POWRE: Isotopic insight into the genesis and evolution of compositionally diverse volcanism in the central Mexican Volcanic Belt: Implications for subduction-related volcanism

0074610 Blater本研究将调查墨西哥中部火山带（MVB）火山活动的同位素组成（Rb-Sr，Sm-Nd，Pb和O），该火山带具有多种火山岩套的特征，但没有同位素数据。 该项目将通过评价该区域同时爆发的三个成分不同的火山系列的成因和演变，促进目前对与俯冲有关的过程的了解。 第一个目标，这是为了确定是否地球化学多样的火山活动在中央MVB可以归因于系统的变化特征的地幔源。 MVB中心是研究俯冲相关弧中地幔过程和火山活动之间联系的最佳地点，原因有三个。 1.新鲜熔岩和火山渣的暴露是极好的，三种不同的成分类型已经很好地描述了年龄，体积和分布。 2.构造环境受到板片倾角、板片深度和收敛速率的制约。 3.浅（近水平）俯冲角产生了一个约200公里宽的弧，这提供了极好的空间分辨率，以揭示三个火山系列的系统空间分布。 第二个目标是研究幔源岩浆在上升通过地壳过程中的变化，并评估晶体分馏和地壳同化对其演化的贡献。 同位素数据，主要和微量元素的地球化学数据，和存储的限制（T，P，fO 2，和重量% H2O），可从高品质的水饱和相平衡实验，将允许量化的时间尺度的一些岩浆过程。 该项目的第三个目标是利用受地壳污染的熔岩的同位素组成来揭示它们喷发时所穿过的基底火山岩的信息。 这些数据将被用来限制墨西哥中部的基底岩石之间的边界。 这项工作将在博尔德的科罗拉多大学与G. Lang Farmer是将放射性同位素数据应用于火成岩学、沉积物源区确定和地壳构造演化的专家。 此外，科罗拉多大学博尔德分校和CIRES（环境科学研究合作研究所）的PI将随时获得所有必要的设备和设施。 研究人员的培训是经典的火成岩岩石学，重点是实验研究和野外工作。 POWRE奖将允许PI通过为她提供追求新的合作和技能的机会来优化这种必要的搬迁，并为同位素地球化学领域贡献她独特的观点。 这项研究将使她学习新的分析技术（质谱法），并为她提供同位素地球化学应用于各种问题的经验，大大提高了她作为岩石学家的多功能性。

0074610BlatterThis study will investigate the isotopic compositions (Rb-Sr, Sm-Nd, Pb, and O) of volcanism in the central Mexican volcanic Belt (MVB) where a diverse volcanic suite has been characterized, yet no isotopic data is available. This project will contribute to current understanding of subduction-related processes by evaluating the genesis and evolution of three compositionally distinct volcanic series that have erupted contemporaneously in this region. The first goal of this is to determine whether geochemically diverse volcanism in the central MVB can be attributed to systematic variations in the characteristics of the mantle source. The central MVB is an optimal place to study the connection between mantle processes and volcanism in subduction-related arcs for three significant reasons. 1. The exposure of fresh lavas and scoriae is excellent and three distinct compositional types have already been well characterized with respect to age, volume, and distribution. 2. The tectonic setting is constrained including slab angle, depth to slab, and convergence rate. 3. The shallow (sub-horizontal) subduction angle produces an ~200 km wide arc, which provides excellent spatial resolution to expose the systematic spatial distribution of the three volcanic series. The second goal is to investigate the modification of mantle-derived magmas during their ascent through the crust, and evaluate the contribution of crystal fractionation and crustal assimilation to their evolution. Isotopic data, major and trace element geochemical data, and storage constraints (T, P, fO2, and wt% H2O) available from high quality water-saturated phase equilibria experiments, will allow quantification of the time-scales of some of these magmatic processes. The third goal of this project will be to use the isotopic compositions of the crustally contaminated lavas to expose information about the basement terranes through which they have erupted. This data will be used to constrain the boundaries between the basement terranes of central Mexico. This work will be conducted at the University of Colorado, Boulder in collaboration with Professor G. Lang Farmer, an expert in the application of radiogenic isotope data to igneous petrology, sedimentary provenance determinations, and the tectonic evolution of the Earth's crust. Additionally, all of the necessary equipment and facilities will be readily available to the PI at University of Colorado, Boulder and CIRES (Cooperative Institute for Research in Environmental Sciences). The training of the investigator has been that of classical igneous petrology with emphasis on experimental studies and fieldwork. The POWRE award will allow the PI to optimize this necessary relocation by providing the opportunity for her to pursue new collaborations and skills, as well as contribute her unique perspective to the field of isotope geochemistry. The research will involve her in learning new analytical techniques (mass-spectrometry) and provide her with experience in the application of isotope geochemistry to a variety of problems, vastly increasing her versatility as a petrologist.