NSFGEO-NERC: Linking geophysics and volcanic gas measurements to constrain the transcrustal magmatic system at the Altiplano-Puna deformation anomaly

NSFGEO-NERC：将地球物理学和火山气体测量联系起来，以约束高原-普纳变形异常处的跨地壳岩浆系统

• 批准号: NE/S008845/1
• 负责人: Joachim Gottsmann
• 金额: $ 31.13万
• 依托单位: University of Bristol
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FS008845%2F1
• 关键词: NSFGEO; NERC; Linking; geophysics; volcanic

The path that magma takes through the crust is not well understood -- where is magma stored and under what conditions will it erupt? While this question is of fundamental scientific interest, it is also directly related to understanding the hazard posed by volcanic systems that are showing signs of activity and unrest. This proposal seeks to understand the cause of unrest and the architecture of the magma storage system within the central Andes, home to the world's largest geophysically imaged zone of silicic partial melt, the Altiplano-Puna Magma (or Mush) Body (APMB).The new paradigm of a transcrustal magmatic system (TCMS) where magma is stored and undergoes chemical changes occurs at several locations throughout the entire crust. This conceptual revolution is being driven by petrological, geochronological, and geochemical studies of magma storage conditions that show (1) many large eruptions tap multiple melt sources, (2) large melt bodies are probably transient features, (3) crystals carried by the transporting melt have been stored at a range of pressures and temperatures. A key location to assess and refine models of currently active TCMS is at the APMB, where a large ground deformation pattern 150 km in diameter lasting several decades has been observed centered on Uturuncu volcano, Bolivia. By collecting and analyzing new interdisciplinary field measurements (gravity, ground deformation, seismic, gas flux and composition) and developing 3D numerical models, this proposal will answer several outstanding questions about the nature of TCMS at the APMB: 1. What is the cause of deformation in the midcrust at the APMB: a magmatic diapir, cyclic up and down movements from magma mush reorganization involving magma and/or volatiles, or something else? 2. What is the nature of a shallow-seated conductivity anomaly -- to what extent is it partial melt, a hydrothermal brine reservoir, or a mature ore body? 3. What is the flux of volatiles through the TCMS? 4. How important is crustal anisotropy in the interpretation of the subsurface magma plumbing architecture?We propose a multi-parametric study to test specific aspects of the TCMS in the central Andes that could be broadly applicable to other TCMS currently active in the world and in the geologic record. Using a closely coordinated international geophysical and geochemical approach with funding from both the US NSF and UK NERC, we will test and refine the possible cause of the ground deformation, better constrain the shallow structure, determine whether deformation is still occurring, and make the first measurements of the volatile flux through the system.

岩浆穿过地壳的路径尚不清楚——岩浆储存在哪里，在什么条件下会喷发？虽然这个问题具有基本的科学兴趣，但它也直接关系到理解火山系统所造成的危害，这些火山系统显示出活动和动荡的迹象。该提案旨在了解安第斯山脉中部动荡的原因和岩浆储存系统的结构，安第斯山脉中部是世界上最大的硅部分熔融的地球物理成像区Altiplano-Puna岩浆（或Mush）体（APMB）的所在地。跨地壳岩浆系统（TCMS）的新范式是岩浆被储存并经历化学变化，发生在整个地壳的几个位置。这一概念革命是由岩石学、地质年代学和地球化学对岩浆储存条件的研究推动的，这些研究表明：(1)许多大型喷发利用了多种熔体来源，(2)大型熔体可能是短暂的特征，(3)由运输熔体携带的晶体在一定的压力和温度下储存。评估和完善目前活跃的TCMS模型的一个关键位置是在APMB，在那里，以玻利维亚的Uturuncu火山为中心，观察到一个直径150公里、持续数十年的大地面变形模式。通过收集和分析新的跨学科领域测量（重力、地面变形、地震、气体通量和成分）和开发三维数值模型，本提案将回答有关APMB TCMS性质的几个突出问题：1。是什么导致了APMB中地壳的变形：岩浆底辟、岩浆和/或挥发物重组引起的上下循环运动，还是别的什么？2. 浅层导电性异常的性质是什么？在多大程度上是部分熔体、热液盐水储层还是成熟矿体？3. 挥发物通过tcm的通量是多少？4. 地壳各向异性在解释地下岩浆管道构造中有多重要？我们提出了一项多参数研究，以测试安第斯山脉中部TCMS的具体方面，该研究可以广泛适用于目前世界上活跃的其他TCMS和地质记录。在美国NSF和英国NERC的资助下，我们将采用密切协调的国际地球物理和地球化学方法，测试和改进地面变形的可能原因，更好地约束浅层结构，确定变形是否仍在发生，并首次测量通过该系统的挥发通量。

项目成果

Rheological Controls on Magma Reservoir Failure in a Thermo-Viscoelastic Crust

热粘弹性地壳中岩浆库破坏的流变控制

• DOI: 10.1029/2021jb023439
• 发表时间: 2022
• 期刊: Solid Earth
• 影响因子: 3.4
• 作者: Head M

The Influence of Viscoelastic Crustal Rheologies on Volcanic Ground Deformation: Insights From Models of Pressure and Volume Change

粘弹性地壳流变对火山地面变形的影响：来自压力和体积变化模型的见解

• DOI: 10.1029/2019jb017832
• 发表时间: 2019
• 期刊: Solid Earth
• 影响因子: 3.4
• 作者: Head M

Exploring the Impact of Thermally Controlled Crustal Viscosity on Volcanic Ground Deformation

探索热控地壳粘度对火山地面变形的影响

• DOI: 10.1029/2020jb020724
• 发表时间: 2021
• 期刊: Solid Earth
• 影响因子: 3.4
• 作者: Head M

Hydrothermal Fluids and Where to Find Them: Using Seismic Attenuation and Anisotropy to Map Fluids Beneath Uturuncu Volcano, Bolivia

热液以及在哪里可以找到它们：利用地震衰减和各向异性来绘制玻利维亚乌图伦库火山下方的流体图

• DOI: 10.1029/2022gl100974
• 发表时间: 2023
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Hudson, T. S.;Kendall, J. M.;Blundy, J. D.;Pritchard, M. E.;MacQueen, P.;Wei, S. S.;Gottsmann, J. H.;Lapins, S.
• 通讯作者: Lapins, S.

From slab to surface: Earthquake evidence for fluid migration at Uturuncu volcano, Bolivia

从板块到地表：玻利维亚乌图伦库火山流体迁移的地震证据

• DOI: 10.1016/j.epsl.2021.117268
• 发表时间: 2022
• 期刊: Earth and Planetary Science Letters
• 影响因子: 5.3
• 作者: Hudson, Thomas S.;Kendall, J-Michael;Pritchard, Matthew E.;Blundy, Jonathan D.;Gottsmann, Joachim H.
• 通讯作者: Gottsmann, Joachim H.