Modeling early Earth tectonics

the case for stagnant lid behaviour

Craig O'Neill, Siqi Zhang

Research output: Chapter in Book/Report/Conference proceedingChapter

Abstract

The geodynamic context of the Earth's oldest rocks is far from clear. The geological record is able to constrain dynamic processes, but these may not be definitive. Geodynamic simulations can offer insight into the plausible dynamics of this period and quantitatively constrain geological processes. To do so, however, they must both reconstruct the relevant thermal configuration of the Earth in the Hadean–early Archean and encapsulate the critical processes operating during this time-including voluminous "heat-pipe" volcanism and volcanic resurfacing and giant impacts.

Our simulations reveal that, in the absence of outside tectonic disruptors, the majority of models configured to the early Earth (Hadean-early Archean) conditions exhibit stagnant lid behavior. Tectonic activity is promoted by (1) strong plumes, arising from an overheated core, and (2) giant impacts, which can both drive subduction directly and prime the mantle for later tectonic activity. "Heat-pipe" volcanism can both drive resurfacing and dominate heat flux, but current implementations employing simple melt extraction algorithms overestimate its efficiency. Integrating current evolving tectonic simulations for the early Earth, with available constraints on these systems, suggests a style of tectonism involving long periods of quiescence-essentially a stagnant lid-interspersed with episodes of violent tectonic activity (crust–mantle overturn events) and is most consistent with the available record and provides quantitative predictions for testing.
Original languageEnglish
Title of host publicationEarth's oldest rocks
EditorsMartin J. Van Kranendonk, Vickie C. Bennett, J. Elis Hoffmann
Place of PublicationAmsterdam, Netherlands
PublisherElsevier
Chapter4
Pages65-80
Number of pages16
Edition2nd
ISBN (Electronic)9780444639028
ISBN (Print)9780444639011
DOIs
Publication statusPublished - 2019

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O'Neill, C., & Zhang, S. (2019). Modeling early Earth tectonics: the case for stagnant lid behaviour. In M. J. Van Kranendonk, V. C. Bennett, & J. E. Hoffmann (Eds.), Earth's oldest rocks (2nd ed., pp. 65-80). Amsterdam, Netherlands: Elsevier. https://doi.org/10.1016/B978-0-444-63901-1.00004-6