Gough track = red, purple Tristan track = blue, turquoise (depleted), yellow (plume-ridge) Center track = green. Symbols = locations of dredge samples with high-precision Pb and Sr-Nd-Hf isotope data. Spatial geochemical zonation of the Tristan-Gough hotspot track since 70 Ma. The difference between modeled and observed paleolatitudes implies significant TPW (purple curve) (Doubrovine et al., 2012).įigure F9. All absolute motion models indicate that the African plate moved nearly monotonically northward, so they do not explain the rapid southward shift in paleolatitudes during the Late Cretaceous or the northward offset of paleolatitudes during the early Cenozoic. Adding the hotspot motion to the moving hotspot model absolute motion equals the total northward motion indicated by the morphology of the TGW chain and the fixed hotspot model. It is less than the fixed hotspot model because the Tristan hotspot is modeled as moving south. Orange line = the northward drift of the African plate in the moving hotspot model (Doubrovine et al., 2012). Green line = the paleolatitudes of the Tristan hotspot from a mantle flow model (Doubrovine et al., 2012), indicating ~7° southward motion in 120 Ma. Blue line = a moving hotspot model (Doubrovine et al., 2012). Black line = the northward drift of a seamount with time if formed at the Tristan hotspot location (Schlömer et al., 2017), assuming a fixed hotspot model (Torsvik et al., 2008). Red line with circles = paleolatitudes estimated from paleomagnetic data (same as lower plot). Blue arrows = estimated ages of proposed drill sites from an age progression model (Homrighausen et al., 2019, 2020). Blue band (VK92) = hotspot drift estimated by Van Fossen and Kent (1992). Orange star (MC) = paleolatitude of Messum gabbros in the Etendeka province (Renne et al., 2002). Black triangle (NPB), white square (CPB), and purple diamond (SPB) = paleolatitudes from the north, central, and south Parana flood basalts, respectively (Ernesto et al., 1990, 1999). Its departure from the paleolatitude curve may be a result of inclination shallowing that is common for sediments (Verosub, 1977). Pink square = a paleolatitude determined for 60-75 Ma sediments from Site 525 (Chave, 1984). Blue line with dots = the same paleolatitude curve for a fixed hotspot model (Torsvik et al., 2008). This polar wander path was constructed with a 20 My window length, averaged every 10 Ma. Thin vertical lines = 95% confidence limits based on paleomagnetic data scatter only. Red line with dots = estimated paleolatitudes calculated from the global average African plate apparent polar wander path (Torsvik et al., 2008) based on a plate motion model with moving hotspots (Doubrovine et al., 2012). Predicted paleolatitude drift of the TGW hotspot, hotspot models, and TPW.
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