THE PALEOGEOGRAPHY OF THE WORLD IN 101 STAGES

Paleogeography is the spatial representation of the world in the geological past. Palaeogeographic maps have long been used as a backdrop for plotting distributional data (e.g. in paleobiogeography). But, the need for more accurate boundary conditions in Earth System Modelling, and the quantitative application of paleoDEMS and drainage reconstructions in oil, gas and mineral exploration, has focussed attention on a quantitative, more rigorous definition and understanding of the Earth’s surface.

In order to address this need, we have built a series of digital, ArcGIS-based atlases of global and regional paleogeography. The global atlases comprise every international stratigraphic stage of the Phanerozoic and late Precambrian (over 100 stages), of which those of the Cenozoic, Cretaceous and Jurassic are now complete. The Permo-Triassic stages are currently being mapped. The underlying plate model is constantly updated as more learning’s are made, resulting in consequent updates to the paleogeographies (each map is versioned). Each stage comprises reconstructions of depositional environment, dominant lithology, tectonophysiographic terranes (areas above base-level attributed according to the last thermo-mechanical event), structural and tectonic elements, intra-stage high and lowstand shorelines, paleodrainage basins and major paleorivers, paleoelevation (bathymetry and topography). These interpretations are underpinned by an extensive geological database and comprehensive documentation. This audit trail is critical for providing mapping confidence and thereby correctly assessing implications for Earth System Modelling and exploration applications. The mapping methodologies used here build on and extend those developed by Professor Ziegler and his group at the University of Chicago back in the 1970s-80s. The next phase of this study is the development of a fully dynamic paleolandscape model that integrates high resolution mantle modelling, dynamic landscape models and 4D plate tectonic reconstructions. The work presented here is part of a commercial exploration platform called Globe of which paleogeography is one part.

In this talk we will briefly outline the concepts behind the mapping, key problems and solutions, and show examples from the completed Cenozoic-Jurassic atlases.