Diapiric ascent of silicic magma beneath the Bolivian Altiplano
Diapiric ascent of silicic magma beneath the Bolivian Altiplano
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DOI：
10.1002/grl.50493
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发表时间：
2013-05-28
影响因子：
5.2
通讯作者：
Gottsmann, Joachim
中科院分区：
文献类型：
--
作者：
del Potro, Rodrigo;Diez, Mikel;Gottsmann, Joachim
大量岩浆的垂直迁移是火山喷发和大陆地壳长期成分演化的驱动力，这是一个备受争议的问题。近年来，岩墙作用被认为是主要的上升机制，但源区熔体填充孔隙的分布结构与浅岩浆储集层之间的结构联系仍然没有解决。在中部安第斯山脉，一个新的高分辨率布格异常数据反演的高原-普纳岩浆体（APMB）揭示了类似的15公里宽，垂直拉长，低密度，三维结构植根于顶部的APMB在20公里的深度。我们将我们的重力反演与现有的地球物理，地质和岩石学观测，并在协议与岩石学/力学的考虑，建议，在这一地区的安第斯山脉，部分熔融的花岗岩体上升底辟通过热韧性中上地壳。
The vertical transport of large volumes of silicic magma, which drives volcanic eruptions and the long-term compositional evolution of the continental crust, is a highly debated problem. In recent years, dyking has been favored as the main ascent mechanism, but the structural connection between a distributed configuration of melt-filled pores in the source region and shallow magma reservoirs remains unsolved. In the Central Andes, inversion of a new high-resolution Bouguer anomaly data over the Altiplano-Puna Magma Body (APMB) reveals similar to 15 km wide, vertically elongated, low-density, 3D structures rooted at the top of the APMB at 20 km depth. We integrate our gravity inversion with the available geophysical, geological, and petrological observations, and in agreement with petrological/mechanical considerations propose that, in this region of the Andes, partially molten granitic bodies ascend diapirically through the hot ductile mid-upper crust.