Global correlation of lower mantle structure and past subduction

Abstract

Advances in global seismic tomography have increasingly motivated identification of subducted lithosphere in Earth's deep mantle, creating novel opportunities to link plate tectonics and mantle evolution. Chief among those is the quest for a robust subduction reference frame, wherein the mantle assemblage of subducted lithosphere is used to reconstruct past surface tectonics in an absolute framework anchored in the deep Earth. However, the associations heretofore drawn between lower mantle structure and past subduction have been qualitative and conflicting, so the very assumption of a correlation has yet to be quantitatively corroborated. Here we show that a significant, time‐depth progressive correlation can be drawn between reconstructed subduction zones of the last 130 Myr and positive S wave velocity anomalies at 600–2300 km depth, but that further correlation between greater times and depths is not presently demonstrable. This correlation suggests that lower mantle slab sinking rates average between 1.1 and 1.9 cm yr−1.

Subduction-transition zone interaction: A review

“…This and the fact that slabs may end up as far as 1000-2000 km from the position where they originally subducted, makes associating lower-mantle slabs with past trenches more difficult with increasing depth in the mantle. This has indeed been noted in studies that have tried to correlate plate-motion history with tomographic anomalies in the lower mantle (Domeier et al, 2016). 8.…”

“…(Grand, 1994;Hafkenscheid et al, 2006;Sig loch and Mihalynuk, 2013). These ages imply lower-mantle slab sinking rates of 1-2 cm/yr (Grand, 1994;Hafkenscheid et al, 2006;Van der Meer et al, 2009;Sigloch and Mihalynuk, 2013;Butterworth et al, 2014;Domeier et al, 2016). Deeper anomalies may correspond to subduction going back as far as 200 m.y.…”

“…9). Both the shape evolution and lateral displacement that accompany it will make it more challenging to relate lowermantle anomalies to plate-motion histories and increasingly so with depth, which may explain the difficulty of correlating plate-motion histories with the deepest mantle structures (Domeier et al, 2016).…”

“…ago and in a few locations even 300 m.y. (Richards and Engebretson, 1992;Ricard et al, 1993;Van der Voo et al, 1999a;Van der Meer et al, 2009), although it has been questioned how robust correlations between plate-motion history and anomalies below 2300 km depth are ( Domeier et al, 2016).…”

Yellowstone Plume Conduit Tilt Caused by Large‐Scale Mantle Flow

“…A location further west could possibly result if the plate reconstruction was modified to include Pacific intraoceanic subduction. A later rise time of the plume could possibly result with slower slab sinking, as the sinking speeds of slabs in the model is faster than what is inferred from matching predicted slab locations with tomography (Domeier et al, ; van der Meer et al, ). Further, more advanced modeling of mantle convection and plumes, with lateral viscosity variations similar to Dannberg and Gassmöller () coupled to improved plate reconstructions, could help to support or refute these speculations.…”