* Astronomy

The deep mantle (2,800 km on the SMEAN tomography model) is dominated by two large low shear wave velocity provinces (LLSVPs) beneath Africa and the Pacific. The 1% slow contour (approximating to the plume generation zones) is shown as a thick red line. 80% of all reconstructed kimberlite locations (black dots) of the past 320 Myr erupted near or over the sub-African plume generation zone.
The most 'anomalous' kimberlites (17%) are from Canada (white dots). Present-day continents are shown as a background, to illustrate the distribution of hotspots classified as being of deep-plume origin and present-day shear-wave velocity anomalies and bear no geographical relationship to reconstructed kimberlites or large igneous provinces.