Latest pulse of Earth: Evidence for a mid-Cretaceous superplume

摘要: A calculation of Earth's ocean crustal budget for the past 150 m.y. reveals a 50% to 75% increase in crust formation rate between 120 and 80 Ma. This "pulse" production is seen both spreading-rate increases from ridges age distribution oceanic plateaus. It primarily Pacific Ocean phenomenon with an abrupt onset, peak rates occurred 100 The pulse decreased intensity Ma, at Ma dropped significantly. There was continued decrease 30 secondary near Cretaceous/Tertiary boundary 65 For m.y., has formed nearly steady rate. Because plateau ridge production, coincides long Cretaceous interval normal magnetic polarity, I interpret it as "superplume" that originated about 125 core/mantle boundary, rose by convection through entire mantle, erupted beneath mid-Cretaceous basin. present-day South "superswell" under Tahiti probably exhausted remnant original upwelling. How this superplume stopped field reversals 41 matter speculation, but involved significant alteration temperature structure convective behavior outer core.