Secular change in orogenic duration reveals alternating tectonic regimes during the Archaean-Proterozoic.

Abstract

Geological constraints and modelling results reveal major yet poorly understood changes in Earth's tectonic regimes during the late Archaean and Proterozoic. These changes are associated with supercontinent cycles, a primary archive of lithosphere and convecting mantle behaviour, and impact orogen duration and thermal state. However, the lack of precise data on orogen duration during Columbia assembly limits our understanding of the long-term tectonic evolution and comparison with younger orogens. Through in-situ garnet Lu-Hf and monazite microdomain U-Pb geochronology, here we constrain a 220 Myr hot collisional orogen during Columbia assembly, significantly longer than contemporary cold orogens (110-160 Myr). Secular changes in collisional orogen duration indicate a non-monotonic trend from Neoarchaean to Neoproterozoic. This trend implies enhanced plate rigidity and mobility during Columbia assembly, followed by a marked decline during Rodinia assembly, consistent with inferred plate velocity proxies. These findings support evolving tectonic regimes alternating between sluggish lid and more active plate tectonics during the Neoarchaean-Proterozoic.