dc.identifier.uri |
http://dx.doi.org/10.15488/12509 |
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dc.identifier.uri |
https://www.repo.uni-hannover.de/handle/123456789/12608 |
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dc.contributor.author |
Marxer, Felix
|
|
dc.contributor.author |
Ulmer, Peter
|
|
dc.contributor.author |
Müntener, Othmar
|
|
dc.date.accessioned |
2022-07-15T05:04:17Z |
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dc.date.available |
2022-07-15T05:04:17Z |
|
dc.date.issued |
2022 |
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dc.identifier.citation |
Marxer, F.; Ulmer, P.; Müntener, O.: Polybaric fractional crystallisation of arc magmas: an experimental study simulating trans-crustal magmatic systems. In: Contributions to Mineralogy and Petrology 177 (2022), Nr. 1, 3. DOI: https://doi.org/10.1007/s00410-021-01856-8 |
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dc.description.abstract |
Crystallisation-driven differentiation is one fundamental mechanism proposed to control the compositional evolution of magmas. In this experimental study, we simulated polybaric fractional crystallisation of mantle-derived arc magmas. Various pressure–temperature trajectories were explored to cover a range of potential magma ascent paths and to investigate the role of decompression on phase equilibria and liquid lines of descent (LLD). Fractional crystallisation was approached in a step-wise manner by repetitively synthesising new starting materials chemically corresponding to liquids formed in previous runs. Experiments were performed at temperatures ranging from 1140 to 870 °C with 30 °C steps, and pressure was varied between 0.8 and 0.2 GPa with 0.2 GPa steps. For most fractionation paths, oxygen fugacity (fO2) was buffered close to the Ni-NiO equilibrium (NNO). An additional fractionation series was conducted at fO2 corresponding to the Re-ReO2 buffer (RRO ≈ NNO+2). High-pressure experiments (0.4–0.8 GPa) were run in piston cylinder apparatus while 0.2 GPa runs were conducted in externally heated pressure vessels. Resulting liquid lines of descent follow calc-alkaline differentiation trends where the onset of pronounced silica enrichment coincides with the saturation of amphibole and/or Fe–Ti–oxide. Both pressure and fO2 exert crucial control on the stability fields of olivine, pyroxene, amphibole, plagioclase, and Fe–Ti–oxide phases and on the differentiation behaviour of arc magmas. Key observations are a shift of the olivine–clinopyroxene cotectic towards more clinopyroxene-rich liquid composition, an expansion of the plagioclase stability field and a decrease of amphibole stability with decreasing pressure. Decompression-dominated ascent trajectories result in liquid lines of descent approaching the metaluminous compositional range observed for typical arc volcanic rocks, while differentiation trends obtained for cooling-dominated trajectories evolve to peraluminous compositions, similar to isobaric liquid lines of descent at elevated pressures. Experiments buffered at RRO provide a closer match with natural calc-alkaline differentiation trends compared to fO2 conditions close to NNO. We conclude that decompression-dominated fractionation at oxidising conditions represents one possible scenario for arc magma differentiation. © 2021, The Author(s). |
eng |
dc.language.iso |
eng |
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dc.publisher |
Berlin ; Heidelberg : Springer |
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dc.relation.ispartofseries |
Contributions to Mineralogy and Petrology 177 (2022), Nr. 1 |
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dc.rights |
CC BY 4.0 Unported |
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dc.rights.uri |
https://creativecommons.org/licenses/by/4.0/ |
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dc.subject |
Arc magmatism |
eng |
dc.subject |
Calc-alkaline rocks |
eng |
dc.subject |
Fractional crystallisation |
eng |
dc.subject |
Liquid line of descent |
eng |
dc.subject |
Magma differentiation |
eng |
dc.subject |
Polybaric differentiation |
eng |
dc.subject |
calc alkaline rock |
eng |
dc.subject |
clinopyroxene |
eng |
dc.subject |
fractional crystallization |
eng |
dc.subject |
fugacity |
eng |
dc.subject |
magma |
eng |
dc.subject |
time series analysis |
eng |
dc.subject |
trajectory |
eng |
dc.subject |
trend analysis |
eng |
dc.subject.ddc |
550 | Geowissenschaften
|
ger |
dc.title |
Polybaric fractional crystallisation of arc magmas: an experimental study simulating trans-crustal magmatic systems |
|
dc.type |
Article |
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dc.type |
Text |
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dc.relation.essn |
1432-0967 |
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dc.relation.doi |
https://doi.org/10.1007/s00410-021-01856-8 |
|
dc.bibliographicCitation.issue |
1 |
|
dc.bibliographicCitation.volume |
177 |
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dc.bibliographicCitation.firstPage |
3 |
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dc.description.version |
publishedVersion |
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tib.accessRights |
frei zug�nglich |
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