Fig. 2: Trilogy of plate subduction related to three-stage evolution of petrogenesis of collision-related Tibetan magmatism and global atmospheric CO2 concentration variations in the Cenozoic.
From: India-Asia collision as a driver of atmospheric CO2 in the Cenozoic
a Three-stage variations of atmospheric CO2 concentrations in the Cenozoic. The data are from ref. 2. b–d Three-stage evolution of the petrogenesis of collision-related Tibetan magmatism in the Cenozoic (see details in Supplementary Figs. 1–6). Neo-Tethyan oceanic lithosphere subduction in (b) resulted in corner flow and intermediate atmospheric CO2 levels of Stage 1 (from 65 to 55 Ma) in (a). Indian continental lithosphere subduction in (c) resulted in a large-scale CMP upwelling and high atmospheric CO2 concentrations of Stage 2 (from 55 to 25 Ma) in (a). India and Asia subduction in (d) resulted in a small-scale of opposing mantle convection and low atmospheric CO2 levels of Stage 3 (from 25 to 0 Ma) in (a). The mixed melts in (c) denote a plume-wedge interaction in Stage 2(a) from 55 to 50 Ma. The black dashed lines labelled I and II denote the first-step and second-step transformation of the mantle source region of the Tibetan magmas during the India-Asia collision (Supplementary Figs. 1–6), respectively. I: the first-step transformation from Neo-Tethyan oceanic lithospheric subduction-induced silicate-rich metasomatism to India subduction-induced carbonate-rich metasomatism, II: the second-step transformation from India subduction-induced carbonate-rich metasomatism to dual India and Asia subduction-induced silicate-rich and carbonate-rich metasomatism.
