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| Titel |
Multiple magma emplacement and its effect on the superficial deformation: hints from analogue models |
| VerfasserIn |
Domenico Montanari, Marco Bonini, Giacomo Corti, Chiara del Ventisette |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250153910
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| Publikation (Nr.) |
 EGU/EGU2017-18949.pdf |
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| Zusammenfassung |
| To test the effect exerted by multiple magma emplacement on the deformation pattern, we have run analogue
models with synchronous, as well as diachronous magma injection from different, aligned inlets. The distance
between injection points, as well as the activation in time of injection points was varied for each model.
Our model results show how the position and activation in time of injection points (which reproduce multiple
magma batches in nature) strongly influence model evolution. In the case of synchronous injection at different
inlets, the intrusions and associated surface deformation were elongated. Forced folds and annular bounding
reverse faults were quite elliptical, and with the main axis of the elongated dome trending sub-parallel to the
direction of the magma input points. Model results also indicate that the injection from multiple aligned sources
could reproduce the same features of systems associated with planar feeder dikes, thereby suggesting that caution
should be taken when trying to infer the feeding areas on the basis of the deformation features observed at the
surface or in seismic profiles. Diachronous injection from different injection points showed that the deformation
observed at surface does not necessarily reflect the location and/or geometry of their feeders. Most notably, these
experiments suggest that coeval magma injection from different sources favor the lateral migration of magma
rather than the vertical growth, promoting the development of laterally interconnected intrusions.
Recently, some authors (Magee et al., 2014, 2016; Schofield et al., 2015) have suggested that, based on seismic
reflection data analysis, interconnected sills and inclined sheets can facilitate the transport of magma over great
vertical distances and laterally for large distances. Intrusions and volcanoes fed by sill complexes may thus
be laterally offset significantly from the melt source. Our model results strongly support these findings, by
reproducing in the laboratory a strong lateral magma migration, and suggesting a possible mechanism. The models
also confirmed that lateral magma migration could take place with little or no accompanying surface deformation.
The research leading to these results has received funding from the European Community’s Seventh Framework
Programme under grant agreement No. 608553 (Project IMAGE).
References:
Magee et al., 2014. Basin Research, v. 26, p. 85–105, doi: 10 .1111 /bre.12044.
Magee et al., 2016. Geosphere, v. 12, p. 809-841, ISSN: 1553-040X.
Schofield et al., 2015. Basin Research, v. 29, p. 41-63, doi:10.1111/bre.12164. |
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