Earth's oldest hotspot track at ca. 1.8 Ga advected by a global subduction system

Abstract

The concurrence of both global orogenesis and large igneous provinces (LIPs) from 2200–1600 Ma remains enigmatic. This apparent contradiction of top-down and bottom-up geodynamics occurred during assembly of Earth's oldest-known supercontinent. We present a multidisciplinary study combining the dismembered portions of major LIP worldwide and correlate them across supercontinent Columbia to the same plume center (Xiong'er of the North China craton). The succession of LIPs is then used to trace the oldest established hotspot track associated with a pulsating plume constraining ancient plate motion. Subduction-controlled plume generation can explain mantle upwelling occurring where subducted slabs forming the supercontinent had previously sunk to the base of the mantle and advected the Xiong'er mantle plume due to return flow. Tectonic motion detected by the hotspot track can account for both those regions of the supercontinent with and without LIPs. Such historical constraints on the interaction between plumes and subduction are critical in linking bottom-up and top-down tectonic processes at the dawn of the supercontinent cycle.