Emplacement of Large Crustal Sills and The Mechanics of Magmatic Underplating

西蒙斯9980664侵入的大型地台状岩浆体在地壳的吸积并最终在岩石圈的化学分异中发挥了重要作用。然而，控制水平岩浆片的启动、侵位和终止的特殊机制却知之甚少。主要突出问题包括环境应力和岩石强度各向异性在控制岩床形成和发育中的相对重要性，岩床、岩脉和岩浆源区之间的关系，伴随岩床侵位的非弹性变形的性质和程度，以及侵入诱发的地震活动。该项目旨在通过解决固体力学的边值问题，明确包括宿主岩石性质的实际变化、自由面的影响以及基于合理的破坏规律的宿主的非弹性变形，来详细地定量地了解单个底板事件。调查人员将通过与基辅地球物理研究所(基辅，乌克兰)实验构造物理系合作进行物理模拟实验，进一步深入了解类地台侵入的动力学。这项工作将直接关系到对推断的同时代地台状岩浆体区域的地震活动性的解释。利用卫星雷达干涉测量(InSAR)，将在新墨西哥州索科罗地区测量地表形变，那里的异常中地壳反射层和大地隆起被解释为指示深部存在岩浆。研究人员将反转观测到的形变，以限制推断的岩浆体的几何形状和岩浆供应的动力学。

Simons 9980664 Intrusion of large sill-like magma bodies plays a major role in the accretion of the Earth's crust and ultimately in the chemical differentiation of the lithosphere. However, the particular mechanisms that control initiation, emplacement, and termination of horizontal magma sheets are poorly understood. Major outstanding problems include the relative importance of ambient stresses and rock strength anisotropy in governing sill initiation and growth, the relationships between sills, feeder dikes, and magma source regions, the character and extent of inelastic deformation accompanying sill emplacement, and intrusion-induced seismicity. This project aims to develop a detailed quantitative understanding of individual underplating events by solving boundary value problems of solid mechanics that explicitly include realistic variations in the host rock properties, effects of the free surface, and inelastic deformation of the host based on reasonable failure laws. The investigators will gain further insight into the dynamics of sill-like intrusions by performing physical analog experiments in collaboration with the Department of Experimental Tectonophysics of Kiev Institute of Geophysics (Kiev, Ukraine). This work will be directly relevant to interpretations of seismicity in the regions of the inferred contemporaneous sill-like magma bodies. By using satellite radar interferometry (InSAR), surface deformation will be measured in the area of Socorro, New Mexico, where anomalous mid-crustal reflector and geodetic uplift have been interpreted as indicating the presence of magma at depth. The investigators will invert the observed deformation to constrain the geometry of the inferred magma body and the dynamics of magma supply.