3D Geodynamic Models of the Present-Day Altiplano-Puna Magmatic System
- Publication type:
- Conference
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- Abstract
- <jats:p> &lt;p&gt;For the past decades, several numerical studies have successfully reproduced the concentric uplift pattern observed above the Altiplano-Puna Magma Body (APMB) in the central Andes. However, the temperature- and strain rate-dependent viscoelastoplastic rheology of rocks, the buoyancy of magma, the effects of modelling in 3D as well as the shape of the magma body have often been simplified or neglected.&lt;/p&gt;&lt;p&gt;Here, we use a joint interpretation of seismic imaging and gravity anomalies to constrain location, 3D shape and density of the magma body. With the help of the thermo-mechanical finite difference code LaMEM, we then model the surface deformation and test our results against observations made by Interferometric Synthetic-Aperture Radar (InSAR) missions. This way, we gain insights into the dynamics and rheology of the present-day magmatic system and can test how a change to the current conditions (e.g., magma influx) could impact it.&lt;/p&gt;&lt;p&gt;We find that only an APMB with a maximum thickness of 14 to 18 km and a corresponding density contrast to the surrounding host rock of 100 to 175 kg/m&lt;sup&gt;3&lt;/sup&gt; satisfies both tomography and Bouguer data. Based on that and the chemistry of eruption products, we estimate the melt content of the APMB to be on the order of 20 - 25%. We also find that the observed uplift can be reproduced by magma-induced buoyancy forces without the need for an additional pressure source or magma injection within the mush, and that the geometry of the top of the magma body exerts a major control on the deformation pattern at the surface.&lt;/p&gt; </jats:p>
- Autoren
- Arne Spang
- Tobias Baumann
- Boris Kaus
- DOI
- 10.5194/egusphere-egu2020-5388
- Datum der Veröffentlichung
- 2020
- Status
- Published
- Herausgeber URL
- http://dx.doi.org/10.5194/egusphere-egu2020-5388
- Datum der Datenerfassung
- 2020
- Titel
- 3D Geodynamic Models of the Present-Day Altiplano-Puna Magmatic System
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