Sedimentological and biostratigraphic investigations in the Triassic of Eastern Pangea, especially of the Tethys Realm appear essential, even after half a century of extensive research.These studies provide a major contribution to the general effort of evaluating the mode and magnitude of the global biological and ecological “revolution” that occurred at the Palaeozoic/Mesozoic boundary, a very significant period of environmental change and life renewal. However, they failed to release global evolution trends because previous studies dealt with individual localities and single fossil groups, comparative studies between distant localities within the Tethys Realm were rarely conducted, and comparisons between Tethyan and Panthalassan provinces at high stratigraphic resolution are almost absent.
This project, based on sedimentology, micropalaeontology and geochemistry, aims at comparing three localities actually located far from each another in order to decipher local, regional and global factors that controlled the evolution of shallow-water carbonate systems in the Tethyan and Panthalassan Realms. Therefore, Upper Triassic mid-oceanic atoll-type carbonates from Sambosan Subterrane (Kyushu Island, Southwest Japan) and from Martin Bridge Formation (Wallowa terrane, north-eastern Oregon, USA), as well time equivalent shallow shelf-types carbonates of Milaha and Ghalilah Formations (western Musandam Peninsula, United Arabian Emirates) were selected.
Establishing the correlation between Japanese and western North American localities with the better known counterparts in the Tethyan Domain would be highly significant to discriminate among the biological (e.g. lineages, endemism of fauna) and environmental factors (e.g. role of oceanic circulation, possible influence of seawater composition).
Special attention will be given to the reefs considering their high sensitivity to ecological factors. Specifically, the study of Involutinid foraminifers, corals and calcareous green algae within the reefs is expected to supply insights into the depositional environments and allow at evaluate the actual climatic conditions.
Refined biostratigraphy of Triassic fossil communities, particularly with regard to foraminifers, will continue and their evolution through time will be considered in the different Tethyan basins, as well as in the Panthalassa Ocean. In order to constrain palaeotectonic models by identifying the Tethyan blocks and their general displacement through time, the required palaeogeographic studies will continue in parallel.