Global tomography and numerical models suggest that mantle plume occurrences are closely linked to the margins of large low-shear velocity provinces (LLSVPs)1–4. In these marginal zones the ascent of material from the core-mantle boundary connects deep mantle dynamics with surface processes through mantle plume activity, forming large igneous provinces (LIPs) and some of the modern hotspot volcanoes5,6. Petrological7 and geodynamic8 evidence suggest a link between the formation of oceanic plateaus and the interactions of mantle plumes and mid-ocean ridges (MORs). Even though the causality relationship between both processes is still unclear (either rifting is initiated by plume impact or it pre-dates plume interaction) larger volumes of upwelling mantle material will preferentially reach the surface when impacting or captured by a MOR8,9. Consequently, it is possible to trace the potential interactions between MORs and mantle plume upwellings by referencing the tectonic and magmatic evolution of the Pacific Plate in time to the current location of the LLSVP, considering the long-lived (B500 Ma) existence of these thermochemical anomalies1,8,10. Here, we identified episodic upwellings of the Pacific LLSVP during the Mesozoic by reconstructing the kinematic evolution of the Pacific Plate in the last B168 Ma using the record of LIP fragments, both accreted in tectonic margins and at the seafloor. To accurately reconstruct the paleo-Pacific Plate layout, we included both the oceanic plateaus and ocean-basin flood basalts, however for the purpose of this paper hereafter we will refer to both groups as oceanic LIPs considering that the processes that formed both types of features are intrinsically related11 as both are generated by extensive adiabatic decompression of material hotter than ambient asthenospheric mantle11,12.
Madrigal, Pilar; Gazel, Esteban; Flores, Kennet E.; Bizimis, Michael; and Jicha, Brian, "Record of Massive Upwellings from the Pacific Large Low Shear Velocity Province" (2016). CUNY Academic Works.