Premium
Diapiric ascent of silicic magma beneath the Bolivian Altiplano
Author(s) -
Potro Rodrigo,
Díez Mikel,
Blundy Jon,
Camacho Antonio G.,
Gottsmann Joachim
Publication year - 2013
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/grl.50493
Subject(s) - silicic , geology , bouguer anomaly , crust , volcano , magma , magma chamber , inversion (geology) , upper crust , volcanism , gravity anomaly , geophysics , continental crust , petrology , seismology , paleontology , tectonics , oil field
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 ~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.