Ductility and Compressibility Accommodate High Magma Flux Beneath a Silicic Continental Rift Caldera: Insights From Corbetti Caldera (Ethiopia)
Abstract Large silicic magma reservoirs preferentially form in the upper crust of extensional continental environments. However, our quantitative understanding of the link between mantle magmatism, silicic reservoirs, and surface deformation during rifting is very limited. Here, we focus on Corbetti...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2020-04-01
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| Series: | Geochemistry, Geophysics, Geosystems |
| Subjects: | |
| Online Access: | https://doi.org/10.1029/2020GC008952 |
| _version_ | 1797638016296026112 |
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| author | J. Gottsmann J. Biggs R. Lloyd Y. Biranhu E. Lewi |
| author_facet | J. Gottsmann J. Biggs R. Lloyd Y. Biranhu E. Lewi |
| author_sort | J. Gottsmann |
| collection | DOAJ |
| description | Abstract Large silicic magma reservoirs preferentially form in the upper crust of extensional continental environments. However, our quantitative understanding of the link between mantle magmatism, silicic reservoirs, and surface deformation during rifting is very limited. Here, we focus on Corbetti, a peralkaline caldera in the densely populated Main Ethiopian Rift, which lies above a focused zone of upper mantle partial melt and has been steadily uplifting at a maximum rate of 6.6±1.2 cm yr−1 for more than 10 yr. Numerical modeling shows that a maximum concomitant residual gravity increase of 9±3 μGal yr−1 by the intrusion of mafic magma at ∼7 km depth into a compressible and inelastic crystal mush best explains the observed deformation and gravity changes. The derived magma mass flux of ∼1011 kg yr−1 is anomalously high and at least 1 order of magnitude greater than the mean long‐term mass eruption rate. This study demonstrates that periodic and high‐rate magmatic rejuvenation of upper‐crustal mush is a significant and rapid contributor to mature continental rifting. |
| first_indexed | 2024-03-11T12:56:35Z |
| format | Article |
| id | doaj.art-82aeefd9c6a44f13beec1876cf668941 |
| institution | Directory Open Access Journal |
| issn | 1525-2027 |
| language | English |
| last_indexed | 2024-03-11T12:56:35Z |
| publishDate | 2020-04-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geochemistry, Geophysics, Geosystems |
| spelling | doaj.art-82aeefd9c6a44f13beec1876cf6689412023-11-03T17:00:28ZengWileyGeochemistry, Geophysics, Geosystems1525-20272020-04-01214n/an/a10.1029/2020GC008952Ductility and Compressibility Accommodate High Magma Flux Beneath a Silicic Continental Rift Caldera: Insights From Corbetti Caldera (Ethiopia)J. Gottsmann0J. Biggs1R. Lloyd2Y. Biranhu3E. Lewi4School of Earth Sciences University of Bristol Bristol UKSchool of Earth Sciences University of Bristol Bristol UKSchool of Earth Sciences University of Bristol Bristol UKSchool of Earth Sciences University of Bristol Bristol UKInstitute of Geophysics, Space Science and Astronomy (IGSAA) University of Addis Ababa Addis Ababa EthiopiaAbstract Large silicic magma reservoirs preferentially form in the upper crust of extensional continental environments. However, our quantitative understanding of the link between mantle magmatism, silicic reservoirs, and surface deformation during rifting is very limited. Here, we focus on Corbetti, a peralkaline caldera in the densely populated Main Ethiopian Rift, which lies above a focused zone of upper mantle partial melt and has been steadily uplifting at a maximum rate of 6.6±1.2 cm yr−1 for more than 10 yr. Numerical modeling shows that a maximum concomitant residual gravity increase of 9±3 μGal yr−1 by the intrusion of mafic magma at ∼7 km depth into a compressible and inelastic crystal mush best explains the observed deformation and gravity changes. The derived magma mass flux of ∼1011 kg yr−1 is anomalously high and at least 1 order of magnitude greater than the mean long‐term mass eruption rate. This study demonstrates that periodic and high‐rate magmatic rejuvenation of upper‐crustal mush is a significant and rapid contributor to mature continental rifting.https://doi.org/10.1029/2020GC008952calderariftingmagmagravity changesmass fluxvolcano geodesy |
| spellingShingle | J. Gottsmann J. Biggs R. Lloyd Y. Biranhu E. Lewi Ductility and Compressibility Accommodate High Magma Flux Beneath a Silicic Continental Rift Caldera: Insights From Corbetti Caldera (Ethiopia) Geochemistry, Geophysics, Geosystems caldera rifting magma gravity changes mass flux volcano geodesy |
| title | Ductility and Compressibility Accommodate High Magma Flux Beneath a Silicic Continental Rift Caldera: Insights From Corbetti Caldera (Ethiopia) |
| title_full | Ductility and Compressibility Accommodate High Magma Flux Beneath a Silicic Continental Rift Caldera: Insights From Corbetti Caldera (Ethiopia) |
| title_fullStr | Ductility and Compressibility Accommodate High Magma Flux Beneath a Silicic Continental Rift Caldera: Insights From Corbetti Caldera (Ethiopia) |
| title_full_unstemmed | Ductility and Compressibility Accommodate High Magma Flux Beneath a Silicic Continental Rift Caldera: Insights From Corbetti Caldera (Ethiopia) |
| title_short | Ductility and Compressibility Accommodate High Magma Flux Beneath a Silicic Continental Rift Caldera: Insights From Corbetti Caldera (Ethiopia) |
| title_sort | ductility and compressibility accommodate high magma flux beneath a silicic continental rift caldera insights from corbetti caldera ethiopia |
| topic | caldera rifting magma gravity changes mass flux volcano geodesy |
| url | https://doi.org/10.1029/2020GC008952 |
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