Changes in the world of geological mapping

Geological information is crucial for the civil society via public authorities, and is produced by scientists from academia and national geological surveys. This information is useful for better use of resources (water, energy, and mineral), adaptation to the climate change, and of course natural hazards. In the meantime, the Earth has become smaller, information technology has improved considerably, and allows to cross-analyze data. If communication is made easier for research and dissemination of the geological knowledge, formats have become the key for scientific exchanges.

The Commission for the Geological Map of the World (CGMW) was created for this exact purpose in the early 20th century in an attempt to bring scientists together, but it took a century to acknowledge that we are more than ever accountable for the preservation of the Earth, and forced to understand the importance of the linkage between geology and global change. As early as 1964, the UNESCO bi-annual program encouraged specialists to develop and use a uniform terminology and classification for the different Earth sciences. CGMW is a rank A UNESCO organization and is affiliated to IUGS and IUGG. The spearheading product of CGMW had been the Geological Map of the World at 1:35M scale for decades, and the opportunity of elaborating a large Geological Map of the World at scale 1:5M – (World5M), was proposed in 2018, as an IUGS Big Science Program DDE (Deep time Digital Earth).

This program, co-funded by the Chinese Academy of Geological Sciences (CAGS), aimed at harmonizing global digital Earth data and securing compatible and interoperable databases, and was rapidly considered as essential for international maps, which can be accessible by a data platform aligned with the vision and mission of the IUGS Big Science Program. This project, (1) integrates at a scale 1:5M the geological maps of continents and oceans which have been produced under supervision of the CGMW, (2) established the legend system and adequate architecture for the map database, and (3) constructed a new seamless and digital geological map of the world at the scale 1:5M. In reality, the geology presented in each small scale continental geological map, differs drastically in terms of stratigraphic cuts and trans-boundary connections of structural continuities. In addition, the databases were constructed originally in different ways with contrasting semantics and data standards, thus requiring a robust collaborative work in Geology and Geomatics. Among the outcomes of the project, is the possibility to integrate selected geological features over a large coverage with a similar resolution. This has been already used in new mapping syntheses, making them more informative.