Possible Causes of the Late Cenozoic Global Activation of the Earth’s Tectonomagmatic Processes

Abstract

The Late Cenozoic global activation of the Earth’s tectonomagmatic processes, which continues to this day, occurred unexpectedly at ~ 30 Ma. It covered almost the entire globe, leading to new orogens and numerous areas of intraplate magmatism associated with the ascension of mantle plumes. However, its nature and mechanism of implementation remain a mystery. According to modern concepts, the origin of mantle plumes occurs at the boundary of the liquid outer core and the mantle due to the penetration of fluids from the core into its bottoms (Maruyama in J Geol Soc Jpn 100(1):24–49, 1994; Dobretsov et al., Deep geodynamics. GEO Publ, 2001; French and Romanowicz Nature 525:95–99, 2015, etc.). Accordingly, the number of mantle plumes—the main drivers of tectonomagmatic processes—directly depends on the fluids coming from the irreversibly solidifying core. We believe that the reason for the considered global tectonomagmatic activation of the Earth was a sharp increase in the content of core’s fluids in the cooling high-Fe liquid of the outer core due to a decrease in their solubility at one of the bifurcation points. The mechanism for implementing this activation was most likely a massive ascent of mantle plumes.