Late Riphean alkaline magmatism in the western margin of the Siberian Craton: A result of continental rifting or accretionary events?

Abstract

Magmatic evolution in the western margin of the Siberian Craton has attracted the attention of many specialists in the context of debatable problems concerning the formation and breakdown of the Meso- and Neoproterozoic Rodinia supercontinent, the evolution of the Paleoasian ocean, and the origin of the Central Asian Foldbelt [1‐3]. The evolution of the Late Riphean and Vendian alkaline igneous complexes occupies a special place in this problem. According to the paleoreconstruction by Yarmolyuk et al. [3], these complexes are traced not only along the western and southern margins of the Siberian Craton, but also in North America (Laurentia). Such complexes are commonly regarded as products of anorogenic conditions related to plumes and/or continental rifting. However, models of accretion processes, when a subducted plate reaches the asthenosphere and generates a new alkaline magma source, are also discussed in the literature [4]. As has been established previously, alkaline rocks, including alkali and nepheline syenites and Li‐F granites, were formed in the Central Asian Foldbelt throughout the Late Riphean and Vendian‐Cambrian accretionary events [3].