Coupled petrological-geodynamical modeling of a compositionally heterogeneous mantle plume

Rummel, Lisa; Kaus, Boris; White, R. W.; Mertz, D. P.; Yang, Jianfeng; Baumann, Tobias

doi:10.1016/j.tecto.2017.12.022

Cited by 10 publications

(8 citation statements)

References 43 publications

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“…We do not explicitly deal with reaction lines; the residual composition and associated phase diagram is computed beforehand (see below for further details). Albeit more sophisticated and correct methods exist and have been already applied (Riel et al, ; Rummel et al, ), they require more computational cost and resources that make them currently unsuitable for obtaining statistically significant results for the Archean dynamics. Radiogenic heat productivity is assumed to diminish at each depletion step, and it discretely varies within an interval whose extremes are the inferred Archean and the modern‐day values for the respective lithologies (e.g., mantle radiogenic heat production interval spans from 0.022 to 0.066 μW/m 3 and each evolutionary stage entails a decrease of 0.022 μW/m 3 ).…”

Section: Methodsmentioning

confidence: 99%

Generation of Earth's Early Continents From a Relatively Cool Archean Mantle

Piccolo

Palin

Kaus

et al. 2019

Geochem Geophys Geosyst

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Several lines of evidence suggest that the Archean (4.0–2.5 Ga) mantle was hotter than today's potential temperature (TP) of 1350 °C. However, the magnitude of such difference is poorly constrained, with TP estimation spanning from 1500 to 1600 °C during the Meso‐Archean (3.2–2.8 Ga). Such differences have major implications for the interpreted mechanisms of continental crust generation on the early Earth, as their efficacy is highly sensitive to the TP. Here we integrate petrological modeling with thermomechanical simulations to understand the dynamics of crust formation during Archean. Our results predict that partial melting of primitive oceanic crust produces felsic melts with geochemical signatures matching those observed in Archean cratons from a mantle TP as low as 1450 °C thanks to lithospheric‐scale RayleighTaylor‐type instabilities. These simulations also infer the occurrence of intraplate deformation events that allow an efficient transport of crustal material into the mantle, hydrating it.

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Section: Methodsmentioning

confidence: 99%

Generation of Earth's Early Continents From a Relatively Cool Archean Mantle

Piccolo

Palin

Kaus

et al. 2019

Geochem Geophys Geosyst

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“…The effect of melt on the viscosity is taken into account using laboratory-constrained creep laws (values are listed in Tables B3-B4 in Supplementary Data B). The numerical code, employed here, has been described in detail elsewhere (Kaus, 2010;Thielmann and Kaus, 2012;Johnson et al, 2014;Rummel et al, 2018) and is only briefly summarized here.…”

Section: General Methodsmentioning

confidence: 99%

“…Phase diagrams in these models are often incorporated as lookup tables, which were precomputed over a prescribed P-T range and for limited bulk rock compositions (e.g. Kaus et al 2004;Rüpke et al, 2004;Yamato et al, 2007;Magni et al, 2014;Rummel et al, 2018;Piccolo et al, 2019). These lookup tables can be used to track the chemical evolution of extracted melts, as it was shown by Rummel et al (2018) for a rising mantle plume.…”

Section: Introductionmentioning

confidence: 99%

“…Kaus et al 2004;Rüpke et al, 2004;Yamato et al, 2007;Magni et al, 2014;Rummel et al, 2018;Piccolo et al, 2019). These lookup tables can be used to track the chemical evolution of extracted melts, as it was shown by Rummel et al (2018) for a rising mantle plume. However, the usage of such phase diagrams is still not standard and simplified melt parameterizations (e.g.…”

Section: Introductionmentioning

confidence: 99%

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Insights into the Compositional Evolution of Crustal Magmatic Systems from Coupled Petrological-Geodynamical Models

Rummel

Kaus

Baumann

et al. 2020

Journal of Petrology

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The evolution of crustal magmatic systems is incompletely understood, as most studies are limited either by their temporal or spatial resolution. Exposed plutonic rocks represent the final stage of a long-term evolution punctuated by several magmatic events with different chemistry and generated under different mechanical conditions. Although the final state can be easily described, the nature of each magmatic pulse is more difficult to retrieve. This study presents a new method to investigate the compositional evolution of plutonic systems while considering thermal and mechanical processes. A thermomechanical code (MVEP2) extended by a semi-analytical dike/sill formation algorithm, is combined with a thermodynamic modelling approach (Perple_X) to investigate the feedback between petrology and mechanics. Melt is extracted to form dikes while depleting the source region. The evolving rock compositions are tracked on markers using a different phase diagram for each discrete bulk-rock composition. The rock compositional evolution is thus tracked with a high precision by means of a database with more than 58,000 phase diagrams. This database describes how density, melt fraction, chemical composition of melt and solid fractions and mineralogical assemblages change over crustal to uppermost mantle P-T conditions for a large range of rock compositions. Each bulk rock composition is composed of the 10 major oxides (SiO2-TiO2-Al2O3-Cr2O3-MgO-FeO-CaO-Na2O-K2O-H2O) including an oxygen buffer. The combined modelling approach is applied to study the chemical evolution of the crust during arc magmatism and related melt extraction and magma mixing processes. Basaltic sills are periodically injected into the crust to model heat/magma influx from the mantle. We find that accumulated sills turn into long-lived mush chambers when using a lower rock cohesion or assuming a higher intrusion depth. Associated partial melting of crustal host rocks occurs around densely distributed dikes and sills. High silica rocks (e.g. granites) are generated by partial melting of the host rocks, melt segregation within dikes, and from fractional crystallization of basalts. Although the volume of these rocks is relatively small in our models compared to rocks with a mafic to intermediate composition, they provide important information about the processes of magma differentiation within arc continental crust.

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“…We do not explicitly deal with reaction lines; the residual composition and associated phase diagram is computed beforehand (see below for further details). Albeit more sophisticated and correct methods exist and have been already applied (Riel et al, 2018;Rummel et al, 2018), they require more computational cost and resources that make them currently unsuitable for obtaining statistically significant results for the Archean dynamics. Radiogenic heat productivity is assumed to diminish at each depletion step, and it discretely varies within an interval whose extremes are the inferred Archean and the modern-day values for the respective lithologies (e.g., mantle radiogenic heat production interval spans from 0.022 to 0.066 W/m 3 and each evolutionary stage entails a decrease of 0.022 W/m 3 ).…”

Section: Petrological Modelingmentioning

confidence: 99%

Generation of Earth’s Early Continents From a Relatively Cool Archean Mantle

Piccolo¹,

Kaus²,

White³

et al. 2022

Preprint

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Several lines of evidence suggest that the Archean (4.0–2.5 Ga) mantle was hotter than today’s potential temperature(TP ) of 1350 ýC. However, the magnitude of such di erence is poorly constrained, with TP estimation spanningfrom 1500 ýC to 1600 ýC during the Meso-Archean (3.2-2.8 Ga). Such di erences have major implications for theinterpreted mechanisms of continental crust generation on the early Earth, as their e cacy is highly sensitive to theTP . Here, we integrate petrological modeling with thermo-mechanical simulations to understand the dynamics ofcrust formation during Archean. Our results predict that partial melting of primitive oceanic crust produces felsicmelts with geochemical signatures matching those observed in Archean cratons from a mantle TP as low as 1450ýC thanks to lithospheric-scale Rayleigh–Taylor-type instabilities. These simulations also infer the occurrence ofintraplate deformation events that allow an e cient transport of crustal material into the mantle, hydrating it.

show abstract

Coupled petrological-geodynamical modeling of a compositionally heterogeneous mantle plume

Cited by 10 publications

References 43 publications

Generation of Earth's Early Continents From a Relatively Cool Archean Mantle

Generation of Earth's Early Continents From a Relatively Cool Archean Mantle

Insights into the Compositional Evolution of Crustal Magmatic Systems from Coupled Petrological-Geodynamical Models

Generation of Earth’s Early Continents From a Relatively Cool Archean Mantle

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