Jian Kuang publishes in Precambrian Research
News from Oct 10, 2023
The new work of Jian Kuang has been published in Volume 397 of Precambrian Research. The paper is titled "Metamorphic constraints on Archean tectonics" and contains a review of Archean tectonics on Earth. Most parts of this work were done in Lankwitz with the help of the Planetary Geodynamics group, among others. The abstract of the paper can be found below, and the full paper can be accessed via this link.
Jian Kuang is currently a guest scientist in the Planetary Geodynamics group under the project "The evolution of the thermal state of the Archean Earth". When he's not researching in Germany, he is associated with the State Key Laboratory of Biogeology and Environmental Geology of the China University of Geosciences in Wuhan.
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.