pyrrhotite. Analysis of magnetic fabric in pseudotachylytes provides valuable insights into paleoearthquakes mechanisms, paleostress orientation, and paleostrain characteristics. By integrating rock magnetism with paleomagnetism, geochemistry, numerical simulations, and microstructural analysis, key seismogenic parameters—such as coseismic frictional melting temperatures, seismogenic depths, redox conditions, and fluid interactions—can be constrained. A comprehensive approach combining rock magnetic analyses, nanoscale microscopy, microgeochemistry, high- to ultrahigh-temperature heating, and rapid shear experiments holds great promise for decoding the magnetic record of pseudotachylytes and retrieving direct physicochemical and stress information from seismic fault zones. |
| keywords:pseudotachylyte rock magnetism magnetic fabric seismic faulting |
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