DEEP TIME is a European Research Council funded project, running from 2015 to 2020, which aims to generate a quantitative, global geography of the world’s former oceans and their plate boundaries.

Continental reconstructions have been so successful because land records can survive almost indefinitely, whereas very little seafloor older than ~180 Ma is preserved (Engebretson et al. 1985, Seton et al. 2012). Oceanic reconstructions could become similarly successful if we learn to interpret their records where they survive: in the mantle, where most of the absolute spatial information is preserved, and in the mountain belts, where oceanic remnants can be dated. The joint use of these data sets will make it possible to infer the spatial evolution of paleo-oceans over the course of time.

Tethys Focus: Unravelling the subduction history of the Tethys oceans, that once existed between Gondwana and Eurasia, requires joining geological observations from the southern Eurasian mountain belts with tomographically imaged slabs in the mantle beneath the Indian Ocean, Eurasia, the Arabian Peninsula, the Mediterranean and Southeast Asia.
Slabs in the mantle beneath the Indian Ocean
In this figure (above) fast seismic velocity anomalies (isovalue of 0.25%) in the lower mantle (>660 km) beneath the Indian Ocean from the model of Hosseini (2016 – PhD Thesis) may represent slab material from Tethyan subduction systems. While, ophiolites, arc rocks and fossils from the Alpine-Himalayan orogenic belt provide a surface record of the opening and closure of ancient ocean basins and complex subduction histories. This image was made using GPlates, and colouring of the 3D volumes ranges from cyan at 660 km depth, through yellow and orange, to red at the core-mantle boundary (white sphere). Surface topography is from ETOPO1.