Transcrustal Magma Dynamics: Perspectives on Process-Based Numerical Models and Integration with Geochemical and Geophysical Measurements
Abstract
The evolution of transcrustal magmatic systems, as well as the transport of individual parcels of melt, is controlled by processes spanning a range of length and timescales from diffusion on the micron scale to deformation over many kilometers. Individual process-based numerical models have focused on subsets of physical phenomena, e.g. thermal development of these bodies, petrologic and geochemical evolution, deformation of the surrounding crust and surface, transport of melt through the crust, and multiphase dynamics of melt, crystals and bubbles. Often these systems are treated in isolation for computational, disciplinary, and historical reasons; yet in some circumstances they can be closely linked and, importantly, influence the interpretation of geochemical and geophysical observations. This presentation will discuss process-based modeling strategies particularly related to two goals: 1. Integrating thermal, petrologic and dynamics-based models and modular program development, and 2. Integrating geophysical and geochemical observations into models (e.g. examining the seismic implications of a melting scenario, or examining crystal growth-based chronometers in the context of an intrusion scenario). On-going challenges and limitations will also be discussed including 1. describing the complex rheology and phase separation in melt-crystal-bubble systems, 2. resolution and computational limitations, 3. challenges of coupling dynamics at different scales, 4. limitations in experimental constitutive relations, and 5. uncertainty propagation. After a general comparison of modeling strategies, two models of varying complexity will be used to illustrate how these goals and challenges manifest themselves and will be further addressed in the context of the associated panel discussion. In the first simplified approach, a user-friendly thermal model is used to explore geochemical variation subject to multiple intrusions. In the second, a three-dimensional multiphase model is used to assess magmatic evolution subject to tectonic stresses, with forward models for melt chemistry, geophysical properties and kinetics of zircon growth. Both sets of models will be used to highlight open questions related to numerical modeling of magmatic systems.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMV037...01D
- Keywords:
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- 1037 Magma genesis and partial melting;
- GEOCHEMISTRY;
- 3613 Subduction zone processes;
- MINERALOGY AND PETROLOGY;
- 4315 Monitoring;
- forecasting;
- prediction;
- NATURAL HAZARDS;
- 8434 Magma migration and fragmentation;
- VOLCANOLOGY