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Neues Paper von Jian Kuang in Precambrian Research

News vom 10.10.2023

Die Arbeit von Jian Kuang wurde in Volume 397 von Precambrian Research veröffentlicht. Das Paper trägt den Titel "Metamorphic constraints on Archean tectonics" und enthält einen Überblick über die archaische Tektonik auf der Erde. Große Teile dieser Arbeit wurden in Lankwitz mit Hilfe der Arbeitsgruppe Planetare Geodynamik durchgeführt. Der Abstract des Papers ist unten zu finden, das gesamte Paper kann über diesen Link aufgerufen werden. 

Jian Kuang ist derzeit Gastwissenschaftler in der Arbeitsgruppe Planetare Geodynamik im Rahmen des Projekts "The evolution of the thermal state of the Archean Earth". Er ist außerdem mit dem State Key Laboratory of Biogeology and Environmental Geology der China University of Geosciences in Wuhan assoziiert.


The tectonic style of the Archean Earth is contentious, with ongoing debate concerning the dominant surface processes controlled by either a plate tectonics regime or alternative styles of tectonics (stagnant lid, heat pipe, drip tectonics, sluggish plates, and other planetary modes of heat loss). We assess the viability of interpretations of tectonics during the Archean using a newly compiled metamorphic database. A total of 142 metamorphic data points from Archean cratons have a majority of Neoarchean ages, followed by Paleoarchean, with few Eoarchean and Mesoarchean ages. This database is categorized into three groups of low, medium, and high metamorphic thermobaric ratio (T/P), with the inherent distributional characteristics pointing to subduction tectonics and non-subduction tectonics. We relate Archean cratons and continental history, crustal growth and reworking, and the horizontal motion of ancient cratons to infer which tectonic styles and processes operated. Our analysis is synthesized by the highlighting of three distinct Archean periods with different tectonic activity, starting at 3.8 billion years ago (Ga), from when the first metamorphic data are available. We find that in the interval 3.8–3.5 Ga, tectonics was dominated by short-lived subduction tectonics and non-subduction tectonics, possibly in cohabitation. Between 3.4 and 3.0 Ga, subduction was present and contributed to the lateral growth of the continents and emersion above sea level. In the 2.8–2.5 Ga period, the assembly of the supercontinent/supercratons signals the action of modern-style plate tectonics. In summary, Archean metamorphic data allow timing the Earth’s progression from pre-modern tectonics to modern plate tectonics including the supercontinent cycle.

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