Martin, Simon A, Závada, Prokop and Kavanagh, Janine L 
ORCID: 0000-0003-0274-9843
(2023)
Plaster and magnets: Modelling magnetic fabric development in magma intrusions using scaled analogue experiments.
Tectonophysics, 855.
p. 229820.
Abstract
Understanding magma behaviour during emplacement within the crust is vital for understanding the dynamic processes occurring in volcanic systems. However, linking the static record of magma flow to its dynamic origin is challenging, particularly as macroscopic indicators of magma flow are often not observed, absent and/or have been modified after emplacement. Anisotropy of magnetic susceptibility (AMS) has been used as an important tool in field studies to infer magma flow direction, using the magnetic fabric as a record of the magma intrusion dynamics and to identify magma source regions. Here, we describe a new method to explore magnetic fabric development in magma intrusions and lava flows using scaled analogue laboratory experiments. Coloured mixtures of Plaster of Paris (the magma analogue) seeded with magnetite particles were loaded concentrically into a piston and injected through a central port in the base of a box filled with compacted fine-grained wheat flour (the crust analogue). This created a series of interconnected sheet and tube-like ‘magma’ intrusions which eventually breached the surface to feed a model ‘lava flow’. Once solidified, the intrusions were excavated and sampled for AMS, with the results showing that magnetic fabrics were preserved. A new dynamic scaling analysis shows the plaster mixture represents the intrusion of dacite magma into the shallow crust. These models provide proof-of-concept that this new methodology and scaling analysis can be used to explore AMS development in viscous (dacite) magma intrusions in nature, with the potential for direct comparison with field-based indicators of magma flow dynamics.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | Analogue modelling, Intrusion emplacement, Fluid flow, Anisotropy of magnetic susceptibility, Magma, Dyke |
| Divisions: | Faculty of Science and Engineering > School of Environmental Sciences |
| Depositing User: | Symplectic Admin |
| Date Deposited: | 11 Apr 2023 10:17 |
| Last Modified: | 31 May 2023 16:29 |
| DOI: | 10.1016/j.tecto.2023.229820 |
| Open Access URL: | https://www.sciencedirect.com/science/article/pii/... |
| Related URLs: | |
| URI: | https://livrepository.liverpool.ac.uk/id/eprint/3169502 |
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