Emplacement of Large Crustal Sills and The Mechanics of Magmatic Underplating

大型岩状岩浆体的侵入在地壳的增生中起着重要作用，并最终在岩石圈的化学分异中起着重要作用。然而，控制水平岩浆片的起始、就位和终止的特殊机制却知之甚少。主要的突出问题包括环境应力和岩石强度各向异性在控制基台起始和生长中的相对重要性，基台、给料墙和岩浆源区之间的关系，基台侵位时非弹性变形的特征和程度，以及侵入诱发的地震活动性。该项目旨在通过解决固体力学的边值问题，明确地包括宿主岩石性质的实际变化，自由表面的影响以及基于合理破坏规律的宿主非弹性变形，从而对单个底板事件进行详细的定量理解。研究人员将通过与基辅地球物理研究所（基辅，乌克兰）的实验构造物理系合作进行物理模拟实验，进一步了解类技能侵入的动力学。这项工作将直接关系到对推断的同生岩样岩浆体区域地震活动性的解释。利用卫星雷达干涉测量（InSAR），将测量新墨西哥州索科罗地区的地表变形，在那里，异常的地壳中部反射和大地隆起被解释为表明岩浆在深处存在。研究人员将对观测到的变形进行反演，以约束推断出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.