Abstract

An important Paleoproterozoic mobile belt event took place in the North China Craton (NCC), termed the Hutuo Movement. This event has been interpreted to represent cratonic reworking characterized by rifting–subduction–collision processes. The NCC then evolved into a stable platform or para-platform tectonic setting in Earth's middle age period more than ~1.0Ga. Thick Late Paleoproterozoic–Neoproterozoic sedimentary sequences were extensively deposited on the early metamorphic basement. The major sedimentary basins include the Xiong'er aulacogen system in the south-central NCC, the Yan-Liao aulacogen system in the north-central NCC, the Northern marginal rift system in the northwestern NCC and the Eastern marginal rift system in the eastern NCC. The following four stages of magmatic activity are recognized in the Late Paleoproterozoic to Neoproterozoic interval: (1) ~1800 to 1780Ma Xiong'er igneous province (XIP), (2) ~1720 to 1620Ma anorogenic magmatic association, (3) ~1350 to 1320Ma diabase sill swarms, and (4) ~900Ma mafic dyke swarms. These four magmatic events suggest that the NCC was situated in an intra-plate setting for a long time from ~1.8Ga to ~0.7Ga or even younger, and the magmatic events were associated with multi-stage rifting activities. We document that the NCC was in a long-term extensional tectonic setting during Late Paleoproterozoic–Neoproterozoic era. The main ore deposits in this period are magmatic type iron deposits related to anorthosite-gabbro bodies, REE–Nb–Fe and Pb–Zn–Cu–Fe deposits related to Mesoproterozoic–Neoproterozoic rifts. Orogenic metal deposits are absent. There is no evidence indicating that the Grenville or other orogenic events affected the NCC. The reason for the absence of Grenvillian aged events in the NCC is probably because it was far from the edge of the Nuna supercontinent, if such a supercontinent did exist. There is another possibility that the Earth's middle age represented a particular tectonic evolution period, during which the Earth had a stable lithosphere with underlying secular warm mantle that resulted in multi-magmatism and rifting from the Late Paleoproterozoic to Neoproterozoic.

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