A History of Global Mantle Potential Temperatures from Oceanic Crustal Thicknesses

Abstract:

We have collated a global inventory of  ~1000 seismic reflection profiles and ~500 wide-angle refraction experiments from the oceanic realm. Data are predominantly located along passive margins, but there are also multiple surveys in the centres of the major oceanic basins. Oceanic crustal thickness has been mapped, taking care to avoid areas of secondary magmatic thickening near seamounts or later thinning such as across transform faults. These crustal thicknesses are a proxy for mantle potential temperature at the time of melt formation beneath a mid-ocean ridge system. We combine these results with plate reconstructions to produce a history of mantle potential temperature through time beneath oceanic spreading centres. The temporal evolution of mantle temperature immediately following continental break-up is particularly well constrained in the Atlantic Ocean.