Magmatic Records of the Late Paleoproterozoic to Neoproterozoic Extensional and Rifting Events in the North China Craton: A Preliminary Review

Abstract

The North China Craton (NCC) is characterized by multistages of extensional and continental rifting and deposition of thick marine or interactive marine and terrestrial clastic and carbonate platform sediments without angular unconformity during Earth’s middle age of 1.70–0.75 Ga. Factors controlling these multistages of extensional and continental rifting events in the NCC can be either from the craton itself or from the neighboring continents being connected during these periods. Two large igneous provinces including the ca. 1.32 Ga mafic sill swarms in Yanliao rift (aulacogen) in the northern NCC and the ca. 0.92–0.89 Ga Xu-Huai–Dalian–Sariwon mafic sill swarms in southeastern and eastern NCC, have recently been identified from the NCC. Rocks from these two large igneous provinces exhibit similar geochemical features of tholeiitic compositions and intraplate characteristics. Formation of these two large igneous provinces was accompanied by pre-magmatic uplift as indicated by the field relations between the sills and their hosted sedimentary rocks. The Yanliao and Xu-Huai–Dalian–Sariwon large igneous provinces represent two continental rifting events that have led to rifting to drifting transition and breakup of the northern margin of the NCC from the Columbia (Nuna) supercontinent and the southeastern margin of the NCC from the Rodinia supercontinent, respectively. As shown by the ca. 200 Ma Central Atlantic Magmatic Province related to breakup of the Pangea supercontinent and initial opening of the Central Atlantic Ocean and the ca. 180 Ma Karoo-Ferrar large igneous province related to initial breakup of Gondwana, magmatism related to continental breakup and rifting to drifting transition can occur as mafic dykes, sills, and/or lavas across the neighboring continents and is mainly tholeiitic in chemical composition. This kind of magmatism should be large in volume and constitute a large igneous province. In many cases, eruption or/and emplacement of breakup-related magmatism were accompanied by pre-magmatic uplift. Large volumes of mafic sill swarms near continental margins and accompanied pre-magmatic uplift in marginal rift basins can most likely be used as important indicators for continental breakup and paleogeographic reconstruction.