Collaborative Research: The Jemez Tomography Experiment (JTEX)

Jemez断层扫描实验（JTEX）是一个合作项目， 跨学科研究计划，涉及来自六个国家的科学家 洛斯阿拉莫斯国家实验室（Los Alamos National Laboratory） 能源部和美国地质调查局 Jemez山脉 火山场（JMVF）是晚新生代一座重要的硅质火山 系统 也许它最著名的特征是Valles Caldera， 1.1至1.6 Ma的爆发性火山产物，包括 班德利尔凝灰岩 与JMVF有关的基本问题 和其他最近的火山系统， 在该项目是： 1. 地壳卷入的性质和程度是什么， 伴随着地壳的变化， JMVF的火山活动 是地壳侵入， 存在于地壳中的深成岩体或底侵区 在瓦勒斯火山口和杰梅斯山脉下 2. JMVF在过去的15 Ma中是如何演变的， 最终导致班德利尔流纹岩的喷发 熔结凝灰岩和破火山口坍塌 岩石学模型 岩浆的生成表明， 镁铁质侵入体（体积约为 喷发物质）存在于地壳下方 主要的硅质火山中心。 我们能想象一下 入侵，并解释其 与观测到的火山地质的关系 为了解决这些问题和其他具体有关的问题， 到JMVF和一般大陆岩浆作用， 调查人员将对这一地区进行深入的地球物理研究， JMVF，分析收集的数据并解释结果， 与岩石学和地球化学信息相一致。 新 地球物理数据将包括：地震折射/反射， 重力、磁场、电磁波的延迟时间和波形， 大地电磁（MT）数据。 该计划旨在提供一个 下面被岩浆改造的铁锈的三维图像 JMVF。 爆炸地震波层析反演与 测井资料及联合解释 野外、MT和地质数据将产生最高分辨率 目前可用的地壳尺度特征三维研究。

The Jemez Tomography Experiment (JTEX) is a cooperative and interdisciplinary research program involving scientist from six major Universities, the Los Alamos National Laboratory with support from the DOE, and the U.S. Geological Survey. The Jemez Mountains volcanic field (JMVF) is a major Late Cenozoic silicic volcanic system. Perhaps its best-known feature is the Valles Caldera and associated 1.1 to 1.6 Ma explosive volcanic products including the Bandelier Tuff. The fundamental questions that relate to the JMVF and other recent silicic volcanic systems and which are addressed in the project are: 1. What is the nature and extent of crustal involvement and accompanying modifications of the crust during the volcanic activity in the JMVF? Are crustal intrusions, pluton, or underplated regions present in the crust beneath the Valles Caldera and Jemez Mountains? 2. How has the JMVF evolved through the last 15 Ma, culminating in eruption of the Bandelier rhyolite ignimbrite and caldera collapse? Petrologic models of silicic magma generation suggest that large volumes of mafic intrusions (on the order of ten times the volume of erupted material) are present in the crust beneath major silicic volcanic centers. Can we image these intrusions geophysically and interpret their relationships to the observed volcanic geology? In order to address these and other questions related specifically to the JMVF and generally to continental magmatism, the principal investigators will conduct intensive geophysical studies of the JMVF, analyze the data collected and interpret the results in concert with petrologic and geochemical information. The new geophysical data will include: seismic refraction/reflection, teleseismic delay time and waveform, gravity, magnetic, and magnetotelluric (MT) data. The program is designed to provide a three-dimensional image of the magmatically modified c rust beneath the JMVF. Tomographic inversion of the explosion seismic and teleseismic data and combined interpretation with the potential field, MT and geologic data will produce the most high resolution 3-D study of crustal scale features that is currently available.